Lanzhou City Research Articles

Relationship between Built-Up Environment, Air Pollution, Activity Frequency and Prevalence of Hypertension-An Empirical Analysis from the Main City of Lanzhou.

In the process of promoting the strategy of a healthy China, the built environment, as a carrier of human activities, can effectively influence the health level of residents in the light of its functional types. Based on the POI data of four main urban areas in Lanzhou, this paper classifies the built environment in terms of function into four types. The association between different types of built environments and the prevalence of hypertension was investigated by using the community as the study scale, and activity frequency, air pollution and green space were used as mediating variables to investigate whether they could mediate the relationship between built environments and hypertension. The results indicate that communities with a high concentration of commercial service facilities, road and traffic facilities and industrial facilities have a relatively high prevalence of hypertension. By determining the direct, indirect and overall effects of different functional types of built environment on the prevalence of hypertension, it was learned that the construction of public management and service facilities can effectively mitigate the negative effects of hypertension in the surrounding residents. The results of the study contribute to the rational planning of the structure of the built environment, which is beneficial for optimizing the urban structure and preventing and controlling chronic diseases such as hypertension.

Decoding the Multidimensional Structuring of Urban Poles of Growth of Nighttime Economics—An Inter-Discipline Study in Lanzhou City, China, Based on Geomodeling and Big Data

The nighttime economy, or NTE—the combination of nocturnal specialties and the extension of the diurnal economy into the night—has been implemented as an effective boosting instrument set to “revitalize the urban space”. The instrument, applied in regions around world, develops new socioeconomic dynamics and poles of growth within cities. Although some cases emphasize the functional success of NTE practices, disequilibrium between urban elements—social groups, communities, and the cultures in which they live—are ongoing. The present article argues that urban nights must be considered within a broader reflection on the question of sustainability because a closer integration between brands, cultural elements, employment, and capital in different scales is demonstrated at night. Based on growth pole theory, this study combines data mining, spatial modeling, and other complementary approaches, and successfully (1) identifies the growth poles of the NTE in Lanzhou City, a postindustrial city transitioning towards a nighttime economy that forms dotted and non-uniform nocturnal zones through its geography and demography; (2) characterizes their socioeconomic organization, and (3) analyzes various causes and manifestations of the disequilibrium.

Enrichment, contamination, ecological and health risks of toxic metals in agricultural soils of an industrial city, northwestern China

BackgroundThe impacts of rapid urbanization and industrialization often cause toxic metal contamination in agricultural soils, which has been a global environmental issue. MethodsAgricultural soil samples were obtained from Lanzhou city, a typical industrial city in northwestern China. The levels of six toxic metals (i.e., Cd, Cr, Cu, Pb, Sb, and Zn) were determined in soil samples using Inductively Coupled Plasma Optical Emission Spectrometer. Afterwards, enrichment, contamination, ecological and health risks of them were comprehensively evaluated. ResultsThe average concentrations of toxic metals were 0.30, 79.7, 21.6, 26.7, 0.97, and 69.0 mg kg−1 for Cd, Cr, Cu, Pb, Sb, and Zn, respectively in soils. Cd was moderately enrichment while other metals were minimally enriched in soils of Lanzhou. The agricultural soils were characterized by moderate to considerable contamination of Cd and low contamination of other metals. Moreover, Cd might cause noticeable ecological risks at most sites. In addition, the average target hazard quotient (THQ) for children was 0.727, almost ten times higher than that for adults. Cr, Pb, and Sb were the most sensitive factors affecting the health risk assessment and contributed over 99% to the THQ. ConclusionLithogenic source, industrial and mining activities, and phosphorus fertilizer usage were the three main factors affecting the concentrations of Cd, Cr, Cu, Pb, Sb, and Zn in agricultural soils of Lanzhou, which should be taken into consideration in future supervision and management. Health risks of these metals, especially Cd, Cr, and Sb, for children should receive considerable attention due to their health hazard.

Technical and economic performance study on winter heating system of air source heat pump assisted solar evacuated tube water heater

Winter heating with clean energy is very important for coal substitution in rural areas of China. In Northwestern China, winter weather is usually below zero and winter heating lasts at least 5 months, which is a big expense for rural residents. It is well known that solar energy, air source heat pump and other energy-saving technologies could effectively cut down the expenditure. However, it is difficult to consider the economics and stability of winter heating with free solar energy alone, and the cost of winter heating with heat pump alone is too high for locals to afford. Therefore, the concept of air source heat pump assisted solar energy was proposed and a solar evacuated tube water heater -air source heat pump system was built in Lvhua Village, Lanzhou City. Experiment and simulation studies were carried out to discover the technical and economic performances when the system operates in three modes, namely, heating by solar water heater, air source heat pump and solar water heat pump (heat pump used hot water from solar collector as heat). Simulation results were verified and highly consistent with experimental results on December 20th, 2021. The results show that in whole heating season, air source heat pump assisted solar energy system greatly improves technical and economic performance in comparison with heating by solar water heater and air source heat pump. The average daily collector efficiency in the heating season is 45.5 %, and the average daily effective solar heat collection is 43.6 kWh. During the heating season, the effective solar heat collection is 6587.1 kWh, the electricity consumption is 5229.7 kWh, the heat supply is 16392.2 kWh, the solar fraction is about 40.2 %, the energy efficiency ratio is 3.1, the average COP of solar water heat pump is 3.5, and the average COP of air source heat pump is 3.0. The primary energy saving rate of the system is 66.4 %, the dynamic investment pay-back period is 6.5 years, and the CO2 emission reduction is 10960.7 kg. The results demonstrate the feasibility of the winter heating system of air source heat pump assisted solar evacuated tube water heater, which provides a new way for the heating of rural single buildings in cold areas.

Predicting ozone formation in petrochemical industrialized Lanzhou city by interpretable ensemble machine learning

Ground-level ozone (O3) formation depends on meteorology, precursor emissions, and atmospheric chemistry. Understanding the key drivers behind the O3 formation and developing an accurate and efficient method for timely assessing the O3–VOCs-NOx relationships applicable in different O3 pollution events are essential. Here, we developed a novel machine learning ensemble model coupled with a Shapley additive explanation algorithm to predict the O3 formation regime and derive O3 formation sensitivity curves. The algorithm was tested for O3 events during the COVID-19 lockdown, a sandstorm event, and a heavy O3 pollution episode (maximum hourly O3 concentration >200 μg/m3) from 2019 to 2021. We show that increasing O3 concentrations during the COVID-19 lockdown and the heavy O3 pollution event were mainly caused by the photochemistry subject to local air quality and meteorological conditions. Influenced by the sandstorm weather, low O3 levels were mainly attributable to weak sunlight and low precursor levels. O3 formation sensitivity curves demonstrate that O3 formation in the study area was in a VOCs-sensitive regime. The VOCs-specific O3 sensitivity curves can also help make hybrid and timely strategies for O3 abatement. The results demonstrate that machine learning driven by observational data has the potential to be a very useful tool in predicting and interpreting O3 formation.

Construction of the green infrastructure network for adaption to the sustainable future urban sprawl: A case study of Lanzhou City, Gansu Province, China

Nature-based green infrastructure (GI) is considered as a sound solution to mitigate the urban issues resulting from rapid urbanization. It is exceedingly essential to construct GI network for adaption to the dynamics of natural and social conditions. However, it has not been well studied until now. In this study, taking Lanzhou City, Gansu Province, China as a case, we proposed an improved framework of GI construction for adaption to sustainable urban sprawl. First, we predicted the land use and land cover (LULC) in Lanzhou City in 2030 by using the FLUS (future land use simulation) model. Then, based on the predicted LULC, we extracted ecological sources and corridors by integrating MSPA (Morphological spatial pattern analysis) and MCR (minimum cumulative resistance) model. Finally, as a case, an optimized GI network for adaption to the future sustainable urban sprawl in Lanzhou City in 2030 was established, which included 10 ecological sources, 56 ecological corridors as well as 19 nodes. In this case study, the improved framework was proven to be reliable, and thus can be promoted to construct the GI network in other regions for adaption to different future scenarios. This case study would provide some new insights for future urban planning both in Lanzhou City and cities in other regions, and then contribute to GI protection and regional ecological security.

Isolation, molecular typing and antimicrobial resistance of Clostridium difficile in dogs and cats in Lanzhou city of Northwest China.

Clostridium difficile infection (CDI) in human and animals belonged usually to antibiotic-associated diarrhea, ranging in severity from mild to life-threatening intestinal tract illnesses. This study aimed to isolation and characterization, toxin genes test, molecular typing, and drug sensitivity of Clostridium difficile (C. difficile) which were isolated from clinical diseased dogs and cats. A total of 247 clinical samples were collected from five animal hospitals in Lanzhou City of Northwest China, of which dogs and cats accounted for 74.9% (185/247) and 25.1% (62/247), respectively. We successfully identified 24 C. difficile strains by 16S rRNA and Matrix-Assisted Laser Desorption/Ionization Time of Fight Mass Spectroscopy (MALDI-TOF-MS). 10.3% (19/185) of dogs and 8.1% (5/62) of cats were positive for C. difficile. Among them, 16 strains were toxic and 8 were non-toxic, with a toxic rate of 57.9% (11/19) in dogs and 100% (5/5) in cats. A total of 10 STs and 10 RTs were identified in this study. The percentages of ST42 (RT106) and ST2 (RT014/LW01) among 16 toxic strains were 41.7 and 12.5%, respectively. However, ST3 (RT001), ST1 (RT027), ST133 (LW04), and ST-UN (LW04) had only one strain. ST42 (RT106) was the most common genotype and RT027 strain was first isolated in China from pets. Antimicrobial susceptibility test showed that isolates were extremely sensitive to vancomycin and metronidazole but were resistant to erythromycin and ciprofloxacin. The drug resistant rates to clindamycin, levofloxacin, moxifloxacin and meropenem were 62.5, 20.8, 16.7, and 8.3%, respectively. In conclusion, C. difficile was quietly prevalent in dogs and cats in Lanzhou city with RT106 and RT014 as the main ribotypes. The CDI in pets should be paying more attention and further studies are needed.

Characteristic analysis and potential hazard assessment of reclaimed mountainous areas in Lanzhou, China

The limited available land and unique geomorphological features of the Loess Plateau have restricted the urbanization process, causing the spread of land reclamation (LR). This study examined the city of Lanzhou using remote sensing, statistical methods and a numerical model to analyze the distribution law and the potential disaster impact within the LR areas to suggest prevention and control measures. The results showed that the numbers of 93 LR can be divided into remove-mountaintop (RM), cut-one-side-slope (COSS) and cut-both-side-slopes (CBSS), and their numbers increased from 2000 to 2010, thereafter decreasing; a good exponent relationship was also observed between land creation area and excavation volume. A large number of LR areas are distributed on both sides of the Yellow River, which can potentially generate more mudflows and cause huge economic losses and casualties, especially in the core urban areas. A positive exponential relationship was found between the mudflow volume and accumulation area in the simulation results and the statistical data, and the fitting results were generally similar. The mudflow impact scale, simulated using a modified LAHARZ model, was found to be reliable. The analysis of disaster risk demonstrates that the potential hazards of LR are both preventable and controllable and that a focus on long-term risk is required. This study aims to support geological disaster prevention, control and emergency management.

Differential Gene Expression and Bioinformatics Analysis of Copper Resistance-Related Gene afe_1948 from Acidithiobacillus sp. L1

Acidithiobacillus sp. L1, isolated from a coal mine in Agan Town, Lanzhou City, was introduced in this study. The gene afe_1948 relevant to copper resistance from the test bacterial strain was cloned and transformed into Escherichia coli BL21 (DE3) for heterologous prokaryotic expression, and analyzed by SDS-PAGE to evaluate its optimal expression conditions in E. coli. The expressions of afe_1948 in the presence of copper or cadmium were detected by qRT-PCR. The bioinformatics online analysis software was used to predict the physicochemical properties, structural features, functional domains, and possible metabolic pathways of the protein encoded by afe_1948. The result indicated that putative product AFE_1948 is a stable hydrophilic protein that locates on the cytoplasmic membrane or outside the cell. The gene afe_1948 is 1320 bp in length and encodes a total of 439 amino acids. In the experiment, the target gene was noticed to be very sensitive to copper and cadmium. Exposure to different Cu2+ concentration (0.05, 0.1, and 0.2 mol/L) resulted in the up-regulation of relative mRNA expression levels of afe_1948 in Acidithiobacillus sp. L1 by 2, 4, and 11-fold compared with the control, respectively. Similarly, the relative mRNA expression levels when exposed to Cd2+ at 0.02, 0.04, and 0.06 mol/L were increased by 2, 11, and 23-fold, respectively. To further understand the function of the gene, the variation of resistance to Cu2+ or Cd2+ after transferring into the recipient strain was examined by overexpression analysis. In the presence of 1.0 mmol/L Cu2+ or 0.2 mmol/L Cd2+, the highest relative expression levels regarding AFE_1948 were respectively determined to be more than 23% or close to 25% in recombinant E. coli cells. The assay demonstrated that the biomass of recombinant cells decreased significantly in the presence of Cu2+ or Cd2+ with different concentrations, but the content of intracellular AFE_1948 was enhanced, which may be contributed to a strong induction by the increase of the quantity of heavy metals entering into the cell and introduction of the resistance-related gene.

Differentiation of Vegetation Community Characteristics by Altitude within Urban Parks and Their Service Functions in a Semi-Arid Mountain Valley: A Case Study of Lanzhou City

As the primary component of urban green space, parks play an important role in improving local environments and quality of life for city inhabitants. To date, much research on urban park plant community characteristics has been conducted worldwide, but studies focusing on differences across altitudes have been rare. Here, we have investigated fractional vegetation cover (FVC), plant species diversity, plant species composition, and plant life-form types along altitude gradients within four urban parks (Jincheng, Renshoushan, Baitashan, and Lanshan) in Lanzhou city (China) by field sampling and remote sensing. Spatial variations in plant community characteristics at different elevations, as well as their ecological, social, and integrated service levels, were analyzed using combined methods of remote sensing interpretation, mathematical statistics, and service function assessment. The results showed that: (1) spatial variations in plant communities along elevation gradients exhibited a distinct regional differentiation between parks; (2) Lanshan Park had the lowest FVC (43.6%) and plant species diversity (59 species), and these two parameters exhibited the most dramatic spatial change as elevation increased; the opposite phenomenon occurred in Renshoushan Park (FVC of 56.6%; 81 species); (3) the differences in the natural service level of the plant community were smaller for the social and integrated service levels. The highest natural service level occurred in Renshoushan Park, while Jincheng Park had the highest social and integrated service levels; the smallest values occurred in Lanshan Park. We conclude that scientific park management is urgently required to ensure the safety and sustainable development of the local urban ecosystems and to improve the ecological and social service levels of the individual urban parks, especially Lanshan Park. These findings also provide key insights to improve urban park communities and service levels in similar mountainous, semi-arid zones.

Evaluation of Rural Tourism Resources Based on the Tourists Perspective: A Case Study of Lanzhou City, China

Rural tourism has become a hot spot in China's tourism development. Based on the AHP model and the comprehensive evaluation method of fuzzy cognition, this paper builds an evaluation system for the evaluation of rural tourism resources, including resource value, environmental factors, reception conditions with three criterion layers, and 25 evaluation factors. We recovered 574 valid questionnaires through two online forms and field research in Lanzhou city, and then used them to complete the empirical analysis. The results show four main aspects of the tourists' perspective on rural tourism resources. Firstly, rural tourists are concerned about higher service facilities. The evaluation of rural tourism resources pays more attention to the reception conditions, and tourists pay more attention to the facilities of the reception conditions. In addition, the reception condition value accounts for a more concentrated 8–10 points (61.4%), which is higher than environmental elements (58.87%) and the value of the resource itself (54.26%). Secondly, tourists' attention to rural tourism resources mainly focuses on the pleasurable (0.1152), tour line design (0.1014), experience (0.0765), ornamental (0.0747) and other aspects. Thirdly, the degree of cognition mainly focuses on nature (4508), environmental safety (4469), pleasantness (4387), accommodation conditions (4367), tour line design (4363) and other aspects of the rural tourism resources. Fourthly, the cognition of rural tourism resources is basically given priority with 6–9 points, and environmental factors accounted for the highest portion. However, rural tourists have higher expectations for the popularization and education of rural tourism resources, but the sense of acquisition is relatively low. Through the further improvement and improvement of the naturalness of environmental resources, environmental safety of reception conditions, and the enjoyment of external traffic and resource value, the overall benefit of rural tourism resources is maximized. The results of this study can provide reference for the theoretical foundation of rural tourism resources.

Exploring the Cascading Failure in Taxi Transportation Networks

To explore the ability of taxi transportation service capacity in unexpected conditions, based on the taxi GPS trajectory data, this paper presented a taxi transportation network and explored a cascading failure model with the non-linear function of traffic intensity as the initial load. Moreover, the cascading failure conditions for different initial loads with different parameter settings were derived by combining the complex network theory. We verified the ability of taxi transportation networks to withstand unexpected conditions and analyzed the differences and features of taxi transportation service capacity for different areas of Lanzhou city. Three sets of comparative simulation experiments were implemented. The results show that when the initial load regulation factor α<1/θ, the failure of nodes with smaller initial loads in the network is more likely to cause cascading failure phenomena. When α>1/θ, the failure of nodes with larger initial loads in the network is more likely to cause cascading failure phenomena. Additionally, when α=1/θ, there is no significant correlation between whether cascading failure phenomena occur in the network and node loads. This study can provide a prior basis for decision-making in the management of urban taxi operations under different passenger flow intensities.

Technical and economic performance analysis of large flat plate solar collector coupled air source heat pump heating system

In rural areas of China, clean energy heating in winter is important for coal replacement. Winter temperatures in northwest China are usually below 0°Celsius and the heating season lasts for a long time, which is a huge expense for local residents. Solar energy, air source heat pumps(ASHP), and other energy-saving technologies are known to be effective in reducing heating expenses. However, due to the intermittent and unstable nature of solar energy itself, relying on solar heating is difficult to ensure stable heating and is certainly not economical. ASHP adds a financial burden to local residents due to the relatively high cost of winter heating. In response to the above problems, a new idea of ASHP coupled with solar energy for stable heating is proposed, and a large flat plate solar collector-air source heat pump(LFPSC-ASHP) heating system was established in Green Village, Lanzhou City. Experimental and simulation studies were conducted for this system to reveal the performance and economic benefits of the system for the heating season in three modes: solar collector heating, solar heat pump heating, and air source heat pump heating. The results show that the ASHP-assisted solar heating system is a great technical and economical improvement over the use of solar collectors or ASHP heating throughout the heating season. The LFPSC-ASHP system can continuously and stably heat the target building and has excellent economic and environmental benefits. In the operation of the whole heating season, the average collector efficiency of LFPSC is 0.42, the average COP of solar heat pump heating season is 3.75, and the average COP of ASHP heating season is 2.94. The solar fraction of the system in the whole heating season is 31.8 %, and the system energy efficiency ratio is 3.08. The system can save 7,690.5 CNY by running the whole heating season with a dynamic payback period of 6.58 years. ​Sensitivity analysis of the dynamic payback period shows that lower coal prices extend the dynamic payback period, while lower electricity prices and system costs reduce it. The primary energy saving rate of the system in the whole heating season is 67.5 %. The system can conserve 4,700.06 kg of standard coal in a whole heating season, which is equivalent to a reduction of 12,323.55 kg of CO2.

Correlation analysis between drought and outpatient visits for diarrhea in children aged 0-6 in Lanzhou city and Tianshui city, Gansu Province

In this study, the data of pediatric diarrhea clinic of Gansu Provincial Maternal and Child Health Hospital from January 1, 2014 to December 31, 2018 and Tianshui First Hospital from January 1, 2015 to December 31, 2018 were collected. Standardized precipitation index (SPI) and meteorological drought composite index (MCI) were used as drought indicators. Quasi-Poisson generalized additive model was used to analyze the correlation between drought and pediatric diarrhea outpatient visits. During the study period, the dry days in Lanzhou city and Tianshui city were 298 and 379 days according to SPI-1, 303 and 398 days according to MCI, respectively. There were 57 147 and 18 703 cases of diarrhea in children aged 0-6 years in Gansu Provincial Maternal and Child Health Hospital and Tianshui First Hospital, respectively. MCI and SPI (SPI-1) based on monthly precipitation were negatively correlated with the number of pediatric diarrhea outpatients. Compared with the non-drought period, SPI-1 showed the strongest correlation between middle drought and pediatric diarrhea outpatients, with an increase of 13.4% (95%CI: 7.9%-19.3%) and 20.0% (95%CI: 12.7%-27.8%) in Lanzhou city and Tianshui city, respectively. According to MCI, the outpatients with diarrhea in Tianshui children increased by 60.5% (95%CI: 3.4%-149.0%) due to extreme drought.

Acupuncture Enhances Gastrointestinal Motility and Improves Autonomic Nervous Function in Patients with Septic Gastrointestinal Dysfunction.

Gastrointestinal dysfunction (GD) is a common complication after endotoxemia, which can further aggravate the progress of infection. Acupuncture uses metal needles of different shapes and techniques to stimulate specific points on the human body, which are effective in treating various diseases, including gastrointestinal diseases. We aimed at exploring the clinical effect of acupuncture on the recovery of visceral sensation, proximal gastric compliance, and autonomic nervous function in patients with septic GD. A total of 73 sepsis with GD patients were selected using modified single section ultrasonography combined with clinical symptoms in the First People's Hospital of Lanzhou City during 2019. The participants were randomly allocated to routine-treatment (control group) and study group receiving acupuncture. The indexes before and after treatment included gastric residue, gastric dilatation, pressure and volume, gastric compliance, autonomic nerve function, APACHE II score, and infection index were measured and compared. Before treatment, there was no significant difference in the basic information of the two groups, including gastric volume and pressure, gastric residue, gastric compliance, autonomic nerve function, and APACHE II score. After treatment, the maximum gastric volume and pressure, gastric residue, and APACHE II score of the two groups were significantly improved (P < 0.05). In addition, the maximum gastric volume and pressure of the study group were significantly higher, while gastric residual, autonomic nerve function, and APACHE II were significantly lower than those of the control group (P < 0.05). However, our results showed that acupuncture did not further reduce inflammatory markers, including white blood cells, C-reactive protein, and procalcitonin. To sum up, on the basis of basic treatment, the application of acupuncture can further improve the clinical symptoms of GD in patients with sepsis, enhance gastrointestinal motility, and improve autonomic nervous function, which is worthy of clinical application and promotion.

Risk Assessment and Attribution Analysis of "Five Toxic" Heavy Metals in Cultivated Land in Lanzhou

Heavy metals in cultivated soil may migrate and transform through the food chain to harm the ecological environment and human health. At present, the ecological environment and human health risks of heavy metals in cultivated soil in Lanzhou city remain unclear, which impacts the effective management and control of heavy metals. The potential ecological risk hazard index was used to evaluate the ecological environmental risks of As, Cd, Cr, Hg, and Pb in the surface soil of cultivated land in Lanzhou, and the health risk model proposed by USEPA and the recommended standard were used to evaluate their human health risk. The main factors influencing the spatial differentiation of human health risk were explored by using geographic detectors. The risk of heavy metals to the ecological environment of the cultivated land surface soil in the study area was mainly medium (65.25%), and small portions were low (13.80%) and high (20.95%). The low-risk areas were mainly located in the southeast of Yongdeng County, the middle and north of Yuzhong County, and the southwest of Gaolan County. Moderate risk areas were distributed in three counties and five districts. The high-risk areas were located in the north and southeast of Yongdeng County, the south of Chengguan District, the northeast of Qilihe, the east of Xigu District, and the middle of Yuzhong County. The non-carcinogenic and carcinogenic risks of five types of heavy metal exposure pathways were as follows:oral ingestion>skin contact>respiratory ingestion; generally speaking, children were at higher risk than adults. The non-carcinogenic risk in children was higher than that in adults; however, there was no such risk for local residents, as they were all less than 1. At the same time, the carcinogenic risk of As was greater than 1×10-5 (children 2.04×10-5) and less than 1×10-4 (adults 1.91×10-5), respectively. This indicated an acceptable medium risk to the local residents, and the risk to children was again greater than that to adults. Geographical detector analysis showed that average precipitation during the sampling season had the greatest impact on the spatial differentiation of human health risks of As and Cd, GDP had the greatest impact on the spatial differentiation of human health risks of Cr, and distance from the railway had the greatest impact on the spatial differentiation of human health risks of Hg and Pb. Interaction detection showed that all factors were enhanced by double factors. In addition to leading factors, other factors such as pH, slope, and altitude also enhanced the influence of leading factors on the spatial differentiation of heavy metal risk in cultivated soil.

Family functioning and health-related quality of life of inpatients with coronary heart disease: a cross-sectional study in Lanzhou city, China

BackgroundA key outcome in coronary heart disease (CHD) is Health Related Quality of Life (HRQoL), and family functioning is important in the management of CHD. But few studies have examined both together, and little is known about them among inpatients with CHD in less developed areas of China. Therefore, this study aimed to assess the HRQoL and family functioning status of inpatients with CHD in Lanzhou from Northwest China, and identify the factors that affect their HRQoL.MethodsA cross‑sectional study was conducted in 224 CHD inpatients at one major hospital. Sociodemographic data and disease information of CHD inpatients were collected by face-to-face using a structured questionnaire and data were also obtained from patient medical records. HRQoL was measured using the Sickness Impact Profile (SIP). Family functioning was measured using the family APGAR index. Multiple binary logistic regression analysis (MBLRA) was used to explore potential risk factors associated with HRQoL, and Pearson’s correlations were used to assess the relationship between family functioning and HRQoL.ResultsThe overall, physical and psychosocial SIP scores were 25.03 ± 8.52, 18.61 ± 9.90 and 28.08 ± 9.64, respectively. The total family APGAR score was 6.11 ± 2.45. MBLRA found older age, poorer cardiac function and more severe disease were associated with poorer HRQoL, while better family functioning, higher monthly income, and urban living were associated with better HRQoL. Family functioning was weakly to moderately correlated with total and psychosocial HRQoL.ConclusionsOlder and less affluent inpatients with lower educational level, less family support and more severe CHD have poorest quality of life, and health care providers should consider interventions to support them.

Stability Analysis of Composite Soil Nailing Wall Based on Improved Energy Method

Composite soil nailing wall is widely used in slope support because of its low cost and safety, but its global stability still needs more accurate calculation. Based on plastic limit upper limit analysis and vertical strip partition method, the calculation formula of stability coefficient was derived for prestressed anchor composite soil nailing wall. FLAC3D and GeoStudio were used to calculate and analyze an engineering project supported by composite soil nailing wall in Lanzhou City, and the feasibility and correctness of the derived formula were verified. Finally, the grey correlation analysis of the sensitivity of the derived formula was analyzed. The results show that for calculating the stability coefficient, the limit equilibrium method needs to consider the complex force analysis, while the energy method can well avoid the inter-slice force, making the physical meaning of the formula clearer. The formula introduced in this paper is more efficient and feasible. The stability coefficient is most sensitive to the internal friction angle, followed by slope angle, cohesion, and finally unit weight of soil.

Synergistic reduction potentials for VOCs in solvent-using industrial sectors: A case study of the packaging and printing industry in China

Strong volatile organic compound (VOCs) emissions from solvent-using industries are one of the most pressing environmental challenges in China, and urgently require a cost-effective and carbon-reduction benefit synergistic control strategy. Here, we proposed a novel comprehensive assessment system to optimize a whole-process control strategy that can simultaneously meet triple goals of reduction potential, cost-benefits, and carbon reduction. By focusing on Inner Mongolia Autonomous Region, Shenzhen City, Lanzhou City, Nanyang City and Shunde District of Foshan City, each exhibiting different emission characteristics in packaging and printing (P&P) industry, we proposed various synergistic control strategies and options for reduction potential, cost-benefits, and carbon reduction. This new comprehensive assessment system was shown to be beneficial for obtaining a coordinated control option with better comprehensive effects. Overall our results indicate how to formulate efficient policies, optimized for different regions, to mitigate VOC pollution in industrial sectors.

Feasibility of annual dry anaerobic digestion temperature-controlled by solar energy in cold and arid areas.

In cold and arid areas, variations of ambient temperature not only lead to a large amount of heat loss from anaerobic digestion reactors but also greater challenges in the stable production of biogas. Common temperature-controlled methods of biogas production, such as coal combustion, electric heating, biogas combustion and so on, are expensive and high energy-consuming. Openly, solar energy is economical and suitable for stable biogas production. However, no pilot studies have yet shown the feasibility of controlling the temperature of annual biogas production with solar energy in cold and arid areas. This paper first theoretically analyzed the energy balance between evacuated tube solar collectors and anaerobic reactors. Then a biogas production system was developed in Lanzhou City, China, consisting mainly of a 3m3 insulated anaerobic reactor and a solar collector with 30 sticks Φ58×L1800mm evacuated tubes. Annual batch experiments have been carried out to test the feasibility of stable biogas production at a temperature-controlled by solar energy in cold and arid areas. The results show that dry anaerobic digestion with 20% total solid (TS) can start and operate smoothly even under the condition of low solar irradiation for 3-4 consecutive days. The system can run stability by anaerobic digestion at 26±1°C in winter and spring, by mesophilic (37±1°C) and thermophilic (52±1°C) anaerobic digestion in summer and autumn, which implies a highly efficient operation strategy for agricultural and animal husbandry wastes treatment. These theoretical and experimental results provide a scientific basis and engineering reference for the application of biogas production temperature-controlled by solar energy and have important value for the efficient and low-cost anaerobic digestion treatment of agricultural and animal husbandry wastes in cold and arid areas.