Guilin City Research Articles

桂林岩溶石山青冈群落植物功能性状的尺度变化与关联

桂林岩溶石山青冈群落植物功能性状的尺度变化与关联

Modelling spring discharge and solute transport in conduits by coupling CFPv2 to an epikarst reservoir for a karst aquifer

Karst aquifers differ from unconsolidated granular aquifers with respect to their groundwater flow behavior because of the dual-permeability characteristics (discrete conduit network coupled to a fissured matrix), the duality of recharge (point vs. diffuse recharge) as well as the duality of flow (laminar vs. turbulent state). In many karst aquifers, the epikarst frequently plays an important role in redistributing precipitation as diffuse recharge into the fissured matrix and as point recharge into the conduit network as well as for the temporal distribution of recharge input. In this paper, a coupled groundwater model CE (CFPv2 + ERCH) is developed, consisting of a combination of a simple reservoir model generating the recharge source function assuming the concept of an epikarst horizon (ERCH) with CFPv2, a discrete conduit-continuum groundwater flow model of the phreatic karst aquifer. The CE model is applied to simulate spring discharge and a tracer breakthrough in a karst aquifer near Guilin City in southwest China. In order to examine the effect of an added epikarst reservoir model, simulations are carried out with CFPv2 but without including ERCH. Simulation results of both, spring hydrograph and tracer breakthrough, indicate that CFPv2 with ERCH performs much better. A sensitivity analysis of the CE reveals the relative importance of parameters characterizing the epikarst reservoir. Point recharge is a main factor determining the large variation in spring discharge and its proportion to total recharge can reach 58%. These simulation results highlight the importance of the temporal and spatial distribution of recharge to karst spring discharge response. The coupled model provides an effective approach to include the effect of an epikarst zone in CFPv2 and it can easily be applied for the simulation of karst aquifers with similar characteristics as the study site.

Comparison of chemical composition and airborne bacterial community structure in PM2.5 during haze and non-haze days in the winter in Guilin, China

Haze is a typical type of air pollution and frequently has occurred in the winter in Guilin city recently, but information relating to chemical compositions and airborne bacterial community structure of atmospheric particulate matter (PM2.5) during haze days remains very limited. In this study, the PM2.5 concentration, chemical components including water-soluble ions and metal elements, and bacterial community compositions of PM2.5 on both haze and non-haze days were characterized, and the relationships between them were studied. The results showed that levels of the secondary aerosol particles of SO42−, NO3−, and NH4+ in haze PM2.5 associated with local fuel combustion and vehicle emissions were significantly higher than non-haze samples. Similar trends were observed for the detected trace metal elements. High-throughput sequencing results indicated that higher PM2.5 concentration caused lower bacterial richness and diversity. However, the airborne bacterial community structure remained stable, and no significant difference was found between haze and non-haze PM2.5. Firmicutes, Proteobacteria, and Bacteroidetes were the most abundant phyla accounting for a total of 97.2% on average. In contrast to non-haze PM2.5, the bacterial community structure of haze PM2.5 was mostly positively correlated with SO42−, NO3−, NH4+, K+, and Cl−, suggesting these secondary aerosol particles were probably of great importance on haze pollution and variability of the bacterial compositions of PM2.5.

Relationship between the modest leadership behaviors of nurses in operating rooms and the status of nurses′ work-family gains

Objective To investigate the modest leadership behaviors of nurses in operating rooms and the status of nurses′ work-family gains, and to analyze their relationship. Methods From October to November 2017, a convenient sampling method was used to select 230 operating rooms from 3 tertiary-level A hospitals, 2 secondary A hospitals, and a tertiary A hospital in Guilin City, Guangxi Zhuang Autonomous Region. The nurses used the general information questionnaire, the humble leadership scale, and the work household income scale to conduct questionnaire surveys. Results The total score of the head nurse behavior scale of the operating room was (3.16±0.38) points, and the total score of the nurse work family was (2.95±0.46) points; the headroom behavior of nurses in the operating room was humble leadership behavior and the family income of nurses was increased. Positive correlation (r=0.678, P<0.05). Conclusions The humility leadership behavior of the head nurse can play a positive role in the growth of the work-room nurses′ family. The head nurse should pay attention to cultivate the leadership characteristics of the humility leadership behavior, so as to effectively enhance the work-family gain level. Key words: Operating room; Nurse; Humble leader; Work family gain

The climatic characteristics and formation mechanism of acid rain in Guilin, China

A comprehensive study on climatic conditions and the chemical compositions of the rainwater had been undertaken from 2011 to 2015. Over 200 samples were taken and analyzed for pH in each year. Particularly, 240 samples taken in 2015 were analyzed for major ions. The results showed that the average frequency of acid rain in Guilin City was as high as 60% from 2011 to 2015. The order of the anion and cation concentration in precipitation was SO42->NO3->Cl->F-, Ca2+>NH4+>K+>Na+>Mg2+, respectively. Ca2+ plays an important catalytic role on the photochemical conversion process of SO42-. The formation of a large number of sulfates led to the occurrence of acid rain in Guilin. The adverse meteorological conditions in the winter and spring season were found to be a main reason for most serious acid rain pollution episodes during this period.

Short-term effects of meteorological factors and air pollution on childhood hand-foot-mouth disease in Guilin, China

BackgroundPrevious studies have always focused on the impact of various meteorological factors on Hand–foot–mouth disease (HFMD). However, only few studies have investigated the simultaneous effects of climate and air pollution on HFMD incidence. MethodsDaily HFMD counts among children aged 0–14 years in Guilin city were collected from 2014 to 2016. Distributed lag nonlinear models (DLNM) were used to assess the effects of extreme meteorological factors and air pollution indicators, as well as the effects of different lag days on HFMD incidence. Furthermore, this study explored the variability across gender and age groups. ResultsExtreme temperatures, high precipitation and low-O3 concentration increased the risk of HFMD. Hot effect was stronger and longer lasting than cold effect. Risks of rainy effect and low-O3 effect continued to increase as lag days extended, with the maximum RR values: 1.60 (1.38, 1.86) (90th vs median) and 1.48 (1.16, 1.89) (1th vs median) at 0–14 lag days, respectively. By contrast, extremely high wind speed, low precipitation, low PM2.5 and high O3 exerted a certain protective effect on HFMD incidence. The corresponding minimum RR values were: 0.85 (0.74, 0.98) (90th vs median) at 0–14 lag days, 0.98 (0.97, 0.99) (10th vs median) at 0–14 lag days, 0.73 (0.61, 0.88) (1th vs median) at 0–14 lag days and 0.81 (0.73, 0.90) (99th vs median) at 0–7 lag days, respectively. Male children and children aged 0–1 years (followed by 1–3 years) were the most susceptible subgroups to extreme climatic effects and air pollution. ConclusionsOur results indicated that daily meteorological factors and air pollution exert non-linear and delayed effects on pediatric HFMD, and such effects vary depending on gender and age. These findings may serve as a reference for the development of an early warning system and for the adoption of specific interventions for vulnerable groups.

Eco-feedback for thermal comfort and cost efficiency in a nearly zero-energy residence in Guilin, China

City residence development in China is increasing at an annual rate of 0.5–0.6 billion m2, causing vast increases in energy consumption by HVAC facilities and other appliances. Thus, governments and researchers are encouraging the use of renewable energy sources such as solar and geothermal energy in residential areas. However, high equipment costs and low energy conversion efficiency have reduced their acceptability to residents. Thus, researchers must determine the eco-feedback equilibrium point that achieves both economic benefit and thermal comfort. The objective of this study is to design and build a nearly zero-energy building (NZEB) with an HVAC system and an onsite solar photovoltaic system. Because HVAC systems typically account for more than 40% of total energy consumption in residences, a 24 h monitoring system was installed in the considered residential setting to measure the temperature, wind velocity, and energy in-out value with/without the HVAC system for several days in summer and winter. The thermal comfort period was analyzed and confirmed, and the air conditioner was switched on during thermal discomfort periods in one summer and one winter month. Temperature, humidity, wind, and energy data was recorded to calculate the average monthly energy consumption that provides all-day thermal comfort. Finally, two analyses were conducted; first, the real measured temperature after construction was recorded for thermal comfort analysis; second, the cost of renewable energy facilities and power consumption was converted to cost efficient rates to assess the feasibility of renewable energy input for the residence. The results of the experiment showed that the house could achieve better thermal comfort in summer than in winter. Contrary to our assumptions, energy consumption was highest in September and October rather than in July and August. Moreover, with a payback period of approximately 11 year, the cost-effectiveness is high for a house in the city of Guilin.

Cover Feature: Copper‐Catalyzed Carbonyl Group Controlled Coupling of Isatin Oximes with Arylboronic Acids To Prepare N‐Aryloxindole Nitrones (Eur. J. Org. Chem. 2/2018)

The Cover Feature shows a copper-catalyzed carbonyl group controlled coupling reaction of isatin oximes and arylboronic acids under air conditions. The key role of the carbonyl group is demonstrated by a flying kite; the carbonyl group connects to the kite, which represents the Cu(OAc)2 catalyst. The kite flying shows the directing and controlling role of the carbonyl group. The picture was taken from a famous sight on the Lijiang river in Guilin city. The reflection of the mountains in water represents the configuration of oximes towards a defined configuration of nitrones under catalyst conditions in air. More information can be found in the Full Paper by D.-L. Mo et al.

The Reconstruction of Guilin's Urban Ecological Landscape Based on the Concept of Sponge City

Guilin is an international tourist city famous for its landscape, but the prominent contradiction in water usage becomes one of the key factors that influences and restricts the construction and development of the city. As an effective measure to relieve the contradiction of urban water usage, the concept of “sponge city” has achieved success in many places. Thus, building Guilin urban ecological landscape on the basis of the concept of “sponge city” is of great significance for the effective relief of the contradiction in water usage and the realization of sustainable development. Academic studies point out that for the purpose of the construction of sponge city, the construction of Guilin's urban ecological landscape first need to adopt sponge strategies in urban residential areas, transform or build a virtuous circulating green space system to collect, purify and store rainwater in an effective way. Secondly, build rainwater collection, purification, storage facilities or systems extensively and replenish urban ecological water reserve in the grey system of the city, according to the concept of “sponge”. Thirdly, considering the large area of Guilin city parks, build rainwater self-use rain systems extensively in city parks based on the concept of sponge and substantially reduce external ecological water reserve. Fourthly, reinforce training and learning related to the concept of “sponge city” and the implementation of “sponge city” policies.

Ecological risk assessment of typical karst basin based on land use change: A case study of Lijiang River basin, Southern China

Taking Lijiang River basin as study area, and based on the remote sensing images of 1973, 1986, 2000 and 2013, the land-use data were extracted, the ecological risk index was constructed, and the characteristics of spatiotemporal variation of ecological risk were analyzed by "3S" technique. The results showed that land use structure of Lijiang River basin was under relatively reasonable state and it was constantly optimizing during 1973-2013. Overall, the ecological risk of Lijiang River basin was maintained at a low level. Lowest and lower ecological risk region was dominant in Lijiang River basin, but the area of highest ecological risk expanded quickly. The spatial distribution of ecological risk was basically stable and showed an obvious ring structure, which gra-dually decreased from the axis of Xingan County Town-Lingchuan County Town-Guilin City-Yangshuo County Town to other regions. Region with lowest ecological risk mainly distributed in natural mountain forest area of the north and mid-eastern parts of Lijiang River basin, and region with highe-st ecological risk concentrated in Guilin City. The ecological risk distribution of Lijiang River basin presented significant slope and altitude differences, and it decreased with increasing slope and altitude. During the study period, the area of low ecological risk converted to high ecological risk gra-dually decreased and vice versa. On the whole, the ecological risk tended to decline rapidly in the Lijiang River basin.

Identification of the dominant hydrological process and appropriate model structure of a karst catchment through stepwise simplification of a complex conceptual model

Conceptual models often suffer from the over-parameterization problem due to limited available data for the calibration. This leads to the problem of parameter nonuniqueness and equifinality, which may bring much uncertainty of the simulation result. How to find out the appropriate model structure supported by the available data to simulate the catchment is still a big challenge in the hydrological research. In this paper, we adopt a multi-model framework to identify the dominant hydrological process and appropriate model structure of a karst spring, located in Guilin city, China. For this catchment, the spring discharge is the only available data for the model calibration. This framework starts with a relative complex conceptual model according to the perception of the catchment and then this complex is simplified into several different models by gradually removing the model component. The multi-objective approach is used to compare the performance of these different models and the regional sensitivity analysis (RSA) is used to investigate the parameter identifiability. The results show this karst spring is mainly controlled by two different hydrological processes and one of the processes is threshold-driven which is consistent with the fieldwork investigation. However, the appropriate model structure to simulate the discharge of this spring is much simpler than the actual aquifer structure and hydrological processes understanding from the fieldwork investigation. A simple linear reservoir with two different outlets is enough to simulate this spring discharge. The detail runoff process in the catchment is not needed in the conceptual model to simulate the spring discharge. More complex model should need more other additional data to avoid serious deterioration of model predictions.

论民族社会工作的本土化发展——以东山瑶族乡上塘村为例

随着社会工作的本土化发展，民族社会工作作为社会工作的一个重要分支，本土化发展的呼声亦愈来愈高，但目前这一领域的发展仍处于起步阶段，具有很大的发展空间。本文以广西省桂林市全州县东山瑶族乡少数民族为研究对象，通过问卷调查和深度访谈,了解了东山瑶乡在发展过程中文化传承与保护的有关问题，并试图从社会工作的优势理论视角立足瑶乡文化、挖掘并调动在地优势、提倡社区发展来探讨民族社会工作在当地本土化发展的可行性和必要性。 With the localization of social work, national social work as an important branch of social work, localization of the voice is also getting higher and higher, but the current development of this area is still in its infancy, with great room for development. This paper takes the minority nationality of Dongshan Yao nationality in Quanzhou county of Guilin city of Guangxi province as the research object. Through questionnaire survey and in-depth interview, this paper focuses on the related problems of Dongshan Yao Township in the process of cultural inheritance and protection, and tries to learn from the advantages of social work Theoretical perspective based on Yao culture, mining and mobilize the advantages of land, to promote community development to explore the national social work in the local localization of the feasibility and necessity.

Effects of different inundation periods on soil enzyme activity in riparian zones in Lijiang

The most important environmental processes in riparian zones are the release of carbon, nitrogen, and phosphorus from various organic compounds. The extracellular enzymes of soil microorganisms are involved in the biogeochemical cycling of organic matter nutrients and may be important for regulating water quality. The objectives of the present study were to determine whether the activities of soil enzymes were affected by different inundation periods in the riparian zone and to identify major factors that influence soil enzyme activity. We subjected three study plots to different inundation conditions (long inundation, moderate inundation, and rare inundation) within the transects perpendicular to the river flow at three sites (Weijiadu, Lijiaocun, and Daxu) in Lijiang, Guilin City, China. Soil physicochemical properties, dissolved nutrient composition, and soil enzyme activities were analyzed. The activity of acid phosphatase, alkaline phosphatase, and arylsulfatase significantly increased as the inundation frequency decreased, whereas the activity of glucosidase, β-N-acetylglucosaminidase, glycine aminopeptidase, l-leucine aminopeptidase, and dehydrogenase were significantly higher in study plots that received long inundation than in those subjected to moderate or rare inundation. Linear regression indicated that most hydrolase and dehydrogenase activities were affected by soil clay content, soil organic matter, and soil water content, among other factors. NO3−-N limited the activity of acid phosphatase, l-leucine aminopeptidase, and glycine aminopeptidase. Polyphenol oxidase activity was constrained by soil water content and available potassium but promoted by NO3−-N. Our study demonstrated that imposing longer inundation periods can increase soil enzyme activities. To maintain microbial activity and to minimize water pollution, it is important to reduce high NO3−-N loads.

Preliminary study on infection status and gene types of Cryptosporidium among HIV/AIDS patients in Guangxi

To understand the infection status and gene types of Cryptosporidium among HIV/AIDS patients in Guangxi Zhuang Autonomous Region. The fecal samples were collected from 285 HIV/AIDS cases in Nanning, Guilin, Qinzhou, Baise, Hechi cities of Guangxi and 150 HIV negative persons in Nanning City. The modified acid-fast staining and nested-PCR based on 18S rRNA were employed to detect the infection status of Cryptosporidium. The nested PCR products were sequenced, and the homology searches and identification for the gene types of Cryptosporidium were done by DNAStar software. The infection rate of Cryptosporidium in HIV/AIDS patients was 0.70% (2/285), and the rate of those with chronic diarrhea was 6.67% (2/30), the latter was significantly higher than that of the HIV negative persons (0, 0/150) (P = 0.002). Both the two HIV/AIDS patients infected with Cryptosporidium were from Guilin City. By molecular identification, the Cryptosporidium strains which the above 2 patients were infected with were Cryptosporidium andersoni and Cryptosporidium hominis respectively. Cryptosporidium co-infection can be found in HIV/AIDS patients in Guangxi. The genotypes of the infection strains include Cryptosporidium andersoni and Cryptosporidium hominis.

Fabrication of a novel RF switch device with high performance using In0.4Ga0.6As MOSFET technology**Project supported by the National Natural Science Foundation of China (Nos. 61274077, 61474031), the Guangxi Natural Science Foundation (No. 2013GXNSFGA019003), the Guangxi Department of Education Project (No. 201202ZD041), the Guilin City Technology Bureau (Nos. 20120104-8, 20130107-4), the China Postdoctoral Science Foundation Funded Project (Nos. 2012M521127, 2013T60566), the

A novel radio frequency (RF) switch device has been successfully fabricated using InGaAs metal–oxide–semiconductor field-effect transistor (MOSFET) technology. The device showed drain saturation currents of 250 mA/mm, a maximum transconductance of 370 mS/mm, a turn-on resistance of 0.72 mω·mm2 and a drain current on-off (Ion/Ioff) ratio of 1 × 106. The maximum handling power of on-state of 533 mW/mm and off-state of 3667 mW/mm is obtained. The proposed In0.4Ga0.6 As MOSFET RF switch showed an insertion loss of less than 1.8 dB and an isolation of better than 20 dB in the frequency range from 0.1 to 7.5 GHz. The lowest insertion loss and the highest isolation can reach 0.27 dB and more than 68 dB respectively. This study demonstrates that the InGaAs MOSFET technology has a great potential for RF switch application.

Identification and mating type determination of Phytophthora strains causing blight on two cucurbit crops in South China

To clarify mating types of the pathogen causing phytophthora blight on cucurbit crops, over 400 samples of affected wax gourd and cucumber plants were collected from nine cities in South China during 2007–2010. A total of 198 Phytophthora strains were isolated from the samples and identified as Phytophthora melonis based on their morphological characteristics and rDNA-ITS (internal transcribed spacer) sequences. Mating types of the strains were determined based on mating reactions between a field strain and each of the reference strains of mating types A1 and A2. Five mating types were found in the samples collected. The A0 mating type was predominant in Guilin city, representing 40.9 % of the strains obtained, while the A2 mating type was dominant in the sampling areas with a frequency of 37.5–66.7 %. The A0, A2 and A1A2 mating types were isolated from both hosts. The A1 and A1,A2 mating types were obtained only from the wax gourd and cucumber plants, respectively. The ratio of A1 and A2 mating types isolated from Guilin was close to 1:1, suggesting a possibility for sexual reproduction to occur in South China.

Recharge processes on typical karst slopes implied by isotopic and hydrochemical indexes in Xiaoyan Cave, Guilin, China

Summary Measurements of the hydrogen and oxygen isotopic composition of precipitation and drip stream water at drip site XY5 in Xiaoyan Cave in Guilin City were conducted to investigate the infiltration and vadose flow processes, and to characterize precipitation–discharge relationship in the overlying karst hillslope area. A marked seasonal variability of oxygen and hydrogen isotopes was observed in precipitation ranging from −18.7‰ to −0.6‰ for δ 18 O and −139‰ to +5‰ for δD, respectively during the study period from November 2013 to October 2014. However, the narrow range observed for cave drip stream water (δD of −43‰ to −22‰, δ 18 O of −7.3‰ to −4.3‰) was attributed to homogenization via mixing of meteoric waters in the unsaturated zone above the cave. Although drip stream waters plot close to or slightly above the local meteoric water line, the weighted average δ 18 O value of precipitation is depleted than in dripwater, which is attributed to evaporation predominantly in the rainy season when cave air circulation is most active. The relationship between surface infiltration or leakage and cave discharge is connected by the distinct models of flow through the epikarst zone. Vadose flow showed high peaking hydraulic responses but buffered rain isotope responses with an attenuate magnitude of 5.0–9.4‰ for δ 18 O. The sudden hydrochemical proxy variability was related closely to increase of discharge and the flushing out of old water with higher dissolved calcite. A threshold of flow generation expressed by precipitation amount must be exceeded to create a peak in discharge, as a function of excessing the field capacity of soil and residual capacity of epikarst zone. The sources of vadose seepage are soil and epikarst reservoir water with the attenuation of the isotopic fluctuations (−4.28‰ to −5.92‰ for δ 18 O) and slight hydrological response, indicating mixed signals of infiltration water in epikarst storage reservoir. The total discharge volume of percolating water is 2084 L derived from piston flow due to the increased hydraulic head in the dry season, which provides a quantitative evidence of the potential adaptive capacity of the system to deal with the extreme droughts.

MIM capacitors with various Al2O3 thicknesses for GaAs RFIC application**Project supported by the National Natural Science Foundation of China (Nos. 61274077, 61474031), the Guangxi Natural Science Foundation (No. 2013GXNSFGA019003), the Guangxi Department of Education Project (No. 201202ZD041), the Guilin City Technology Bureau (Nos. 20120104-8, 20130107-4), the China Postdoctoral Science Foundation Funded Project (Nos. 2012M521127, 2013T60566), the National Basic Research Program

The impact of various thicknesses of Al2O3 metal—insulator—metal (MIM) capacitors on direct current and radio frequency (RF) characteristics is investigated. For 20 nm Al2O3, the fabricated capacitor exhibits a high capacitance density of 3850 pF/mm2 and acceptable voltage coefficients of capacitance of 681 ppm/V2 at 1 MHz. An outstanding VCC-α of 74 ppm/V2 at 1 MHz, resonance frequency of 8.2 GHz and Q factor of 41 at 2 GHz are obtained by 100 nm Al2O3 MIM capacitors. High-performance MIM capacitors using GaAs process and atomic layer deposition Al2O3 could be very promising candidates for GaAs RFIC applications.

Modeling the hydrological behavior of a karst spring using a nonlinear reservoir-pipe model

Karst aquifers are commonly simulated based on conceptual models. However, most karst conceptual models hardly consider the function of turbulent conduits. The conduit network acts as the main draining passage of the karst aquifer and may also have a strong influence on the hydrological processes, especially during storm events. A conceptual model with a nonlinear reservoir and a turbulent pipe (representing the conduit system) in series is proposed according to the basic structure of a typical karst aquifer, to simulate the karst spring. The model indicates whether the spring discharge is influenced by the turbulent pipe; this not only depends on the parameters of the nonlinear reservoir and turbulent pipe, but also depends on the volume of spring discharge itself. Even though the spring discharge is strongly influenced by the turbulent pipe during the storm, this influence decreases with the rainfall intensity and volume of spring discharge. In addition, an ‘evapotranspiration store’ is used to consider the moisture loss through evapotranspiration and to calculate the effective rainfall on the proposed model. Then, this simple conceptual model is used to simulate a karst spring (named S31) near Guilin city, China, with satisfactory results, especially with respect to discharge peaks and recession curves of the spring under storm conditions. The proposed model is also compared with the Vensim model of similar complexity, which has been applied to the same spring catchment. The comparison shows the superiority and better performance of the nonlinear reservoir-pipe model.

Geostatistical Analysis of Heavy Metals in Vegetable Soil from Guilin City, China

The main objectives were to investigate the concentrations of heavy metal in Guilin vegetable topsoils by conducting geostatistical analyses, including Kriging method assisted with GIS tool. These results will contribute to the management of regional environment. A total of one hundred and eighty-six samples of topsoils (0~20cm) were collected from all over Guilin, China. Concentrations of topsoil Cu, As, Ni, Zn, Pb and Cd in Guilin area were measured and contour maps were constructed to describe the metals’ spatial distribution. The concentrations of heavy metals in vegetable soil are in log-normal distribution, so the Geometric means of Cu, As, Ni, Zn, Pb and Cd are 28.30, 20.00, 23.97, 91.01, 36.76 and 0.62 mg/kg, respectively. Concentration of 6 heavy metals were comparable with background values of Guilin except Cd, but all of them were much lower than the second level of environmental quality standard for soil of China.