Input Ratio Research Articles

Analysis of COVID-19 Based on SEQR Dynamic Model in Xiaogan City, Hubei Province

In this study, we established a SEQR model for the spread of COVID-19. The impact of city lockdown measures and other factors on the spread of the epidemic was discussed in this paper through dynamic analysis and numerical simulation of the model. The research results showed that the input ratio of the exposed population should be controlled to at least 0.001 if the government wanted to effectively control the epidemic. Closing the city was the most effective way. The exposed population of COVID-19 in Xiaogan City was hoping to be cleared on February 29 under strict control. The closed city could be released around March 28. But at the same time, we should pay attention to prevent the virus from entering it again. The peak number of existing patients would reduce by about 1,400 if city lockdown measures were taken in Xiaogan City four days in advance.

Thermodynamic analyses of a solar assisted ejector enhanced vapor injection cycle with subcooler for heat pump dryer application

This paper presents a solar assisted ejector enhanced vapor injection cycle with a subcooler (SE-SVIC) for heat pump dryer applications. The proposed cycle improves the heat absorption per unit of mass in the evaporator because the lower subcooler outlet temperature can be obtained with the pressure lift ability of the ejector. The cycle performances of SE-SVIC are evaluated and compared with those of the basic subcooler vapor injection cycle (SVIC) and the ejector enhanced subcooler vapor injection cycle (E-SVIC). The results show that the COPh of SE-SVIC is improved by 23.8 % and 19.0 % compared with SVIC and E-SVIC under the typical operating condition, respectively. The heating performance of SE-SVIC is largely dependent on the solar energy input ratio. Overall, the input of solar energy can achieve significant improvement in the heating capacity of SE-SVIC if there is sufficient solar radiation available for the solar collector. Further, the largest exergy destruction of SE-SVIC occurs in the solar collector. As the increase of the solar radiation intensity, the exergy input increases more obviously than the exergy destruction, and thus the exergy efficiency of SE-SVIC is increased. The theoretical results show the energy saving potential of the proposed cycle and its application perspective in the heat pump dryer.

Thermodynamic, economic and environmental performance of a flute-type distributor embedded micro-channel evaporator for RACs

Room air conditioners embedded with micro-channel heat exchangers generally manifest excellent thermal performance. However, the non-uniform refrigerant distribution in micro-channels remains as a bottleneck problem. To address this problem, a micro-channel evaporator with a built-in flute-type distributor was designed and fabricated based on a finned-tube evaporator. This paper studies the influence of the structure of the built-in flute-type distributor on the gas–liquid two-phase refrigerant flow in the micro-channel flat tubes. The effects of the primary throttling depth, the placement angle between the opening of inlet header and the inlet of micro-channel flat tube, and the indoor dry-bulb temperature were studied using the enthalpy difference method. The cooling capacity, power input and energy efficiency ratio of the testing unit were compared regarding each influencing factor, and the optimal primary throttling depth was obtained. The thermodynamic performance of various room air conditioner evaporators with and without micro-channels and flute-type distributors were also compared. In addition, an economic and environmental analysis was conducted on the optimal configuration. The results showed that, the evaporator achieved a higher inlet pressure, lower pressure loss, and higher cooling capacity and energy efficiency ratio when the placement angle was 180°±6°. Compared to micro-channel evaporator embedded room air conditioner with no distributor, the energy efficiency ratio of room air conditioner with flute-type distributor embedded micro-channel evaporator with a 180° placement angle was improved by 11.8%. When the angle was within β = 180°±6°, the change of refrigeration capacity was not obvious. It was also showed that the annual power consumption, life cycle cost and total equivalent warming impact of the flute-type distributor embedded micro-channel evaporator was reduced by 13.6%, 12.0% and 12.9% respectively.

Budget of Plant Litter and Litter Carbon in the Subalpine Forest Streams

Investigations on the budget of plant litter and litter carbon in forest streams can provide a key scientific basis for understanding the biogeochemical linkages of terrestrial–aquatic ecosystems and managing forest catchments. To understand the biogeochemical linkages among mountain forests, riparian vegetation, and aquatic ecosystems, the changes in litter input and output from the subalpine streams with stream characteristics and critical periods were investigated in an ecologically important subalpine coniferous forest catchment in the upper reaches of the Yangtze River. The annual litter input to the stream was 20.14 g m−2 and ranged from 2.47 to 103.13 g m−2 for 15 streams during the one-year investigation. Simultaneously, the litter carbon input to the stream was 8.61 mg m−2 and ranged from 0.11 to 40.57 mg m−2. Meanwhile, the annual litter output varied from 0.02 to 22.30 g m−2, and the average value was 0.56 g m−2. Correspondingly, the litter carbon output varied from 0.01 to 1.51 mg m−2, and the average value was 0.16 mg m−2. Furthermore, the average ratio of litter carbon input to output was 270.01. The maximum and minimum values were observed in the late growing season and the snowmelt season, respectively. Additionally, seasonal variations in temperature, together with the stream length, dominated the input of litter and litter carbon to the stream, while the precipitation, temperature, water level, and sediment depth largely determined their output. Briefly, the seasonal dynamics of litter and litter carbon were dominated by stream characteristics and precipitation as well as temperature patterns.

Does Engagement Partners’ Effort Affect Audit Quality? With a Focus on the Effects of Internal Control System

An audit team includes engagement partners, CPAs, and staff. Among them, partners play a vital role in performing tasks that require expertise and experience, such as analyzing and understanding the industry, and supervising the overall audit process. In detail, the partners establish an audit plan, determine the overall audit time, provide the audit input ratio of the engagement team, and review the audit reports. This study examines for association between the partner’s audit hour ratio and audit quality depending on the client firms’ characteristics. Although the role of partners is important, the information about partner audit hours is limited. However, the Korean government requires audit firms to disclose the partner hour information in the audit report starting in the 2014 fiscal year. By the disclosure, it is possible to examine the association between partner audit hours and audit quality. In this study, the information on partner audit hour is hand-collected from the firms’ business reports. Using 6340 observations from 2014 to 2017, the partner audit hour ratio is associated with audit quality, under the characteristics of client firms. Firms’ risks are adopted for client characteristics, and we focused on the operation of internal control. The internal control operation level is measured by the following: (1) the ratio of internal control personnel and (2) experience of the internal control personnel in the accounting and IT departments. The result suggests that for the firms where internal control is not effectively operated, partners make more effort to enhance audit quality.

INTEGRATED ENERGY BALANCE OF THE PRODUCTION OF QUALITY “CACHAÇA” AND BIOFUEL

The production of small-scale farm fuel alcohol is a viable economic activity, but in Brazil, there are few studies on the energy balance of its production. In the present work, the energy balance of the integrated production of quality “cachaça” and fuel alcohol at the farm level was carried out, as well as the determination of technical coefficients in a microdistillery in Minas Gerais (Zona da Mata), Brazil, for the production of sugar cane, cachaça and farm fuel alcohol. The productive capacity of this microdistillery in the analyzed period was 5,271.63 liters of cachaça and 658.95 liters of farm alcohol per day. Energy expenditure in the production of sugar cane (agricultural phase) was 245.14 MJ per ton of cane (MJ TC-1), with 80% of the total of this energy going to the production of cachaça and 20% for the production of sugarcane fuel alcohol. The energy expenditure for the production of cachaça and fuel alcohol from sugar cane was 30.44 MJ TC-1 (industrial phase), of which 80% went to obtain cachaça and 20% for the farm fuel alcohol. The energy output / input ratio was 4.61 (fuel alcohol + excess bagasse). Much of the energy demand is due to the use of nitrogen fertilizers and diesel oil. The farm alcohol produced had a renewability index of 0.27, showing it to be a renewable fuel.

The usefulness of extended input\u2013output tables incorporating firm heterogeneity

This study examines the usefulness of an extended input–output table (EIOT) incorporating the heterogeneity of Japanese firms based on differences in ratios of imported intermediate goods to total output. Using an EIOT, the vertical specialization indicator of Japan was calculated, which corresponds to the foreign value added included in exports. In this process, differences in intermediate input ratios were measured examining different types of firms using firm-level microdata from the Basic Survey of Japanese Business Structure and Activities. The results indicate that distinguishing between exporting and non-exporting firms is relevant for assembly industries such as electronics and automobiles, as widely discussed in the literature. In contrast, for primary materials industries, such as paper, chemical, and metal industries, other distinctions appear to be more relevant. For example, for the chemical industry, wherein firms tend to have large, integrated manufacturing plants, the differences in intermediate import ratios are largest when distinguishing large firms from small and medium firms. For paper and metal industries, which rely on foreign raw materials, the difference is largest when distinguishing between firms with and without foreign affiliates. By incorporating such heterogeneity, the vertical specification indicator increases by 70%; thus, the EIOT captures the foreign value added more comprehensively.

Measured global thermal performance of a directly irradiated suspension-flow solar particle receiver with an open aperture

We present an experimental investigation of the thermal performance of a 1-kW directly irradiated suspension-flow solar particle receiver with an open (windowless) aperture under simulated solar conditions. Silicon carbide and air were used as the particulate and fluid media, respectively. A 5 kWel xenon-arc solar simulator was used as the energy source. An outlet-suction strategy was employed to induce a net inflow through the aperture as means to mitigate particle and hot fluid egress from the device. The influence of various operating parameters, namely particle loading, air inlet mass flow rate and net air ingress through the aperture on the global thermal performance (thermal efficiency, exergy disruption, specific heat losses and wall temperature distribution) of the device was investigated systematically. It was found that the ratio of the solar input to total heat capacity of the two-phase flow and the level of suction have controlling influence on the global performance of the device. For the operating conditions investigated here, the heat absorbed by the air through the receiver was found to be 3–15 times higher than that of the solid phase, depending primarily on the mass loading and total inlet fluid flow rate. The presence of the solid phase was found to enhance the total heat absorbed by the two-phase flow albeit at the expense of lowering the value of the maximum outlet air temperature.

About long period sequences

This paper presents estimation results of the ratio of input to output sequence periods for combination schemes and the ratio of input to internal sequence periods for schemes with a memory element. A decrease in the length of output sequence period, which is possible in the case with circuits with a memory element, is not discussed. The following results are given:(1) for any \({\varvec{m}}\) sequences with period lengths of \({{\varvec{T}}}_{1}\),…,\({{\varvec{T}}}_{{\varvec{m}}}\), \({\varvec{m}}>1\), a lower bound of their modification period length is given using the combination function \(\varvec{\upvarphi }({{\varvec{y}}}_{1},\dots ,{{\varvec{y}}}_{{\varvec{m}}})\) that is bijective for some variables;(2) the modification period length for \({\varvec{m}}>1\) sequences generated by maximum-length linear feedback shift registers is proved to be maximal, using the combination function \(\varvec{\upvarphi }({{\varvec{y}}}_{1},\dots ,{{\varvec{y}}}_{{\varvec{m}}})\), that depends essentially on all variables, and the number of ones per period of the output sequence is estimated;(3) for a certain class of non-autonomous automata, it is shown that the ratio of the period lengths of the internal sequence to the input sequence can be large, in particular, reach the number of automaton states.The conditions under which the period lengths of resulting sequences are maximum are specified.

A compact simple microstrip lowpass filter based on elliptical analyzed resonator

Abstract In this article, a compact microstrip lowpass filter (LPF) using elliptical shaped resonators with ultra-wide stopband is rendered. In this respect, LC equal structures of the elliptical shaped resonators are calculated based on the formula of circumference. In addition, to calculate transmission zeros of the presented elliptical shaped resonator, the LC equal structure and its output to input ratio are employed. The proposed LPF has a −3 dB cut-off frequency at 1.50 GHz and the stopband bandwidth of the designed filter is about 13fc, which refers to its ultra-wide stopband. The occupied circuit size of the presented filter is 0.151λ g × 0.044λ g (λ g is the guided wavelength at 1.50 GHz). The designed filter is fabricated on RT/Duroid 5880 substrate. The results of the fabricated and designed filter have clearly demonstrated that not only has the proposed LPF shown a suitable agreement between measured and simulated S-parameters, but also an appropriate stopband bandwidth.

Mechanisms of an innovative hybrid arc welding process in enhancing joint penetration and weld property control through resistive and induction heat

Low costs (material, energy and time), high joint properties are the eternal pursuit of modern welding. In this paper, mechanisms of an innovative high frequency electric cooperated arc welding (HFAW) in enhancing welding productivity (joint penetration) and weld property control were comprehensively investigated. The process properties and weld mechanisms of this method were systematically compared with that of the traditional GMAW welding under typical process parameters. The results showed that 4.8 mm joint with an large aspect ratio of 4 was achieved by single pass HFAW at a high welding speed (15 mm/s) and a low welding heat input (reduced 1/3 than the traditional GMAW). The research on weld property control shows that the microstructure of weld zone and heat affected zone (HAZ) in the HFAW joint was much smaller than that in the GMAW joint under optimal parameters. The width of each zone in the HAZ, thermal cycle parameters such as elevated temperature holding time and cooling rate can be regulated independently by the high frequency electric heat input ratio. Such regulation is of great significance for high strength steel welding, which needs to control the welding thermal cycle process accurately. Combined with three-dimensional solid reconstruction of liquid filler metal, the mechanism of the HFAW in enhancing joint penetration was demonstrated. An interesting “self-tracking heating” of the high frequency current was found. The cutting-edge of the liquid metal was violently heated and more than half of the weld in thickness direction was achieved by a novel ultra-speed “interfacial tension driving penetrating” weld forming mechanism, which promises the HFAW high welding speed and large aspect ratio on the premise of satisfactory welding quality.

Ефективність використання стимуляторів і регуляторів росту під час вирощування біомаси міскантусу в умовах лівобережного лісостепу України

The article presents the indicators of economic efficiency of growing miscanthus biomass for the production of solid biofuels. The energy efficiency coefficient is calculated as the ratio of energy input to energy output. The aim of the study was to assess the efficiency of the use of plant growth-promoting and regulating products Vympel-K and Quantum-Gold in the cultivation of miscanthus biomass in the Left-Bank Forest-Steppe of Ukraine. Results. Return on investments starts since the third year of harvesting. The gross income after the fourth vegetation season was 392 900 UAH per hectare. The highest energy efficiency index (4.2−4.4) calculated for the first-year harvest was in the following treatments: single and double dose of NPK, single and double treatment with Vympel-K. Profitability in these treatments was the highest and ranged from 345.3 to 341.4%. The proposed new component of cultivation technology − soaking the rhizomes before planting in the growth-regulating and promoting products Quantum Gold and Vympel-K is economically justified. The return on investments after the sale of the miscanthus biomass for the use of these techniques starts since the third year of cultivation.

Energy intensity of manufacturing enterprises under competitive pressure from the informal sector: Evidence from developing and emerging countries

The informal sector, which is prevalent in many developing countries, is an important factor influencing the strategic decisions of formal enterprises. Using a sample of manufacturing enterprises in developing and emerging countries from the World Bank Enterprise Survey from 2006 to 2020, this study investigates the mechanism of formation of the energy intensity of enterprises from the perspective of the informal sector. The results show that formal manufacturers significantly reduce their energy intensity in response to competitive pressure from informal producers. Informal competition reduces the price markup of manufacturing enterprises and the ratio of energy input to other factors while increasing total factor productivity. The abatement effect on energy intensity also exhibits the characteristics of industry and enterprise heterogeneity. A good institutional environment generally weakens the abatement effect of informal competition on energy intensity, particularly for legalization. Our findings suggest that the interaction between informal producers and formal enterprises contributes to market competition in developing and emerging countries.

High‐performance nano‐splitters containing aggregation‐induced emission luminogens for stereoselective crystallization obtained via polymerization‐induced self‐assembly

AbstractCollecting both enantiomorphs with high optical purity and yield in a single crystallization process can be achieved by adding aggregated polymeric “tailor‐made” additives, known as nano‐splitters. Inefficient preparation and large addition amount have hindered the practical application of such amazing nanoparticles. Herein, we report the first nano‐splitters containing aggregation‐induced emission luminogens prepared via polymerization‐induced self‐assembly of block copolymer, poly[(S)‐2‐(tert‐butoxycarbonylamino)‐6‐(methacrylamido)hexanoic acid]‐b‐polystyrene, followed by the removal of tert‐butoxycarbonyl groups. When added into the supersaturated solution of racemic amino acids (a.a.) with seeds, the fluorescent labeled nano‐assemblies enantioselectivity dyed the crystals of S‐a.a. and enabled the separation from colorless R‐a.a. crystals in terms of fluorescent difference. Both enantiomers were obtained with high optical purity and yield (e.g., R‐ asparagine monohydrate, >99 ee%; S‐ asparagine monohydrate, ∼94 ee%; 88% total yield). Owing to a low detection limit of fluorescence, the addition amount was reduced to 0.03 wt% without remarkably compromising the ee values of both enantiomorphs. Due to the low addition amount and efficient synthesis, the output–input ratio was increased greatly.

Unravelling CO2 capture performance of microalgae cultivation and other technologies via comparative carbon balance analysis

Microalgae cultivation, absorption, adsorption, and membrane separation are widely applauded as promising technologies to sequester CO2 from flue gas. Herein, comparative carbon balance was used to elucidate their CO2 capture performance in the aspects of CO2 emission rates (direct, indirect, total, and net), CO2 removal efficiencies (apparent and actual), and CO2 removal rate per power input ratio. Screening criteria for effective CO2 capture system rule out energy-intensive sorption processes, put forward low energy membrane separation, and disclose alterable competency of microalgae cultivation. For CO2 capture from flue gas, microalgae (Chlorella vulgaris) cultivation in open raceway ponds was only inferior to membrane separation. To improve microalgal CO2 capture, the sensitivity analysis was performed by replacing original microalgae species (C. vulgaris) or cultivation system (open raceway pond). The microalgal CO2 capture in open raceway ponds became worse following the substitution of C. vulgaris with alternatives (Botryococcus braunii, Chlorella kessleri, Chlorella pyrenoidosa, Scenedesmus obliquus, Spirulina sp., or Tetraselmis suecica). For microalgal (C. vulgaris) CO2 capture, the competent cultivation systems included open raceway pond and airlift photobioreactor, while the bubble column, flat panel, or tubular photobioreactors were classified as non-competent systems. In short, microalgal (C. vulgaris) CO2 capture was technically feasible in open raceway pond or airlift photobioreactor; further, the use of airlift photobioreactor was preferred for better CO2 capture and microalgae biomass production. Due to the necessity of a huge working volume, the low scalability of microalgae cultivation could hamper the industrial application of microalgal CO2 capture from flue gas.

Calcium Oxalate Crystallization: Influence of pH, Energy Input, and Supersaturation Ratio on the Synthesis of Artificial Kidney Stones.

The removal of kidney stones can lead to small residual fragments remaining in the human body. Residual stone fragments can act as seeds for kidney stone crystallization and may necessitate another intervention. Therefore, it is important to create a consistent model with a particle size comparable to the range of kidney stone fragments. Thus, the size-determining parameters such as supersaturation ratio, energy input, and pH value are examined. The batch crystallizations were performed with supersaturation ratios between 5.07 and 6.12. The compositions of the dried samples were analyzed with Raman spectroscopy, infrared spectroscopy, and X-ray diffraction (XRD). The samples were identified as calcium oxalate monohydrate with spectroscopic analysis, while calcium oxalate dihydrate being the most prominent crystalline species at all supersaturation ratios for the investigated conditions. The aggregate size, obtained with analytical centrifugation, varied between 2.9 and 4.3 μm, while the crystallite domain size, obtained from XRD, varied from 40 to 61 nm. Our results indicate that particle sizes increase with increasing supersaturation, energy input, and pH. All syntheses yield a high particle heterogeneity and represent an ideal basis for reference materials of small kidney stone fragments. These results will help better understand and control the crystallization of calcium oxalate and the aggregation of such pseudopolymorphs.

Performance implications of knowledge inputs in inter-organisational new product development projects: the moderating roles of technology interdependence

Successful inter-organisational new product development (NPD) is a key source of competitive advantage, yet many NPD projects are still failing. To generate new insights on the phenomenon, we examine the performance implications of knowledge inputs among collaborating organisations, both in terms of external input ratio and input concentration. We test a set of hypotheses using multi-industry primary and secondary data on 210 inter-organisational NPD projects. Results support our hypotheses about the negative effect of input concentration on design quality, which in turn is positively associated with product market performance. Although we surprisingly find a negative linear effect of external input ratio on design quality, our post-hoc analysis confirms the relationship to be an inverse U-shaped relationship. We also find support for the roles of technology interdependence in moderating the performance implications of external input ratio and input concentration. By clarifying how knowledge inputs affect project outcomes under different levels of technology interdependence, the study provides managerial implications regarding how to select innovation partners in order to create a knowledge portfolio that best improves NPD project performance.

AUTOMATED CALCULATION OF THE QUALITY CHARACTERISTICS OF THE LENDERKA RIVER FLOW THROUGH THE GAUGING STATION AT LENDERKA VILLAGE

The quality characteristics of the transboundary flow of the Lenderka River across the border to Finland were calculated using an automated software complex (APC) with the input of data obtained during regime observations of the North-Western Administration for Hydrometeorology and Environmental Monitoring for the period from 2003 to 2012. The main characteristics of the river flow quality were, firstly, volume shares of the water flow contaminated with individual chemical components and, secondly, volume shares of the water flow differing in total pollution (Vpoll%). In the first case, the average values of Vpoll% in the series Fetotal, pH, Cu2+, O2 %, BOD5, and oil products decreased over the study period from 100 to 2.4 %. In the second case, the calculations showed that the river flow averaged over the entire period in accordance with the Guideline 52.24.643-2002 consists of 73.91 % “relatively clean” 1st class water and 26.09 % “slightly polluted”2nd class water. Factor analysis showed that factor 1, which accounted for more than 48 % of the total variance, was of primary significance for the interannual variation of the water flow quality. It depends on interannual fluctuations in the water discharge. Factor 2 (contributing more than 21 %) depends on the water temperature in the cold period, and factor 3 (explaining more than 14 %) depends on the water temperature in the warm period. The mechanism of the water temperature influence on the flow quality is not yet clear; it is possible that its values depend on the ratio of snow and rain input to the river.

Multilaboratory assessment of metagenomic next-generation sequencing for unbiased microbe detection

IntroductionMetagenomic next-generation sequencing (mNGS) assay for detecting infectious agents is now in the stage of being translated into clinical practice. With no approved approaches or guidelines available, laboratories adopt customized mNGS assays to detect clinical samples. However, the accuracy, reliability, and problems of these routinely implemented assays are not clear. ObjectivesTo evaluate the performance of 90 mNGS laboratories under routine testing conditions through analyzing identical samples. MethodsEleven microbial communities were generated using 15 quantitative microbial suspensions. They were used as reference materials to evaluate the false negatives and false positives of participating mNGS protocols, as well as the ability to distinguish genetically similar organisms and to identify true pathogens from other microbes based on fictitious case reports. ResultsHigh interlaboratory variability was found in the identification and the quantitative reads per million reads (RPM) values of each microbe in the samples, especially when testing microbes present at low concentrations (1 × 103 cell/ml or less). 42.2% (38/90) of the laboratories reported unexpected microbes (i.e. false positive problem). Only 56.7% (51/90) to 83.3% (75/90) of the laboratories showed a sufficient ability to obtain clear etiological diagnoses for three simulated cases combined with patient information. The analysis of the performance of mNGS in distinguishing genetically similar organisms in three samples revealed that only 56.6% to 63.0% of the laboratories recovered RPM ratios (RPMS. aureus/RPMS. epidermidis) within the range of a 2-fold change of the initial input ratios (indicating a relatively low level of bias). ConclusionThe high interlaboratory variability found in both identifying microbes and distinguishing true pathogens emphasizes the urgent need for improving the accuracy and comparability of the results generated across different mNGS laboratories, especially in the detection of low-microbial-biomass samples.

Imbalanced nitrogen–phosphorus input alters soil organic carbon storage and mineralisation in a salt marsh

A large imbalance in soil nitrogen (N) and phosphorus (P) inputs induced by anthropogenic activities is anticipated to profoundly influence soil carbon (C) budgets in salt marshes. In this study, we hypothesized that imbalances in the nitrogen–phosphorus (N–P) input would result in the nonlinear response of soil organic carbon (SOC) content, fractions and mineralization to the N–P input ratio. We applied three N–P input ratios (low (5:1), medium (15:1), high (45:1)) in a salt marsh of the Yellow River Delta (YRD) for four years (in which N added increased from 8.67 to 26.01 g N m−2 y−1 and P added decreased from 1.73 to 0.58 g P m−2 y−1) and quantified their impacts on SOC fractions and SOC mineralisation. The control treatment did not receive fertilization. The results showed that the N and P input led to overall increases in the availability of soil nutrients (i.e., inorganic N (IN) and available P (AP)), stimulation of plant biomass and changes of microbial community structure (i.e., γ- and δ-Proteobacteria and Acidobacteria). N and P input increased soil dissolved organic carbon (DOC) and decreased aromatic DOC components through improving N availability and stimulating plant growth. Notably, though, there may be a threshold N–P input ratio between 15:1 and 45:1 that, once crossed, triggers the loss of SOC. Appropriate increase in N availability induced by low and medium N-P input ratios would stimulate the SOC mineralization. However, excessive N-P input ratio would reduce SOC mineralization. Path analysis indicated that N–P input ratios dominantly regulate SOC mineralisation by changing soil DOC and microbial biomass (MBC)contents and microbial community structure. Thus, we speculate that the continuous increase in N input causes a growing N–P imbalance that reduces SOC stocks, despite a reduction in SOC mineralisation.