Coupled multiphysical model for investigation of influence factors in the application of microbially induced calcite precipitation

The study presents a comprehensive coupled thermo-bio-chemo-hydraulic(T-BCH)modeling framework for stabilizing soils using microbially induced calcite precipitation(MICP).The numerical model considers relevant multiphysics involved in MICP,such as bacterial ureolytic activities,biochemical reactions,multiphase and multicomponent transport,and alteration of the porosity and permeability.The model incorporates multiphysical coupling effects through well-established constitutive relations that connect parameters and variables from different physical fields.It was implemented in the open-source finite element code OpenGeoSys(OGS),and a semi-staggered solution strategy was designed to solve the couplings,allowing for flexible model settings.Therefore,the developed model can be easily adapted to simulate MICP applications in different scenarios.The numerical model was employed to analyze the effect of various factors,including temperature,injection strategies,and application scales.Besides,a TBCH modeling study was conducted on the laboratory-scale domain to analyze the effects of temperature on urease activity and precipitated calcium carbonate.To understand the scale dependency of MICP treatment,a large-scale heterogeneous domain was subjected to variable biochemical injection strategies.The simulations conducted at the field-scale guided the selection of an injection strategy to achieve the desired type and amount of precipitation.Additionally,the study emphasized the potential of numerical models as reliable tools for optimizing future developments in field-scale MICP treatment.The present study demonstrates the potential of this numerical framework for designing and optimizing the MICP applications in laboratory-,prototype-,and field-scale scenarios.

Research on development of urban taxi supply based on influence factors classification

In order to determine the regulations of the development of taxi supply under entry regulations in Chinese cities, an improved neural network model is applied to find the particular years when the government artificially puts new taxis into the market, and then extract the political influence from the taxi supply. The model is also utilized to study the relationships between the adjusted taxi supply and non-policy factors. A case study of Nanjing city is conducted. The results show that 2001 and 2007 are the particular years that the Nanjing government artificially put new taxis into its taxi market, which is in accordance with the five-year plan of China and the local development plans. The results also show that the improved neural network model has a good performance in expositing the evolution of adjusted taxi supply related to non-policy factors.

Advances on Internal Influence Factors of Adventitious Rooting of Forest Trees

This paper reviews the internal influence factors of adventitious root, in- ducing oxidase activity, endogenous hormones, rooting inhibiting substances, and fu- ture research ideas are also proposed.

Research of Influence Factors on Apple NIR Spectroscopy Acquisition

[Objective] The aim was to optimize experimental conditions of Gala apple NIR（Near Infrared）spectroscopy acquisition through study on the accuracy of NIR spectroscopy information under different influence factors.[Method]Gala apple was taken as the experimental material,and FieldSpec3 spectrometer（Analytical Spectral Device Company,America）was employed to acquire the NIR spectroscopy at room temperature.Then,the effects of different conditions including the environmental stray light,instrument stability,different distance,different chromatic aberration,different sites and different shelf-life on spectroscopy acquisition were investigated.[Result]The stray light had a significant effect on the visible light region of NIR spectroscopy;FieldSpec3 spectrometer had higher stability in 9 h;the measure distance of 2.5-12.5 mm could obtain good repeatability of absorbance;the effects of different chromatic aberration of the same apple on spectra was acceptable;the spectral stability of equatorial plane of the apple was better than those of the bottom and stalk;at room temperature;different shelf-life could make significant influence to NIR spectroscopy of the apple simple.[Conclusion]This study will provide reference for the researchers and analysis workers of apple NIR spectroscopy.

Study on the Key Influence Factors of Environmental Mass Incidents by Delphi-PCA-Frequency Analysis Composite Method

In order to prevent and control environmental mass incidents,by comprehensively using literature research,case analysis and logical reasoning method,27 factors influencing environmental mass incidents were selected. Among them,15 key influencing factors were screened by Delphi-PCA-frequency analysis composite method. The key influencing factors were analyzed,and corresponding countermeasures were put forward.

Review on the decomposition and influence factors of coarse woody debris in forest ecosystem

Coarse woody debris （CWD） is an important and particular component of forest ecosystems and is extremely important to forest health. This review describes the decomposition process, decomposition model and influence factors. CWD decomposition is a complex and continuous process and characterizes many biological and physical processes, including biological respiration, leaching, and fragmentation. All these processes have closed relationships between each other and work synergistically. During decomposition, there are many controlling factors mainly including site conditions （temperature, humidity, and OJCO2concentration）, woody substrate quality （diameter, species and compound） and organism in CWD. The decomposition rate is generally expresses through a constant k which indicate the percent mass, volume or density loss over time, and can be determined by long-term monitoring, chronosequence approach and the radio between input and the total mass. Now using mathematical models to simulate decomposition patterns and estimate the decomposition rate is widely applied, especially the exponential model. We brought forward that managing and utilizing for the CWD in forest was a primary objective on all forest lands. And it is should be intensified to integrate many related research subjects and to carry a comprehensive, long-term and multi-scale research which mainly focus on seven sections.

Coupling effects of influence factors on probability of corrosion initiation time of reinforced concrete

The coupling model of major influence factors such state affecting the chloride diffusion process in concrete is as environmental relative humidity, load-induced crack and stress discussed. The probability distributions of the critical chloride concentration Cc, the chloride diffusion coefficient D, and the surface chloride concentration Cs were determined based on the collected natural exposure data. And the estimation of probability of corrosion initiation considering the coupling effects of influence factors is presented. It is found that the relative humidity and curing time are the most effective factors affecting the probability of corrosion initiation before and after 10 years of exposure time. At the same exposure time, the influence of load-induced crack and stress state on the probability of corrosion initiation is obvious, in which the effect of crack is the most one

Stability influence factors analysis and construction of a deep beam anchorage structure in roadway roof

Deep beam anchorage structures based on spatial distribution analysis of the cable prestressed field have been proposed for roadway roof support, Stability and other factors that influence deep beam structures are studied in this paper using mechanical calculations, numerical analysis and field measurements, A mechanical model of deep beam structure subjected to multiple loading is established, including analysis of roof support in the return airway of S1203 working face in the Yuwu coal mine, China, The expression of maximum shear stress in the deep beam structure is deduced according to the stress superposition criterion, It is found that the primary factors affecting deep beam structure stability are deep beam thickness, cable pre-tension and cable spacing, The variation of maximum shear stress distribution and prestressed field diffusion effects according to various factors are analyzed using Matlah and FLAC3DTM software, and practical support parameters of the S1203 return airway roof are determined, According to the observations of rock pressure, there is no evidence of roof separation, and the maximum values of roof subsidence and convergence of wall rock are 72 and 48 mm, respectively, The results show that the proposed roof support design with a deep beam structure is feasible and achieves effective control of the roadway roof,

Study on Influence Factors of Pressure Injury Risk in the Elderly Inpatients with Kidney Disease Based on LASSO Regression

Objective: This paper aims to explore clinical status and related influence factors of pressure injury (PI) in the elderly inpatients with kidney disease, so as to provide reference for the prevention and treatment of PI in the elderly inpatients with kidney disease. Methods: Retrospective collection method is adopted to collect 158 clinical cases of the elderly inpatients with kidney disease aged ≥ 60 in the Nephrology Department, the First Affiliated Hospital of Jinan University from January 2017 to December 2019, and then least absolute shrinkage and selection Operator (LASSO) regression analysis is used to analyze 17 possible influence factors;finally Logistic regression model is established to analyze and screen influence factors of risk. Results: 1) Among 158 elderly inpatients with medium and high risk of PI, the incidence of PI is 20.25%;the most common stage of injury is stage I (42.5%);sacrococcygeal (60%) is the high-risk site of pressure injury. 2) LASSO regression analysis shows that history of present respiratory infection/respiratory failure (β = 1.2714. P < 0.05) and hospitalization time (β = 0.4177. P < 0.05) are independent factors influencing PI risk in the elderly inpatients with kidney disease. Conclusion: The elderly patients with kidney disease and PI risk are the high incidence population of hospital acquired PI;for the elderly inpatients with kidney disease and having respiratory infection history or respiratory failure, prolonged hospitalization will significantly increase the risk of PI. Therefore, targeted preventive and control measures should be taken to reduce the incidence of PI.

The Need and Its Influence Factors for Community-based Rehabilitation Services for Disabled Persons in One District in Beijing

Purpose To explore the needs for basic community-based rehabilitation services for disabled persons in Xuanwu District, Beijing, China, and to identify factors which influence disabled persons to accept rehabilitation services. Method One hundred and eight disabled persons were selected by systematic sampling and simple random sampling to assess their needs for community-based rehabilitation services. Results Of the interviewees, 57A% needed the community-based rehabilitation services, but only 13.9% took advantage of it. The main factors influencing the interviewees to accept these services were cost （P〈0.05）, knowledge about rehabilitation medicine （P〈0.05）; and the belief in the therapeutic benefit of the community-based rehabilitation service （P〈0.05）. Conclusion A considerable gap exists between the supply of community-based rehabilitation services in Beijing and the needs for these services by disabled residents underscoring the need for improved availability, and for additional research.

Analysis of the Influence Factors of Grain Supply-Demand Gap in China

Based on the analysis of the grain supply and demand gap’s current situation in China, this paper establishes an indicator system for the influence factors of grain supply and demand gap. Then this paper calculates the correlation degree between the main grain varieties’ supply and demand gap and its influence factors. The results show that sown area and unit yield have the greatest impact on wheat supply and demand gap;per capita disposable income and unit yield have the greatest impact on corn supply and demand gap;per capita disposable income and agricultural mechanization level have the greatest impact on the supply and demand gap of soybean and rice. From the analysis results, we can obtain the difference between the factors affecting the grain supply and demand gap, and provide a certain theoretical basis and new ideas for the balance of grain supply and demand in China.

Regional Geochemical Characteristics and Influence Factors of Soil Elements in the Pearl River Delta Economic Zone, China

Soil heavy metal pollution is one of the main environmental problems in Pearl River Delta Economic?Zone of China. Based on multi-purpose regional geochemical survey, regional eco-geochemical assessment, local eco-geochemical assessment and comprehensive appraisal, the eco-geochemical survey and assessment in Pearl River Delta Economic Zone of 41,698 km2?were completed. Samples from soils were collected in accordance with the two-layer grid method. Totally 54 elements and indicators for soils were determined. Compared to deep soils, the sampled surface soils are enriched in OrgC, N, P, Cd, S,Hg, Ag, B, Au, S and poor with As, Ni, I, Co, Cr, V, MgO, Sc, Al2O3, Fe2O3?etc. The characteristics of geochemical reference value of element in soil that inherited soil parent material and regional elements combined features reflected that the elements enriched in the soil was interrelated with acid rock, sandstone and shale. The spatial distribution characteristics of element regional geochemistry were conditional by regional environmental geological conditions,and effected by human activities. The Pearl River Delta plain is a typical geochemical landscape area with regional anomaly of multiple-elements. The north, western and eastern parts of the Pearl River Delta Economic Zone are quite different in geochemical features due to regional geological background, soil parent materials, geomorphic characteristics and human activities. Environment quality evaluation results show that the grade I and grade II soil accounted for 19.9% and 57.3% of the total area. Many samples that widely distributed in the economic developed of Pearl River Delta Plain area reached the third-grade of national soil environment standard. The soil enriched in Cd, Hg, As, and the area ratio accounting for 22.8% of the total area. It is mainly controlled by the geochemical background, the Pearl River Delta formation evolution process, especially the marine transgression process lead to Cd, Cu, Zn and Pb enrichment in Pearl River Delta plain. At the same time, under the influence of higher pressure of human activities, all kinds of exogenous input material carrying heavy metal pollutants on soil environmental quality also could not to ignore.

Analysis of phreatic evaporation law and influence factors of typical lithology in Hebei Plain

Based on three typical mediums(sandy loam, loam and sandy clay loam) in Hebei Plain, this paper designs phreatic evaporation experiments under different lithology and phreatic depth. Based on the analysis of experimental data, the phreatic evaporation law and influencing factors of three mediums were studied. The results showed that:(1) The shallower the phreatic depth, the larger the phreatic evaporation.(2) Sandy clay loam has the biggest response to the increase of the phreatic depth, sandy loam is the second and loam is the smallest.(3) The limit depth of phreatic evaporation of sandy clay loam is about 3 m and that of loam and sandy loam is about 2 m and 3 m, seperately.(4) By fitting the daily evaporation of phreatic water and phreatic depth, the results showed that sandy loam and sandy clay loam are exponential functions and loam is power functions.

Analysis of the mechanical property of mudstone/shale in paralic coal measures and its influence factors

The mechanical property of mudstone/shale in coal measures is a key factor of engineering mechanics that influences the development of shale gas. A rock mechanics test was performed in order to analyze the complete stress-strain mechanic characteristics and influence factors of mudstone/shale in paralic coal measures, from the Carboniferous-Permian periods in a coal field of Northern China. The relationship between the mechanical properties of mudstone/shale in coal measures, and its chemical component, water content are established, and their models are constructed. Research results show that mud- stone/shale has low mechanical strength, low elastic modulus and a high Poisson＇s ratio. The complete stress-strain curve has apparent elastoplastic deformation characteristics, and after reaching peak strength, it exhibits obvious strain softening characteristics. The uniaxial compressive strength of mudstone/shale and its elastic modulus increases exponentially with the increase of SiO2 content, and as the ignition loss increases, the uniaxial compressive strength and elastic modulus of mudstone/shale will decrease according to the law of power function. The compressive strength of mudstone/shale and its elastic modulus will decrease with the increase of water content in mudstone/shale.

The influence factors of gas-bearing and geological characteristics of Niutitang Formation shale in the southern margin of Xuefeng Mountain ancient uplift: A case of Well Huangdi 1

In order to evaluate the geological characteristics and gas-bearing factors of Niutitang Formation within the Lower Cambrian of northern Guizhou,the Huangping area located at the southern edge of the ancient uplift belt of Xuefeng Mountain was selected as the target area,and Well Huangdi 1 was drilled for the geological survey of shale gas.Through geological background analysis and well logging and laboratory analysis such as organic geochemical test,gas content analysis,isothermal adsorption,and specific surface area experiments on Well Huangdi 1,the results show that the Niutitang Formation is a deep-water shelf,trough-like folds and thrust fault.The thickness of black shale is 119.95 m,of which carbonaceous shale is 89.6 m.The average value of organic carbon content is 3.55%,kerogen vitrinite reflectance value is 2.37% and kerogen type is sapropel-type.The brittle mineral content is 51%(quartz 38%),clay mineral content is 38.3%.The value of porosity and permeability are 0.5%and 0.0014 mD,which the reservoir of the Niutitang Formation belongs to low permeability with characteristics of ultra-low porosity.The gas content is 0.09‒1.31 m^3/t with a high-value area and a second high-value area.By comparing with the geological parameters of adjacent wells in the adjacent area,the accumulation model of“sediment control zone,Ro control zone,structure controlling reservoir”in the study area is proposed.Therefore,deep-water shelf-slope facies,Ro is between high maturity-early stage of overmaturity and well-preserved zones in the Niutitang Formation in this area are favorable direction for the next step of shale gas exploration.

Study on influence factors of cement-stabilized soil compressive strength

The cement dry jet mixing method has been used to reinforce soft cohesive ground to increase the strength of soft cohesive ground and to decrease its deformation. The study briefly introduces the curing mechanism of cement-soil,presents the factors of influencing on compressive strength,mainly analyses the factors including cement mixing ratio,cement strength grade,curing age,moisture content and soil texture and puts forward some rational proposals at last.

RESEARCH ON DROUGHT / FLOOD INFLUENCE FACTORS IN CHINA

In the fifth paper listed in the references, East China was divided into eight drought/ flood regions. But we, taking earth rotation velocity, sunspots, southern oscillation, etc. as the influence factors, through step-wise regression analysis and typical analysis, discussed drought/ flood influence factors of the eight regions. On the basis of them, applying spectrum analysis, we calculated the cycles of every influence factor variation and cycles of drought/ flood variations of every region as well as cycles of vibration between them. The results indicate that the drought/ flood influence factors of East China are southern oscillation, earth rotation velocity, etc. Specially, the influence of EL-Nino is more evident to drought/ flood in most regions than that of others. Generally, there are good correlations between the year of EL-Nino and the year of drought/ flood in most regions. The ways of these factors influencing drought/ flood are shown in lag correlation, by 2-5-year high-frequency

Electricity Price Influence Factors Analysis Using Stochastic Matrix for Real-Time Electricity Price Forecasting

Real-time electricity price( RTEP) influence factor extraction is essential to forecasting accurate power system electricity prices. At present,new electricity price forecasting models have been studied to improve predictive accuracy,ignoring the extraction and analysis of RTEP influence factors. In this study,a correlation analysis method is proposed based on stochastic matrix theory.Firstly, an augmented matrix is formulated, including RTEP influence factor data and RTEP state data. Secondly, data correlation analysis results are obtained given the statistical characteristics of source data based on stochastic matrix theory.Mean spectral radius( MSR) is used as the measure of correlativity.Finally,the proposed method is evaluated in New England electricity markets and compared with the BP neural network forecasting method. Experimental results show that the extracted index system comprehensively generalizes RTEP influence factors,which play a significant role in improving RTEP forecasting accuracy.

Analysis on the Influence Factors of Capacitor Voltage Transformer Dielectric Loss Measurement

Capacitor voltage transformer (CVT), which is with simple structure, convenient maintenance, functional diversity and high impact pressure strength, is widely used. And its capacitance and dielectric loss Angle measurement is an important test on testing the insulation of the equipment. This paper is mainly to introduce and discuss one of the CVT test methods——the “self excitation method”, combined with the actual situation encountered in the work, sums up and expounds the maintenance of CVT and preventive test of influence factors.

Analysis on the Climatic Change Characteristics of the Snow Cover Days and Its Influence Factors in Suzhou during Recent 50 Years

[Objective] The research aimed to study climatic variation characteristics of snow cover days and its influence factors in Suzhou of Anhui Province during recent 50 years. [Method] According to annual snow cover days and correlated data in Suzhou during 1961-2010, by using linear trend method, accumulative anomaly and complete correlation coefficient method, etc., the climatic variation characteristics of snow cover days and its influence factors in Suzhou were analyzed. [Result] In recent 50 years, the snow cover period in Suzhou presented shortened trend. Except days of snow cover (≥20 cm), the annual snow cover days at each thickness all showed varying degrees of decrease trend. The annual snow cover days had wavy decline trend, and the decline amplitude was 0.84 d/10 a. From the 1960s to prior period of the 1970s, the annual snow cover days presented increase trend. From middle and later periods of the 1970s to middle period of the 1980s, the snow cover days was less and gradually increased from later period of the 1980s to the early 1990s. From middle period of the 1990s to 2003, it entered into less snow period again. From 2004 to now, it presented oscillation of snowy and less-snow alternating. The main climatic factor which affected annual snow cover days in Suzhou was average temperature. The second one was average surface temperature. [Conclusion] The research provided theoretical basis for analyzing climate variation in Suzhou under the background of global climate warming.