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Identifying influencing factors and characterizing key issues in urban sustainable development capacity through machine learning
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作者 Houbo Zhou Lijie Gao +1 位作者 Longyu Shi Qiuli Lva 《Chinese Journal of Population,Resources and Environment》 2024年第3期291-304,共14页
In response to the United Nations Sustainable Development Goals and China’s“Dual Carbon”Goals(DCGs means the goals of“Carbon Peak and carbon neutrality”),this paper from the perspective of the construction of Ch... In response to the United Nations Sustainable Development Goals and China’s“Dual Carbon”Goals(DCGs means the goals of“Carbon Peak and carbon neutrality”),this paper from the perspective of the construction of China’s Innovation Demonstration Zones for Sustainable Development Agenda(IDZSDAs),combines carbon emission-related metrics to construct a comprehensive assessment system for Urban Sustainable Development Capacity(USDC).After obtaining USDC assessment results through the assessment system,an approach combining Least Absolute Shrinkage and Selection Operator(LASSO)regression and Random Forest(RF)based on machine learning is proposed for identifying influencing factors and characterizing key issues.Combining Coupling Coordination Degree(CCD)analysis,the study further summarizes the systemic patterns and future directions of urban sustainable development.A case study on the IDZSDAs from 2015 to 2022 reveals that:(1)the combined identification method based on machine learning and CCD models effectively quantifies influencing factors and key issues in the urban sustainable development process;(2)the correspondence between influencing factors and key subsystems identified by the LASSO-RF combination model is generally consistent with the development situations in various cities;and(3)the machine learning-based combined recognition method is scalable and dynamic.It enables decision-makers to accurately identify influencing factors and characterize key issues based on actual urban development needs. 展开更多
关键词 Urban sustainable development capacity SDGs Dual Carbon Goals factor identification Issue characterization Machine learning
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A Cross-Sectional Study on The Prevalence of Anemia in Maintenance Hemodialysis and Peritoneal Dialysis Patients and Its Related Factors
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作者 Mingrong Huang 《Journal of Clinical and Nursing Research》 2024年第3期134-140,共7页
Objective:To study the prevalence of anemia,the proportion of hemoglobin(Hb)levels,the treatment methods,and the influencing factors of Hb levels in maintenance hemodialysis(MHD)and peritoneal dialysis patients.Method... Objective:To study the prevalence of anemia,the proportion of hemoglobin(Hb)levels,the treatment methods,and the influencing factors of Hb levels in maintenance hemodialysis(MHD)and peritoneal dialysis patients.Methods:In this study,602 patients with maintenance hemodialysis and continuous ambulatory peritoneal dialysis were enrolled from December 2020 to December 2022 in our hospital,and their medical records were collected and summarized.The main contents included the patient’s gender,age,primary disease,dialysis duration,dialysis method,the use of erythropoietic stimulating agents(ESA),intravenous iron,and laboratory tests.A Hb index exceeding 110 g/L was set as the standard for the prevalence of anemia.Results:The rate of anemia in patients undergoing blood purification was 83%.The proportion of ESA use was 84.1%,and the proportion of iron use was 76.7%,of which the proportion of intravenous iron used was 17.0%,and the proportion of folic acid used was 28.3%.Conclusion:The incidence of anemia in MHD patients was relatively high,with a low proportion of patients reaching the standard Hb levels.Risk factors include albumin(ALB)levels,iron storage,white blood cells,C-reactive protein,cholesterol,etc.Nutritional support,iron supplementation,and prevention of micro-inflammatory reactions can effectively promote the improvement of Hb indicators in dialysis patients to prevent anemia. 展开更多
关键词 HEMODIALYSIS Peritoneal dialysis ANEMIA related factors Cross-sectional study
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Analysis of Factors Related to Vasovagal Response in Apheresis Blood Donors and the Establishment of Prediction Model Based on BP Neural Network Algorithm
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作者 Xin Hu Hua Xu Fengqin Li 《Journal of Clinical and Nursing Research》 2024年第6期276-283,共8页
Objective:To analyze the factors related to vessel vasovagal reaction(VVR)in apheresis donors,establish a mathematical model for predicting the correlation factors and occurrence risk,and use the prediction model to i... Objective:To analyze the factors related to vessel vasovagal reaction(VVR)in apheresis donors,establish a mathematical model for predicting the correlation factors and occurrence risk,and use the prediction model to intervene in high-risk VVR blood donors,improve the blood donation experience,and retain blood donors.Methods:A total of 316 blood donors from the Xi'an Central Blood Bank from June to September 2022 were selected to statistically analyze VVR-related factors.A BP neural network prediction model is established with relevant factors as input and DRVR risk as output.Results:First-time blood donors had a high risk of VVR,female risk was high,and sex difference was significant(P value<0.05).The blood pressure before donation and intergroup differences were also significant(P value<0.05).After training,the established BP neural network model has a minimum RMS error of o.116,a correlation coefficient R=0.75,and a test model accuracy of 66.7%.Conclusion:First-time blood donors,women,and relatively low blood pressure are all high-risk groups for VVR.The BP neural network prediction model established in this paper has certain prediction accuracy and can be used as a means to evaluate the risk degree of clinical blood donors. 展开更多
关键词 Vasovagal response related factors Prediction BP neural network
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Correlation between Chromatograph Capacity Factors and Structural Parameters of Indole Derivatives 被引量:1
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作者 ZHENG Qing WANG Zun-Yao +1 位作者 SUN Li YU Bin 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第12期1381-1386,共6页
Sixteen indole derivatives have been computed at B3LYP/6-31 IG^** level using density functional theory (DFF). Based on linear solvation energy theory, the structural parameters were employed to present correlatio... Sixteen indole derivatives have been computed at B3LYP/6-31 IG^** level using density functional theory (DFF). Based on linear solvation energy theory, the structural parameters were employed to present correlation between the parameters of chromatograph capacity factor (CCF) and molecular structural parameters. As a result, the correlation equation of the reversed phased high performance liquid chromatograph capacity factor to the intercept lgk'w and slope S of CCF were obtained, from which the correlation coefficients of lgk'w to the structural parameters are r^2 = 0.9596 and q^2 = 0.9262. While the correlation coefficients of the parameter S r^2 q^2 with structures are = 0.9750 and = 0.9252. Moreover, the effect of water as solvent on the present two models was also considered using SCRF method, and the result shows that the predicting capacity of correlation equation of lgkw' increases, while that of the model for S decreases slightly. Both two correlation equations achieved in this work are more advantageous than those using theoretical descriptors from molecular connectivity indices. 展开更多
关键词 indole derivatives quantitative structure-retention relationship (QSRR) chromatograph capacity factor (CCF) reversed phased high performance liquid chroma-tograph (RP-HPLC) density functional theory (DFT) self-consistent reaction field(SCRF)
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Factors Related to Functional Capacity and Quality of Life for Elderly People in a Middle-Sized City of São Paulo, Brazil
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作者 Giovana Fumes-Ghantous José Eduardo Corrente Ana Flavia G. Tatis 《Health》 2020年第12期1562-1574,共13页
<strong>Introduction:</strong> It is a fact that the elderly population has been increasing all around the world and also in Brazil. This has been a challenge for governments and managers in the developmen... <strong>Introduction:</strong> It is a fact that the elderly population has been increasing all around the world and also in Brazil. This has been a challenge for governments and managers in the development of public policies to promote healthy and quality aging. And one of the conditions for healthy aging is to assess the functional capacity and quality of life of elderly people. <strong>Objective:</strong> The aim of the present study was to evaluate the factors that influence the loss of functional capacity and the worsening of the quality of life of a representative sample of elderly people from a medium-sized city in the inner of S<span style="white-space:nowrap;">&#227;</span>o Paulo State, Brazil. <strong>Methodology:</strong> Questionnaires about activities of daily living (ADL), instrumental activities of daily living (IADL), Flanagan quality of life scale (FQOLS), sociodemographic and morbidities aspects were applied to the elderly people. In order to assess associated factors to functional capacity and quality of life, chi-square tests and logistic regression models were fitted including variables: gender, age group, marital status, income, education level, body mass index, abdominal circumference and some morbidities reported by the elderly people. The level of significance adopted for the statistical tests was 5%. <strong>Results:</strong> Elderly with age over 75 years old and not married had more risk to be dependent on ADL, while elderly with more than 75 years old, not married, income below one minimal wage, cardiovascular disease and be diabetic had more risk to be dependent by IADL. Already, people with excess of weight had smallest risk to be dependent by IADL, paradoxically. The elderly not married and with an income below a minimum wage had the worst quality of life. <strong>Conclusions: </strong>Population aging in Brazil is an evident factor, so it is hoped that this study will contribute to the greatest diligence on the issues of the elderly and related social problems. 展开更多
关键词 Functional capacity Life Quality Odds Ratio Risk factors
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Alkaline sphingomyelinase deficiency impairs intestinal mucosal barrier integrity and reduces antioxidant capacity in dextran sulfate sodium-induced colitis
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作者 Ye Tian Xin Li +7 位作者 Xu Wang Si-Ting Pei Hong-Xin Pan Yu-Qi Cheng Yi-Chen Li Wen-Ting Cao Jin-Dong Ding Petersen Ping Zhang 《World Journal of Gastroenterology》 SCIE CAS 2024年第10期1405-1419,共15页
BACKGROUND Ulcerative colitis is a chronic inflammatory disease of the colon with an unknown etiology.Alkaline sphingomyelinase(alk-SMase)is specifically expressed by intestinal epithelial cells,and has been reported ... BACKGROUND Ulcerative colitis is a chronic inflammatory disease of the colon with an unknown etiology.Alkaline sphingomyelinase(alk-SMase)is specifically expressed by intestinal epithelial cells,and has been reported to play an anti-inflammatory role.However,the underlying mechanism is still unclear.AIM To explore the mechanism of alk-SMase anti-inflammatory effects on intestinal barrier function and oxidative stress in dextran sulfate sodium(DSS)-induced colitis.METHODS Mice were administered 3%DSS drinking water,and disease activity index was determined to evaluate the status of colitis.Intestinal permeability was evaluated by gavage administration of fluorescein isothiocyanate dextran,and bacterial translocation was evaluated by measuring serum lipopolysaccharide.Intestinal epithelial cell ultrastructure was observed by electron microscopy.Western blotting and quantitative real-time reverse transcription-polymerase chain reaction were used to detect the expression of intestinal barrier proteins and mRNA,respectively.Serum oxidant and antioxidant marker levels were analyzed using commercial kits to assess oxidative stress levels.RESULTS Compared to wild-type(WT)mice,inflammation and intestinal permeability in alk-SMase knockout(KO)mice were more severe beginning 4 d after DSS induction.The mRNA and protein levels of intestinal barrier proteins,including zonula occludens-1,occludin,claudin-3,claudin-5,claudin-8,mucin 2,and secretory immunoglobulin A,were significantly reduced on 4 d after DSS treatment.Ultrastructural observations revealed progressive damage to the tight junctions of intestinal epithelial cells.Furthermore,by day 4,mitochondria appeared swollen and degenerated.Additionally,compared to WT mice,serum malondialdehyde levels in KO mice were higher,and the antioxidant capacity was significantly lower.The expression of the transcription factor nuclear factor erythroid 2-related factor 2(Nrf2)in the colonic mucosal tissue of KO mice was significantly decreased after DSS treatment.mRNA levels of Nrf2-regulated downstream antioxidant enzymes were also decreased.Finally,colitis in KO mice could be effectively relieved by the injection of tertiary butylhydroquinone,which is an Nrf2 activator.CONCLUSION Alk-SMase regulates the stability of the intestinal mucosal barrier and enhances antioxidant activity through the Nrf2 signaling pathway. 展开更多
关键词 Alkaline sphingomyelinase Intestinal mucosal barrier Antioxidant capacity Dextran sulfate sodium-induced colitis nuclear factor erythroid 2-related factor 2
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Characterization of rock thermophysical properties and factors affecting thermal conductivity−A case study of Datong Basin,China
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作者 Meng-lei Ji Shuai-chao Wei +5 位作者 Wei Zhang Feng Liu Yu-zhong Liao Ruo-xi Yuan Xiao-xue Yan Long Li 《Journal of Groundwater Science and Engineering》 2024年第1期4-15,共12页
Rock thermal physical properties play a crucial role in understanding deep thermal conditions,modeling the thermal structure of the lithosphere,and discovering the evolutionary history of sedimentary basins.Recent adv... Rock thermal physical properties play a crucial role in understanding deep thermal conditions,modeling the thermal structure of the lithosphere,and discovering the evolutionary history of sedimentary basins.Recent advancements in geothermal exploration,particularly the identification of high-temperature geothermal resources in Datong Basin,Shanxi,China,have opened new possibilities.This study aims to characterize the thermal properties of rocks and explore factors influencing thermal conductivity in basins hosting high-temperature geothermal resources.A total of 70 groups of rock samples were collected from outcrops in and around Datong Basin,Shanxi Province.Thermal property tests were carried out to analyze the rock properties,and the influencing factors of thermal conductivity were studied through experiments at different temperature and water-filled states.The results indicate that the thermal conductivity of rocks in Datong,Shanxi Province,typically ranges from 0.690 W/(m·K)to 6.460 W/(m·K),the thermal diffusion coefficient ranges from 0.441 mm^(2)/s to 2.023 mm^(2)/s,and the specific heat capacity of the rocks ranges from 0.569 KJ/(kg·℃)to 1.117 KJ/(kg·°C).Experimental results reveal the impact of temperature and water saturation on the thermal conductivity of the rock.The thermal conductivity decreases with increasing temperature and rises with high water saturation.A temperature correction formula for the thermal conductivity of different lithologies in the area is proposed through linear fitting.The findings from this study provide essential parameters for the assessment and prediction,development,and utilization of geothermal resources in the region and other basins with typical high-temperature geothermal resource. 展开更多
关键词 Datong Basin Rock thermal conductivity Thermal diffusivity Specific heat capacity Influencing factors
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Analysis of factors related to postpartum depression in pregnancyinduced hypertension syndrome patients and construction and evaluation of nomograms
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作者 Jie-Wei Pan Gang Zhao 《World Journal of Psychiatry》 SCIE 2023年第9期654-664,共11页
BACKGROUND It is positive to integrate and evaluate the risk factors for postpartum depression in patients with pregnancy-induced hypertension syndrome and to detect highrisk patients as early as possible,which has ap... BACKGROUND It is positive to integrate and evaluate the risk factors for postpartum depression in patients with pregnancy-induced hypertension syndrome and to detect highrisk patients as early as possible,which has application value for the clinical development of personalized prevention programs and prognosis of patients.AIM To analyze factors related to postpartum depression in patients with pregnancyinduced hypertension and construct and evaluate a nomogram model.METHODS The clinical data of 276 patients with pregnancy-induced hypertension admitted to Huzhou Maternity and Child Health Care Hospital between January 2017 and April 2022 were retrospectively analyzed.We evaluated the depression incidence at 6 wk postpartum.The depression group included patients with postpartum depression,and the remainder were in the non-depression group.Multivariate logistic regression analysis and the LASSO regression model were applied to analyze the factors related to postpartum depression in patients with pregnancyinduced hypertension.After that,a risk prediction model nomogram was constructed and evaluated.RESULTS Multivariate logistic regression analysis showed that vitamin A deficiency(VAD)during pregnancy and puerperium,family history of hypertension,maternal intestinal flora imbalance,eicosapentaenoic acid(EPA),and docosahexaenoic acid(DHA)were independent risk factors for postpartum depression in patients with pregnancy-induced hypertension(P<0.05).We constructed the nomogram model based on these five risk factors.The area under the curve,specificity,and sensitivity of the model in predicting postpartum depression in patients with pregnancy-induced hypertension was 0.867(95%confidence interval:0.828–0.935),0.676,and 0.889,respectively.The average absolute error was 0.037(Hosmer-Lemeshow testχ2=10.739,P=0.217).CONCLUSION VAD during pregnancy and puerperium,family history of hypertension,maternal intestinal flora imbalance,EPA,and DHA affect postpartum depression in patients with pregnancy-induced hypertension. 展开更多
关键词 Pregnancy-induced hypertension syndrome Postpartum depression Unhealthy emotions related factors NOMOGRAMS EVALUATION
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Factors affecting relative humidity during wood vacuum drying 被引量:1
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作者 肖辉 蔡英春 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第2期165-167,I0004,共4页
Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber. The setting temperature during vacuum dry... Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber. The setting temperature during vacuum drying included dry-bulb temperature ta, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the cooling water in the condenser. Results indicated that relative humidity during vacuum drying was affected by the dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the water in the condenser. Relative humidity of wood decreased with the increase in temperature at the given temperature of the water in the condenser. The relative humidity was affected slightly by pressure in the vacuum chamber pA, and it decreased from 70% to 65% with pA increased from 50 kPa to 101 kPa. Moreover, there was nearly no evaporation under the vacuum without external heating. 展开更多
关键词 influencing factors radio frequency relative humidity wood vacuum drying
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Influences of nonassociated flow rules on seismic bearing capacity factors of strip footing on soil slope by energy dissipation method 被引量:13
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作者 杨小礼 郭乃正 +1 位作者 赵炼恒 邹金锋 《Journal of Central South University of Technology》 EI 2007年第6期842-847,共6页
Seismic bearing capacity factors of a strip footing placed on soil slope were determined with both associated and nonassociated flow rules. Quasi-static representation of earthquake effects using a seismic coefficient... Seismic bearing capacity factors of a strip footing placed on soil slope were determined with both associated and nonassociated flow rules. Quasi-static representation of earthquake effects using a seismic coefficient concept was adopted for seismic bearing capacity calculations. A multi-wedge translational failure mechanism was used to obtain the seismic bearing capacity factors for different seismic coefficients and various inclined angles. Employing the associated flow rule, numerical results were compared with the published solutions. For bearing capacity factors related to cohesion and equivalent surcharge load, the maximum difference approximates 0.1%. However, the difference of bearing capacity factor related to unit weight is larger. With the two flow rules, the seismic bearing capacity factors were presented in the form of design charts for practical use. The results show that seismic bearing capacity factors related to the cohesion, the equivalent surcharge load and the unit weight increase greatly as the dilatancy angle increases, and that the nonassociated flow rule has important influences on the seismic bearing capacity. 展开更多
关键词 nonassociated flow rule seismic bearing capacity factor EARTHQUAKE
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Recurrent acute pancreatitis and its relative factors 被引量:8
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作者 WeiZhang Hong-ChaoShan YanGu 《World Journal of Gastroenterology》 SCIE CAS CSCD 2005年第19期3002-3004,共3页
AIM: To evaluate the causes and the relative factors of recurrent acute pancreatitis.METHODS: From 1997 to 2000, acute pancreatitis relapsed in 77 of 245 acute pancreatitis patients. By reviewing the clinical treatmen... AIM: To evaluate the causes and the relative factors of recurrent acute pancreatitis.METHODS: From 1997 to 2000, acute pancreatitis relapsed in 77 of 245 acute pancreatitis patients. By reviewing the clinical treatment results and the follow-up data, we analyzed the recurrent factors of acute pancreatitis using univariate analysis and multivariate analysis.RESULTS: Of the 245 acute pancreatitis patients, 77 were patients with recurrent acute pancreatitis. Of them, 56 patients relapsed two times, 19 relapsed three times, each patient relapsed three and four times. Forty-seven patients relapsed in hospital and the other 30 patients relapsed after discharge. Eighteen patients relapsed in 1 year, eight relapsed in 1-3 years, and four relapsed after 3 years. There were 48 cases of biliary pancreatitis, 3 of alcohol pancreatitis, 5 of hyperlipidemia pancreatitis, 21 of idiopathic pancreatitis. Univariate analysis showed that the patients with local complications of pancreas, obstructive jaundice and hepatic function injury were easy to recur during the treatment period of acute pancreatitis (P = 0.022<0.05, P = 0.012<0.05 and P = 0.002<0.05, respectively). Multivariate analysis showed that there was no single factor related to recurrence. Of the 47 patients who had recurrence in hospital, 16 had recurrence in a fast period, 31 after refeeding. CONCLUSION: Acute pancreatitis is easy to recur even during treatment. The factors such as changes of pancreas structure and uncontrolled systemic inflammatory reaction are responsible for the recurrence of acute pancreatitis. Early refeeding increases the recurrence of acute pancreatitis. Defining the etiology is essential for reducing the recurrence of acute pancreatitis. 展开更多
关键词 Acute pancreatitis relative factors
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Actuality and Influencing Factors of Integrated Production Capacity of Foodstuff in Heilongjiang Province 被引量:3
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作者 Zhou Hui-qiu Zhang De-hua 《Journal of Northeast Agricultural University(English Edition)》 CAS 2012年第1期82-90,共9页
Heilongjiang Province is an important marketable grain depot in China. Since the reform and opening up, Heilongjiang Province production capacity of foodstuff is increasingly growing into a new level. This paper start... Heilongjiang Province is an important marketable grain depot in China. Since the reform and opening up, Heilongjiang Province production capacity of foodstuff is increasingly growing into a new level. This paper started with the actuality of Heilongjiang Province integrated production capacity of foodstuff, and analyzed its major factors empirically through the mathematical model, then proposed some measures to enhance Heilongjiang Province production capacity of foodstuff which ensured China foodstuff security 展开更多
关键词 Heilongjiang Province integrated foodstuff production capacity influencing factor
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Integrating Factors and Conservation Theorems of Nonholonomic Dynamical System of Relative Motion 被引量:2
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作者 QIAO Yong-Fen ZHAO Shu-Hong LI Ren-Jie 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期217-220,共4页
The integrating factors and conservation theorems of nonholonomic dynamical system of relative motion are studied. First, the dynamical equations of relative motion of system are written. Next, the definition of integ... The integrating factors and conservation theorems of nonholonomic dynamical system of relative motion are studied. First, the dynamical equations of relative motion of system are written. Next, the definition of integrating factors is given, and the necessary conditions for the existence of the conserved quantities are studied in detail. Then, the conservation theorem and its inverse of system are established. Finally, an example is given to illustrate the application of the result. 展开更多
关键词 nonholonomic system relative motion integrating factor conservation theorem
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Analysis of influencing factors on suction capacity in seabed natural gas hydrate by cutter-suction exploitation 被引量:2
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作者 XU Hai-liang KONG Wei-yang HU Wen-gang 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第12期2883-2895,共13页
The mathematical and simulation models of working head in the deep-sea working environment were built to analyze the effects of cutter-suction flow,cutter-head rotating speed,cutting depth and suction port position on... The mathematical and simulation models of working head in the deep-sea working environment were built to analyze the effects of cutter-suction flow,cutter-head rotating speed,cutting depth and suction port position on the cutter-suction capacity.The efficiency of the cutter-suction is analyzed based on the analysis of the variation law of the solid-phase volume fraction of the flow field,the variation law of the velocity distribution in the flow field and the distribution law of the solid-phase concentration.The results show that the increase of cutter-suction flow can significantly improve the cutter-suction efficiency when it is less than1000m3/h.However,when it is more than1000m3/h,it is helpless.When the cutter-head rotate speed is within the range of10–25r/min,the cutter-suction efficiency stabilizes at about95%.While the speed is greater than25r/min,the cutter-suction efficiency decreases sharply with the increase of cutter-head rotate speed.With the increase of cutting depth,the cutter-suction efficiency first increases and then remains stable and finally decreases.The cutter-suction efficiency remains at about94%when the suction port position deviation ranges from0°to30°,but it has a sharply reduction when the deviation angle is more than30°. 展开更多
关键词 seabed natural gas hydrate working head solid-liquid two-phase flow cutter-suction capacity influencing factor
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Spatial-temporal characteristics and influencing factors of relative humidity in arid region of Northwest China during 1966–2017 被引量:1
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作者 CHEN Ditao LIU Wenjiang +3 位作者 HUANG Farong LI Qian Friday UCHENNAOCHEGE LI Lanhai 《Journal of Arid Land》 SCIE CSCD 2020年第3期397-412,共16页
Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the a... Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the arid and semi-arid area.However,information on the spatial-temporal variation and the influencing factors of RH in these regions is still limited.This study attempted to use daily meteorological data during 1966–2017 to reveal the spatial-temporal characteristics of RH in the arid region of Northwest China through rotated empirical orthogonal function and statistical analysis method,and the path analysis was used to clarify the impact of temperature(T),precipitation(P),actual evapotranspiration(ETa),wind speed(W)and sunshine duration(S)on RH.The results demonstrated that climatic conditions in North Xinjiang(NXJ)was more humid than those in Hexi Corridor(HXC)and South Xinjiang(SXJ).RH had a less significant downtrend in NXJ than that in HXC,but an increasingly rising trend was observed in SXJ during the last five decades,implying that HXC and NXJ were under the process of droughts,while SXJ was getting wetter.There was a turning point for the trend of RH in Xinjiang,which occurred in 2000.Path analysis indicated that RH was negatively correlated to T,ETa,W and S,but it increased with increase of P.S,T and W had the greatest direct effects on RH in HXC,NXJ and SXJ,respectively.ETa was the factor which had the greatest indirect effect on RH in HXC and NXJ,while T was the dominant factor in SXJ. 展开更多
关键词 relative humidity spatial-temporal characteristics path analysis influencing factor arid region
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Spatial and Dynamic Analysis of Regional Sustainable Development Using Geographic Information System and Relative Carrying Capacity of Resources 被引量:3
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作者 Qi Wang Xiaodan Wang +3 位作者 Hua Tang Jun Li Haihu Ma Tianxing Cheng 《Natural Resources》 2011年第1期28-34,共7页
Relative carrying capacity of resources is an index to measure sustainable development through carrying capacity. Case studies of eleven cities in Zhejiang (Hangzhou, Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua... Relative carrying capacity of resources is an index to measure sustainable development through carrying capacity. Case studies of eleven cities in Zhejiang (Hangzhou, Ningbo, Wenzhou, Jiaxing, Huzhou, Shaoxing, Jinhua, Quzhou, Zhoushan, Taizhou and Lishui) illustrated regional sustainable development approach. In this study, to provide insight into spatial and dynamic analysis of region sustainable development, we calculated the relative carrying capacity of land resources and economical resources and synthetical carrying capacity of resources in different cities in Zhejiang, and geographic information system was carried out. The results showed that all cities but Hangzhou and Ningbo were ecologically sustainable, and relative carrying capacity of land resources in northern and eastern Zhejiang was larger than those in southern and western Zhejiang. The sampling years of Wenzhou, Hangzhou and Ningbo contribution rates of land resource to synthetic carrying capacity were grouped into three stages, and there were two milestones trends and changes in 1996 and 2004, respectively. This study demonstrated that geographic information system and relative carrying capacity of resources are effective for assessment of region sustainable development, and provide policy guidelines for decision-making. 展开更多
关键词 GEOGRAPHIC Information System Arcgis relative Carrying capacity of RESOURCES REGIONAL SUSTAINABLE Development CONTRIBUTION Rate
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Normal reference value of forced vital capacity of Chinese younger women and geographical factors
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作者 Miao Ge1,Ya-Ping Zhang1,Jin-Wei He1,Yan-Chun Yan1,Xin Wang1,Li-Xia Cao1,Hai-Yan Fu2 1.Department of Geography,Shaanxi Normal University,Xi’an 710062 2.Department of Biochemistry and Molecular Biology,School of Basic Medicine,Fourth Military Medical University,Xi’an 710032,China 《Journal of Pharmaceutical Analysis》 SCIE CAS 2010年第1期34-38,共5页
Objective To supply a scientific basis for standardizing the normal reference value of forced vital capacity(FVC)of Chinese younger women.Methods We studied the relationship between the normal reference value of 21767... Objective To supply a scientific basis for standardizing the normal reference value of forced vital capacity(FVC)of Chinese younger women.Methods We studied the relationship between the normal reference value of 21767 samples of FVC of younger women and eight geographical factors in 157 areas in China.Results It was found that the correlation between geographical factors and the normal reference value of FVC of younger women was quite significant(F=5.884,P=0.000).By adopting the method of mathematical regression analysis,one regression equation was inferred:=3.146+0.00006919X1+0.01315X4-0.006966X6+0.09524X8±0.254.In the above equation,is the normal reference value of younger women’ FVC(L);X1 is the altitude(m);X4 is the annual mean air temperature(℃);X6 is the annual mean relative humidity(%);X8 is the annual mean wind speed(m/s);0.254 is the value of the residual standard deviation.Conclusion If geographical values are obtained in a certain area,the normal reference value of FVC of younger women in this area can be obtained by using the regression equation.Furthermore,according to the geographical factors,China can be divided into eight regions:Northeast China Region,North China Region,Shanxi-Shaanxi-Inner Mongolia Region,middle and lower reaches of the Yangzte River Region,Southeast China Region,Northwest China Region,Southwest China Region,and Qinghai-Tibet Plateau Region. 展开更多
关键词 forced vital capacity normal reference value geographical factor regression analysis
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QSRR Study on the Relationship between the Chromatographic Capacity Factor and Lipophilicity and Structure Parameters of Halogenated Thiophenols
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作者 张学胜 陈斌媛 李定龙 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2012年第6期903-909,共7页
The capacity factors (k') of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography (RP-HPLC) and the relat... The capacity factors (k') of fourteen types ofhalogenated thiophenols in different phases of methanol-water eluent were determined by reversed phased high-performance liquid chromatography (RP-HPLC) and the relationships between the logarithm of capacity factor lgK' and methanol ratio ψ were analyzed. A fair linear relationship is found between lgK' and ψ, and the correlation coefficients R2 of the constructed linear equations are all greater than 0.990. Relationship between the chromatographic data lgKw' when extrapolated to pure water and n-octanol/water partition coefficient lgKow obtained by the group contribution method has shown a good linear correlation with R2= 0.956. The structure parameters of fourteen halogenated thiophenols were calculated by using DFT, and the correlation equation of lgKw' and structure parameters was obtained by using SPSS, lgKw' = -0.409 + 0.039a and R2 = 0.981, meaning that lgKw' is mainly determined by the polarizability α. 展开更多
关键词 halogenated thiophenol capacity factor n-octanol/water partition coefficient quantitative structure-chromatographic retention relationship
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Factors affecting relative humidity during wood vacuum drying
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作者 XIAO Hui, CAI Ying-chun Key Laboratory of Bio-based Material Science and Technology, Northeast Forestry University, Harbin 150040, P.R China 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第A2期165-167,共3页
Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber.The setting temperature during vacuum dryi... Effects of pressure and temperature in the chamber during vacuum drying on the relative humidity and evaporation of wood surface were investigated by using the vacuum chamber.The setting temperature during vacuum drying included dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the cooling water in the condenser.Results indicated that relative humidity during vacuum drying was affected by the dry-bulb temperature td, the wet-bulb temperature tw and the temperature difference between the air in the vacuum chamber and the water in the condenser.Relative humidity of wood decreased with the increase in temperature at the given temperature of the water in the condenser.The relative humidity was affected slightly by pressure in the vacuum chamber pA, and it decreased from 70% to 65% with pA increased from 50 kPa to 101 kPa.Moreover, there was nearly no evaporation under the vacuum without external heating. 展开更多
关键词 influencing factors radio frequency relative humidity wood vacuum drying
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Study on the driving factors and regulation mode for coal production capacity
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作者 Wen-Sheng Wang Jing-Jing Zhang 《Petroleum Science》 SCIE CAS CSCD 2021年第5期1564-1577,共14页
Coal production capacity regulation is a complex system involving economic growth,structural optimization,high-efficiency mining,and environmental protection.Based on its driving factors,this paper forms four regulati... Coal production capacity regulation is a complex system involving economic growth,structural optimization,high-efficiency mining,and environmental protection.Based on its driving factors,this paper forms four regulation modes representing different control orientations,establishes a system dynamics model,and predicts the regulation effects of single-factor and combined control mode.The result shows:(1) Except for the mechanization degree and recovery rate,the other nine individual production capacity control policies are all conducive to reducing coal production capacity and restraining the excessive growth of coal production capacity.(2) The effect of combined regulation mode on slowing down the growth of coal demand,regulating the excessive growth of coal production capacity and new capacity investment are obviously better than that of single policy.(3) The combined control modes have obvious differences in the suppression effect on coal production capacity:transformational development mode > technology-driven mode > structural optimization mode > efficiency improvement mode.Therefore,in the process of achieving optimal regulation of coal production capacity,attention should be paid to the preferential use of transformational development and technology-driven mode.At the same time,the comprehensive use of regulation and control methods should also be considered to improve the regulation effect and the regulation efficiency of coal production capacity. 展开更多
关键词 Coal production capacity Regulation mode Driving factors System dynamics model
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