期刊文献+
共找到2,939篇文章
< 1 2 147 >
每页显示 20 50 100
Analysis of the Employment Situation of Non Private Enterprises in Various Regions of China
1
作者 Junyi Wang 《Open Journal of Applied Sciences》 2024年第1期131-144,共14页
In the past 30 years, Chinese enterprises have been a hot topic of discussion and concern among the general public in terms of economic and social status, ownership structure, business mechanism, and management level.... In the past 30 years, Chinese enterprises have been a hot topic of discussion and concern among the general public in terms of economic and social status, ownership structure, business mechanism, and management level. Solving the problem of employment for the people is an important prerequisite for their peaceful living and work, as well as a prerequisite and foundation for building a harmonious society. The employment situation of private enterprises has always been of great concern to the outside world, and these two major jobs have always occupied an important position in the employment field of China that cannot be ignored. With the establishment of the market economy system, individual and private enterprises have become important components of the socialist economy, making significant contributions to economic development and social progress. The rapid development of China’s economy, on the one hand, is the embodiment of the superiority of China’s socialist market economic system, and on the other hand, it is the role of the tertiary industry and private enterprises in promoting the national economy. Since the 1990s, China’s private enterprises have become a new economic growth point for local and even national countries, and are one of the important ways to arrange employment and achieve social stability. This paper studies the employment of private enterprises and individuals from the perspective of statistics, extracts relevant data from China statistical Yearbook, uses the relevant knowledge of statistics to process the data, obtains the conclusion and puts forward relevant constructive suggestions. 展开更多
关键词 Correlation analysis of Employment numbers Factor analysis Principal Component analysis Cluster analysis
下载PDF
Development of a new 17-item Asthenopia Survey Questionnaire using Rasch analysis
2
作者 Na Lin Xiao-Man Li +7 位作者 Mao-Yuan Yang Li Tian Zhi-Hua Li Jie-Li Mao Jia-Fang Zhang Jie Chen Fan Lyu Ru-Zhi Deng 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2023年第11期1867-1875,共9页
AIM:To develop the 17-item Asthenopia Survey Questionnaire(ASQ)-17 by Rasch analysis,and to generate a predictiveness score.METHODS:Totally 739 participants were recruited and 680 were involved in the result analysis ... AIM:To develop the 17-item Asthenopia Survey Questionnaire(ASQ)-17 by Rasch analysis,and to generate a predictiveness score.METHODS:Totally 739 participants were recruited and 680 were involved in the result analysis in this prospective,cross-sectional study.Three rounds of Rasch analysis were used to analyze the psychometric characteristics of items and options.RESULTS:Phase 1 assessed the original ASQ-19,adjusted the item scoring mode to a four-point Likert response rating scale and combined the 18th and 19th items into a new item.Phase 2 deleted the 11th item.Phases 3 and 4 assessed the new ASQ-17.All the evaluation indexes of ASQ-17 were acceptable.The Infit and Outfit MnSq values of items were 0.67-1.48,the variance explained by the principal component and the unexplained variance explained by the first contrast were 53.90%-59.40%and 1.50-1.80 in three dimensions.The curve peaks of scores in each dimension were separated and in the same order.The PSR and PSI values were 2.80 and 0.89,respectively.The mean scores of dimensions A(9.5±4.1 vs 3.5±3.2),B(7.3±3.3 vs 2.5±2.7),C(4.3±2.2 vs 1.4±2.0)and total(21.1±8.1 vs 7.4±7.0)in asthenopia participants were significantly higher than those without asthenopia(all P<0.001).The area under the curve in two groups was 0.899(P<0.001).Youden’s index was up to the maximum value of 0.784 when the cut-off value was 12.5.CONCLUSION:ASQ-17 has stronger option sorting and suitability than ASQ-19.It is an effective assessment tool for asthenopia with an optimal cut-off threshold value of 12.5,which is suitable for diagnosis and curative effect evaluation. 展开更多
关键词 AStheNOPIA 17-item Asthenopia survey Questionnaire Rasch analysis scoring mode
下载PDF
On the Performances of Estimating Stellar Atmospheric Parameters from CSST Broad-band Photometry
3
作者 Rui-Feng Shi Yang Huang +1 位作者 Xin-Yi Li Hua-Wei Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第4期161-173,共13页
Deriving atmospheric parameters of a large sample of stars is of vital importance to understand the formation and evolution of the Milky Way.Photometric surveys,especially those with near-ultraviolet filters,can offer... Deriving atmospheric parameters of a large sample of stars is of vital importance to understand the formation and evolution of the Milky Way.Photometric surveys,especially those with near-ultraviolet filters,can offer accurate measurements of stellar parameters,with the precision comparable to that from low/medium resolution spectroscopy.In this study,we explore the capability of measuring stellar atmospheric parameters from Chinese Space Station Telescope(CSST)broad-band photometry(particularly in the near-ultraviolet bands),based on synthetic colors derived from model spectra.We find that colors from the optical and near-ultraviolet filter systems adopted by CSST show significant sensitivities to the stellar atmospheric parameters,especially the metallicity.According to our mock data tests,the precision of the photometric metallicity is quite high,with typical values of0.17 and 0.20 dex for dwarf and giant stars,respectively.The precision of the effective temperature estimated from broad-band colors are within 50 K. 展开更多
关键词 methods:data analysis stars:abundances surveys
下载PDF
Clinical manifestations and the prenatal diagnosis of trisomy 7 mosaicism:Two case reports
4
作者 Fei Hou Yan Li Hua Jin 《World Journal of Clinical Cases》 SCIE 2024年第8期1544-1548,共5页
BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.... BACKGROUND The clinical manifestations of trisomy 7 mosaicism are diverse and nonspecific,so prenatal diagnosis is very difficult.CASE SUMMARY Two pregnant women with abnormal prenatal screening results were included.One was a 22-year-old woman(G1P0).At 31st week of gestation,ultrasound revealed that the posterior horn of the left lateral ventricle was 10 mm and the right renal pelvis had a separation of 7 mm.The other pregnant woman was 33 years old(G2P1L1A0),and her fetus was found to have a cardiac malformation at the 24th week of gestation.Copy number variation sequencing,whole-exome sequencing and karyotype analysis were carried out after amniocentesis,and both fetuses were diagnosed with trisomy 7 mosaicism.After parental counseling,one woman continued the pregnancy,and the other woman terminated the pregnancy.CONCLUSION In trisomy 7 mosaicism,the low proportion of trisomy does not lead to abortion,but can result in abnormal fetal development,which can be detected via ultrasound.Therefore,clinicians need to pay more attention to various aspects of fetal growth and development,combining with imaging,cellular,molecular genetics and other methods to perform comprehensive evaluations of fetuses to provide more reliable genetic counseling for pregnant women. 展开更多
关键词 Trisomy 7 mosaicism Copy number variation sequencing Whole-exome sequencing Karyotype analysis Prenatal diagnosis Case report
下载PDF
Modelling Foot and Mouth Disease in the Context of Active Immigrants
5
作者 Issa Shabani Mfinanga Nyimvua Shaban Theresia Marijani 《Journal of Applied Mathematics and Physics》 2024年第1期147-167,共21页
This study employs mathematical modeling to analyze the impact of active immigrants on Foot and Mouth Disease (FMD) transmission dynamics. We calculate the reproduction number (R<sub>0</sub>) using the nex... This study employs mathematical modeling to analyze the impact of active immigrants on Foot and Mouth Disease (FMD) transmission dynamics. We calculate the reproduction number (R<sub>0</sub>) using the next-generation matrix approach. Applying the Routh-Hurwitz Criterion, we establish that the Disease-Free Equilibrium (DFE) point achieves local asymptotic stability when R<sub>0</sub> α<sub>1</sub> and α<sub>2</sub>) are closely associated with reduced susceptibility in animal populations, underscoring the link between immigrants and susceptibility. Furthermore, our findings emphasize the interplay of disease introduction with population response and adaptation, particularly involving incoming infectious immigrants. Swift interventions are vital due to the limited potential for disease establishment and rapid susceptibility decline. This study offers crucial insights into the complexities of FMD transmission with active immigrants, informing effective disease management strategies. 展开更多
关键词 Next-Generation Matrix Approach Routh-Hurwitz Quadratic Lyapunov Function Active Immigrants Reproduction number analysis
下载PDF
The FAST Galactic Plane Pulsar Snapshot Survey.II.Discovery of 76 Galactic Rotating Radio Transients and the Enigma of RRATs 被引量:1
6
作者 D.J.Zhou J.L.Han +15 位作者 Jun Xu Chen Wang P.F.Wang Tao Wang Wei-Cong Jing Xue Chen Yi Yan Wei-QiSu Heng-Qian Gan Peng Jiang Jing-Hai Sun Hong-Guang Wang Na Wang Shuang-Qiang Wang Ren-Xin Xu Xiao-Peng You 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2023年第10期1-70,共70页
We have carried out the Galactic Plane Pulsar Snapshot(GPPS)survey by using the Five-hundred-meter Aperture Spherical radio Telescope(FAST),the most sensitive systematic pulsar survey in the Galactic plane.In addition... We have carried out the Galactic Plane Pulsar Snapshot(GPPS)survey by using the Five-hundred-meter Aperture Spherical radio Telescope(FAST),the most sensitive systematic pulsar survey in the Galactic plane.In addition to more than 500 pulsars already discovered through normal periodical search,we report here the discovery of 76 new transient radio sources with sporadic strong pulses,detected by using the newly developed module for a sensitive single-pulse search.Their small DM values suggest that they all are Galactic rotating radio transients(RRATs).They show different properties in the follow-up observations.More radio pulses have been detected from 26 transient radio sources but no periods can be found due to a limited small number of pulses from all FAST observations.The followup observations show that 16 transient sources are newly identified as being the prototypes of RRATs with a period already determined from more detected sporadic pulses,and 10 sources are extremely nulling pulsars,and 24 sources are weak pulsars with sparse strong pulses.On the other hand,48 previously known RRATs have been detected by the FAST,either during verification observations for the GPPS survey or through targeted observations of applied normal FAST projects.Except for one RRAT with four pulses detected in a session of 5-minute observation and four RRATs with only one pulse detected in a session,sensitive FAST observations reveal that 43 RRATs are just generally weak pulsars with sporadic strong pulses or simply very nulling pulsars,so that the previously known RRATs always have an extreme emission state together with a normal hardly detectable weak emission state.This is echoed by the two normal pulsars J1938+2213 and J1946+1449 with occasional brightening pulses.Though strong pulses of RRATs are very outstanding in the energy distribution,their polarization angle variations follow the polarization angle curve of the averaged normal pulse profile,suggesting that the predominant sparse pulses of RRATs are emitted in the same region with the same geometry as normal weak pulsars. 展开更多
关键词 (stars:)pulsars:general surveys methods:data analysis
下载PDF
Computational Analysis of Surface Pressure Distribution over a 2D Wedge in the Supersonic and Hypersonic Flow Regimes
7
作者 Javed S.Shaikh Krishna Kumar +1 位作者 Khizar A.Pathan Sher A.Khan 《Fluid Dynamics & Materials Processing》 EI 2023年第6期1637-1653,共17页
The complex fluid-dynamic instabilities and shock waves occurring along the surface of a two-dimensional wedge at high values of the Mach number are studied here through numerical solution of the governing equations.M... The complex fluid-dynamic instabilities and shock waves occurring along the surface of a two-dimensional wedge at high values of the Mach number are studied here through numerical solution of the governing equations.Moreover,a regression model is implemented to determine the pressure distribution for various Mach numbers and angles of incidence.The Mach number spans the interval from 1.5 to 12.The wedge angles(θ)are from 5°to 25°.The pressure ratio(P2/P1)is reported at various locations(x/L)along the 2D wedge.The results of the numerical simulations are compared with the regression model showing good agreement. 展开更多
关键词 CFD analysis SUPERSONIC wedge angle Mach number
下载PDF
Fuzzy cluster analysis of water mass in the western Taiwan Strait in spring 2019
8
作者 Zhiyuan Hu Jia Zhu +4 位作者 Longqi Yang Zhenyu Sun Xin Guo Zhaozhang Chen Linfeng Huang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第12期1-8,共8页
The classification of the springtime water mass has an important influence on the hydrography,regional climate change and fishery in the Taiwan Strait.Based on 58 stations of CTD profiling data collected in the wester... The classification of the springtime water mass has an important influence on the hydrography,regional climate change and fishery in the Taiwan Strait.Based on 58 stations of CTD profiling data collected in the western and southwestern Taiwan Strait during the spring cruise of 2019,we analyze the spatial distributions of temperature(T)and salinity(S)in the investigation area.Then by using the fuzzy cluster method combined with the T-S similarity number,we classify the investigation area into 5 water masses:the Minzhe Coastal Water(MZCW),the Taiwan Strait Mixed Water(TSMW),the South China Sea Surface Water(SCSSW),the South China Sea Subsurface Water(SCSUW)and the Kuroshio Branch Water(KBW).The MZCW appears in the near surface layer along the western coast of Taiwan Strait,showing low-salinity(<32.0)tongues near the Minjiang River Estuary and the Xiamen Bay mouth.The TSMW covers most upper layer of the investigation area.The SCSSW is mainly distributed in the upper layer of the southwestern Taiwan Strait,beneath which is the SCSUW.The KBW is a high temperature(core value of 26.36℃)and high salinity(core value of 34.62)water mass located southeast of the Taiwan Bank and partially in the central Taiwan Strait. 展开更多
关键词 water mass classification western Taiwan Strait fuzzy cluster analysis T-S similarity number
下载PDF
A Comparative Analysis of the New -3(-n) - 1 Remer Conjecture and a Proof of the 3n + 1 Collatz Conjecture
9
作者 Mike Remer 《Journal of Applied Mathematics and Physics》 2023年第8期2216-2220,共5页
This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An... This scientific paper is a comparative analysis of two mathematical conjectures. The newly proposed -3(-n) - 1 Remer conjecture and how it is related to and a proof of the more well known 3n + 1 Collatz conjecture. An overview of both conjectures and their respective iterative processes will be presented. Showcasing their unique properties and behavior to each other. Through a detailed comparison, we highlight the similarities and differences between these two conjectures and discuss their significance in the field of mathematics. And how they prove each other to be true. 展开更多
关键词 -3(-n) - 1 Remer Conjecture 3n + 1 Collatz Conjecture Comparative analysis PROof Natural numbers Integer Sequences Factorial Processes Par-tial Differential Equations Bounded Values Collatz Conjecture Collatz Algo-rithm Collatz Operator Collatz Compliance And Mathematical Conjectures
下载PDF
MODAL PART ANALYSIS OF SLOSH OF THE LIQUID IN A CYLINDRICAL CONTAINER IN THE CASE OF SMALL BOND NUMBER 被引量:1
10
作者 苟兴宇 王本利 +2 位作者 马兴瑞 黄怀德 李铁寿 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1999年第9期979-984,共6页
Reconstruction of liquid free slosh modes by curved quiet free surface was investigated in the case of small Bond number by means of modal part analysis method in this paper. It is shown that the curved liquid quiet f... Reconstruction of liquid free slosh modes by curved quiet free surface was investigated in the case of small Bond number by means of modal part analysis method in this paper. It is shown that the curved liquid quiet free surface would couple the modes to form new eigen-modes while the orthogonality of the modes which participate the liquid slosh are given only by their Bessel modal parts and it would change their eigen-frequencies respectively while the orthogonality are given by their triangle function modal parts. By studying the laterally forced slosh of the liquid in a cylindrical container based on the new eigen-modes, a characteristic of modes-choosing was found. 展开更多
关键词 slosh Bond number modal part modal part analysis
下载PDF
Combination of genetic analysis and ancient literature survey reveals the diverge nee of traditional Brassica rapa varieties from Kyoto, Japan
11
作者 Yaichi Kawakatsu Tomoaki Sakamoto +9 位作者 Hokuto Nakayama Kaori Kaminoyama Kaori Igarashi Masaki Yasugi Hiroshi Kudoh Atsushi JNagano Kentaro Yano Nakao Kubo Michitaka Notaguchi Seisuke Kimura 《Horticulture Research》 SCIE 2021年第1期1877-1886,共10页
Since ancient times,humans have bred several plants that we rely on today.However,little is known about the divergence of most of these plants.In the present study,we investigated the divergence of Mibuna(Brassica rap... Since ancient times,humans have bred several plants that we rely on today.However,little is known about the divergence of most of these plants.In the present study,we investigated the divergence of Mibuna(Brassica rapa L.subsp.nipposinica L.H.Bailey),a traditional leafy vegetable in Kyoto(Japan),by combining genetic analysis and a survey of ancient literature.Mibuna is considered to have been bred 200 years ago from Mizuna,another traditional leafy vegetable in Kyoto.Mibuna has simple spatulate leaves,whereas Mizuna has characteristic serrated leaves.The quantitative trait loci(QTL)and gene expression analyses suggested that the downregulation of BrTCP15 expression contributed to the change in the leaf shape from serrated to simple spatulate.Interestingly,the SNP analysis indicated that the genomic region containing the BrTCP15 locus was transferred to Mibuna by introgression.Furthermore,we conducted a survey of ancient literature to reveal the divergence of Mibuna and found that hybridization between Mizuna and a simple-leaved turnip might have occurred in the past.Indeed,the genomic analysis of multiple turnip cultivars showed that one of the cultivars,Murasakihime,has almost the same sequence in the BrTCP15 region as Mibuna.These results suggest that the hybridization between Mizuna and turnip has resulted in the establishment of Mibuna. 展开更多
关键词 CULTIVAR survey analysis
下载PDF
Analysis of the Diffractive Deep Inelastic Scattering Data with Running Coupling and Gluon Number Fluctuations
12
作者 向文昌 胡志海 +2 位作者 刘万松 彭俊金 蔡绍洪 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第8期33-37,共5页
We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and g... We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient. 展开更多
关键词 of QCD analysis of the Diffractive Deep Inelastic Scattering Data with Running Coupling and Gluon number Fluctuations in is that with
下载PDF
Consideration on the Flow Velocity in the Experimental Analysis of the Flame Displacement Speed Using DNS Data of Turbulent Premixed Flames with Different Lewis Numbers
13
作者 Kazuya Tsuboi Shingo Morishita Eiji Tomita 《Open Journal of Fluid Dynamics》 2014年第3期278-287,共10页
The flame displacement speed is one of the major characteristics in turbulent premixed flames. The flame displacement speed is experimentally obtained from the displacement normal to the flame surface, while it is num... The flame displacement speed is one of the major characteristics in turbulent premixed flames. The flame displacement speed is experimentally obtained from the displacement normal to the flame surface, while it is numerically evaluated by the transport equation of the flame surface. The flame displacement speeds obtained both experimentally and numerically cannot be compared directly because their definitions are different. In this study, two kinds of experimental flame displacement speeds—involving the mean inflow velocity and the local flow velocity—were simulated using the DNS data with the different Lewis numbers, and were compared with the numerical flame displacement speed. The simulated experimental flame displacement speed involving the mean inflow velocity had no correlation with the numerical flame displacement speed, while the simulated displacement speed involving the local flow velocity had a clear correlation with the numerical displacement speed in the cases of higher Lewis number than unity. The correlation coefficient of the simulated displacement speed involving the local flow velocity with the numerical displacement speed had a maximum value on the isosurface of the reaction progress variable with the maximum temperature gradient where the dilation effect of the flame is strongest. 展开更多
关键词 FLAME DISPLACEMENT SPEED Simulating Experimental Measurement and analysis LEWIS number DILATION Effect Turbulent PREMIXED FLAME Direct Numerical Simulation
下载PDF
Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China
14
作者 Jun-jian Sun Jia-yue Shi +2 位作者 Qi Zhang Xiao-tao Shi Jun-jun Tan 《Water Science and Engineering》 EI CAS CSCD 2024年第1期83-91,共9页
To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in China.The Angu hydropower station involved diverse importa... To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in China.The Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest China.Therefore,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream habitats.Hydrodynamic and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two fishways.The results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish species.During the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream area.Some species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of fish.Meanwhile,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the VSF.These findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF. 展开更多
关键词 Vertical slot fishway Nature-like fishway Aguatic ecological survey Fishwaymonitoring Statistical analysis
下载PDF
Characteristics of Haze Weather and Its Meteorological In-fluencing Factors in Hangzhou
15
作者 Yani ZHANG Rui LIU +2 位作者 Yunbiao ZHANG Yongliang HU Weishi AN 《Meteorological and Environmental Research》 CAS 2023年第1期24-28,共5页
Based on the observation data of the annual number of haze days,rainy days,fog days and gale days,sunshine hours,relative humidity and maximum wind speed at Hangzhou station from 1960 to 2021,the variation characteris... Based on the observation data of the annual number of haze days,rainy days,fog days and gale days,sunshine hours,relative humidity and maximum wind speed at Hangzhou station from 1960 to 2021,the variation characteristics of haze days and meteorological influencing factors were studied by mathematical statistical methods such as Mann-Kendall nonparametric test,sliding T test,wavelet analysis and Pearson correlation two-tailed test.The results show that the annual number of haze days generally showed an upward trend,and the climate tendency rate was 20 d/a;there was a sudden change around 2001,and it changed from stable to rapid growth;the number of haze days was the largest in spring and winter,followed by autumn,while it was the smallest in summer.The annual number of haze days had a strongly significant period of 40 a and a mesoscale variation period of 13 a.The number of haze days was negatively correlated with the number of rainy days,fog days and gale days,sunshine hours,relative humidity and maximum wind speed,which passed the 0.05 significance test.In recent 60 years,the number of rainy days and gale days,relative humidity,and maximum wind speed in Hangzhou have decreased,resulting in the weakening of atmospheric wet deposition capacity and power transmission conditions,which provided favorable meteorological conditions for the increase of haze weather. 展开更多
关键词 number of haze days Wavelet analysis Influencing factor Correlation
下载PDF
Analysis on Residents’ Satisfaction and Its Influencing Factors with Water Environment Management: Based on the Data from Xiaoqing River
16
作者 Lingshan Zhou Yu Wang Xiujuan Wang 《Open Journal of Modern Hydrology》 CAS 2023年第2期129-140,共12页
Xiaoqing River is one of the key rivers in the Yellow River Basin, and its management satisfaction is the content that the government should consider when formulating policies. This paper concentrates on residents’ s... Xiaoqing River is one of the key rivers in the Yellow River Basin, and its management satisfaction is the content that the government should consider when formulating policies. This paper concentrates on residents’ satisfaction of water environment management in Jinan section of Xiaoqing River, using questionnaires to find out the problems and effects of Xiaoqing River management. Based on the correlation analysis of the questionnaire data, the results show that five factors including the impact of water pollution, understanding of Xiaoqing River governance, willingness to participate in Xiaoqing River governance, policy publicity, and government regulation have a positive impact on the satisfaction of Xiaoqing River water environment governance. Finally, the paper puts forward some countermeasures and suggestions to increase residents’ satisfaction from five aspects, such as increasing publicity efforts, paying attention to the cultivation of public participation consciousness, etc. 展开更多
关键词 Water Environment Management Satisfaction survey Correlation analysis
下载PDF
Risk Analysis on Groundwater Resources Carrying Capacity Based on Blind Number Theory 被引量:5
17
作者 ZHANG Ji1,2,YU Sujun31. Key Laboratory of Mountain Hazards and Surface Process,Chinese Academy of Sciences/Institute of Mountain Hazards and Environment,Chinese Academy of Sciences,Chengdu 610041,Sichuan,China 2. Graduate University of the Chinese Academy of Sciences,Beijing 100049,China 3. School of Environmental Science and Engineering,Southwest Jiaotong University,Chengdu 610041,Sichuan,China 《Wuhan University Journal of Natural Sciences》 CAS 2007年第4期669-676,共8页
Blind numbers of evaluation indices about groundwater resources carrying capacity are defined from the concomitancy of randomness, fuzziness, grey property and unascertainment of groundwater system. Based on fuzzy the... Blind numbers of evaluation indices about groundwater resources carrying capacity are defined from the concomitancy of randomness, fuzziness, grey property and unascertainment of groundwater system. Based on fuzzy theory, a comprehensive evaluation model on groundwater resources carrying capacity is constructed with blind information. Then a risk assessment model of surcharge about groundwater resources carrying capacity is established on blind reliability theory. The probable value "*" matrix of fuzzy membership degree about carrying capacity corresponding to each judgment level can be obtained with the aid of blind algorithm as well as the subjective reliability "×" matrix. And then a graph of "groundwater carrying capacity v.s. accumulative reliability" can be gained Based on the graph, fuzzy membership degree of groundwater resources carrying capacity to each judgment level under different risk probability can be got. Thus, a comparatively reasonable judgment to groundwater resources carrying capacity might be obtained, with comprehensive analysis to the state of society, economy technology and ecology. 展开更多
关键词 blind number theory groundwater resources carrying capacity evaluation risk analysis
下载PDF
Mathematical Analysis of Novel Coronavirus (2019-nCov) Delay Pandemic Model 被引量:9
18
作者 Muhammad Naveed Muhammad Rafiq +4 位作者 Ali Raza Nauman Ahmed Ilyas Khan Kottakkaran Sooppy Nisar Atif Hassan Soori 《Computers, Materials & Continua》 SCIE EI 2020年第9期1401-1414,共14页
In this manuscript,the mathematical analysis of corona virus model with time delay effect is studied.Mathematical modelling of infectious diseases has substantial role in the different disciplines such as biological,e... In this manuscript,the mathematical analysis of corona virus model with time delay effect is studied.Mathematical modelling of infectious diseases has substantial role in the different disciplines such as biological,engineering,physical,social,behavioural problems and many more.Most of infectious diseases are dreadful such as HIV/AIDS,Hepatitis and 2019-nCov.Unfortunately,due to the non-availability of vaccine for 2019-nCov around the world,the delay factors like,social distancing,quarantine,travel restrictions,holidays extension,hospitalization and isolation are used as key tools to control the pandemic of 2019-nCov.We have analysed the reproduction number𝐑𝐑𝐧𝐧𝐧𝐧𝐧𝐧𝐧𝐧of delayed model.Two key strategies from the reproduction number of 2019-nCov model,may be followed,according to the nature of the disease as if it is diminished or present in the community.The more delaying tactics eventually,led to the control of pandemic.Local and global stability of 2019-nCov model is presented for the strategies.We have also investigated the effect of delay factor on reproduction number𝐑R_(nCov).Finally,some very useful numerical results are presented to support the theoretical analysis of the model. 展开更多
关键词 2019-nCov delay model reproduction number stability analysis numerical results
下载PDF
Hydrodynamic characteristics of a typical karst spring system based on time series analysis in northern China 被引量:4
19
作者 Yi Guo Feng Wang +5 位作者 Da-jun Qin Zhan-feng Zhao Fu-ping Gan Bai-kun Yan Juan Bai Haji Muhammed 《China Geology》 2021年第3期433-445,共13页
In order to study the hydrodynamic characteristics of the karst aquifers in northern China,time series analyses(correlation and spectral analysis in addition with hydrograph recession analysis)are applied on Baotu Spr... In order to study the hydrodynamic characteristics of the karst aquifers in northern China,time series analyses(correlation and spectral analysis in addition with hydrograph recession analysis)are applied on Baotu Spring and Heihu Spring in Jinan karst spring system,a typical karst spring system in northern China.Results show that the auto-correlation coefficient of spring water level reaches the value of 0.2 after 123 days and 117 days for Baotu Spring and Heihu Spring,respectively.The regulation time obtained from the simple spectral density function in the same period is 187 days and 175 days for Baotu Spring and Heihu Spring.The auto-correlation coefficient of spring water level reaches the value of 0.2 in 34-82 days,and regulation time ranges among 40-59 days for every single hydrological year.The delay time between precipitation and spring water level obtained from cross correlation function is around 56 days for the period of 2012-2019,and varies among 30-79 days for every single hydrological year.In addition,the spectral bands in cross amplitude functions and gain functions are small with 0.02,and the values in the coherence functions are small.All these behaviors illustrate that Jinan karst spring system has a strong memory effect,large storage capacity,noticeable regulation effect,and time series analysis is a useful tool for studying the hydrodynamic characteristics of karst spring system in northern China. 展开更多
关键词 Karst spring Karst aquifer HYDRODYNAMIC Time series analysis Correlation analysis Spectral analysis Hydrogeological survey engineering Jinan Shandong Province China
下载PDF
A method of measuring the [α/Fe] ratios from the spectra of the LAMOST survey 被引量:1
20
作者 Ji Li Chen Han +13 位作者 Mao-Sheng Xiang Jian-Rong Shi Jing-Kun Zhao Xiao-Wei Liu Hua-Wei Zhang Hai-Bo Yuan Xuan Ci Xiao-Feng Zhang Yue-Xiang Wang Yang Huang Yong Zhang Yong-Hui Hou Yue-Fei Wang Zi-Huang Cao 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第7期83-96,共14页
The [α/Fe] ratios in stars are good tracers to probe the formation history of stellar populations and the chemical evolution of the Galaxy. The spectroscopic survey of LAMOST provides a good opportunity to determine ... The [α/Fe] ratios in stars are good tracers to probe the formation history of stellar populations and the chemical evolution of the Galaxy. The spectroscopic survey of LAMOST provides a good opportunity to determine [α/Fe] of millions of stars in the Galaxy. We present a method of measuring the [α/Fe]ratios from LAMOST spectra using the template-matching technique of the LSP3 pipeline. We use three test samples of stars selected from the ELODIE and MILES libraries, as well as the LEGUE survey to validate our method. Based on the test results, we conclude that our method is valid for measuring [α/Fe]from low-resolution spectra acquired by the LAMOST survey. Within the range of the stellar parameters Teff= [5000, 7500] K, log g = [1.0, 5.0] dex and [Fe/H]= [onsistent with values derived from high-resolution spectra,-1.5, +0.5] dex, our [α/Fe] measurements are c and the accuracy of our [α/Fe] measurements from LAMOST spectra is better than 0.1 dex with spectral signal-to-noise higher than 20. 展开更多
关键词 GALAXY evolution stars abundances stars fundamental parameters techniques spectroscopy surveys methods data analysis
下载PDF
上一页 1 2 147 下一页 到第
使用帮助 返回顶部