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Euler’s First-Order Explicit Method–Peridynamic Differential Operator for Solving Population Balance Equations of the Crystallization Process
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作者 Chunlei Ruan Cengceng Dong +2 位作者 Kunfeng Liang Zhijun Liu Xinru Bao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第3期3033-3049,共17页
Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridyna... Using Euler’s first-order explicit(EE)method and the peridynamic differential operator(PDDO)to discretize the time and internal crystal-size derivatives,respectively,the Euler’s first-order explicit method–peridynamic differential operator(EE–PDDO)was obtained for solving the one-dimensional population balance equation in crystallization.Four different conditions during crystallization were studied:size-independent growth,sizedependent growth in a batch process,nucleation and size-independent growth,and nucleation and size-dependent growth in a continuous process.The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods.The method is characterized by non-oscillation and high accuracy,especially in the discontinuous and sharp crystal size distribution.The stability of the EE–PDDO method,choice of weight function in the PDDO method,and optimal time step are also discussed. 展开更多
关键词 population balance equation CRYsTALLIZATION peridynamic differential operator Euler’s first-order explicit method
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Efficient and Cost-Effective Vehicle Detection in Foggy Weather for Edge/Fog-Enabled Traffic Surveillance and Collision Avoidance Systems
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作者 Naeem Raza Muhammad Asif Habib +3 位作者 Mudassar Ahmad Qaisar Abbas Mutlaq BAldajani Muhammad Ahsan Latif 《Computers, Materials & Continua》 SCIE EI 2024年第10期911-931,共21页
Vision-based vehicle detection in adverse weather conditions such as fog,haze,and mist is a challenging research area in the fields of autonomous vehicles,collision avoidance,and Internet of Things(IoT)-enabled edge/f... Vision-based vehicle detection in adverse weather conditions such as fog,haze,and mist is a challenging research area in the fields of autonomous vehicles,collision avoidance,and Internet of Things(IoT)-enabled edge/fog computing traffic surveillance and monitoring systems.Efficient and cost-effective vehicle detection at high accuracy and speed in foggy weather is essential to avoiding road traffic collisions in real-time.To evaluate vision-based vehicle detection performance in foggy weather conditions,state-of-the-art Vehicle Detection in Adverse Weather Nature(DAWN)and Foggy Driving(FD)datasets are self-annotated using the YOLO LABEL tool and customized to four vehicle detection classes:cars,buses,motorcycles,and trucks.The state-of-the-art single-stage deep learning algorithms YOLO-V5,and YOLO-V8 are considered for the task of vehicle detection.Furthermore,YOLO-V5s is enhanced by introducing attention modules Convolutional Block Attention Module(CBAM),Normalized-based Attention Module(NAM),and Simple Attention Module(SimAM)after the SPPF module as well as YOLO-V5l with BiFPN.Their vehicle detection accuracy parameters and running speed is validated on cloud(Google Colab)and edge(local)systems.The mAP50 score of YOLO-V5n is 72.60%,YOLOV5s is 75.20%,YOLO-V5m is 73.40%,and YOLO-V5l is 77.30%;and YOLO-V8n is 60.20%,YOLO-V8s is 73.50%,YOLO-V8m is 73.80%,and YOLO-V8l is 72.60%on DAWN dataset.The mAP50 score of YOLO-V5n is 43.90%,YOLO-V5s is 40.10%,YOLO-V5m is 49.70%,and YOLO-V5l is 57.30%;and YOLO-V8n is 41.60%,YOLO-V8s is 46.90%,YOLO-V8m is 42.90%,and YOLO-V8l is 44.80%on FD dataset.The vehicle detection speed of YOLOV5n is 59 Frame Per Seconds(FPS),YOLO-V5s is 47 FPS,YOLO-V5m is 38 FPS,and YOLO-V5l is 30 FPS;and YOLO-V8n is 185 FPS,YOLO-V8s is 109 FPS,YOLO-V8m is 72 FPS,and YOLO-V8l is 63 FPS on DAWN dataset.The vehicle detection speed of YOLO-V5n is 26 FPS,YOLO-V5s is 24 FPS,YOLO-V5m is 22 FPS,and YOLO-V5l is 17 FPS;and YOLO-V8n is 313 FPS,YOLO-V8s is 182 FPS,YOLO-V8m is 99 FPS,and YOLO-V8l is 60 FPS on FD dataset.YOLO-V5s,YOLO-V5s variants and YOLO-V5l_BiFPN,and YOLO-V8 algorithms are efficient and cost-effective solution for real-time vision-based vehicle detection in foggy weather. 展开更多
关键词 vehicle detection YOLO-V5 YOLO-V5s variants YOLO-V8 DAWN dataset foggy driving dataset IoT cloud/edge/fog computing
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Allozyme Diversity and Population Genetic Structure of Three Medicinal Epimedium Species from Hubei 被引量:4
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作者 徐艳琴 李作洲 +1 位作者 王瑛 黄宏文 《Journal of Genetics and Genomics》 SCIE CAS CSCD 北大核心 2007年第1期56-71,共16页
Three Epimedium species, E. pubescens Maxim., E. sagittatum (Sieb. & Zucc.) Maxim., and E. wushanense T. S. Ying, which are sympatrically distributed in the western Hubei Province, have been used in traditional Chi... Three Epimedium species, E. pubescens Maxim., E. sagittatum (Sieb. & Zucc.) Maxim., and E. wushanense T. S. Ying, which are sympatrically distributed in the western Hubei Province, have been used in traditional Chinese medicine (TCM) for about 2,000 years. Genetic variability and population genetic structure of 11 natural populations of these Epimedium species were investigated using isoelectric focusing in thin-layer polyacrylamide slab gels. Of the 22 enzyme systems prescreened, six coding for 13 loci and 45 alleles were resolved, which were used for analyzing genetic diversity and population structure at both intraspecific and interspecific levels. The results showed that: l) high levels of genetic diversity were observed in all three species (A = 2.6-3.2, P = 69.2%-84.6%, Ho= 0.274-0.377, HE= 0.282-0.369), which were higher than that of other herbaceous and aulmal-pollinated species with similar life-history characteristics; 2) there was significant deviation from Hardy-Weinberg Equilibrium, with one half of the loci showing heterozygote excess and the other homozygote excess, in all populations, suggesting the complicated breeding system of Epimedium species; 3) the low level of intraspecific and interspecific genetic differentiation (GST= 0.0246-0.0409 and 0.0495-0.1213, respectively) indicated a high level of gene flow among populations and close genetic relationship among the three species; and 4) UPGMA cluster analysis further showed that E. pubescens was more closely related to E. sagittatum than to E. wushanense, which was in good agreement with the morphological characters and the recent phylogenetic analysis of these species. On the basis of these results, it was concluded that the mixed breeding system, long-lived perennial life form, ancient evolutionary history, and seed dispersal by ants in Epimedium are responsible for the genetic variation and population structure of these species. 展开更多
关键词 Epimedium pubescens Maxim. E. sagittatum sieb. Zucc.) Maxim. E. wushanense T. s. Ying ALLOZYME genetic diversity population structure
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Comparative Analysis of Improving Effects of 12 Maize Populations with Improved S_1 Selection Method
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作者 孙峰成 冯勇 +6 位作者 付增娟 苏二虎 张来厚 赵瑞霞 刘志雄 石海波 李美娜 《Agricultural Science & Technology》 CAS 2014年第10期1687-1692,1713,共7页
ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of... ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment. 展开更多
关键词 lmproved s1 selection method Maize population Genetic gain Comparative analysis
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Comparisons of Three Recurrent Selection Methods in the Improvement of Maize Populations 被引量:2
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作者 PENG Ze-bin LI Ming-shun LIU Xin-zhi LI Jun-qiang 《Agricultural Sciences in China》 CAS CSCD 2007年第6期657-664,共8页
The maize population Csyn 4 was improved for three cycles with three recurrent selection methods MS1, MS1-HS, and MHSRRS in northern China. A total of 40 NC Ⅱ testcrosses were made by four testers with Csyn 4 and 10 ... The maize population Csyn 4 was improved for three cycles with three recurrent selection methods MS1, MS1-HS, and MHSRRS in northern China. A total of 40 NC Ⅱ testcrosses were made by four testers with Csyn 4 and 10 improved populations, which were evaluated in four environments in the cropping season of 2005. Analysis of variance indicated a significant progress (P〈 0.05) in yield and other chief agronomic traits in the improved populations and testcrosses, demonstrating that the three recurrent selection methods were effective for increasing grain yield of testcrosses and improvement of general combining ability in maize population. The average grain yield increase of population Csyn 4 in MS1, MS1-HS, and MHSRRS recurrent selections was 266.7 kg ha^-1 (5.3%), 288.0 kg ha^-1 (5.7%), and 231.3 kg ha^-1 (4.6%) per cycle, while the grain yield of S 1 progeny of population for Csyn 4 was increased by 420.0 kg ha^-1 (10.9%), 376.0 kg ha^-1 (9.8%), and 414.7 kg ha^-1 (10.8%) per cycle in MS1, MS1-HS, and MHSRRS recurrent selections, respectively. Linear responses (b) in the MS1, MS1-HS, and MHSRRS recurrent selections were the same as the realized responses of the selection (G) for grain yield increase of Csyn 4 and S1 progeny of the populations. The grain yield of testcrosses increased by 3.3-5.2% on average per cycle. The value of heterosis did not display any differences amongst the different cycles of selections. The GCA for yield component traits of population Csyn 4 was improved significantly by means of three selection methods, whereas the GCA for plant height, ear height, days to silking, and days to pollen did not show significant increase in the recurrent selections. GCA for the number of tassel branches were decreased in the selections, while GCA for the number of plant leaves were increased, but the difference was not significant. 展开更多
关键词 maize (Zea mays L.) population improvement recurrent selection modified s 1 family selection (Ms 1) modified s 1 family-half-sib family combining selection (Ms 1-Hs modified half-sib reciprocal recurrentselection (MHsRRs
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Stability Analysis on Speed Control System of Autonomous Underwater Vehicle 被引量:2
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作者 李晔 庞永杰 +2 位作者 万磊 王芳 廖煜雷 《China Ocean Engineering》 SCIE EI 2009年第2期345-354,共10页
The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle(AUV).The divergence of control,which the unstable system may be brought about,is fat... The stability of the motion control system is one of the decisive factors of the control quality for Autonomous Underwater Vehicle(AUV).The divergence of control,which the unstable system may be brought about,is fatal to the operation of AUV.The stability analysis of the PD and S-surface speed controllers based on the Lyapunov's direct method is proposed in this paper.After decoupling the six degree-of-freedom(DOF)motions of the AUV,the axial dynamic behavior is discussed and the condition is deduced,in which the parameters selection within stability domain can guarantee the system asymptotically stable.The experimental results in a tank and on the sea have successfully verified the algorithm reliability,which can be served as a good reference for analyzing other AUV nonlinear control systems. 展开更多
关键词 autonomous underwater vehicle AUV) control system stability analysis Lyapunov's stability theory
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Dynamics of vehicles with high gravity centre 被引量:1
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作者 Szymon Tengler Andrzei Harlecki 《Theoretical & Applied Mechanics Letters》 CAS 2012年第4期75-78,共4页
The vehicles with high gravity centre are more prone to roll over. The paper deals with a method of dynamics analysis of fire engines which is an example of these types of vehicle. Algorithms for generating the equati... The vehicles with high gravity centre are more prone to roll over. The paper deals with a method of dynamics analysis of fire engines which is an example of these types of vehicle. Algorithms for generating the equations of motion have been formulated by homogenous transformations and Lagrange's equation. The model presented in this article consists of a system of rigid bodies connected one with another forming an open kinematic chain. Road maneuvers such as a lane change and negotiating a circular track have been presented as the main simulations when a car loses its stability. The method has been verified by comparing numerical results with results obtained by experimental measurements performed during road tests. 展开更多
关键词 DYNAMICs vehicles high gravity center Lagrange's equation
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An Alternative Algorithm for Vehicle Routing Problem with Time Windows for Daily Deliveries 被引量:2
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作者 Nor Edayu Abdul Ghani S. Sarifah Radiah Shariff Siti Meriam Zahari 《Advances in Pure Mathematics》 2016年第5期342-350,共9页
This study attempts to solve vehicle routing problem with time window (VRPTW). The study first identifies the real problems and suggests some recommendations on the issues. The technique used in this study is Genetic ... This study attempts to solve vehicle routing problem with time window (VRPTW). The study first identifies the real problems and suggests some recommendations on the issues. The technique used in this study is Genetic Algorithm (GA) and initialization applied is random population method. The objective of the study is to assign a number of vehicles to routes that connect customers and depot such that the overall distance travelled is minimized and the delivery operations are completed within the time windows requested by the customers. The analysis reveals that the problems experienced in vehicle routing with time window can be solved by GA and retrieved for optimal solutions. After a thorough study on VRPTW, it is highly recommended that a company should implement the optimal routes derived from the study to increase the efficiency and accuracy of delivery with time insertion. 展开更多
关键词 vehicle Routing Problem with Time Windows (VRPTW) Genetic Algorithm (GA) Random population Method
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Hu Huanyong:Father of China's Population Geography 被引量:1
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《China Population Today》 1998年第4期21-21,共1页
ProfesorHuHuanyong,oneoftheforefathersinmodernChina’sdemographyandalsothefounderofChina’spopulationgeography... ProfesorHuHuanyong,oneoftheforefathersinmodernChina’sdemographyandalsothefounderofChina’spopulationgeography,diedofilnesonApr... 展开更多
关键词 Huanyong population HU China’s GEOGRAPHY
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A single nucleotide polymorphism in the IL1RL1 gene is associated with Behcet's disease in a Chinese Han population 被引量:1
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作者 Xin-Shu Liu Zi-Yan Wu +7 位作者 Si Chen Chan Zhao Fei Gao Ming-Hang Pei Shan-Shan Jia Yong-Zhe Li Pei-Zeng Yang Mei-Fen Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2021年第9期1315-1320,共6页
AIM:To explore the association of single nucleotide polymorphisms(SNPs)in the IL33/IL1RL1 gene region with the susceptibility to Behcet’s disease(BD)in a Chinese Han population.METHODS:A total of eight SNPs in the ca... AIM:To explore the association of single nucleotide polymorphisms(SNPs)in the IL33/IL1RL1 gene region with the susceptibility to Behcet’s disease(BD)in a Chinese Han population.METHODS:A total of eight SNPs in the candidate gene region(rs11792633,rs7025417,rs10975519 and rs1048274 in IL33;rs2310220,rs12712142,rs13424006 and rs3821204 in IL1RL1)were genotyped in783 BD patients and 701 healthy controls by the Sequenom Mass Array i PLEX platform.RESULTS:A statistically significant association was observed between IL1RL1 rs12712142 and BD patients.The frequency of IL1RL1 rs12712142 variant allele A was significantly lower in BD patients than that in controls(OR=0.8,95%CI:0.69-0.94,Pc=0.039);the genotype distribution(Pc=0.043)and additive and dominant genetic model analyses(OR=0.8,95%CI:0.69-0.94,Pc=0.040 and OR=0.72,95%CI:0.58-0.88,Pc=0.011)also indicated a strong association between rs12712142 and BD patients.CONCLUSION:This is the first study to reveal the association between IL1RL1 rs12712142 variant allele A and the decreased risk of BD in the Chinese Han population,indicating a protective role of IL1RL1 in the pathogenesis of BD. 展开更多
关键词 Behcet’s disease single nucleotide polymorphism Chinese Han population IL33 IL1RL1
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Auto-Test on Motor Temperature Rising in Electric Vehicles with Mutual MRAS 被引量:1
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作者 王志福 张承宁 《Journal of Beijing Institute of Technology》 EI CAS 2008年第4期395-399,共5页
A new method to calculate the motor temperature rising in electric vehicle (EV) is proposed based on the stator resistance identification. The measure theory of the motor temperature rising with the stator resistanc... A new method to calculate the motor temperature rising in electric vehicle (EV) is proposed based on the stator resistance identification. The measure theory of the motor temperature rising with the stator resistance is discussed at first. An enhanced magnetism motor dynamic math model is built which is the research object. Then the resistance identification system model is built on the mutual model reference adaptive,system (MRAS) theory. The simulation diagram of the mutual MRAS model is constructed and the resistance identification performance is studied in different motor states. Simulation results indicate that the stator resistance identification model with the mutual MRAS is effective. At the same time, the identification of motor temperature rising is possible with the identification of the stator resistance. 展开更多
关键词 electric vehicle (EV) motor's temperature rising model reference adaptive system (MARs resistance identification
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Purchase willingness of new energy vehicles: A case study in Jinan City of China 被引量:3
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作者 Xueqing Tian Qingling Zhang +1 位作者 Yuzhu Chi Yu Cheng 《Regional Sustainability》 2021年第1期12-22,共11页
Speeding up the promotion of new energy vehicles is an important measure to optimize the energy structure,promote energy conservation and emission reduction,and develop the economy sustainability.The research uses a q... Speeding up the promotion of new energy vehicles is an important measure to optimize the energy structure,promote energy conservation and emission reduction,and develop the economy sustainability.The research uses a questionnaire survey to analyze the residents’willingness to purchase new energy vehicles in Jinan Gty of China,and utilizes the binomial logistic regression model and Global Moran's I to explain the impact of three factors(including responden ts'personal characteristics and subjective cognition,products,and social environment)on the purchase willingness of new energy vehicles.According to the survey,75.12%of the responden ts consider buying new energy vehicles in the future,but only 11.66%of the respondents know new energy vehicles well.It can be seen that the respondents in Jinan City generally have an insufficient understanding of new energy vehicles.It may lead to a decline in residents’trust in new energy vehicles,which will in turm affect their purchase willingness.Based on the survey,we find that women who live far from the city center enjoy high incomes and have a low-carbon awareness,generally exhibit a higher willingness to purchase new energy vehicles.Spatial distribution of the purchase willingness has certain aggregation characteristics,showing a positive spatial correlation pattern.Purchase willingness has a certain positive diffusion effect in space,and areas with a higher purchase willingness have a positive driving effect on their surrounding regions.Spatial distribution of the purchase willingness can be used as one of the breakthroughs in promoting new energy vehicles.In addition,safety,price,after-sales service,and infrastruicture of new energy vehicles are important determinants of people's purchase willingness.Among the types of subsidies,financial subsidy is most effective on the residents’purchase wilingness.Our research provides an impor tant information for the promotion of new energy vehicles in the region. 展开更多
关键词 New energy vehicles Purchase willingness Public acceptance Global Moran’s I Jinan City
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Flexible predictive power-split control for battery-supercapacitor systems of electric vehicles using IVHS 被引量:1
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作者 HE Defeng LUO Jie +1 位作者 LIN Di YU Shiming 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第1期224-235,共12页
The utilization of traffic information received from intelligent vehicle highway systems(IVHS) to plan velocity and split output power for multi-source vehicles is currently a research hotspot. However, it is an open ... The utilization of traffic information received from intelligent vehicle highway systems(IVHS) to plan velocity and split output power for multi-source vehicles is currently a research hotspot. However, it is an open issue to plan vehicle velocity and distribute output power between different supply units simultaneously due to the strongly coupling characteristic of the velocity planning and the power distribution. To address this issue, a flexible predictive power-split control strategy based on IVHS is proposed for electric vehicles(EVs) equipped with battery-supercapacitor system(BSS). Unlike hierarchical strategies to plan vehicle velocity and distribute output power separately, a monolayer model predictive control(MPC) method is employed to optimize them online at the same time. Firstly, a flexible velocity planning strategy is designed based on the signal phase and time(SPAT) information received from IVHS and then the Pontryagin’s minimum principle(PMP) is adopted to formulate the optimal control problem of the BSS. Then, the flexible velocity planning strategy and the optimal control problem of BSS are embedded into an MPC framework, which is online solved using the shooting method in a fashion of receding horizon. Simulation results verify that the proposed strategy achieves a superior performance compared with the hierarchical strategy in terms of transportation efficiency, battery capacity loss, energy consumption and computation time. 展开更多
关键词 electric vehicle(EV) model predictive control(MPC) Pontryagin’s minimum principle(PMP) power-split
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SLC26A4 gene polymorphism and late-onset Alzheimer’s disease in a Han Chinese population from Qingdao,China 被引量:1
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作者 Jifang Zhang Yantuan Li 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第8期754-759,共6页
In a recent genome-wide association study, the SLC26A4 gene rs2072064 polymorphism was found to be associated with late-onset Alzheimer's disease in Caucasians. Here, we investigated this association in a large North... In a recent genome-wide association study, the SLC26A4 gene rs2072064 polymorphism was found to be associated with late-onset Alzheimer's disease in Caucasians. Here, we investigated this association in a large Northern Han Chinese cohort consisting of 599 sporadic late-onset Alzheimer's disease patients and 598 healthy controls matched for sex and age in a Northern Han Chinese population from Qingdao, China. Genotyping by the polymerase chain reaction-ligase detection reaction revealed that there were significant differences in the genotype (P = 0.017) and allele (P = 0.007) frequencies of the rs2072064 polymorphism between late-onset Alzheimer's disease patients and controls. The A allele of this polymorphism was significantly associated with a reduced risk of late-onset Alzheimer's disease (odds ratio (OR) = 0.792, 95% confidence interval (CI) = 0.670-0.937, P = 0.007). When the data were stratified by the apolipoprotein E E4 status, there was a significant difference only among apolipoprotein E E4 non-carriers (genotypic P = 0.001, allelic P = 0.001). Furthermore, the association between rs2072064 and late-onset Alzheimer's disease remained significant by logistic regression analysis after adjustment for age, gender, and the apolipoprotein E E4 carrier status (dominant model: OR = 0.787, 95% CI = 0.619-1.000, P = 0.050; recessive model: OR = 0.655, 95% CI = 0.448-0.959, P= 0.030; additive model: OR = 0.792, 95% CI = 0.661-0.950, P = 0.012). These findings suggest that SLC26A4 is a susceptibility gene for late-onset Alzheimer's disease in a Northern Han Chinese population from the Qingdao area. 展开更多
关键词 neural regeneration neurodegenerative diseases late-onset Alzheimer's disease sLC26A4 rs2072064 POLYMORPHIsM genetic association Han Chinese population apolipoprotein E NEUROREGENERATION
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China’s Tibetan Population and Population in Tibet 被引量:1
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作者 Guo Daping(China Population information and Research Centre) 《China Population Today》 1996年第2期7-8,共2页
China’sTibetanPopulationandPopulationinTibetGuoDaping(ChinaPopulationinformationandResearchCentre)TheTibet(X... China’sTibetanPopulationandPopulationinTibetGuoDaping(ChinaPopulationinformationandResearchCentre)TheTibet(Xizang)AutonomousR... 展开更多
关键词 China s Tibetan population and population in Tibet
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GROWTH, REPRODUCTION & POPULATION STRUCTURE OF THE FRESHWATER CRAB SINOPOTAMON YANG TSEKIENSE BOTT, 1967, FROM ZHEJIANG, CHINA
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作者 陈涛 赖伟 堵南山 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1994年第1期84-90,共7页
Monthly investigatiom were made on the population of Chinese freshwater crab, Sinopotamon yangteskiense Bott, 1967 from April, 1984 to Match, 1985. The data on 4413 specimens show that the growth was affected mainly b... Monthly investigatiom were made on the population of Chinese freshwater crab, Sinopotamon yangteskiense Bott, 1967 from April, 1984 to Match, 1985. The data on 4413 specimens show that the growth was affected mainly by temperature. During the April to November growth period, the crabs’ major development occured from June through October. One year was required for a fine white oocyte to develop into a mature egg. The reproduction period was June-October. Females bearing eggs were taken from June-August, and crabs with young were found from July-October. The females reproduced once a year but could for more than one year. The number of eggs carried by a female varied greatly according to the size of the crab, ranging from 30 to 100 eggs. New-bom crabs become mature after 1-2 yeats. The sex ratio was approximately 1:1 in the overall population. However, the larger crabs are predominantly male. The age distribution of S. yangtsekinese was estimated from size frequency histograms. There were more adult 展开更多
关键词 GROWTH curve vitellogenesis. population s. yangtsekiense sEX ratio
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Design of Novel S-plane Controller of Autonomous Underwater Vehicle Established on Sliding Mode Control 被引量:2
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作者 Chunmeng Jiang Lei Wan Yushan Sun 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2017年第2期58-64,共7页
Based on the deep analysis of the mathematical model of an autonomous underwater vehicle( AUV),comprehensive considerations are given to the coupling effect of AUV's longitudinal velocity on the other degrees of f... Based on the deep analysis of the mathematical model of an autonomous underwater vehicle( AUV),comprehensive considerations are given to the coupling effect of AUV's longitudinal velocity on the other degrees of freedom. In the meantime,discussions are made on the influence of residual buoyancy and restoring moment.A novel S-plane controller established on sliding mode control( SMC) is hereby proposed in this study. The strengths of traditional S-plane controller including simple structure and easily adjustable parameters are maintained in the improved design while the weakness of unsatisfactory control effect at the time of high-speed operation is also overcome. Lyapunov function is introduced to make the stability analysis of the controller before it is successfully applied to the basic motion control of AUV-X. Then the comparative experiment test is carried out between the traditional S-plane controller and the novel S-plane controller. The effectiveness and feasibility of the novel S-plane controller established on sliding mode control in the AUV basic motion control is verified by the comparative analysis of experiment results. 展开更多
关键词 sliding mode control s-plane controller stability analysis Lyapunov function autonomous underwater vehicle
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Fair Plan 8: Earth’s Climate Future—Pope Francis’ Population Mistake 被引量:1
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作者 Michael E. Schlesinger Michael Ring Emily F. Cross 《Atmospheric and Climate Sciences》 2016年第1期103-111,共9页
Pope Francis wrote in his Encyclical Letter Laudato Si’: On Care for Our Common Home: “Instead of resolving the problems of the poor and thinking of how the world can be different, some can only propose a reduction ... Pope Francis wrote in his Encyclical Letter Laudato Si’: On Care for Our Common Home: “Instead of resolving the problems of the poor and thinking of how the world can be different, some can only propose a reduction in the birth rate.” … “To blame population growth instead of extreme and selective consumerism on the part of some is one way of refusing to face the issues.” Here, we test the hypothesis that population size does not matter. We do so in terms of the effect of the size of the human population on its emission of greenhouse gases. We find that the hypothesis is false = PO-PULATION MATTERS. Ceteris paribus, the larger the population of human beings on Planet Earth, the more difficult it will be to reduce, and finally eliminate, the emission of greenhouse gases by humanity and, thereby, constrain human-caused climate change = Anthropogenic Global Warming. 展开更多
关键词 Earth’s Climate Future population Matters
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Sand-dust Storm, Population and Environment in Northwest China
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作者 Liu Shao Guangzhou Research Institute of Environmental Protection, Guangzhou 510620, China 《Chinese Journal of Population,Resources and Environment》 2004年第4期17-24,共8页
Sand-dust storms are the result of the integrated influences of climate, geography, society and human factors. A theoretical framework is built to explain the coherence of population growth, agriculture change and env... Sand-dust storms are the result of the integrated influences of climate, geography, society and human factors. A theoretical framework is built to explain the coherence of population growth, agriculture change and environmental degradation. On the basis of the analysis of the causes of the sand-dust storm in terms of human factors, a discussion will be given to show that these factors are internally consistent with the theoretical framework. After that, it will look at China's Agenda 21 and try to find relevant measures to reduce such large sand-dust storms happening in Northwest China and eventually make this area develop sustainably. 展开更多
关键词 sand-dust storm population ENVIRONMENT china’s Agenda 21 sUsTAINABILITY
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tatistics about China's Population In 1997
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《China Population Today》 1998年第3期14-14,共1页
StatisticsaboutChina’sPopulationIn1997Astatisticalbuletinonthenationaleconomicandsocialdevelopmentin1997was... StatisticsaboutChina’sPopulationIn1997Astatisticalbuletinonthenationaleconomicandsocialdevelopmentin1997wasreleasedbytheStat... 展开更多
关键词 In tatistics population ABOUT China’s
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