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草原与草坪 1984年第4期 4-9页

作者： h.Breman c.T.deWit 朱来东

萨赫勒(Sahel)意为荒漠草原,在地理系上系指西北非包括毛里塔尼亚、塞内加尔、马里、上沃尔特、尼日尔、冈此亚、乍得和佛得角等国的广大地带,它以干旱、炎热称著,是非洲大陆的一个重要的畜牧业地区。这个地区的上述国家几乎都以草原畜... 详细信息

萨赫勒(Sahel)意为荒漠草原,在地理系上系指西北非包括毛里塔尼亚、塞内加尔、马里、上沃尔特、尼日尔、冈此亚、乍得和佛得角等国的广大地带,它以干旱、炎热称著,是非洲大陆的一个重要的畜牧业地区。这个地区的上述国家几乎都以草原畜牧业为国民经济的支柱。萨赫勒地区经常发生严重的旱灾。1973—1974年的大旱,曾使这个地区的40—70%的家畜死亡。目前这个地区又遭受着本世纪以来最严重的一次大旱。去年。塞内加尔粮食比常年减产40%;毛里塔尼亚粮食产量只收常年的25%,家畜死亡一半;佛得角遇到了独立以来最严重的干旱。为了抵御干旱,1973年9月成立了西非萨赫勒地区国家抗旱斗争委员会,委员会积极协调成员国之间的抗旱工作,制定了包括中、长期直到2000年的战略目标。本文是马里和荷兰合作对萨赫勒地区初级生产研究的总结。读者从中可以了解该地区草原畜牧业的基本特征,以及科学家们为了发展萨赫勒荒漠草原地区畜牧业生产对它的农业作出的重新评价及提出的解决办法。

关键词：畜牧业生产力牧业生产方式萨赫勒漠境草原荒漠草原畜群家畜单位家畜牲畜

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六年級幾何課的計劃(續)

数学通报 1953年第11期 22-33页

作者： h.c.伊斯托米那吳鴻邁

第二十一課本課主題:三角形的相等應用於實際問題的解法實用教具。掛圖。藉助於三角形相等的鑒定以證明兩線段相等與兩負相等的問題(圖36)。本課計畫 I.課外作業檢查。II.復習提問(要緊湊些)。1.解問題1與2(見掛圖).2.解問題3.已知:ABc... 详细信息

第二十一課本課主題:三角形的相等應用於實際問題的解法實用教具。掛圖。藉助於三角形相等的鑒定以證明兩線段相等與兩負相等的問題(圖36)。本課計畫 I.課外作業檢查。II.復習提問(要緊湊些)。1.解問題1與2(見掛圖).2.解問題3.已知:ABcD是四角形:AB=cD;AD=Bc。求證:(?)繪圖並證明。III.新教材的學習。三角形相等的鑒定與求作三角形等於已知三角形的作法,這種知識與技巧能解決一系列的實際問題。問題。不得

关键词：等腰三角形逆定理

列控-安全信息传输系统可靠性及安全性的形式化分析

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北京交通大学学报 2018年第2期42卷 61-68页

作者：高莺张琦陈黎洁刘宏杰中国铁道科学研究院研究生部北京100081 中国铁道科学研究院通信信号研究所北京100081 中国铁道科学研究院国家铁路智能运输系统工程技术研究中心 100081 中国铁道科学研究院标准计量研究所 100081 北京交通大学轨道交通控制与安全国家重点实验室北京100044 北京交通大学轨道交通运行控制系统国家工程研究中心北京100044

基于通信的列控(cBTc)系统使用基于IEEE 802.11系列的无线局域网实现车-地双向信息传输,但是无线局域网无法满足安全苛求列控系统在信息传输可靠性和安全性方面的需求.为了解决该问题,可以采用双网冗余的结构提高无线局域网信息传输的... 详细信息

基于通信的列控(cBTc)系统使用基于IEEE 802.11系列的无线局域网实现车-地双向信息传输,但是无线局域网无法满足安全苛求列控系统在信息传输可靠性和安全性方面的需求.为了解决该问题,可以采用双网冗余的结构提高无线局域网信息传输的可靠性,再在无线局域网之上增加安全通信协议来保证信息传输的安全性.本文提出在双网冗余无线局域网基础之上增加安全通信协议形成列控-安全信息传输系统(china-Radio),使用随机Petri网建立了双网冗余结构的无线局域网的可靠性模型,并与单网结构进行了定量对比和形式化分析,验证了双网冗余结构可靠性的提升;使用有色Petri网对china-Radio系统建模,并采用模型检验的方法证明china-Radio系统的功能安全性,能够满足列控系统的需求.

关键词：列控-安全信息传输系统 Petri网可靠性安全性模型检验

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clinical implications of exercise immunology

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Journal of Sport and health Science 2012年第1期1卷 12-17页

作者： David c.Nieman human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

Maintaining leanness and a physically active lifestyle during adulthood reduces systemic inflammation,an underlying factor in multiple chronic *** anti-inflammatory influence of near-daily physical activity in lowering c-reactive protein,total blood leukocytes,interleukin-6,and other inflammatory cytokines may play a key role in lowering risk of cardiovascular disease,certain types of cancer,type 2 diabetes,sarcopenia,and *** exercise training causes favorable perturbations in immunity and a reduction in incidence of upper respiratory tract infection(URTI).During each bout of moderate exercise,an enhanced recirculation of immunoglobulins,neutrophils,and natural killer cells occurs that persists for up to 3-h *** exercise-induced surge in immune cells from the innate immune system is transient but improves overall surveillance against *** moderate exercise continues on a near-daily basis for 12-15 weeks,the number of symptoms days with URTI is decreased 25％-50％ compared to randomized sedentary *** and animal studies support this inverse relationship between URTI risk and increased physical ***(c)2012,Shanghai University of *** and hosting by Elsevier *** rights reserved.

关键词： Inflammation Natural killer cells Neutrophils Physical activity Upper respiratory tract infection

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Whole-body heat exposure induces membrane c.a.ges in spermatozoa from the cauda epididymidis of laboratory mice

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Asian Journal of Andrology 2010年第4期12卷 591-598页

作者： harsha Wechalekar Brian P. Setchell Eleanor J. Peirce Mario Ricci chris Leigh William g. Breed Discipline of Anatomy and Pathology School of Medical Sciences Faculty of Health Sciences University of Adelaide Adelaide South Australia 5005 Australia Division of health Sciences University of South Australia City East Campus Adelaide South Australia 5000 Australia

This study was carried out to determine if exposure to hot environmental temperatures had a direct, detrimental effect on sperm quality. For this the effect of whole-body heat exposure on epididymal spermatozoa of laboratory mice was investigated. c57BL/6 mice （n = 7） were housed in a microclimate chamber at 37℃-38℃ for 8 h per day for three consecutive days, while control mice （n = 7） were kept at 23℃-24℃. cauda epididymal spermatozoa were obtained 16 h after the last heat treatment. The results showed that sperm numbers were similar in the two groups （P = 0.23）, but after heat treatment, a significant reduction in the percentage of motile sperm was present （P 〈 0.0001）. Membrane c.a.ges of the spermatozoa were investigated by staining with phycoerythrin （PE）- conjugated Annexin V, which detects exteriorization of phosphotidylserine from the inner to the outer leaflet of the sperm plasma membrane, and 7-aminoactinomycin D （7-AAD）, which binds to the sperm nucleus when the plasma membrane is damaged. The percentage of spermatozoa showing positive staining with Annexin V-PE or 7-AAD or both, was significantly higher （P 〈 0.05） in heat-exposed mice compared with controls. These results show that whole-body heat exposure to 37℃-38℃ induces membrane c.a.ges in the epididymal spermatozoa of mice, which may lead to apoptosis.

关键词： laboratory mice sperm membrane damage whole-body heat

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为尼加拉瓜拟定的抗震设计方法

世界地震工程 1981年第5期 15-18页

作者： h.c.Shah T.c.Zsutty h.Krawinkler L.Padilla J.Dizon 刘锡荟

引言使用尼加拉瓜的等震线图和主要城市的加速度区划图相结合,就有可能确定一结构物在其使用期间所遇到的地震的地面加速度峰值(PgA)。这些地震危险性的超过概率为已知。因此有可能选定确切的给定场地的设计地震大小,使其危险性的发生... 详细信息

引言使用尼加拉瓜的等震线图和主要城市的加速度区划图相结合,就有可能确定一结构物在其使用期间所遇到的地震的地面加速度峰值(PgA)。这些地震危险性的超过概率为已知。因此有可能选定确切的给定场地的设计地震大小,使其危险性的发生率与拟用的

关键词：抗震设计防震设计结构设计反应谱曲线抗侧力延性要求设计谱地震荷载地震力尼加拉瓜

Adaptive cell Zooming Strategy Toward Next-generation cellular Networks with Joint Transmission

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computers, Materials & continua 2021年第10期69卷 81-98页

作者： Abu Jahid Mohammed h.Alsharif Raju Kannadasan Mahmoud A.Albreem Peerapong Uthansakul Jamel Nebhen Ayman A.Aly Department of Electrical and computer Engineering University of OttawaOttawaK1N 6N5ONCanada Department of Electrical Engineering College of Electronics and Information EngineeringSejong UniversitySeoul05006Korea Department of Electrical and Electronics Engineering Sri Venkateswara College of EngineeringSriperumbudur602117India Department of Electronics and communications Engineering A’Sharqiyah UniversityIbra400Oman School of Telecommunication Engineering Suranaree University of TechnologyNakhon RatchasimaThailand Prince Sattam Bin Abdulaziz University College of Computer Engineering and SciencesAlkharj11942Saudi Arabia Department of Mechanical Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia

The Internet subscribers are expected to increase up to 69.7%(6 billion)from 45.3%and 25 billion Internet-of-things connections by ***,the ubiquitous availability of data-hungry smart multimedia devices urges research attention to reduce the energy consumption in the fifthgeneration cloud radio access network to meet the future traffic demand of high data *** propose a new cell zooming paradigm based on joint transmission(JT)coordinated multipoint to optimize user connection by controlling the cell coverage in the downlink communications with a hybrid power *** endeavoring cell zooming technique adjusts the coverage area in a given cluster based on five different JT schemes,which will help in reducing the overall power consumption with minimum inter-cell *** provide heuristic solutions to assess wireless network performances in terms of aggregate throughput,energy efficiency index(EEI),and energy consumption gain under a different scale of network *** suggested algorithm allows efficient allocation of resource block and increases energy and spectral efficiency over the conventional location-centric cell zooming *** system-level simulations show that the proposed framework reduces energy consumption yielding up to 17.5%and increases EEI by 14%.Subsequently,a thorough comparison among different JT-based load shifting schemes is pledged for further validation of varying system bandwidths.

关键词： Wireless networks green communications c-RAN coordinated multipoint energy efficiency

阿尔茨海默病与死亡率:一项15年的流行病学研究

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世界核心医学期刊文摘（神经病学分册） 2005年第9期1卷 21-22页

作者： ganguli M. Dodge h.h. Shen c. 孟云宵 Western Psychiatric Institute and clinic 3811 O'Hara St Pittsburgh PA 15213-2593 United StatesDr.

Background: Alzheimer disease (AD) is considered a leading cause of death, but few studies have examined the contribution of AD to mortality based on follow- up of representative US cohorts. Objective: To examine mortality rates, duration of survival, causes of death, and the contribution of AD to the risk of mortali ty in an aging community-based cohort, controlling for other predictors. Design : Fifteen-year prospective epidemiological study. Mortality rates per 1000 pers on-years and the population-attributable risk of mortality were determined. co x proportional hazards models were used to estimate relative risk of mortality d ue to AD, adjusting for relevant covariates. Death certificates were abstracted for listed causes of death. Setting: A largely blue-collar rural community in s outh-western Pennsylvania. Participants: A community-based cohort of 1670 adul ts 65 years and older at study enrollment. Main Outcome Measure: Mortality. Resu lts: In the overall cohort, AD was a significant predictor of mortality, with a hazard ratio of 1.4 after adjusting for covariates. The population-attributable risk of mortality from AD was 4.9%based on the same model. Examining the sexes separately, AD increased mortality risk only among women. Death certificates of AD subjects were more likely to list dementia/AD, other brain disorders, pneumo nia, and dehydration, and less likely to include cancer. conclusions: Alzheimer disease was responsible for 4.9%of the deaths in this elderly cohort. Alzheimer disease increased the risk of mortality 40%in the cohort as a whole and separa tely in women but not in men. The mean (SD) duration of survival with AD was 5.9 (3.7) years, and longer with earlier age at onset.

关键词：阿尔茨海默病流行病学研究死亡原因随访研究协变量死亡风险生存时间死亡证明脑病宾夕法尼亚州

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Resting metabolic rates increase with elevation in a mountain-dwelling lizard

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Integrative Zoology 2020年第5期15卷 363-374页

作者： Melissa PLASMAN Amando BAUTISTA Marshall D.MccUE Aníbal h.DÍAZ DE LA VEgA-PÉREZ centro Tlaxcala de Biología de la conducta Universidad Autónoma de TlaxcalaTlaxcalaMéxico Sable Systems International Las VegasNevadaUSA consejo Nacional de ciencia y Tecnología–centro Tlaxcala de Biología de la conducta Universidad Autónoma de TlaxcalaTlaxcalaMéxico

ndividuals that inhabit broad elevational ranges may experience unique environmental *** temperature decreases with increased elevation,the ectotherms living at high elevations have to manage limited activity time and high thermoregulatory *** resting metabolic rate(RMR)of a postabsorptive animal is related to its total energy requirements as well as many other fitness *** lizards(Sceloporus grammicus)living on La Malinche Volcano,Mexico,inhabit a wide elevational range with some populations apparently thriving above the tree *** measured the RMR of lizards from different elevations(i.e.,2,600,3,200,and 4,100 m)at four ecologically relevant temperatures(i.e.,15,25,30,and 35°c)and found that RMR of mesquite lizards increased with temperature and body *** importantly,lizards from the high-elevation population had mass specific RMR that was higher at all *** the higher RMRs of high-elevation populations imply higher metabolic costs at a given temperature these lizards were also *** of these traits may allow these high elevation populations to thrive in the face of the thermal challenges imposed by their environment.

关键词： altitudinal gradient energetics reptile Sceloporus temperature