三种主要干扰造成中国森林植被向大气中的碳排放量     

付超  方华军  于贵瑞 《资源与生态学报(英文版)》2011,(3):202-209

对重要干扰过程导致森林植被向大气中的碳排放量进行评估,对于合理评估森林碳汇功能及其在应对全球气候变化中的作用是有重要意义的。本文基于有关森林干扰发生情况的林业统计资料和有关干扰引起生物量C转移过程与比例的假设条件,估算了近20年来采伐、火灾与病虫鼠害三种主要干扰每年从森林植被直接排放到大气中的C量。结果表明,近20年来,中国森林遭受了比较强烈的采伐、火灾与病虫鼠害干扰,并且这三种干扰在进入21世纪后有着比较明显的增加趋势。相应地,在1990-2009年间,采伐、火灾与病虫鼠害的C排放量年均分别为3425.16万tC、161.29万tC、428.80万tC,合计为4015.24万t。三种干扰的总C排放量在1990-1999年间年均为3079.40万t,在2000-2009年间年均为4951.09万t。从不同森林类型分布区的排放来看,中国森林主要干扰的年均C排放量及其年代际变化呈现比较明显的区域特征。干扰对中国森林碳平衡有着重大影响,针对干扰的森林管理可能具有较大的增汇潜力,并且在未来有关森林与陆地生态系统碳收支的模型研究中需考虑主要干扰的影响。  相似文献   

传染病防控下的市民慢性病药品现场购药需求的周期优化     

王晓凡  方志祥  仲浩宇  邹欣妍 《地球信息科学学报》2021,23(2):307-317

呼吸道传染疾病在人群间的传播,容易引发大规模的公共卫生事件。在疫情防控期间,通过限制购药周期可以有效控制和降低因购药聚集而产生的感染风险。本文聚焦传染病疫情防控中封闭与复工初期慢性病患者的购药需求,针对到店购药场景,提出一个慢性病患者购药周期的优化方法。首先,依据武汉市疫情防控期间“不得跨区购药”的原则,通过复杂网络模型,构建药店与小区之间可能的服务关系;然后基于共享单车订单数据提取购药人流量随距离的衰减规律,在此基础上建立小区购药人流在为其提供服务的各药店间的分配机制,进而确定药店侧的顾客到达速率,实现小区和药店的空间分布特征与排队论模型的耦合;接着采用离散事件仿真方法对不同购药周期下的系统状态进行仿真;最后基于仿真结果,以最大程度地兼顾患者的购药需求和药店的使用率为优化目标,通过二分法查找购药周期的最优解。实验以武汉市中心城区为例,首先通过条件概率估算各类慢性病患者的数量,再通过上述方法求解得到最优购药周期为28 d。该周期下,患者的人均等待时长为8.55 min,接近最佳的排队容忍时长,绝大多数的购药需求能够被满足,且药店资源能够得到充分利用（达到繁忙状态的药店比例达到87%以上）,药店的日均备货量不超过100（瓶或盒）,处于药店备货能力范围之内。本文的方法和结论,可用于指导慢性病患者的购药决策及药店的慢性病备药。  相似文献   

Probiotics as Control Agents in Aquaculture   总被引：3，自引：0，他引：3  

Gómez R. Geovanny D  Balcázar José Luis  MA Shen 《中国海洋大学学报(英文版)》2007,6(1):76-79

1 Introduction Intensive aquaculture system produces substantially higher yields than do semi-intensive systems. However, intensification results in stressful environmental changes which can produce various kinds of problems in aquatic organisms, principally diseases of diverse aetiology (Angulo, 2000). The most common control of the dis-eases was concentrated on the use of antibiotics. However,the utility of antibiotics as a preventive measure has been questioned by acquisition of genes that…  相似文献   

Researching the geography of health and health care: Connecting with the Third World     

David R. Phillips  Mark W. Rosenberg 《GeoJournal》2000,50(4):369-378

In the context of doing research on the geography of health and health care, ‘connecting’ takes on multiple meanings. First, there are the connections between research topics although the political and socio-economic realities of the various geographical contexts can lead to foci on different aspects and social and geographic processes. There are then the connections between researchers from developed and developing countries who share an interest in the geography of health and health care, who perhaps transfer or refine research methods to look at the different contexts and even different topics. Finally, in this context, there are the connections between researchers and the IGU Commission on Health, Environment and Development (HED) promoted by the HED for the past eight years through its activities. This paper uses examples from the literature and the activities of HED to illustrate these various connections. It argues that if the geography of health and health care is to continue to develop, these three sets of connections must continue to grow and strengthen. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Effects of weather types on hospital admissions for respiratory diseases in Castilla-La Mancha,Spain     

F. De Pablo Dávila  L. Rivas Soriano  J.M. Sánchez Llorente  A. Nájera López 《Atmósfera》2013,26(1):95-107

The aim of this study is to evaluate the relationship between the risk of hospital admission for respiratory diseases (RD) and the daily weather types during the period 2000-2006. A synoptic climatological approach is used to investigate links between air-mass types (weather situations) and all respiratory hospital admissions in the Castilla-La Mancha (CLM) area in Spain. This afforded the main circulation weather types (CWTs) for the winter and spring periods (since respiratory hospital admissions reached their maximum during these seasons) and the frequency distributions of these types were analyzed. A summary of the main characteristics of the hospital admission series and their distribution over the seven years studied, together with the frequency distributions of the admissions classified by sex and ages, for season, month and for each day of the week, is reported. In addition, a comparison between air-mass classification and hospital admissions is made using an admission index (AI). The results reveal different responses of respiratory admission rates to the eight air-mass types identified in winter and in spring. In winter, three air massess southwesterly (SW), anti-cyclonic (A) and hybrid anti-cyclonic southwesterly (HASW), are associated with values 1.5 times higher than the respective average admission rates, while in spring no significant differences are seen.  相似文献   

Protective effects of oyster extract against hepatic tissue injury in alcoholic liver diseases     

ZHANG Cuiping  LI Xiaoyu  JING Xue  ZHANG Bo  ZHANG Qi  NIU Qinghui  WANG Jianjun  and TIAN Zibin 《中国海洋大学学报(英文版)》2014,13(2):262-270

Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and immune defense functions. The role of oyster extract in treating liver injury has been paid more attention. We use Wistar rats to make alcoholic liver disease model through injecting alcohol into rats' stomachs. These rats were randomly divided into five groups: model group, control group, low-dose, middle-dose and high-dose experimental group with a dose of 0.12 g kg-1, 0.40 g kg-1, and 1.20 g kg-1 alcoholic. After nine weeks, serum biomarkers(ALT, AST, TG and TCHO), malondialdehyde(MDA), glutathione(GSH), C3a, C5a, IL-17, TNF-ɑ, anti-MAA-HAS IgG, CD3+, CD4+, CD8+, NK cell activation and zinc content were assessed. The results showed that the serum biomarkers(ALT, AST, TG and TCHO), MDA content, anti-MAA-HSA IgG, serum C3a, C5a IL-17 and TNF-ɑ levels of oyster extract treatment groups were significantly decreased in comparison with model group. On the contrary, GSH showed adverse trend. Serum CD3+, CD4+ and NK cell activation were significantly increased in middle-dose group and high-dose group compared with model group, and there was decrease of CD8+ activity in high-dose group. Plasma Zn level was decreased in model group compared with that in control group. Meanwhile, Mean plasma Zn levels increased dramatically following the dose increase of a given oyster extract.  相似文献   

CT导引T胸部病变穿刺活检体会     

王杰  罗晓燕  黄淑琴  马志龙  李淑华 《CT理论与应用研究》2001,10(3):18-21

目的：研究CT导向胸部病灶穿刺活检的方法及应用价值，材料与方法：83例中，脑内病变70例，纵膈病变10例，胸壁及胸膜病变3例，穿刺针为肺活检针，共穿93针，结果：穿刺成功率为100％，取材病理检验效果，理想占80．7％，可行占13．3％，总可靠率为94．－％，不可靠6．0％，结论：精确的定位，熟练的技术及病人的良好配合可提高穿刺成功率和取材的可靠性。  相似文献   

A Geography of Children's Vulnerability: Gender,Household Resources,and Water‐Related Disease Hazard in Northern Pakistan*     

Sarah J. Halvorson 《The Professional geographer》2003,55(2):120-133

Water‐related diseases continue to pose major threats to children's survival and well‐being in many places in the developing world. This article develops a theoretical perspective on the ways in which children's vulnerability to water‐related disease hazard is produced within the everyday circumstances of livelihood and child care. Central to this analysis is the role that household resources play in mediating or shaping particular microenvironments of health risk. Further, the effects of local geographies of gender on how household resources are accessed and on how child care is structured are examined. Children's vulnerability is evaluated in a community in the District of Gilgit in northern Pakistan, a region presently undergoing tremendous social and economic transformation. The case study highlights household‐level response and adaptation to child health risks associated with diarrheal disease transmission and infection in this mountain environment. The case study draws from ethnographic fieldwork involving qualitative household microstudies and interviewing to elicit mothers' resource and risk‐response strategies in the context of changes in livelihood systems and household dynamics.  相似文献   

作物病虫害遥感监测与预测研究进展   总被引：1，自引：0，他引：1  

黄文江  张竞成  师越  董莹莹  刘林毅 《南京气象学院学报》2018,10(1):30-43

作物病虫害作为严重的生物灾害已危及到世界农业生产和粮食安全,病虫害对我国粮食生产造成的损失日益加剧,植保部门目前使用的测报和防控方式无法满足大范围的精准、高效、绿色科学防控需求.因此,建立基于遥感手段的高效、无损的大面积病虫害监测预测方法,将提升我国大面积作物病虫害的监测和测报精度与防控水平,有利于减少农药施用,对保障国家粮食和食品安全,实现农业可持续发展具有重要战略意义.近年来出现的多种形式的作物病虫害遥感监测方法和技术手段为病虫害的有效防治和管理提供了重要支撑,通过对相关技术方法进行综述,本文从多尺度下的作物病虫害遥感监测与预测机理、监测方法、预测预报方法、典型模型与应用等方面阐述了作物病虫害遥感监测和预测预报研究进展,并探讨了作物病虫害遥感监测当前面临的挑战以及未来发展趋势,建议通过建立全国尺度的作物病虫害遥感监测预测系统,构建作物病虫害绿色智能防控体系,实现病虫害大面积、快速的监测、预测预报和精准、高效、绿色科学防控.  相似文献   

东山九孔鲍细菌性疾病研究   总被引：28，自引：0，他引：28  

张朝霞  王军  张蕉南  苏永全  黄英  鄢庆枇 《台湾海峡》2001,20(2):193-199,T001

本文分离纯化了1999年春东山县患病九孔鲍的2株主要病原菌，进行了回归感染、药敏试验、病变组织的超薄切片观察。结果表明此次暴发性流行鲍病的致病菌主要是溶藻弧菌和副溶血弧菌。在所进行的48种药物的药敏试验中，2株菌仅对氯霉素和复方新诺明等8种药物共同敏感，药物联合抗菌试验还表明复方新诺明与磺胺甲基异恶唑等有协同作用，氯霉素与复方新诺明等有加成作用。  相似文献