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1.
本文利用果洛州气象台1960-2006年气温、降水量、蒸发量、风速、日照时数资料,分析了大武镇年及各季、年代际气候变化特征.结果表明:该地区气温变化趋势与全球及我国的气温变化总趋势是一致的,呈明显增暖趋势,增温速率为0.23℃/10a,冬季增温幅度最大,达0.37℃/10a,秋季增温最小,为0.11℃/10a.年降水量呈减少趋势,气候倾向率为-7.37mm/10a,冬、春季呈增多趋势,而夏、秋季呈减少趋势,且夏季降水减少幅度最大,达6.9mm/10a.年蒸发量呈明显的减少趋势,减少幅度为46.5mm/10a,春、夏减少量最为明显,分别为15.3mm/10a、15.2mm/10a.年平均风速总趋势是增加的,增加幅度为O.05m·s-/10a.年日照时数呈增加趋势,增加率为12.3h/10a.  相似文献   

2.
为了进一步研究茶卡盐湖旅游季的气候适应性特征,笔者利用1981-2016年茶卡气象站5-10月气候资料,采用气候统计诊断分析方法计算气温、降水、日照、风速、相对湿度的年、年代际、月平均值以及气候倾向率,研究其线性趋势及突变特点。结果表明:近36年来茶卡盐湖在年平均气温、最高气温、最低气温显著增温的同时日照时数在显著减少,但气候突变基本发生在90年代中后期;降水量虽有显著的上升趋势但气候突变不明显;相对湿度与平均风速虽有趋势变化,但变化不显著,也无气候突变。  相似文献   

3.
本利用1981-2018年内蒙古自治区卓资县的气温、降水以及日照时数观测资料,首先分析了近38年卓资县的气候变化特征,接着探讨其对农业生产的影响。结果表明:近38年卓资县平均温度整体上呈现上升变化趋势,线性倾向率为0.627℃/10a;四季年平均温度均呈波动性增温变化趋势,增温幅度最大的为春季,其次为冬季,秋季增温幅度略高于夏季。卓资县降水量整体上呈波动增加的变化趋势,线性倾向率为7.284mm/10a,增加趋势并不明显。卓资县降水年际波动起伏变化比较大,极易引发旱涝灾害。日照时数主要呈不断减少的变化趋势,线性倾向率-83.187h/10a,气候的显著变暖,降水量年际间大幅度起伏波动以及日照时数的显著减少均会影响到卓资县水热光资源的平衡性,进而各类农作物的稳定生长发育以及农业气象灾害、作物病虫害造成一定的影响。只有采取科学合理的措施及时应对异常气候变化,才可以促使卓资县农业的健康、持续发展。  相似文献   

4.
利用鄂尔多斯市8个气象台站1961年~2013年逐月平均气温、降水量资料,用趋势分析和累积距平、信噪比等方法,分析了鄂尔多斯市近53a的气温和降水变化特征。结果表明:1年平均气温上升趋势明显,近53a升温2.1℃,且通过0.001显著检验,突变发生在1986年,近13a是最温暖时期。四季与年平均气温变化趋势基本一致,但略有不同。增温幅度冬季最大,夏季最小;突变时间秋季最早,夏季最晚。2年降水量略呈减少趋势,近53a仅减少1.4mm,四季降水量的变化不同步,夏、秋季降水趋于减少,冬、春季略有增加,相关系数均未达到0.10的显著水平。  相似文献   

5.
作物布局与种植结构是长期适应气候变化的结果。在全球气候变暖的背景下,农业气候资源相应发生变化,对区域农业生态系统必然产生一定的影响,因此分析区域农业气候热量资源的变化特征,为充分利用热量资源以及指导区域农业发展提供理论依据。西藏"一江两河"农区是西藏最重要的农作物集中分布区,农业气候资源的变化必然对该区作物和牧草的生长产生影响。本文基于"一江两河"地区主要站点的气象数据,采用平均气温、≥0℃和≥10℃初日、终日、持续日数和积温作为农业气候热量资源的指标,分析"一江两河"地区农业气候热量资源年际变化趋势及其热量资源变化在年内的分配。结果表明:①"一江两河"地区气温显著升高,增温以冬季最为明显;热量资源年际变化表现出显著的增加趋势;②研究区主要代表气象站点表现出≥0℃和≥10℃初日提前,终日推迟,持续日数延长的趋势;③从研究区各站点逐月积温年际变化来看,≥0℃积温在春季增幅明显,尤其以3月积温增加明显;≥10℃积温8-10月增加幅度较其他月份明显;④热量资源的增加正值作物或牧草生长始末期,热量的增加将影响作物或牧草的生长,如拉萨地区适宜冬小麦播种期明显推迟。  相似文献   

6.
毛乌素沙漠气候变化空间分布比较研究   总被引:3,自引:0,他引:3  
随着全球气候的变化,毛乌素沙漠区气候日趋暖干化。该文应用毛乌素沙漠区内部包括内蒙古(乌审旗)、陕西(府谷)、宁夏(盐池)三个地区1971年--1998年均温,春、夏、秋、冬各季月平均气温及1961年--1998年降水量,春、夏、秋、冬各季月平均降水量,研究气候暖干化在毛乌素沙漠区内部的空间差异。分析结果表明:①近30a来整个毛乌素沙漠区气候趋于暖干,但其内部尚存在较明显的差异;②乌审旗、盐池及府谷年均温显著升高,尤其冬季是三个地区增温幅度最大的时期,且远大于全国的冬季增温率。其中府谷升温幅度较小,乌审旗是者中增温幅度最大的地区;③乌审旗、盐池及府谷年降水量减少趋势明显,乌审旗减少幅度最大,秋季是三个地区降水减少幅度最大的季节,春、夏、冬三季减少趋势不明显,这三个地区春季降水有明显的相关性。总的来说,乌审旗、盐池及府谷在气候变化方面有一定的差异,但其暖干化的趋势是一致的,尤其是秋季的暖干化趋势更为相近。  相似文献   

7.
气候变暖背景下中国东部季风区秋季气温的变化特征   总被引:2,自引:1,他引:1  
韩通  陈少勇  高蓉  张燕霞 《资源科学》2009,31(10):1740-1748
利用中国东部季风区375个测站,近46a年平均地面气温资料,采用线性趋势分析、EOF、REOF、Mann-Kendall、子波分析等方法,分析了季风区秋季气温的变暖特征.结果表明:①中国东部季风区秋季气温增温明显,1961年~2006年46年期间增温率为0.22℃/10a,其中11月份增温最大;从1974年开始气温呈增加趋势,1987年有一次显著突变;秋季气候变暖中,平均气温、最高气温、最低气温的增温率存在区域差异,大部分地方以最低气温的升高为主,而中西部最高气温的增温比较突出;②秋季气温的稳定性,黄河南部高于北部;③季风区大多数区域秋季气温变化有明显上升趋势,增温率从南向北增大,气温变化趋势不显著的区域主要在季风区的南部;④根据REOF分析,将该区秋季气温异常细分为北、中、南、东南和中南5个分区;全区性的前10个偏暖年,70%出现在1990年以后:气温异常变化存在准7年和11年的周期;⑤气温的转折北部和南部比中部早5~10年,南部从本世纪初期开始转为降温,值得关注;气温的突变北部和南部比中部早3~5年.  相似文献   

8.
基于内蒙古元上都遗址区1981-2010年(近30年)的气象资料,采用线性回归分析法、Mann—kendall突变检验法对该区域气温、降水量、日照时数、风速和相对湿度的时空变化特征与突变进行了分析。结果表明:元上都遗址区近30年年均气温上升幅度(年代际变率0.65℃/10a)明显高于全国平均水平,年降水量变化趋势不显著,年日照时数、年均风速和年均相对湿度都呈下降趋势;而气温、降水量、日照时数突变显著,风速、相对湿度突变不明显。最低气温的升高在气候变暖中占主要作用,气候总体呈暖干化趋势。  相似文献   

9.
利用线性回归分析和Mann-Kendall检验法,统计分析了河西走廊东部1960年-2009年近50a来的太阳总辐射和日照时数的变化规律。结果表明:河西走廊东部年平均太阳总辐射为5988.7MJ/m2,为太阳能资源丰富区,太阳总辐射存在明显的季节变化,月和日太阳总辐射变化趋势均呈单峰型。河西走廊东部年平均太阳总辐射在波动中上升,其线性倾向率为+12.7MJ(/m2·a);春、夏、秋、冬季的太阳总辐射呈不同程度的上升趋势,线性倾向率为+4.72MJ(/m2·a)、+5.69MJ(/m2·a)、+2.0MJ(/m2·a)、+0.17MJ(/m2·a)。年太阳总辐射、年日照时数的突变增大年与区域内气候开始变暖年同步,气候变暖使区域内中北部川区降水呈增多趋势,说明全球增暖的气候背景下,降水增多对空中的大气污染物有抑制作用,有利于河西走廊东部太阳能总辐射值、日照时数的增大。河西走廊东部年日照时数在空间分布呈现由北向南逐渐减少,季节分布呈现由夏-春-秋-冬季减少。研究区域太阳能资源总量丰富,有利于太阳能资源的开发利用。  相似文献   

10.
王亚  冯异 《西藏科技》2013,(11):59-61
利用1962年~2012年嘉黎逐月日照时数资料,采用气候倾向率、M~K等方法,分析了近50年嘉黎日照时数的变化趋势、异常年份和突变特征。结果表明:近50年嘉黎年日照时数的线性趋势表现为显著的增加,平均每10年增加60.6h。四季日照时数都表现为增加趋势,增幅为8.92~18.62h/10a。但近30年四季日照时数均趋于减少,减幅为2.97~23.17h/10a,牟日照时数减幅达53.65h/10a。20世纪60至70年代季日照均偏少,80年代日照均偏多;90年代夏、秋季日照略偏少,春、冬2季偏多;进入21世纪前10年,秋季日照偏多,其他季节偏少。50年里,季、年日照时数在60年代多异常偏少年,异常偏多年仅出现在1982年。除夏季外,其他3个季节和年日照时数都发生了气候突变,季日照时数突变点均出现在70年代初;年日照指数突变较早,从1967年开始。  相似文献   

11.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

12.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

13.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

14.
Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.  相似文献   

15.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

16.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

17.
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.  相似文献   

18.
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.  相似文献   

19.
Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.  相似文献   

20.
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence  相似文献   

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