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51.
Mahar Ali Nawaz Munir Muhammad Elawad Sami Gowen Simon Richard Hague Nigel Graham Meckenzi 《浙江大学学报(A卷英文版)》2004,5(10):1183-1190
Cells and cell-free solutions of the culture filtrate of the bacterial symbiont, Xenorhabdus nematophila taken from the entomopathogenic nematode Steinernema carpocapsae in aqueous broth suspensions were lethal to larvae of the diamondback moth Plutella xylostella. Their application on leaves of Chinese cabbage indicated that the cells can penetrate into the insects in the absence of
the nematode vector. Cell-free solutions containing metabolites were also proved as effective as bacterial cells suspension.
The application of aqueous suspensions of cells of X. nematophila or solutions containing its toxic metabolites to the leaves represents a possible new strategy for controlling insect pests
on foliage. 相似文献
52.
目的:探讨射击运动员目标取向、竞赛状态焦虑的特点及二者之间的关系.方法:采用射击运动员目标取向测验和竞赛状态焦虑问卷对国家射击队、辽宁射击队、北京市射击队36名射击运动员进行调查.结果:(1)射击运动员的任务取向显著高于自我取向.国际健将级运动员任务取向显著高于国家健将和国家一级运动员,而自我取向显著低于后两者;(2)射击运动员的状态自信心得分较高.国家一级运动员的认知状态焦虑显著高于国际健将级和国家健将级运动员;国际健将级运动员的躯体状态焦虑显著低于国家一级运动员;国际健将级运动员的状态自信心显著高于国家健将级和国家一级运动员;(3)自我取向高分组的运动员认知状态焦虑更高,状态自信心更低;任务取向高分组的运动员认知和躯体状态焦虑更低,状态自信心更高.(4)自我取向显著正向预测认知状态焦虑,解释率为31.3%;任务取向显著负向预测躯体状态焦虑,解释率为17%;自我取向显著负向预测状态自信心,解释率为27.3%,任务取向显著正向预测状态自信心,解释率为35.5%.结论:运动级别越高的运动员越倾向于任务取向,认知和躯体状态焦虑越低,状态自信心越高. 相似文献
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This study examines the extent of concentration in the journal publishing industry. A number of aspects are considered: publishers, journal impacts, countries, and languages. For journals indexed in JCR from 1997 to 2009, just 0.2% of publishers produce 50% of journals and articles, and 0.3% of publishers account for the top 50% of citations, impact factors and immediacy indices. More than a half of publishers in JCR are from four countries: USA, UK, Germany and Japan. In addition, more than a half of journals come from the USA and UK. Examining the publishers' interactions in terms of buying and selling journals shows the extent of change by acquisition, and the acquisition links between publishers. The findings confirm that the international market of journal publishing is essentially dominated by a few publishers. 相似文献
55.
Ali Reza Zohoori 《广播与电子媒介杂志》2013,57(1):105-113
This study compared uses of U.S. television by foreign children residing in the U.S. and their American counterparts in light of theories of acculturation, cultivation, and uses and gratifications. Compared with U.S. children, foreign children: used television more for learning purposes, were relatively more interested in television programs, spent more time watching television, identified more frequently with television characters, and expressed stronger beliefs in the social reality portrayed by television. 相似文献
56.
Internationalization of scientific publishing over time: Analysing publishers and fields differences 下载免费PDF全文
The changes in journal internationality in mainstream science were examined using 1,398 journals and 2,557,229 papers during 1991–2014. The authors’ country of affiliation in journals’ papers and references of multinational and national publishers were analysed. The results showed that journals’ papers and references have become more globalized over time. On average, older journals are more international than the newer ones. Although multinational publishers publish more international journals than the national ones do, journals from national publishers have internationalized faster than those from multinationals. The difference between these two groups of publishers is much greater in authoring compared to referencing. For both groups of publishers, the most changes in journal internationality occurred between the fourth and sixth year of indexing in Web of Science. Journals and papers in Humanities journals have the highest rate of increase of internationality although Natural Sciences and Engineering and Technology have the most international papers. Agricultural Sciences has the least international papers; however, these papers cite a wider range of countries’ papers compared to other fields. Journals in Medical and Health Sciences, Natural Sciences, and Agricultural Sciences have the most international references. 相似文献
57.
Carbon encapsulated iron nanoparticles(CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature(AIT) of 800 ℃. The results of high resolution transmission electron microscope(HRTEM), energy dispersive X-ray(EDX) spectroscope, X-ray diffraction(XRD), and X-ray photoelectron spectroscope(XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5—5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization(Ms) and coercivity(Hc) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly. 相似文献
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