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1.
Early this year, the U.S. land-based force of nuclear missiles became vulnerable to a preemptive attack by the Soviet Union, as the Soviets deployed a large number of highly accurate warheads on their own missiles. They first demonstrated this capability in 1977. Since then, U.S. missile vulnerability has come to assume great importance in superpower relations. Western observers have portrayed the Soviet achievement as a sign of aggression, and made missile vulnerability into a symbol of declining American military strength. The government has proposed a vast military buildup of nuclear weapons, supposedly made necessary by this new threat. But the public is increasingly skeptical, and support for some form of arms control is growing. The first article in this series examines how the United States learned of the Soviet accuracy, and why it caused such great alarm. The next article will examine the Reagan Administration's response to this threat.  相似文献   

2.
Early this year, the U.S. land-based force of nuclear missiles became vulnerable to destruction in a preemptive attack by the Soviet Union. The Air Force has worried about this situation for a long time, searching high and low for a better place to put both the existing silo-based missiles and a new missile, the MX. The first article in this series examined the reasons that U.S. officials became alarmed about missile vulberability, and the second examined the short-term plan to put missiles into silos. This article explores the Ait Force's least favourite long-term basing mode. Subsequent articles will explore the alternatives.  相似文献   

3.
Since World War II the American medical school has become a highly complex institution and, like other American institutions today, the medical school is being challenged to respond to diverse and often conflicting demands. In part the pressure comes from activists who insist that the medical school more fully meet the needs of the community by reforming both training and the delivery of medical care. But another sort of pressure is exerted as a result of changes in internal relationships that have occurred in the last two decades in large measure because of the federal support of biomedical research. As in most institutional conflicts the dispute is expressed in contests over power and money, but, at a more fundamental level, what is involved is the value and reward system of academic medicine and the question of how the medical school is to be governed. This is the first of three articles which will attempt to discuss these issues in the context of the development of one medical school-Stanford's. The first article will describe the pattern and policies of expansion since World War II, and the other two will examine the effects of internal and external pressures for change.  相似文献   

4.
Our foregoing analysis of the role of a comprehensive test ban leads us to the following conclusions. 1) A CTB by itself will have little direct effect on the arms race between the superpowers. It would not hinder their nuclear arms production and deployment nor would it necessarily present a significant obstacle to the development of new nuclear weapons systems, despite limiting the development of new nuclear warhead designs. It can hardly make a dent in the destructive capability of the superpowers or in their ability to step up the pace of the arms race. 2) The chief merits of a CTB reside in the political sphere. It would help promote detente and could help to escalate interest in arms control agreements of broader scope. But in neither of these effects would it be as significant as a successful SALT (strategic arms limitation talks) agreement. The CTB also lingers as a piece of unfinished business since the signing of the LTB in 1963. The question can be and has been raised, "If the superpowers are serious about arms control, why have they not accepted the CTB, which is simple in concept and in form and is also free of serious military risks?" Such doubts about the sincerity of the superpowers' willingness to limit their own arms development will persist as long as there is no CTB. Substantial agreement at SALT would lessen some of this effect too, but would not eliminate it completely. 3) Recent progress in seismic identification has been impressive, and other means of obtaining technical intelligence about nuclear testing have probably also improved greatly. In addition, research on the technical means of on-site inspection has demonstrated its limited effectiveness. Therefore, the role of on-site inspections as an added deterrent to cheating on a CTB has diminished substantially. This is not to say that detection and identification of all nuclear tests is possible now, or ever, but only that on-site inspection would add very little to the other technical means now available for verification. 4) It will become increasingly difficult in the United States to oppose the CTB on the basis of risks that accompany possible Soviet evasion of a treaty that does not include the right of onsite inspection. The opposition to a CTB is now likely to shift to the more direct argument that nuclear testing is important to keep pace with continuing worldwide technical and military developments. The justification for U.S. testing is only in part because of advances in Soviet nuclear technology per se. Those opposing a CTB may argue that it makes little sense, and may even be courting danger, to freeze nuclear technology alone and that banning nuclear tests should await an agreement that copes with all military research and development and all qualitative improvements in weapons systems. This directly confronts the argument that the unique virtue of a CTB is that it provides a simple and feasible first step in the very complicated problems of controlling military technology. 5) The mutual deterrence of the superpowers will not be compromised if a CTB agreement is reached and one side or the other clandestinely violates such an agreement. The state of nuclear technology in both countries is mature, and the destructive capability of their nuclear arsenals can be easily maintained. Whatever small improvements can come as a consequence of clandestine testing would hardly affect the strategic balance. 6) It seems unlikely that China and France will agree to stop testing in the near future. These countries refused to join the nonproliferation treaty, which did not affect their nuclear programs, and it is doubtful that, proceeding from military considerations alone, they would join a CTB. Their nuclear programs are still not mature, and a CTB would freeze their positions of inferiority with respect to the superpowers. There may, however, be wider political and security arrangements to induce them to participate. Cessation of tests by the other nuclear powers might serve as an inducement to China and France to refrain from testing. 7) The key near-nuclear powers, such as Japan, India, and Israel, are much more concerned with the military activities of their neighbors than they are with those of the superpowers. The modest nuclear restraints that a CTB imposes on the superpowers are hardly likely to have a direct impact on the approach of these countries to their own security. However, for these critical near-nuclear countries a CTB may be much more acceptable than the nonproliferation treaty. A CTB would not prohibit the production of fissionable material, the development of nuclear weapons technology short of testing, nor the stockpiling of untested nuclear weapons, and is therefore less restrictive. Consequently, these powers may be willing to ratify a CTB, but not the nonproliferation treaty. On the other hand, the CTB may provide them with a ready excuse for not succumbing to the pressure to ratify the nonproliferation treaty, if indeed they need excuses or would bow to such pressure. 8) A CTB is of very little added, direct significance to other nonnuclear powers who have already ratified or are about to ratify the nonproliferation treaty. It may only lessen their pique about the treaty's being highly discriminatory-the treaty imposes no restraints on the nuclear weapons programs of the nuclear powers, while the CTB restricts all parties to the agreement. 9) Peaceful nuclear explosions do not now show great promise and significance for economic development. What can be done with peaceful explosions can often be done by other means, although possibly at a slightly higher cost. On the other hand, making allowance for peaceful explosions greatly complicates a CTB. A useful approach to the problem of banning military tests but not foregoing indefinitely the use of peaceful explosions might, therefore, be to ban all nuclear explosions for a period of several years and to stipulate in the agreement that in that time there would be negotiations on how peaceful explosions may be controlled in a way that would not jeopardize the CTB.  相似文献   

5.
Nuclear weapons that are safe and secure, reliable, survivable, and effective will be a critical element of this nation's deterrent for the foreseeable future. The existence of these weapons reflects the tension that exists between the United States and the Soviet Union. Nuclear test bans will not reduce or eliminate nuclear weapons or this tension. Imprudent nuclear test bans, however, could impair the viability of this vital element of U.S. security. New, more restrictive test limitations would not enhance our national security. They do not address the two most important issues-namely, major reductions in strategic and conventional forces of both the Soviet Union and the United States, and a widespread lessening of tension between our two countries. In fact, it is conceivable that the diversion of political attention from arms reduction efforts and the distrust generated by test-ban verification problems could actually increase tensions between the two countries. We believe that more restrictive test limitations or a nuclear test ban should be considered only as part of an integrated and comprehensive approach to arms control. We must reduce the numbers of the most destabilizing weapons and the overall size of the strategic arsenals through negotiations. A restrictive test ban may be a proper last step in our quest for nuclear arms control and a stable peace, but it would, in our opinion, be an imprudent first step. Further test limitations will be consistent with increased stability and decreased tension between the United States and the Soviet Union only if they are instituted after major stabilizing reductions are made in the strategic nuclear and conventional forces of both countries.  相似文献   

6.
基于文献计量的农业面源污染研究发展态势分析   总被引:25,自引:0,他引:25  
【目的】客观地分析国内外农业面源污染研究现状,明确当前的研究前沿与热点问题,为农业环境领域科研工作者与决策者提供参考。【方法】利用文献计量学方法,基于ISI Web of Science和CNKI数据库,根据发文量、发文期刊、被引频次等指标,分析近30年来农业面源污染研究的发展态势、前沿领域、研究机构以及国际合作状况等。【结果】共检索得到农业面源污染相关英文文献280篇,中文文献1 517篇。7个研究方向中,农业面源污染治理、现状调查与分析、以及对环境的影响最受关注,三峡库区、太湖流域、密云水库等典型流域污染控制是研究热点。沟渠氮、磷去除对面源污染治理有很重要的意义,目前仍缺乏深入研究,将是今后的一个重要突破口。过程模型模拟是主要的研究方法,野外观测与试验是对模型进行验证的重要手段。国际上研究农业面源污染影响力比较强的单位主要有美国的威斯康星大学、加州大学、爱荷华大学,英国的兰喀斯特大学等,国内实力较强的有中国科学院、北京师范大学、以及厦门大学。中国与美、英等国之间的合作比较多,有助于该领域研究紧跟国际前沿、瞄准热点问题、与世界高水平机构共同探讨解决问题的办法。美欧等发达国家和地区高影响力论文与期刊较多,中国在研究层次、团队实力、论文质量、主办期刊质量等方面有待于进一步提高,原创性成果与重要发现偏少,具有国际影响力的团队少,核心作者不突出。主要原因包括项目周期短,大规模系统性监测数据较少;国产模型普及率不高,各研究单位之间合作不够深入,模型与数据共享机制不完善;缺少中远期团队建设规划,研究群体不稳定等。为解决以上问题,需要从多方面努力。首先,制定农业面源污染观测长期规划,形成系统性成果;其次,鼓励原创性研究,紧跟当前研究前沿与热点,探讨未知的科学问题;第三,整合各行业资金来源,稳定资助力度,凝聚高效研究群体,广泛开展合作交流与数据共享;最后,优化对单位以及个人的评价指标体系,促进国内期刊快速成长。【结论】流域尺度面源污染治理与过程模型模拟是当前农业面源污染研究的前沿领域,农业面源污染物在沟渠与河流网络中的迁移转化机理将成为未来的研究重点,中国虽然发文量增长迅速,但高影响力论文偏少,优秀国际期刊不足。中国主办的期刊中,表现较好的有《Journal of Environmental Sciences-China》和《中国农业科学》。  相似文献   

7.
以“草莓”为主题词,检索CNKI数据库中1990—2020年草莓的文献信息,利用文献计量学方法对年度发文量、研究作者及机构、关键词进行统计分析并作出评价。同时概述草莓研究的现状、趋势和热点。结果表明,草莓研究的发文量增长迅速,以品质与产量为前提,栽培技术、新品种、施肥制度、病虫害防治、连作障碍为草莓研究领域内的热点,未来研究热点可能侧重于栽培技术、病虫害防治、新品种选育、基因表达分析。由于对草莓连作的致病机制尚不清晰,今后仍需深入研究连作对土壤生态的影响。  相似文献   

8.
Early this year, the U.S. land-based force of nuclear missiles became vulnerable-on paper-to destruction in a preemptive attack by the Soviet Union. The Air Force has worried about this problem for a long time, searching high and low for a better place to put both the existing, silo-based Minuteman missiles and a new missile, the MX. Under the Carter Admnistration, the Air Force agreed to a missle basing plan known as MPS, for multiple protective shelters. The Reagan Administration has ostensibly dropped this plan in favour of several alternatives. Previous articles in this series explored why U.S. officials became alarmed about missile vulnerability; the genesis of a short-term plan to put more missiles into silos; continuing Air Force opposition to a plan for missiles on constantly roving aricraft; and a bizare plan to bury missiles deep underground.  相似文献   

9.
The animal rights movement is a serious challenge to current agricultural practices. Agriculture's response, in part, depends on how successfully it can mobilize its natural constituency, farmers. However, theories of the mainstream press suggest that the mainstream press generally covers events, rarely reports or adopts the perspective of alternative movements, rarely includes mobilizing information, and suggests that routine social structures can, should, and will contain the movement. Hence, current theory indicates that the mainstream press does not act to mobilize the general public. However, very little research has examined how specialized presses, such as the farm press, respond to movements. The study reported here was based on an analysis of 406 articles from ten farm magazines. The findings suggest that the farm press acted more as an advocacy press than does the mainstream press. Collectively, the farm press articles included as many positions pieces and stories explaining animal rights as an issue as they did event stories. The articles reported, and countered, the positions of the animal rights movement; suggested that routine social structures might not contain the animal rights movement; called for agriculture to mobilize; and included specific recommendations concerning how agriculture should mobilize.Ann Reisner is an assistant professor of agricultural communications and a fellow at the Program for the Study of Cultural Values and Ethics at the University of Illinois at Urbana-Champaign. Her primary interest area is agriculture, communications, and values and she has written numerous research articles in this area. She is also co-editor of this special issue on communications.  相似文献   

10.
海洋酸化和升温对中间球海胆幼虫发育和生长的影响   总被引:1,自引:0,他引:1  
为了研究海洋酸化和气候变暖对海洋生物的联合作用,按照文献[4]和[7]中对海洋环境变化的预测趋势,设置了3组海水,即对照组(pH为7.93~7.99,水温T为18℃)、试验组E3(在对照组基础上pH减小0.3,T升高3℃)、试验组E6(在对照组基础上pH减小0.6,T升高6℃),在此条件下对中间球海胆Strongylocentrotus intermedius幼虫的发育及生长情况进行了研究。结果表明:酸化及升温海水对海胆孵化率没有显著影响;E3组海胆与对照组发育进程一致,而E6组则较慢;E3和E6组海胆分别存活了18 d和12 d,分别发育至八腕幼虫和四腕幼虫阶段,可见试验海水环境严重影响海胆幼虫的存活;E3组海胆幼虫的生长在受精后的前10 d与对照组差异不显著(P>0.05),之后显著低于对照组(P<0.05),而E6组海胆幼虫的生长在整个试验阶段均显著低于对照组(P<0.05);将骨针长度分解为口后腕骨针长度和躯干部骨针长度,各组海胆的生长差异主要表现在口后腕骨针长度上;试验组长腕幼虫畸形均不同程度地表现为腕短小、萎缩、腕骨针折断、骨针弯曲变形等。研究表明,中间球海胆对海洋酸化和气候变暖的海洋环境非常敏感,如果按照预测趋势,海洋环境变化将会对该海胆产生严重的负面影响。  相似文献   

11.
The animal rights movement is a serious challenge to current agricultural practices. Agriculture's response, in part, depends on how successfully it can mobilize its natural constituency, farmers. However, theories of the mainstream press suggest that the mainstream press generally covers events, rarely reports or adopts the perspective of alternative movements, rarely includes mobilizing information, and suggests that routine social structures can, should, and will contain the movement. Hence, current theory indicates that the mainstream press does not act to mobilize the general public. However, very little research has examined how specialized presses, such as the farm press, respond to movements. The study reported here was based on an analysis of 406 articles from ten farm magazines. The findings suggest that the farm press acted more as an advocacy press than does the mainstream press. Collectively, the farm press articles included as many positions pieces and stories explaining animal rights as an issue as they did event stories. The articles reported, and countered, the positions of the animal rights movement; suggested that routine social structures might not contain the animal rights movement; called for agriculture to mobilize; and included specific recommendations concerning how agriculture should mobilize.  相似文献   

12.
A long-running dispute over who should get credit for first reporting landmarks on Mercury's uncharted hemisphere burst into public view on 26 May, when a Boston University press release claimed honors for a BU team without mentioning the contributions of an erstwhile collaborator, amateur astronomer Ron Dantowitz. The row, which has left both sides bitter and unwilling to work with each other, "was the opposite of how a collaboration between amateurs and professionals should be," says one of the scientists involved.  相似文献   

13.
Koch HW 《Science (New York, N.Y.)》1971,174(4012):918-922
A new concept in science communication will be given its first test in calendar year 1972. Primary and secondary contents of a selected subset of the world's journal literature in physics will be provided in a variety of output formats. Among them are a monthly microfilm containing the full texts of all articles in the set of journals (Current Physics Microform); an advance abstracts journal describing the articles (Current Physics Advance Abstracts); a printed, classified index of the titles of the articles (Current Physics Titles); and a computer tape index to the articles (Searchable Physics Information Notices).  相似文献   

14.
果蝇(Drosophila melanogaster)唾腺染色体的制备与分析是果蝇细胞遗传研究的基本实验技术,也是非常流行的遗传学教学实验。国内绝大多数的实验教材介绍了这个实验的操作方法,但对于如何辨别染色体各条臂,并进而识别具体的带纹均未予以介绍。笔者详细介绍唾腺染色体的制备及拍摄、数码照片拼接方法;并着重介绍如何根据各条臂端粒端的形态特征,以及利用Lefevre的唾腺染色体照片图谱中指示的蓬突(puff)、缢缩及带纹组合特征识别染色体臂的方法,供研究和实验教学参考。  相似文献   

15.
It is widely believed that an arms control limit on nuclear-armed sea-launched cruise missiles would be nearly impossible to verify. Among the reasons usually given are: these weapons are small, built in nondistinctive industrial facilities, deployed on a variety of ships and submarines, and difficult to distinguish from their conventionally armed counterparts. In this article, it is argued that the covert production and deployment of nuclear-armed sealaunched cruise missiles would not be so straightforward. A specific arms control proposal is described, namely a total ban on nuclear-armed sea-launched cruise missiles. This proposal is used to illustrate how an effective verification scheme might be constructed.  相似文献   

16.
[目的/意义]鉴别开放科学范式下科研人员需要具备的能力和技能,构建开放科学能力框架并对培养路径进行研究,以期为提高开放科学生态系统中领导者和决策者、科研人员和科研支持人员的开放科学能力,为推进中国开放科学进程、建设开放科学创新生态提供借鉴。[方法/过程]通过分析归纳国内外已有相关研究成果,基于胜任力模型构建开放科学能力框架,并对培养路径进行探讨。[结果/结论]开放科学能力框架包括拥抱开放科学价值观和理念、基于开放科学要素组成的开放科学知识习得和嵌入科研生命周期和数据生命周期的开放科学技能建设3个维度。开放科学能力培养路径包括制定能力建设相关的政策法规和战略规划,加强开放科学宣传和培训,以及提供贯穿科研全流程的全面支持。同时,图书馆是开放科学能力建设的关键行动者,应主导设计科学合理的开放科学培训体系,在推进开放科学范式变革中发挥积极作用。  相似文献   

17.
梨叶锈螨Epitrimeruspyri(Nalepa)是新发现的梨树严重害螨.以成螨、若螨寄生于梨叶背主脉两侧吸汁为害.产卵繁殖,卵单产、裸露,多产于叶背主脉两侧.每年9月中旬以成螨在土壤或主干树皮裂缝中越冬,翌年4月上、中旬出蛰,全年为害期约150d,越冬期约210d.一年中可出现两次螨口高峰:5月上、中旬为第一高峰期,8月中、下旬为次高峰期,影响该螨发生的重要环境因素是温度、降雨、食料、梨树品种和天敌,可用涂粘虫胶环、药剂、保护利用天敌等措施综合治理.50%三环锡、73%克螨特2000倍液均有极好的防治效果.  相似文献   

18.
Drawing from a four-year study of US science institutions that support biological control of arthropods, this article examines the decline in biological control institutional capacity in California within the context of both declining public interest science and declining agricultural research activism. After explaining how debates over the public interest character of biological control science have shaped institutions in California, we use scientometric methods to assess the present status and trends in biological control programs within both the University of California Land Grant System and the California Department of Food and Agriculture. We present available data on the number of scientific positions and the types of positions to discuss the impact on the amount of public interest research on biological control in California. We use sociograms to depict how biological control science networks have been reconfigured over time. Our quantitative and qualitative analyses indicate that the following factors contributed to the decline of biological control science in California over the 45-year period analyzed: (1) the institutional reconfiguration of university research priorities; (2) the fraying networks within and increasing specialization of biological control science; (3) the transformation of the social organization of the life science work, including privatization; and (4) the abandonment of this thematic area by civil society activist groups. This broad array of forces suggests that biological control, as a public interest science, will require a deliberate intervention, based on advocacy of clear public interest criteria.  相似文献   

19.
关于中国农业可持续发展的探讨   总被引:6,自引:0,他引:6  
重点阐述了中国可持续发展过程中的几个问题并提出:要正确认识和把握农业可持续发展的涵义和目标。耕地是农业可持续发展的基础,加强耕地保护是当务之急;保护和改善农业生态环境,是农业可持续发展的重要保证,刻不容缓;驾驶农业科技的研究和推广,不断提高农业可持续发展的能力;加强国家的宏观管理,运用法制,经济和市场机制等手段,保障和促进农业可持续发展。  相似文献   

20.
基于消费者对产品平均质量安全水平的预期不同,在企业可以同时选择生产高、低质量安全水平产品的条件下,分别建立了完全垄断与完全竞争市场中的企业利润最大化模型,比较分析了企业供给产品的数量、利润及相应的消费者效用,得出消费者质量安全水平敏感度、产品需求价格敏感度及产品的高、低质量安全水平对上述决策的影响.据此,结合我国国情,为中国产品质量安全水平的提升提供了参考与启示.  相似文献   

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