Space-based radar

The concept of national air defense against aircraft and cruise missiles has been evolving in parallel with the Strategic Defense Initiative and is being referred to as the Air Defense Initiative. One of the most promising sensor concepts for the Air Defense Initiative is space-based radar. Operated at microwave frequencies as an instrument for wide-area surveillance, space-based radar may be useful in mission areas such as fleet defense and battlefield surveillance.     

Cost of space-based laser ballistic missile defense

Orbiting platforms carrying infrared lasers have been proposed as weapons forming the first tier of a ballistic missile defense system under the President's Strategic Defense Initiative. As each laser platform can destroy a limited number of missiles, one of several methods of countering such a system is to increase the number of offensive missiles. Hence it is important to know whether the cost-exchange ratio, defined as the ratio of the cost to the defense of destroying a missile to the cost to the offense of deploying an additional missile, is greater or less than 1. Although the technology to be used in a ballistic missile defense system is still extremely uncertain, it is useful to examine methods for calculating the cost-exchange ratio. As an example, the cost of an orbiting infrared laser ballistic missile defense system employed against intercontinental ballistic missiles launched simultaneously from a small area is compared to the cost of additional offensive missiles. If one adopts lower limits to the costs for the defense and upper limits to the costs for the offense, the cost-exchange ratio comes out substantially greater than 1. If these estimates are confirmed, such a ballistic missile defense system would be unable to maintain its effectiveness at less cost than it would take to proliferate the ballistic missiles necessary to overcome it and would therefore not satisfy the President's requirements for an effective strategic defense. Although the method is illustrated by applying it to a space-based infrared laser system, it should be straightforward to apply it to other proposed systems.     

An upheaval in u.s. Strategic thought

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.     

Uncertainties in building a strategic defense

Building a strategic defense against nuclear ballistic missiles involves complex and uncertain functional, spatial, and temporal relations. Such a defensive system would evolve and grow over decades. It is too complex, dynamic, and interactive to be fully understood initially by design, analysis, and experiments. Uncertainties exist in the formulation of requirements and in the research and design of a defense architecture that can be implemented incrementally and be fully tested to operate reliably. The analysis and measurement of system survivability, performance, and cost-effectiveness are critical to this process. Similar complexities exist for an adversary's system that would suppress or use countermeasures against a missile defense. Problems and opportunities posed by these relations are described, with emphasis on the unique characteristics and vulnerabilities of space-based systems.     

A comprehensive ban on nuclear testing

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.     

Facing nuclear reality

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.     

糖构型讨论

关于糖的构型,目前仍有许多书面表达方式和不同见解。本文作者认为 1、Hudson的建议与糖构型的书写形式,虽然不能肯定完全一致,但该建议可作为经验规则来处理D、L、α、β及比旋光度之间的关系。这种关系,本文作了归纳。 2、D系糖构型的书面判断,可以只看半缩醛羟基的环上位置就能迅速识别。 3、建议L系糖的链式与环式书写一律使用竖直镜面投影,即可对其构型一目了然,避免混乱。     

基于LQR方法的巡航导弹BTT控制器设计

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.     

Strategic command, control, communications, and intelligence

Command, control, communications, and intelligence (C(3)l) for nuclear forces are essential elements in the deterrence of nuclear war. The present C(3)l) system has vulnerabilities associated with its reliability, survivability, and endurance under attack, thereby weakening deterrence by increasing the ambiguity in our capabilities. Development of a reliable and enduring C(3)l) system would reduce this ambiguity. Its reliable, positive control of nuclear forces would give the national leadership more time to assess situations, ensure discriminate retaliation, and improve our ability to manage crises in general. These capabilities could help to stop a war rapidly should one start. A reliable and enduring C(3)1) system will be needed for a long time to come, even if a freeze on strategic nuclear forces is accomplished or other arms control successes achieved. Indeed, C(3)l) may be the best source today of confidence-building measures to reduce tensions and the threat of nuclear catastrophe.     

国内邮轮旅游消费前景与发展策略研究——基于广西南宁、桂林、北海3地调研数据分析

为了解国内邮轮旅游市场的消费前景,以广西南宁、桂林、北海3地游客为对象,进行了广泛的问卷调研,从而取得了较具参考价值的一手数据。经统计分析得出,未来3年我国邮轮旅游消费市场发展前景甚佳。对此,应采取深挖新型细分市场、打造主题邮轮产品等系列措施来发展国内邮轮旅游消费。     

基于将大西洋蓝鳍金枪鱼列入CITES附录Ⅰ提案的国际渔业管理分析

受国际市场对大西洋蓝鳍金枪鱼产品需求的驱动,非法、不报告、不管制捕捞和捕捞能力过剩等现象频频发生,造成该鱼类资源的数量持续下降。瑞典、摩纳哥先后向濒危野生动植物种国际贸易委员会提议将大西洋蓝鳍金枪鱼列入《濒危野生动植物种国际贸易公约》附录,禁止捕捞和国际贸易该鱼种,引起了广泛关注和激烈争论。为此,通过分析ICCAT对大西洋蓝鳍金枪鱼的管理、相关国家或地区组织的不同意见,研究该提案可能对国际渔业管理及我国带来的影响。一旦该鱼种列入CITES附录,可能导致更多商业开发的水生生物被提到CITES框架上来,从而影响世界渔业的管理格局。对此,中国应采取行动,积极参加国际组织会议,参与规则制定,反映中国关注问题与主张。而作为联合国海洋法公约和ICCAT的一员,我国也有义务与其他国家合作执行ICCAT的养护和管理措施,为提高履约能力,规范国内远洋企业的管理,如按照相关要求及时、准确报送数据等,从而配合国家履行国际义务。     

"需要层次理论"在图书馆年轻职工管理中的应用

在当今大多数图书馆队伍中,年轻职工所占的比例越来越大,发挥着越来越重要的作用。文章首先分析了图书馆中年轻职工的特点及存在的问题,然后根据“需要层次理论”,阐述了如何提高对年轻职工的管理水平,从而最大限度地调动年轻职工的积极性,为图书馆的改革与发展注入新的活力。     

Technology Creep and the Arms Race: ICBM Problem a Sleeper

In three articles, Science will discuss how the creep of technology affects the arms race. The first two articles will deal with the most important current example: first, how ICBM modernization is giving both sides a destabilizing, first-strike capability, and second, how arms control seems to be dealing inadequately with this pressing problem. The third article will describe other cases of incremental technical improvements affecting arms control, such as antisatellite research and ballistic missile defense research, which are bringing both sides closer to the antiballistic missile capability they forswore in a 1972 treaty.     

Safeguardsing our military space systems

The vulnerability military space systems depends on their orbits, functions, and other characteristics. The high-altitude satellites needed for warning and communications in particular could be vulnerable to prompt destruction by certain space-based systems and, in the future, possibly by ground-based high power lasers. A combination of passive countermeasures and arms control agreements could give these satellites some protection against such attack. Deployment of strategic defensive systems with the capability to reach far into space would invalidate this approach.     

邮轮承运人若干法律问题研究

为了使邮轮运输合同中承运人的相关法律规定适应现代邮轮运输的发展需求,在明确从事进出中国港口的国际海上旅客运输合同的法律适用的基础上,主要根据我国《海商法》及有关国际公约,研究了邮轮承运人的含义、责任期间、赔偿责任、免责、赔偿责任限制等问题,最后提出我国邮轮承运人应当为其邮轮投保承运人责任险或者取得相应的财务担保,提供第三方保障,增设邮轮保险项目,明确邮轮旅客直接诉讼的权利,确立中国公民海上旅行的刑事司法管辖制度等几个亟需解决的问题.     

Carter's Plan for MX Lives On

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.     

Science advice in the white house? Continuation of a debate

Thus, we are skeptical of the commonly stated arguments for re-creation of a science office at the White House, but are ultimately convinced that such an office is justified. A three-man CST is a reasonable proposal, although the detailed structure is less critical than the mandate given to the office, and the general understanding within government of its functions and limitations and of its relationship to the President. To give it permanence, the office should be grounded in a science policy management and oversight function that is critically needed today. That kind of strong office could lead a president to use it as his personal science advisory staff, but the decision must be made anew by each president. The President does have other ways of obtaining scientific advice, although the right kind of science office would be a preferable route in our view. The importance of such an office being able to present its analyses and recommendations in policy terms useful to other policy-makers cannot be overestimated. This has important implications for the kind of competence required to staff and work with such a council; it also requires recognition of the fact that policy-relevant studies and advice can never be value-free, even when carried out by scientists and engineers. And finally, such a council could bring intensive and continuous attention to the international dimension of U.S. science policy, which seems to us to be particularly neglected. It is not yet clear whether there will be any structural changes in the new Administration. But it is not too soon to be clearer about the essential factors that should underlie a sensible proposal for this or the next Administration.     

大型码头输油臂安全技术管理

从船岸跨接电缆、紧急脱离系统、内外臂失灵及预防措施四个方面对大型码头输油臂的安全技术管理工作进行了分析,指出应从设计、制造、安装、运行维护等方面对大型码头输油臂进行全面的质量管理和安全管理,提出了有针对性的预防措施。     

杨树天牛灾害控制的应用技术和基础研究策略

该文简要评述了我国杨树天牛灾害的主要成因及现有主要控制措施．指出我国杨树天牛灾害的主要成因是生态性原因,树种选择、配置和栽植利用方式不当是主因．在此基础上,提出杨树天牛灾害的控制需综合考虑寄主树种、天牛、天敌与生存环境之间的关系,并从不同角度阐述了控制杨树天牛灾害的应用技术和基础研究方向和策略．     

磁控摆开式呼吸阀

机械呼吸阀是油罐的重要附件，几址年来我国油库使用的机械呼吸阀基本形式是阀盘在水平面内，靠自重或弹力控制罐内压力，阀盘工作时沿导杆升降。这种呼吸阀的主要问题是：沿导杆运动引起的机械故障多；阀盘自重大，使阀盘工作时开度小，通气量小，严重时造成油罐受损。