首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 565 毫秒
1.
《防务技术》2022,18(11):2034-2044
As an essential component of ammunition, pyrotechnics can control ignition with high reliability. However, due to limits of fabrication technology, traditional pyrotechnics are bulky. To achieve both functionality and miniaturization, MEMS pyrotechnics integrate initiator, safety-and-arming (S&A) device and lead charge and keep all components within a small size. MEMS S&A devices, as the core component to ensure system safety, are difficult to achieve active and rapid response to control signals with high safety and reliability. In order to overcome the difficulty, we propose the design and characterization of a MEMS pyrotechnic with a double-layer barrier S&A device. The MEMS pyrotechnic is a high-integrated device with an overall size of 13.4 × 8.5 × 5.2 mm3. The initiator is a NiCr bridge foil covered with an Al/CuO energetic film, which can generate flame when ignited by an excitation voltage. To match the flame energy, lead styphnate is chosen in this study as the lead charge. The S&A device contains four semi-circular barriers, which are directly driven by V-shape electro-thermal actuators to gain active control of the pyrotechnics' ignition condition with rapid response. To improve the system's reliability, the four barriers are axisymmetrically placed in two layers, two barriers for each layer, to constitute a double-layer structure with a thickness of 100 μm. The ignition test results show that the S&A device can prevent the initiator from detonating the lead charge in safety condition. In arming condition, the lead charge will be detonated.  相似文献   

2.
ABSTRACT

This article gives an overview of the literature on war termination both in the fields of behaviouralism social sciences and policy-oriented strategic studies. It identifies shortcomings and problems related to both lines of research. The main problem is the undifferentiated and indiscriminate use of the term ‘war’. The article proposes a categorisation of wars that could form the basis for more thorough research on the topic of war termination.  相似文献   

3.

This paper explores some of the key issues associated with the restructuring of the defence industry. A comparison is made between the US and the European Defence Industrial Bases in terms of the drivers for change and the paradigms within which change has taken place. Having shown that some very important differences exist, the paper then explores the approaches that have been adopted for industry consolidation and references them to the academic literature on mergers and acquisitions (M&As) and strategic alliances (SAs). Given that most of the key defence players recognise the need to be global players, the paper presents an argument that the European firms’ experience of operating with a wide range of forms of corporate alliance will serve them in good stead for operating on a global defence scale. US firms, in contrast, have focused largely on M&A activity.  相似文献   

4.
ABSTRACT

Since the 1990s, the group of stakeholders working to combat biological weapons (BW) proliferation has broadened to include new actors who have not traditionally focused on security issues, including organizations from the public health sector, researchers in the life sciences, and the biosafety community. This has had significant benefits for the Biological and Toxin Weapons Convention (BWC) and the arms control establishment more broadly. However, the BWC's agenda has become increasingly dominated by issues of international health and global health security. By focusing solely on response strategies, the United States and other interested parties risk losing sight of other important elements of a counter-BW strategy, including deterrence and prevention. Focusing on public health-related issues to the exclusion of more traditional security matters puts the nonproliferation regime at risk, because it limits the amount of time that stakeholders have available to grapple with the critical questions facing the BWC and the biological weapons nonproliferation establishment—questions that must be answered if the regime is to survive.  相似文献   

5.

The US Air Force is asking when to replace its aging aircraft. We develop a framework to identify economically optimal replacement strategies that recognizes cost trade-offs and incorporates age effects. We also preview a stochastic methodology. We use the framework to identify an optimal strategy, defined by the replacement age, for a generic fleet and conduct a sensitivity analysis. Quantitative illustrations show that the range of strategies that provides close-to-optimal outcomes widens as the operating and support (O&S) cost growth rate decreases and the ratio of the acquisition price to the initial O&S cost increases. A wider range implies more decision-making leeway.  相似文献   

6.
The paper presents an analysis of the factors explaining the export performance of firms in the defence sector. We focus on the case of Norway, and make use of two complementary methodologies: the first is based on econometric firm-level data analysis for the whole population of defence companies, and the second is based on qualitative case study research on the three most important defence export products (weapon stations, ammunition and electronics). Our empirical results highlight the importance of four major success factors for exporting firms: (1) the participation in offset agreements; (2) the ability to focus on their set of core competencies; (3) their R&D activities and interactions with the public S&T system; and (4) demand opportunities and, relatedly, user-producer interactions.  相似文献   

7.
ABSTRACT

An arms race in cyberspace is underway. US and Western government efforts to control this process have largely been limited to deterrence and norm development. This article examines an alternative policy option: arms control. To gauge whether arms-control models offer useful lessons for addressing cyber capabilities, this article compiles a new dataset of predominantly twentieth-century arms-control agreements. It also evaluates two case studies of negotiated agreements that regulate dual-use technologies, the 1928 Geneva Protocol prohibiting chemical- and biological-weapon use and the 1944 Chicago Convention on International Civil Aviation. The analysis underscores the limits of norm development for emerging technologies with both civilian and military applications. It finds lessons for developing verifiable, international cooperation mechanisms for cyberwarfare in the regulatory model of international aviation. Conventionally, arms-control agreements take advantage of transparent tests or estimates of arms. To restrict cyberwarfare activities, experts and policy makers must adapt arms-control models to a difficult-to-measure technology at an advanced stage of development and use. Further investigation of international regulatory schemes for dual-use technology of similar diffusion and development to the internet, such as international civil aviation, is needed.  相似文献   

8.
ABSTRACT

There have been calls for the abolition of nuclear weapons from the day they were invented. Over the last fifteen years, some indications can be found that such calls have been getting louder, among them Barack Obama's famous 2009 speech in Prague. In this article, we investigate if support for a comprehensive norm that would prohibit development, possession, and use of nuclear weapons is really growing. To assess the current status of that norm, we use the model of a “norm life cycle,” developed by Martha Finnemore and Kathryn Sikkink. We then analyze 6,545 diplomatic statements from the review process of the Treaty on the Non-Proliferation of Nuclear Weapons as well as from the UN General Assembly First Committee on Disarmament and International Security, covering the years 2000 to 2013. The evidence shows that a comprehensive prohibition can be considered an emerging international norm that finds growing support among states without nuclear weapons and nuclear weapon states alike. Only a core group of states invoke the norm consistently, however. This leads us to conclude that the “tipping point” of the life cycle, at which adherence to a new norm starts to spread rapidly, has yet to be reached.  相似文献   

9.

The impact of defence expenditure on the economy has been widely studied through different types of models. However, the results from these studies have not reached definitive conclusions, and have left a gap in the analysis of the impact of defence R&D expenditure at the economy level. Defence R&D has specific characteristics, which lead to market failures: public good, high risk and uncertainty, national security. Also, defence R&D creates two types of externalities: negative (crowding-out), and positive (spin-off). Crowding-out is the major economic debate about defence R&D. This paper analyses the crowding-out hypothesis by applying three types of models for the UK case: supply, demand, and demand-supply models. From these three models the most reliable is chosen and applied to the individual cases of France, Germany, Japan and USA. The paper also reports the results for the pooled data of these five countries, and for four error component models. The results from estimating such models shed light on the defence R&D crowding-out hypothesis.  相似文献   

10.
ABSTRACT

Despite living in a nuclear-weapon state, young Americans are generally ill-informed about weapons of mass destruction (WMD) and their means of control. The result is both widespread apathy toward nonproliferation and disarmament decision making among the general public and a looming personnel crisis within government sectors that enact policy in these domains. Considering that 67 percent of high school graduates in the United States go on to pursue a bachelor’s degree, exposing more undergraduates to nonproliferation and disarmament issues could contribute to addressing both of these challenges. The present study analyzes how these issues are already being taught at select US colleges and universities and explores ways to introduce them to more students that align with current priorities in higher education, such as interdisciplinary learning, digital humanities, and data-science learning. It also proposes concrete steps that the WMD policy community can take to help institutions of higher education integrate these topics more broadly into their curricula. The anticipated result is greater support for education in this important issue area across different stakeholders in academia, as well as increased engagement with these critical issues among a more diverse population of young people.  相似文献   

11.
ABSTRACT

We argue that Artificial Intelligence (AI) will, in the very near future, have a profound impact on the conduct of strategy and will be disruptive of existing power balances. To do so, we review the psychological foundations of strategy and explore the ways in which AI will impact human decision-making. We then review current and evolving capabilities in ‘narrow’, modular AI that is optimised to perform in a particular environment, and explore its military potential. Lastly, we look ahead to the more distant prospect of a general AI.  相似文献   

12.
《Arms and Armour》2013,10(1):40-52
Abstract

Scientifically analysing important artefacts from the site of historic battles is vital if the best information is to be retrieved from the field. A detailed knowledge of the specific equipment that was available to the combatants from a known battle is also required at a high level so that artefacts and fragments resulting from an historic battlefield archaeological survey can be recognised when found. Access to specialists from all walks of life is required throughout each battlefield-related project, from the fieldwork stages to the dissemination of information. The following paper discusses the importance of working alongside museums and specialists and gives examples of how the Towton Battlefield Archaeology Project has successfully worked with the staff at the Royal Armouries Leeds.  相似文献   

13.
14.
《防务技术》2014,10(1):47-59
Quenched and Tempered (Q&T) steels are widely used in the construction of military vehicles due to its high strength to weight ratio and high hardness. These steels are prone to hydrogen induced cracking (HIC) in the heat affected zone (HAZ) after welding. The use of austenitic stainless steel (ASS) consumables to weld the above steel was the only available remedy because of higher solubility for hydrogen in austenitic phase. The use of stainless steel consumables for a non-stainless steel base metal is not economical. Hence, alternate consumables for welding Q&T steels and their vulnerability to HIC need to be explored. Recent studies proved that low hydrogen ferritic steel (LHF) consumables can be used to weld Q&T steels, which can give very low hydrogen levels in the weld deposits. The use of ASS and LHF consumables will lead to distinct microstructures in their respective welds. This microstructural heterogeneity will have a drastic influence in the fatigue crack growth resistance of armour grade Q&T steel welds. Hence, in this investigation an attempt has been made to study the influence of welding consumables and welding processes on fatigue crack growth behaviour of armour grade Q&T Steel joints. Shielded metal arc welding (SMAW) and Flux cored arc welding (FCAW) were used for fabrication of joints using ASS and LHF consumables. The joints fabricated by SMAW process using LHF consumable exhibited superior fatigue crack growth resistance than all other joints.  相似文献   

15.
This paper attempts to examine the effect of an anticipated foreign military threat on the steady‐state growth rate and the transitional behavior of the economy. The modeling strategy follows the Sandler and Hartley (1995 Sandler, T. and Hartley, K. 1995. The Economics of Defense, Cambridge: Cambridge University Press.  [Google Scholar]) and Dunne et al. (2005 Dunne, J.P., Smith, R.P. and Willenbockel, D. 2005. Models of military expenditure and growth: a critical review. Defence and Peace Economics, 16: 449461. [Taylor & Francis Online], [Web of Science ®] [Google Scholar]) viewpoints to emphasize the role of national defense in affecting growth from the perspective of both the demand and the supply sides. We thus combine the public capital version of endogenous growth with a framework of competitive arms accumulation. It is found that the key factor determining the steady state and the transitional effects of a rise in the foreign military threat on the home weapon–capital ratio, the consumption–capital ratio, and the rate of economic growth, is the degree of relative risk aversion.  相似文献   

16.
17.
The laser technology has made remarkable progress over the past couple of decades.It is being widely employed in diverse domains,such as holography,space sciences,spectroscopy,medical sciences,micro and power electronics,industrial engineering,and most distinctively,as directed energy military weapons.Owing to their active transmissions,laser systems are similar to microwave radars to some extent;however,unlike conventional radars,the laser operates at very high frequencies thus making it a potent enabler of narrow-beam and high energy aerial deployments,both in offensive and defensive roles.In modern avionics systems,laser target indicators and beam riders are the most common devices that are used to direct the Laser Guided Weapons(LGW)accurately to the ground targets.Additionally,compact size and outstanding angular resolution of laser-based systems motivate their use for drones and unmanned aerial applications.Moreover,the narrow-beam divergence of laser emissions offers a low probability of intercept,making it a suitable contender for secure transmissions and safety-critical operations.Furthermore,the developments in space sciences and laser technology have given syner-gistic potential outcomes to use laser systems in space operations.This paper comprehensively reviews laser applications and projects for strategic defense actions on the ground or in space.Additionally,a detailed analysis has been done on recent advancements of the laser technology for target indicators and range-finders.It also reviews the advancements in the field of laser communications for surveillance,its earlier state of the art,and ongoing scientific research and ad-vancements in the domain of high energy directed laser weapons that have revolutionized the evolving military battlefield.Besides offering a comprehensive taxonomy,the paper also critically analyzes some of the recent contributions in the associated domains.  相似文献   

18.
《Arms and Armour》2013,10(1):4-16
Abstract

A review is presented of dual-ignition musket locks, including a matchlock, to identify the key design variants and their subtleties, and to initiate a discussion on their utility.  相似文献   

19.

The main objective of this paper is to evaluate empirically the existence of a budgetary trade-off between military, education and health expenditures in Turkey for the time period 1925-1998. Development economists, peace and defense economists and political economists have extensively investigated the existence of a trade-off between military, education and health spending since the 1970s. However, the literature review reveals that it is hard to establish a general theory of budgetary trade-off between military, education and health spending and make this applicable for all cases. This is mostly due to economic, social, political, and historical differences among the countries Moreover, it is likely that different research techniques, different time periods analyzed may produce different results. As a result of this, researchers have found a variety of outcomes regarding the trade-off between defense-education and health expenditures. This study presents a brief literature review within the framework of trade-offs between defense-education and health expenditures and also concentrates on theoretical model development. The discussion will center on developing a multi-variable single equation regression model and presenting estimable forms of equations.  相似文献   

20.

European defence policy has been dominated by politics. This paper shows how economic principles can be used to derive guidelines for the formulation of European defence policy. The inefficiencies of the EU's existing defence arrangements are identified. It is shown that there is scope for efficiency improvements in the EU's Armed Forces and its defence industries.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号