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101.
Austrian road tunnels within the Trans-European Road Network (TERN) must fulfil the requirements of the Directive 2004/54/EC (European Commission, 2004) not later than April 2019. This regulation has to be applied to all tunnels in the TERN with a length of more than 500 m, whether they are in operation, under construction or at design stage, and aims at ensuring a minimum level of safety for road users. One of the main features of this directive is the requirement for providing an egress possibility to a safe environment every 500 m throughout the whole tunnel.The Arlberg road tunnel has a length of some 15.5 km and is in operation for more than 35 years. It is a single tube tunnel operated with bi-directional traffic, but carries a quite low traffic volume. Hence, the construction of a second tube is not really cost effective. Currently the tunnel is equipped with a transversal ventilation system with remotely controlled smoke extraction dampers providing smoke extraction every 100 m. The maximum distance between egress possibilities to a save environment is some 1500 m. Due to the high costs of a construction of a second tube or a parallel running escape gallery, a novel solution was found. The existing fresh air duct will be used as safe escape way between the existing egress possibilities. This solution has big impacts on the ventilation system and on the requirements for thermal structure protection of the new egress ways, i.e. the fresh air duct. In order to overcome this problem, massive changes in the ventilation design have to be performed, accompanied by the installation of a high-pressure water-mist system for structure protection.  相似文献   
102.
It is possible to estimate CO2 emissions from road freight transport in different ways, depending on the definition of trucking activity, the degree of reliance on survey, vehicle test-cycle and traffic count data and the geographical scope of the calculation. The emergence of differing road freight-related CO2 estimates from official sources and revisions to statistical series can frustrate the policy-making process and erode the confidence of industry stakeholders in the validity of the figures. Using UK data, this paper examines the various methods of carbon auditing road freight transport at the national level and compares the results both for a single year (2006) and over a time period. It highlights a series of statistical anomalies and approximations and tries to explain discrepancies that have arisen in the UK data sets. A concluding section considers the general lessons that can be learned from the recent UK experience in this field.  相似文献   
103.
随着各种现代车辆的出现,要求车辆的性能越来越优良,速度越来越高,因而车辆的悬挂系统对随机路面激励的响应预测,就显得十分重要。本文考虑了车辆匀变速行驶时随机路面激励的非平稳性,提出一种求解匀变速行驶车辆的非线性悬挂系统对随机路面不平度响应的简单而实用的近似方法。  相似文献   
104.
本文叙述了微珠型反光材料的研制,并介绍玻璃微珠反光性能的光学原理,反光材料的原材料选用、配方试验、性能测试。  相似文献   
105.
A model of traffic crashes in New Zealand   总被引:3,自引:0,他引:3  
The aim of this study was to examine the changes in the trend and seasonal patterns in fatal crashes in New Zealand in relation to changes in economic conditions between 1970 and 1994. The Harvey and Durbin (Journal of the Royal Statistical Society 149 (3) (1986) 187-227) structural time series model (STSM), an 'unobserved components' class of model, was used to estimate models for quarterly fatal traffic crashes. The dependent variable was modelled as the number of crashes and three variants of the crash rate (crashes per 10,000 km travelled, crashes per 1,000 vehicles, and crashes per 1000 population). Independent variables included in the models were unemployment rate (UER), real gross domestic product per capita, the proportion of motorcycles, the proportion of young males in the population, alcohol consumption per capita, the open road speed limit, and dummy variables for the 1973 and 1979 oil crises and seat belt wearing laws. UERs, real GDP per capita, and alcohol consumption were all significant and important factors in explaining the short-run dynamics of the models. In the long-run, real GDP per capita was directly related to the number of crashes but after controlling for distance travelled was not significant. This suggests increases in income are associated with a short-run reduction in risk but increases in exposure to a crash (i.e. distance travelled) in the long-run. A 1% increase in the open road speed limit was associated with a long-run 0.5% increase in fatal crashes. Substantial reductions in fatal crashes were associated with the 1979 oil crisis and seat belt wearing laws. The 1984 universal seat belt wearing law was associated with a sustained 15.6% reduction in fatal crashes. These road policy factors appeared to have a greater influence on crashes than the role of demographic and economic factors.  相似文献   
106.
The purpose of this study was to estimate the size of the influence of ambient light level on fatal pedestrian and vehicle crashes in three scenarios. The scenarios were: fatal pedestrian crashes at intersections, fatal pedestrian crashes on dark rural roads, and fatal single-vehicle run-off-road crashes on dark, curved roads. Each scenario's sensitivity to light level was evaluated by comparing the number of fatal crashes across changes to and from daylight saving time, within daily time periods in which an abrupt change in light level occurs relative to official clock time. The analyses included 11 years of fatal crashes in the United States, between 1987 and 1997. Scenarios involving pedestrians were most sensitive to light level, in some cases showing up to seven times more risk at night over daytime. In contrast, single-vehicle run-off-road crashes showed little difference between light and dark time periods, suggesting factors other than light level play the dominant role in these crashes. These results are discussed in the context of the possible safety improvements offered by new developments in adaptive vehicle headlighting.  相似文献   
107.
Prime movers of enterprise innovation are inside the organisation. The enterprise NIIT, studied in this paper, tells us how elicitation and recognition of knowledge and its contents set an enterprise on the move. Recognised knowledge is actionable. Each act of recognition is an addition to knowledge content, and such additions took place in NIIT through acts of communications and self-searching. These contents form a large collage that cannot be strewn into a single novelistic episode. Perspectives and context, motives and suggestions render to each member of the enterprise different disjoint appearances of knowledge. There are thus many knowledge systems and multiple narrations, each with small episode-like finality. Enterprise innovation is achieved not through any grand episodic integration of all knowledge contents, but by constructively eliciting further new contents of knowledge, and encouraging acts of communications and discourses on this new knowledge. Constructive management of knowledge and communication towards enterprise innovation has thus been defined. Through such constructive management, NIIT enabled itself innovationally and empowered its members in eliciting knowledge and acting communicatively. A critical feature of knowledge work is that it requires multidisciplinary expertise and mutual learning in order to achieve a complex synthesis of highly specialised state-of-the-art technologies and knowledge domains. A convivial work culture and a culture of communicative acts enable sharing of the non-informatised yet recognised contents of knowledge.  相似文献   
108.
109.
道路检测是室外移动机器人尤其是智能汽车研究领域的一个重要课题。本文介绍了多功能室外移动机器人THMR-V的道路检测算法,共分为两个部分。结构化道路,采用的是多窗口双阈值法。虽然在该领域已经有许多能够自主驾驶的系统,但很少能有像THMR-V达到150km/h;非结构化道路,采用的则是基于数学形态学的区域分割法。文中详细介绍了算法的实现。  相似文献   
110.
How much do road accidents cost the national economy?   总被引:1,自引:0,他引:1  
This paper presents estimates of how much road accidents cost the national economy, stated as a percentage of the gross national product (GNP). Official estimates of road accident costs from 1990 or later were compiled from easily accessible sources for twelve countries. Estimates of the gross national product were taken from OECD publications. On the average, the total costs of road accidents, including an economic valuation of lost quality of life, were estimated to about 2.5% of the gross national product. Excluding the valuation of lost quality of life, road accident costs on the average amounted to 1.3% of the gross national product. When valuation of lost quality of life is included, costs ranged from 0.5 to 5.7% of GNP. When valuation of lost quality of life is disregarded, costs ranged from 0.3 to 2.8% of GNP.  相似文献   
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