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71.
72.
Time series of satellite data, generated by the AVHRR (1981-1999), CZCS (1979-1985) and SeaWiFS (1998-2002), have been used to assess trends and interactions of physical and bio-geo-chemical features in the Adriatic Sea. The images were processed to estimate Sea Surface Temperature (SST) and Chlorophyll-like Pigment Concentration (CPC). Long-term composites and climatologies were derived, using fixed geographical grids and projections. The AVHRR data show an apparent warming trend, when plotting the sequence of seasonal cycles (monthly mean SST, averaged over the whole basin) against time, due to a steady rise of summer values. Considering 3 regions (north, central and south), split into east and west sections, the northern Adriatic shows high SST fluctuations (possibly associated with the cycle of winter cooling and summer warming, typical of the relatively shallow sub-basin), while the southern Adriatic exhibits a lower variability (possibly influenced by the periodic water incoming from, and outflowing to the Ionian Sea). During summer, an east-west gradient prevails, while during winter only a general north-south gradient can be found. The SeaWiFS-derived CPC values, distributions and trends appear to be consistent with the historical CZCS record. Persistent differences in the quantitative assessment of CPC for coastal waters is due to the use of improved algorithms, less influenced by the presence of dissolved organics and suspended sediments in the water column, for the processing of SeaWiFS data. Apparent incongruities of the space and time patterns in the SeaWiFS record with respect to the reference climatology, obtained by CZCS more than a decade before, occur chiefly when considering the spring bloom in the southern Adriatic and the summer development of the north Adriatic front. The comparison of the long-term times series of satellite data shows that there is a high correlation between patterns in the thermal field and in the colour field. This suggests that different surface waters, identified by the SST index, are also traced by different ecological features, identified by the CPC index. Both indices also show a high correlation with the classical cyclonic circulation scheme of the Adriatic Sea, proposing once again an intimate relationship between the water dynamics and its bio-geo-chemistry.  相似文献   
73.
不论内外,这座建筑都透着动感,令你感受到那种亮丽完美,建筑师们所谓的"天堂制造"的效果。这座建筑浑身上下,都吸引着人们的眼球。为了在视觉上和空间上达到一种流动性的通畅空间效果,建筑师引入了一个公共的空虚空间,将光线投射到地板上,同时从视觉上将不同楼层相连接。为了内外空间之间的衔接,建筑外立面的一侧设计了一个只有12层高的纵深空隙空间,而不是一个与建筑一样纵深的空间。该空间成为建筑内部连接整个建筑的部  相似文献   
74.
Moisture as an important influence factor on fungal growth needs to be considered for service life prediction of wood and wood-based products. Therefore, a long-term moisture measuring and data logging method for wood in weathered conditions was developed. The method is based on measuring the electrical resistance with glued electrodes for sustainable connection. The measuring point at the tip of the electrodes was glued conductively into the wood, the remaining outer part of the electrodes was glued with an isolating glue. For this purpose, special conductive and isolating glues and electrodes were developed and comparatively evaluated in laboratory tests. The most suitable system consisted of a 2k-epoxy resin, serving for the isolating glue and also as conductive glue (when mixed with graphite powder and ethanol) in combination with a partly isolated stainless steel cable, acting as both, electrode and cable. This system was further tested in combination with mobile mini data logger at 29 different exposure sites in Europe and the United States. After 4–6 years of natural weathering with many extreme climatic and moisture changes, no loosening or other detectable abnormality in 541 pairs of electrodes was observed. The data logging systems were working without any problems for 5 years with the first and only battery, and without any additional maintenance. For the calibration of the measuring system, resistance characteristics were determined for different provenances of Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies Karst.), and Douglas fir (Pseudotsuga menziesii Franco).  相似文献   
75.
In innovation and project management studies incremental development projects are perceived as theoreticlly and organisationally uninteresting. By means of a longitudinal study of product improvement projects at an automobile firm, this paper challenges such views and shows how the cumulative impact of the studied sequence resulted in a competitive repositioning of the company's product portfolio during a financially difficult period. Project managers achieved this by transcending the separation between exploration and exploitation projects; they not only adhered to time, cost and quality goals but also tried out new ways of testing and experimenting with controversial technical ideas. The paper analyzes the intensive inter project learning that generated these ambidextrous capabilities and emphasizes that practices at the project-level need to be buttressed by expanded management learning and capability development also at the sequence level.  相似文献   
76.
Abstract

Recently, a literature has emerged using empirical techniques to study the evolution of international cities over many centuries; however, few studies examine long-run change within cities. Conventional models and concepts are not always appropriate and data issues make long-run neighbourhood analysis particularly problematic. This paper addresses some of these points. First, it discusses why the analysis of long-run urban change is important for modern urban policy and considers the most important concepts. Second, it constructs a novel data set at the micro level, which allows consistent comparisons of London neighbourhoods in 1881 and 2001. Third, the paper models some of the key factors that affected long-run change, including the role of housing. There is evidence that the relative social positions of local urban areas persist over time but, nevertheless, at fine spatial scales, local areas still exhibit change, arising from aggregate population dynamics, from advances in technology, and also from the effects of shocks, such as wars. In general, where small areas are considered, long-run changes are likely to be greater, because individuals are more mobile over short than long distances. Finally, the paper considers the implications for policy.  相似文献   
77.
Partnerships between the public sector and private sector are considered to be important foundations for successful local economic development (LED) planning. This article analyses the multiple challenges that need to be addressed in forging viable LED partnerships between the public sector and private sector in South Africa. The findings are examined from a national survey conducted in 2009 with 30 business chamber associations across South Africa. The results point to markedly differing perceptions of the private sector and local government towards LED, questions of trust and mistrust between private sector and the public sector, and highlight the imperative for greater dialogue in order to provide the foundations for local partnerships for promoting LED.  相似文献   
78.
Grundwasser - Topographically induced Alpine regional groundwater flow systems below the unconsolidated valley fillings constitute a substantial unused geothermal resource. Within the...  相似文献   
79.
We studied the frequency response of a magnetically driven atomic force microscope (AFM) cantilever close to a sample surface in liquids. Amplitude–frequency (tuning) curves showed pronounced differences in dependence on the tip–sample separation (from 1 to 50 μm), with significant shifts of the resonance peak. A model was developed in which the cantilever was described in a full shape manner and the hydrodynamic forces acting on the cantilever were approximately calculated. The slight inclination of the cantilever to the surface (15°) leads to a force profile along the cantilever. Therefore, the mathematical problem can be strictly solved only numerically. For an approximate analytical solution, the hydrodynamic force profile was approximated by a constant force along the cantilever for large separations and by a point force acting on the tip of the cantilever for small separations. The theoretical results calculated within this model agreed well with the experimental data and allowed to determine the cantilever mass in liquid M*, the joint mass at the tip end mt*, and the coefficient of viscous interaction of the cantilever with free liquid, γ.  相似文献   
80.
Evidence that dissolved organic matter is one of the most significant sources of chlorine demand of seawaters (Fig. 1) used in cooling circuits is now well recognized. Nevertheless the specific role of the different kinds of compounds which form this organic material has seldom been studied and even less quantified; this is not surprising as less than 20% of the organic substances are identified. In this paper our objective was to define more quantitatively the effect of the dissolved free and combined amino-acids in the oxidant decay. Two main criteria justified the choice of these solutes:
1. (i)|the reactivity of chlorine and/or bromine towards amino groups;
2. (ii)|the role of these nitrogenous compounds in some biological mechanisms.
What happens to the halogen added and to the organic species during the first 20 min was investigated. The experimental conditions selected (concentrations, salinity, temperature and acidity) are those encountered in practice.The reactivity of the amino-acids towards chlorine is of course influenced by physicochemical properties such as the pH, but is particularly dependent upon the nature of the amino group. Whereas β and γ free amino-acids (Fig. 3) as also combined species (proteins) (Table 2) yield stable halogenocompounds like those produced with aliphatic amines (Fig. 2), α free amino-acids (COOH---CH---NH2)|R on the other hand yield unstable haloamines which decompose rapidly (Fig. 4). Regarding these results, only the reactivity of the α compounds was afterwards studied as they are the largest fraction of the free amino-acids encountered in natural waters.After investigating the role of the side groups R in the kinetics and the efficiency of the consumption of the oxidant we examined, by liquid chromatography, the depletion of the nitrogenous species (Table 3). In each case the HPLC data relative to changes in the level of the organic compounds agree with those reported for the residual oxidant decay.A few experiments carried out on samples of seawater (Table 4) treated with 1 ppm of chlorine showed that around 5% of chlorine which dissipated during the first 3 min are consumed by the dissolved free amino-acids, the depletion of which is about 50%.  相似文献   
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