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991.
行业协会作为一种自治性的,非营利性的社会组织,在我国市场经济的发展进程中,越来越明显的呈现出了它的重要性。这一方面得益于新形势下政府职能需要转变的迫切性,另一方面也得益于行业协会本身在衔接企业和政府,企业和企业,以及企业和社会时所发挥出的独特功能。在市场经济浪潮中,电子信息行业的快速发展是科技进步的重要体现,也是国家生产力蓬勃发展的重要组成部分,而行业协会在促进电子信息行业的发展中已起到了重要的推动作用。但是,处于行业协会发展初级阶段的我国,仍然不可避免的碰到了诸多行业协会功能发挥失效的情况。因此认清电子信息类行业协会的发展现状以及理清该类行业协会的功能对电子信息业的发展具有重要的意义。  相似文献   
992.
The characteristics of hydrogen adsorption on Li metal atoms dispersed on graphene with boron substitution is investigated including Li clustering, hydrogen bonding characteristics, and the open metal states of Li adatom using density functional theory calculations. It is found that Li atoms are well dispersed on boron-substituted graphene and can form the (2 × 2) pattern because clustering of Li atoms is hindered by the repulsive Coulomb interaction between Li atoms. One Li adatom dispersed on the double side of graphene can absorb up to 8 hydrogen molecules corresponding to a 13.2% hydrogen storage capacity. In addition, the adsorption behaviors of non-hydrogen atoms such as C and B are calculated to determine whether Li atoms can remain as the open metal state in boron-substituted graphene.  相似文献   
993.
The effect of periodic reversal of current upon concentration over-potential and current efficiencies in electrolysis has been investigated for a metal depositon reaction which is purely diffusion-controlled. In the cathodic part of the cycle the onset of limiting diffusion conditions is deferred, and the current efficiency and average rate of metal deposition are increased. The magnitude of the effect depends upon the ratio of the quantities of electricity passed in anodic and cathodic pulses, and it is greatest under conditions such that diffusion away from the electrode of anodically-formed ions is minimised. Quantitative theoretical treatment is possible in a limiting case to which actual experimental results approximate. Supplementary experiments have been carried out in more complex cases of metal deposition.  相似文献   
994.
Several studies have shown that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases, diabetes, and cancer, mainly due to the presence of dietary fiber (DF) and polyphenols. Taioba (Xanthosoma sagittifolium) is an edible aroid widely grown in many parts of Africa, America, and Asia. The tubers portions of taioba are widely consumed; however, the leafy portions are generally discarded, despite their high nutritive value. In this study, we have partly characterized the DF of lyophiized taioba leaf (LTL), and assessed the possible protective effects on biochemical parameters and on bile acid (BA) production in colon and cecum, when fed to healthy rats for 4 wk. Forty‐five Wistar rats were assigned to either of 5 groups: group 1 received AIN 93G diet (CG: Control); group 2 received AIN 93G containing 2.5% of cellulose + 2.5% inulin (CEIN_5%); group 3 received AIN 93G containing 2.5% of cellulose + 2.5% taioba fiber (CETA_5%); group 4 received AIN 93G containing 5% cellulose + 2.5% taioba fiber (CETA_7.5%); group 5 received AIN 93G containing 5% cellulose + 2.5% of inulin (CEIN_7.5%). LTL showed high contents of total fiber, predominantly comprising insoluble DF with glucose as the major monomer. Rats receiving LTL had increased fecal mass and fat excretion, and improved BA profiles by diminishing the proportion of secondary acids, thus suggesting that consumption of taioba leaf may have the property of lowering the risk of colon cancer.  相似文献   
995.
Densely packed dry‐coated microprojections are shown to deliver vaccines to targeted locations within the skin that are rich in immune cells, thus inducing protective immune responses against a lethal virus challenge. Selectively limiting the antigen coating to the tips of the projections, which penetrate the skin, would significantly reduce the amount of vaccine required in immunization. In this paper a simple technique, dip‐coating the microprojections, is introduced to meet this goal. By increasing the coating solution viscosity, an otherwise strong capillary action is mitigated and the desired controlled coating length on projections is achieved. Following application to the skin, most of the coated vaccine material is rapidly released from the projections (82.6% in mass within 2 min) to the target locations within the skin strata and a potent immune response is induced when a conventional influenza vaccine (Fluvax) is tested in a mouse model. The utility of this coating approach to a variety of molecules representative of vaccines (e.g., chicken egg ovalbumin (OVA) protein, DNA, and fluorescent dyes) is demonstrated. These collective attributes, together with the simplicity of the approach, position the dip‐coating method for practical utility in large vaccination campaigns.  相似文献   
996.
Density functional based theories and experiments agree well on the value of the heat of formation of TiO2 on NiTi surfaces. However, experimental studies of polycrystalline NiTi surfaces tend to indicate that Ti atoms are always abundantly available at the surface. This theoretical study indicates that whether Ti atoms are dominantly available at the surface depends on the surface index. On NiTi(001) in the B2 phase, the surface can be Ti or Ni terminated, with equal probability, while on NiTi(110) in the B2 phase and NiTi(010) in the B19? phase, Ti atoms are favored to be present at the surface.  相似文献   
997.
998.
999.
Wind energy is a growing renewable energy because of its several advantages; this has changed dramatically with more wind energy penetrating the conventional power network. The influence of wind generators on the power quality is becoming an important issue; non-uniform power production causes variations in system voltage and frequency, therefore, a wind farm requires high reactive power compensation. The advances in high power semiconductor devices have led to the development of Flexible AC Transmission System (FACTS). This paper presents the impact of wind energy integration on voltage stability and the goal of FACTS devices such as Static Var Compensator (SVC), which is a power electronic switch, to control the reactive power injection according to the thyristor firing angle, introduced as a state variable in power flow and combined with the nodal voltage magnitudes and angles of the power network for iterative solutions, thereby regulating the bus voltages.  相似文献   
1000.
ABSTRACT

We performed a safety evaluation using the procedure devised by the Joint FAO/WHO Expert Committee on Food Additives (JECFA) of the following four flavouring substances that belong to the class of ‘aliphatic primary alcohols, aldehydes, carboxylic acids, acetals, and esters containing additional oxygenated functional groups’ and are uniquely used in Japan: butyl butyrylacetate, ethyl 2-hydroxy-4-methylpentanoate, 3-hydroxyhexanoic acid and methyl hydroxyacetate. Although no genotoxicity study data were found in the published literature, none of the four substances had chemical structural alerts predicting genotoxicity. All four substances were categorised as class I by using Cramer’s classification. The estimated daily intake of each of the four substances was determined to be 0.007–2.9 μg/person/day by using the maximised survey-derived intake method and based on the annual production data in Japan in 2001, 2005 and 2010, and was determined to be 0.250–600.0 μg/person/day by using the single-portion exposure technique and based on average-use levels in standard portion sizes of flavoured foods. Both of these estimated daily intake ranges were below the threshold of toxicological concern for class I substances, which is 1800 μg/person/day. Although no information from in vitro and in vivo toxicity studies for the four substances was available, these substances were judged to raise no safety concerns at the current levels of intake.  相似文献   
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