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121.
    
This study investigated the effects of reinforcing bar type and reinforcement ratio on the restrained shrinkage behaviors of ultra high performance fiber reinforced concrete (UHPFRC), including autogenous shrinkage stress, degree of restraint, and cracking potential. In addition, the influence of the type and embedment length of reinforcing bars on the bond behavior of UHPFRC was evaluated by performing pullout test. Three different reinforcing bars (deformed steel bar, round steel bar, and GFRP bar) were investigated in the restrained shrinkage and pullout tests. The GFRP bar exhibited the best performance in relation to the autogenous shrinkage stress, degree of restraint, and cracking potential because of its low stiffness. The highest bond strength was obtained for the deformed steel bar, and the bar yielding was observed when the bar embedment length of lb = 2db was used. The round steel bar exhibited the poorest behaviors for both of the restrained shrinkage and pullout.  相似文献   
122.
    
Incident involving failures of anticorrosion plastic alloy composite pipe which was used for oilfield gathering and transportation had caused serious burst after several years of usage. Investigations were performed to identify the most probable causes of the pipe failures. The study was conducted by reviewing the background of the incident, inspecting visual physical morphology of the failed pipe, analyzing FTIR spectra and TG–DSC curves of inner plastic alloy and outer GRP resin. Results revealed that additives in damaged plastic alloy may not be stirred enough before extrusion or the content of additives may exceed their normal range. The lower degree of cure for resin of GRP layer leads to decrease of glass transition temperature as well as its thermal stability, which will make the outer GRP structural layer have a relatively lower mechanical property, thus giving rise to final failure of the composite pipe under the long time service conditions.  相似文献   
123.
Many of the major greenhouse gas emitting countries have planned and/or implemented domestic mitigation policies, such as carbon taxes, feed-in tariffs, or standards. This study analyses whether the most effective national climate and energy policies are sufficient to stay on track for meeting the emission reduction proposals (pledges) that countries made for 2020. The analysis shows that domestic policies of India, China and Russia are projected to lead to lower emission levels than the pledged levels. Australia's and the EU's nationally legally binding policy framework is likely to deliver their unconditional pledges, but not the conditional ones. The situation is rather unclear for Japan, South Korea, Brazil and Indonesia. We project that policies of Canada and the USA will reduce 2020 emission levels, but additional policies are probably needed to deliver their pledges in full. The analysis also shows that countries are implementing policies or targets in various areas to a varying degree: all major countries have set renewable energy targets; many have recently implemented efficiency standards for cars, and new emission trading systems are emerging.  相似文献   
124.
    
Determining the degree of degradation is an important means of assessing the efficiency of biological processes. However, one should consider the fact that during degradation, the reference value, such as volume or the mass of total solids, is also subject to change. The assumption that the incoming and outgoing mass flows are identical is only possible for substrates with a high water content and hence, a low energy density. For substrates with a higher energy density, a correction by the gaseous mass flow is required, but usually its quantification is difficult, especially when examining full-scale plants or open systems. Based on the assumption that the mass of inorganic solids is constant during the process, a universally applicable equation has been developed, requiring only the input and output volatile solids concentrations for calculation.  相似文献   
125.
The rational design of rock slope support is particularly important if the slope is steep, if safety is important, and if the design significantly affects project costs. Theoretically, slopes with stability factors smaller than 1.0 should be reinforced for maximum safety and efficiency. To optimize reinforcement design of a rock slope, an engineer should distinguish those locations needing critical, general, or even no reinforcement from other parts of the slope. The purpose of this paper is to present the concept of the degree of reinforcement demand (DRD) for rock slope projects and the quantitative procedures for the DRD assessment. The main influencing factors can be determined, classified and assigned based on knowledge from theoretical analyses, practical experiences and monitoring. To show variances in the DRD values with time and space, a rock slope to be assessed should be divided into a number of slope zones and the construction schedule into different periods. When geological conditions, mechanical properties of the rock mass, displacement measurements and/or construction have changed in a slope zone, the DRD value in this slope zone will increase or decrease. So for convenience in the DRD assessments, such changes in the main factors and measurements are analyzed via matrices. For example, the influencing factor matrix and the displacement ratio matrix, i.e. [A]k and [E]k, are, respectively, used to indicate possible modifications in the main factors and displacement measurements for all slope zones in the kth period. The DRD matrix, [R]k, can be obtained by multiplying [A]k and [E]k, and those elements along the leading diagonal of the matrix [R]k are the DRD values corresponding to different slope zones in the kth period. To demonstrate the feasibility of the DRD assessment, an application relating to the shiplock slope (including the lower-stream slope) of the Wuqiangxi hydropower station in China is described in this paper.  相似文献   
126.
This paper discusses the degree of completeness of cryptographic functions, which is one of the cryptographic criteria should be considered in the design of stream ciphers. We establish the re- lationships between the degree of completeness and other cryptographic criteria. For resilient Boolean functions, a method to enhance the degree of completeness is proposed, while the nonlinearity and the algebraic degree do not decrease. Moreover, two constructions of resilient functions are provided, which have optimal degree of completeness, high nonlinearity, and high algebraic degree.  相似文献   
127.
介绍了与双辽发电厂相连接的长春220kV城网的结构特点及运行中存在的问题,针对300MW机组的稳定问题,提出了一套计算静稳极限的方法,及防止双辽1号机失稳的调整控制措施。  相似文献   
128.
洪睿  康晓东  李博  王亚鸽 《计算机科学》2018,45(Z11):244-246
文中提出了一种基于复杂网络的图像特征描述方法。将图像的关键点作为复杂网络节点,利用最小生成树分解法完成初始网络的动态演化过程,由不同演化阶段下的复杂网络特征实现对图像的形状描述;根据图像像素和周围邻域的距离与灰度的相似度,由不同的阈值生成度矩阵,统计不同阈值下网络节点的度分布,完成图像的纹理描述。实验证明,该算法具有较强的鲁棒性和旋转不变性,并且在分类实验中也有较好的表现。  相似文献   
129.
    
The angiotensin I-converting enzyme (ACE) inhibitory activity and hypocholesterolemic effect of Achatina fulica snail foot muscle protein hydrolysates (SFMPH) and its hydrolysates were studied. The SFMPHs were prepared at a temperature of 121°C for 60 min. To obtain the enzymatic hydrolysates, the SFMPHs were further hydrolysed with three proteases (papain, trypsin, or alcalase). Among all the hydrolysates, alcalase hydrolysate showed the highest degree of hydrolysis and was dominated by a small molecular size fraction (189–686 Da). The SFMPH treated by alcalase was effective in disintegrating intact cholesterol micelles. Furthermore, alcalase hydrolysate with a hydrolysis time of 60 min showed a strong ACE inhibitory activity in vitro with an IC50 of 0.024 mg/mL. Therefore, alcalase hydrolysate may be a promising ingredient for the use in functional foods.  相似文献   
130.
    
Security of supply is at the forefront of energy policy in the EU and elsewhere. This paper develops a methodology to forecast peak-day gas consumption for the consideration of gas transmission system operators. It is developed for the domestic and small-to-medium enterprise (SME) gas market, based on a review of current practice. From this assessment, a climate-adjusted network degree day (NDDCA) variable is developed to estimate the weather-dependent gas consumption of such markets. We show that solar radiation significantly affects gas consumption and should be considered in consumption models. The study also quantifies the difference in capacity required under alternative gas supply standards.  相似文献   
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