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排序方式: 共有556条查询结果,搜索用时 13 毫秒
1.
The aim of our project is to experimentally access the practical applications of ethanol and blending it with some lubricating oils in a direct injection compression ignition engine. This replacement of conventional diesel with ethanol requires some of the properties of ethanol to be altered. In order to increase the lubricating property of ethanol, it is blended with some lubricating oils. Some of the preferred lubricating oils are methyl esters of Jatropha oil, Pongamia oil, etc. Ethanol is blended with these lubricating oils to reduce the corrosive property of ethanol. The different fuel blends [Pongamia–ethanol (50–50) and Jatropha–ethanol (50–50)] are used in the direct injection CI engine, the combustion characteristics are calculated and they are compared with diesel and a perfect blend is analysed. The engine combustion parameters such as peak pressure, heat release rate (HRR) and cumulative heat release rate were computed. The combustion analysis revealed that the early rate of pressure rise causes the cylinder pressure to rise early in the case of alternate fuels with a resulting lower rate of pressure rise and peak pressure. However, HRR and cumulative HRR show a maximum for Pongamia–ethanol (50–50) when compared with the neat diesel fuel. 相似文献
2.
Energy demand is the hot topic of all developing and developed countries. Energy demand has been increasing day by day at a high rate. So, it is necessary to find an alternative solution that is eco-friendly. Biodiesel can be the alternative solution for this problem. The main purpose of this paper is to test the engine performance and emission parameters of a diesel engine using pure cinnamon oil blended with diesel and using cerium oxide as a catalyst. The parameters measured are brake power, brake thermal efficiency, specific fuel conception, CO2, CO, NOx and HC. 相似文献
3.
Investigations are increasingly being carried out in the area of utilizing Fiber Reinforced Plastic (FRP) materials for retrofitting and repairing existing damaged concrete structures due to their excellent properties. Favorable mechanical and material characteristics of FRP composites make them attractive for strengthening applications, whereas relatively higher material costs, insufficient knowledge in mechanics of their behavior, long-term durability and lack of related design codes are the issues that need to be addressed for mainstream application of these materials. Although there has been growing interest and field applications of strengthening concrete structures using Carbon Fiber Reinforced Plastic (CFRP) sheet/plate, very little information exists regarding the flexural fatigue behavior of reinforced concrete beams strengthened with CFRP. A common cause of failure in such strengthened members is associated with the debonding of CFRP substrate from the concrete in an abrupt manner. In order to understand the mechanism of debonding in strengthened concrete structures, embedment of strain sensors (Fiber Bragg Grating (FBG) array) between the concrete and CFRP is proposed in this paper. Due to the compatibility with CFRP material and being small in size, fiber optic sensor is a good choice for embedding at the interface to measure interfacial strain. This paper presents the experimental studies carried out on CFRP strengthened concrete members subjected to cyclic loading. A special emphasis has been placed on understanding the failure pattern using the embedded FBG sensors. Based on the studies it is concluded that the strain at the interface of CFRP strengthened concrete members can be measured. 相似文献
4.
Indraneel Biswas A. Senthil Kumar Mustafizur Rahman 《The International Journal of Advanced Manufacturing Technology》2010,50(9-12):931-940
Profile accuracy of components ground with ultra-precision machine tools is primarily dependent on wheel wear. Quantitative analysis of wheel wear is therefore an important aspect for precision grinding with electrolytic in-process dressing (ELID). In this paper, wheel wear is measured from ELID grinding experiments with different dressing and machining parameters. The grinding forces and dressing current characteristics of the experiments are also compared. Based on the results, a benchmark function is defined for wheel wear rate. A relation for identifying insufficient dressing from sufficient dressing for particular machining conditions is also identified. It is found that insufficient dressing produces pitting and/or arcing on the wheel surface, and wheel wear can be linearly correlated to ELID grinding conditions when the wheels are sufficiently dressed. 相似文献
5.
The wear and sliding friction response of a hybrid copper metal matrix composite reinforced with 10 wt% of tin (Sn) and soft solid lubricant (1, 5, and 7 wt% of MoS2) fabricated by a powder metallurgy route was investigated. The influence of the percentages of reinforcement, load, sliding speed, and sliding distance on both the wear and friction coefficient were studied. The wear test with an experimental plan of six loads (5–30 N) and five sliding speeds (0.5–2.5 m/s) was conducted on a pin-on-disc machine to record loss in mass due to wear for two total sliding distances of 1,000 and 2,000 m. The results showed that the specific wear rate of the composites increased at room temperature with sliding distance and decreased with load. The wear resistance of the hybrid composite containing 7 wt% MoS2 was superior to that of the other composites. It was also observed that the specific wear rates of the composites decreased with the addition of MoS2. The 7 wt% MoS2 composites exhibited a very low coefficient of friction of 0.35. The hardness of the composite increased as the weight percentage of MoS2 increased. The wear and friction coefficient were mainly influenced by both the percentage of reinforcement and the load applied. Wear morphology was also studied using scanning electron microscopy and energy-dispersive X-ray analysis. 相似文献
6.
This work aims on the efficient use of animal fat in a diesel engine by making its stable emulsions with ethanol and water. A single cylinder direct injection diesel engine is tested using neat diesel, neat animal fat and animal fat emulsion (optimal emulsion) as fuels under variable load operating conditions. Results show increased peak pressure and ignition delay with ethanol animal fat emulsion as compared to neat fat. Heat release pattern shows improvement in the premixed combustion phase with animal fat emulsion as compared to neat animal fat. Drastic reduction in smoke, nitric oxide, hydrocarbon and carbon monoxide emissions are observed with the emulsion as compared to neat fat and neat diesel mainly at high power outputs. Only, hydrocarbon and carbon monoxide emissions are found as high with the emulsion at light loads. In general, animal fat emulsion shows considerable reduction in all emissions and improvement in engine performance as compared to neat fat. 相似文献
7.
In a given size of symmetric involute gear designed through conventional approach, as the load carrying capacity is restricted at the higher pressure angle due to tipping formation, the use of the asymmetric toothed gear to improve the fillet capacity in bending is examined in this study. Non-standard asymmetric rack cutters with required pressure angles and module are developed to generate the required pinion and gear of a drive with asymmetric involute surfaces and trochoidal fillet profiles. The respective profiles thus generated are optimized for balanced fillet stresses that are equal and possibly the lowest also. For this study of optimization, several non-standard asymmetric rack cutters are designed to accommodate different combinations in the values of pressure angle, top land thickness ratio, profile shift, speed ratio and the asymmetric factors. However for any drive with a given center distance and a speed ratio, only two non-standard asymmetric rack cutters, one for the pinion and other for the gear are used to generate a required numbers of pinion and gear with different cutter shift values for the purpose of optimization. The influence of these parameters on the maximum fillet stress has been analyzed to suggest the optimum values of these parameters that improve the fillet capacity in bending. The optimization of the asymmetric spur gear drive is carried out using an iterative procedure on the calculated maximum fillet stresses through FEM for different rack cutter shifts and finally the optimum values of rack cutter shifts are suggested for the given center distance and the speed ratio of an asymmetric gear drive. Comparisons have also been made successfully with the results of the AGMA and the ISO codes for symmetric gears to justify the results of the finite element method pertaining to this study. 相似文献
8.
Fenbufen, a member of nonsteroidal antiinflammatory drugs and widely used in the treatment of rheumatoid arthritis was imprinted by utilizing a zwitterionic polymeric format, N-[(phenylenediammonium) maleimidopropane sulfonate] copolymer. Imprinting was carried out by grafting polymer on a photoiniferter modified silica gel via living radical polymerization. Electrostatic interactions along with complementary H-bonding and other hydrophobic interactions inducing additional synergetic effect between the template (fenbufen) and the imprinted surface led to the formation of imprinted sites. Grafted molecularly imprinted polymer (MIP) was characterized by FTIR and surface area measurements besides the recognition, rebinding and selectivity studies. The surface area, pore diameter and pore volume of the MIP are 259.06 m2/g, 4.99 nm and 0.32 cm3/g, respectively. The MIP was able to selectively and specifically take up fenbufen quantitatively. Hence, a facile, specific and selective technique using surface-grafted specific molecular contours developed for specific and selective uptake of fenbufen in the presence of various interferrants, in different kinds of matrices is presented. 相似文献
9.
Kumar DD Mitra S Senthil K Sharma DK Rajan RN Sharma A Nagesh KV Chakravarthy DP 《The Review of scientific instruments》2008,79(4):045104
A design approach giving the optimum number of stages in a magnetic pulse compression circuit and gain per stage is given. The limitation on the maximum gain per stage is discussed. The total system volume minimization is done by considering the energy storage capacitor volume and magnetic core volume at each stage. At the end of this paper, the design of a magnetic pulse compression based linear induction accelerator of 200 kV, 5 kA, and 100 ns with a repetition rate of 100 Hz is discussed with its experimental results. 相似文献
10.
P. Senthil K. S. Amirthagadeswaran 《Journal of Mechanical Science and Technology》2012,26(4):1141-1147
This paper reports a research in which an attempt was made to prepare AC2A aluminium alloy castings of a non symmetrical component
through squeeze casting process. The primary objective was to investigate the influence of process parameters on mechanical
properties of the castings. Experiments were conducted based on orthogonal array suggested in Taguchi’s offline quality control
concept. The experimental results showed that squeeze pressure, die preheating temperature and compression holding time were
the parameters making significant improvement in mechanical properties. The optimal squeeze casting condition was found and
mathematical models were also developed for the process. 相似文献