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1.
Exocytosis plays an essential role in the communication between cells in the nervous system. Understanding the regulation of neurotransmitter release during exocytosis and the amount of neurotransmitter content that is stored in vesicles is of importance, as it provides fundamental insights to understand how the brain works and how neurons elicit a certain behavior. In this minireview, we summarize recent progress in amperometric measurements for monitoring exocytosis in single cells and electrochemical cytometry measurements of vesicular neurotransmitter content in individual vesicles. Important steps have increased our understanding of the different mechanisms of exocytosis. Increasing evidence is firmly establishing that partial release is the primary mechanism of release in multiple cell types.  相似文献   
2.
段振洪 《水泥技术》2020,(2):82-87,92
介绍了湖州南方物流有限公司中转仓储及输送工程项目的建设背景、建设条件,以及线路规划、主要技术方案,该项目是国内采用长距离越野曲线带式输送机系统运输熟料距离最长的绿色环保工程。项目以电力驱动运输替代汽车运输,日输送量达4.5~5万吨。采用密闭廊道输送,粉尘排放量低,噪声<50dB,日均减少汽车运输3000辆次,年节约燃油2000余吨,减少了尾气排放,缓解了沿线的交通拥堵,实现了良好的经济效益和社会效益。  相似文献   
3.
对我国常用的闭口闪点测定方法宾斯基-马丁闭口杯法、阿贝尔闭口杯法和泰格闭口杯法的测定原理进行对比分析,并采用这3种方法分别对2种有证标准样品、4种有机试剂样品和7种喷气燃料样品的闭口闪点进行测定。结果表明:这3种方法在适用范围、仪器结构、升温速率和点火操作要求等方面都有一定差异,导致采用这3种方法测定同一样品的闭口闪点结果略有差异,闪点测定结果之间的最大差值与样品闪点的高低呈正相关;与阿贝尔闭口杯法相比,宾斯基-马丁闭口杯法测得的闪点结果较高,对于3号喷气燃料,二者之差为0~1.0 ℃,阿贝尔闭口杯法更适合3号喷气燃料闭口闪点的测定;对于纯有机试剂样品,阿贝尔闭口杯法和宾斯基-马丁闭口杯法测得的闪点结果呈现较好的线性关系。  相似文献   
4.
A 3D numerical investigation has been carried out to examine periodic laminar flow and heat transfer character-istics in a circular tube with 45° V-baffles with isothermal wal . The computations are ba...  相似文献   
5.
This paper describes the design of a guidance law used for guiding a hypersonic gliding vehicle against a ground target from a near-vertical orientation with a specified final speed and a near-zero final load factor. The guidance law consists of two terms: one is Trajectory-Shaping Guidance (TSG) used for steering the vehicle to the target from the specified orientation; the other is Final-Speed-Control Scheme (FSCS) used for controlling the vehicle to perform lateral maneuver to adjust the final speed. Further, the generalized closed form solutions of TSG are obtained from a more general linearized engagement model, where the speed of the vehicle can be an arbitrary positive function of time. By analyzing these solutions, the stability domain of the guidance coefficients is obtained such that the final load factor is zero. This domain is not affected by the change rate of the speed. Thus, according to this analysis, the proposed guidance law can achieve a near zero final load factor by properly selecting the guidance coefficients in the stability domain.  相似文献   
6.
The increased concentration of CO2 due to continuous breathing and no discharge of human beings in the manned closed space, like spacecraft and submarines, can be a threat to health and safety. Effective removal of low concentration CO2 from the manned closed space is essential to meet the requirements of long-term space or deep-sea exploration, which is an international frontier and trend. Ionic liquids (ILs), as a widespread and green solvent, already showed its excellent performance on CO2 capture and absorption, indicating its potential application in low concentration CO2 capture. In this review, we first summarized the current methods and strategies for direct capture from low concentration CO2 in both the atmosphere and manned closed spaces. Then, the multi-scale simulation methods of CO2 capture by ionic liquids are described in detail, including screening ionic liquids by COSMO-RS methods, capture mechanism by density functional theory and molecular dynamics simulation, and absorption process by computational fluid dynamics simulation. Lastly, some typical IL-based green technologies for low concentration CO2 capture, such as functionalized ILs, co-solvent systems with ILs, and supported materials based on ILs, are introduced, and analyzed the subtle possibility in manned closed spaces. Finally, we look forward to the technology and development of low concentration CO2 capture, which can meet the needs of human survival in closed space and proposed that supported materials with ionic liquids have great advantages and infinite possibilities in the vital area.  相似文献   
7.
A new method is described, in which 3D‐printed structures are implemented in bubble column reactors to dissolve the macroscopic and the microscopic influences. The effect of these structuring method on the fluid dynamic behavior, the gas distribution, mass transfer, and fluid velocity inside bubble columns is shown in this contribution.  相似文献   
8.
In chemical process engineering, fast gas-liquid reactions often suffer from an inefficient distribution of gas and therefore mixing and mass transfer performance. This study deals with the possibility of influencing the local gas holdup and bubble size distribution in a gas-liquid process using additively manufactured lattice structures (AMLS). The used measuring technique to study bubble size, velocity, and the local gas holdup is a photo-optical needle probe. By using AMLS, a significant radial homogenization of the local gas holdup and the mean bubble size is achieved. Furthermore, it can be demonstrated that the bubble size can be tailored by the geometry of the inserted structure. It is illustrated that the mean bubble velocities are lowered within the lattice resulting in a higher residence time of the dispersed phase with an impact on the mass transfer performance within the AMLS.  相似文献   
9.
Adsorptions of Zr atom onto the perfect rutile TiO2(110) and the oxygen vacancy rutile TiO2 (110) ([TiO2+Vo]) to form Zr–TiO2 and Zr‒[TiO2+Vo] were studied using periodic density functional theory (DFT) method. Three configurations of both Zr–TiO2 and Zr‒[TiO2+Vo] surfaces were found and binding energies of Zr atom of the most stable Configurations of Zr–TiO2 and Zr‒[TiO2+Vo] surfaces are respectively −3.36 and −3.26 eV. The most stable Configurations of the Zr–TiO2 and Zr‒[TiO2+Vo] surfaces were selected in hydrogen adsorption study. Adsorption energies of single H2 molecule on the most stable Zr–TiO2 and Zr‒[TiO2+Vo] are −1.43 and −1.45 eV, respectively. Based on the second H2 molecular adsorption on the hydrogen pre‒adsorbed Zr–TiO2 and Zr‒[TiO2+Vo] surfaces, adsorption energies of −1.90 and −2.55 eV were found, respectively. The second H2 molecule adsorption was found to be much stronger than the first H2 molecule adsorbed onto the Zr–TiO2 and Zr‒[TiO2+Vo] surfaces by 32.9% and 75.9%, respectively. Either the Zr–TiO2 or Zr‒[TiO2+Vo] surface is suggested as hydrogen–storage material and the Zr–TiO2 can be proposed as an electrical resistance‒based hydrogen sensor.  相似文献   
10.
This study aims to examine the practicality of a novel passive heat transport system “thermosyphon heat transport device” (THTD). It is a fluid-filled unit, with both source and sink amalgamated within it. A vertical tube-in-tube design has been incorporated, consisting of heat source, adiabatic height, and sink. To showcase the performance, a transient numerical analysis is performed using ANSYS Fluent, which is compared with the simple closed thermosiphon (SCT) for heat transport capability (1 kW) and different adiabatic heights (0.25, 1, and 1.5 m). Also, the influence of axial conduction is examined. The proposed Therminol VP1-based THTD has better heat transport capability over SCT due to a uniform flow pattern. Although the time response diminishes with adiabatic height, the novelty is justified as the heat gained by THTD (adiabatic height: 1.5 m) is 1.5 times more than SCT. Furthermore, the THTD performance is experimentally analyzed by varying the coolant flow rate (0.01, 0.02, and 0.03 kg/s), heat load (100−600 W), and transport distance (0.25 and 0.75 m), which yielded 80%−90% energy efficiency. As the THTD is crucial for a conceptual solar indoor cooker, the response under transient heating/cooling conditions is also investigated, which depicted 300 s for transient heating and 10−50 s for transient cooling.  相似文献   
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