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31.
The proteins with lysin motif (LysM) are carbohydrate-binding protein modules that play a critical role in the host-pathogen interactions. The plant LysM proteins mostly function as pattern recognition receptors (PRRs) that sense chitin to induce the plant’s immunity. In contrast, fungal LysM blocks chitin sensing or signaling to inhibit chitin-induced host immunity. In this review, we provide historical perspectives on plant and fungal LysMs to demonstrate how these proteins are involved in the regulation of plant’s immune response by microbes. Plants employ LysM proteins to recognize fungal chitins that are then degraded by plant chitinases to induce immunity. In contrast, fungal pathogens recruit LysM proteins to protect their cell wall from hydrolysis by plant chitinase to prevent activation of chitin-induced immunity. Uncovering this coevolutionary arms race in which LysM plays a pivotal role in manipulating facilitates a greater understanding of the mechanisms governing plant-fungus interactions.  相似文献   
32.
Titanium carbide (TiC) nanoparticles with well-designed exposed crystal planes perform intriguing prospects for functional and engineering applications. In this study, a simple and controllable in situ synthesis strategy was proposed for the synthesis of TiC nanoparticles with specific morphology. Reaction behaviors suggested that most of TiC nanoparticles were formed by an instantaneous reaction between Al3Ti and Al4C3 in the Al-rich melt and the resultant morphology was controlled by the discrepant growing rates of (100) and (111) crystal planes. In addition, a growth morphology control model was presented for the prediction and manipulation of the morphology of TiC nanoparticles by the doping of different alloying elements Me (Me = Cu, Mg, Mn, Zn, and Si). According to the morphological observations and density functional theory analyses including the interface energy, charge density differences, and orbital hybridization: Cu, Mg, and Zn atoms could stabilize the Al/TiC(111) interface, whereas Mn and Si atoms promoted the rapid growing and disappearance of the TiC(111) planes in the Al melt. This work provides a feasible way to intelligently design and manipulate TiC nanoparticles with desirable exposed crystal planes, and exhibits a promising prospect for personalized applications.  相似文献   
33.
A comparative study was performed with juvenile Atlantic salmon Salmo salar from three stocks in Western Norway that differ in their natural conditions. One is from warm, lowland river conditions (Årdal), one is from cold glacial river conditions (Stryn) and the last one (Suldalslågen) is from a hydropower‐regulated river. The salmon parr were tagged and reared at 4, 5.5 and 7 °C and simulated natural water temperature (SNT) for river Suldalslågen. Size distribution was unimodal at 4 °C, with a change to a bimodal distribution, representing potential 1+ and 2+ smolts, at the other temperature regimes. The relative biomass of 1+ smolts varied between the stocks as Stryn (cold glacial river) stock had the highest number of smolts at 7 °C and the Suldalsågen stock (hydropower‐regulated river) displaying the highest number at the SNT regime. Overall, the Stryn stock, originating from cold river conditions, seemed to be well adapted to growth and smoltification at cold temperatures, whereas salmon parr from river Suldalslågen seem to be better adapted to the natural temperature regime (SNT) of this river than the other two stocks. This was reflected in the gill Na+,K+‐ATPase as the Suldalslågen stock showed increasing activity from 16 April (4.2 µmol ADP mg protein?1 h?1) to 10 May (9.2 µmol ADP mg protein?1 h?1), and at the end of the experiment, enzyme activity in Suldalslågen stock was significantly higher than both Stryn (5.7) and Årdal (5.9 µmol ADP mg protein?1 h?1) stock. In contrast, the warm lowland stock, Årdal, fish had low Na+,K+‐ATPase activity with no distinct peak at any of the sampled dates from March through May. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
34.
A photoresponsive organogel surface (POS), which integrates characteristics of the photothermal property of Fe3O4 nanoparticles and the low hysteresis feature of lubricant‐infused organogels, is shown. A photothermally induced dynamic temperature gradient can be formed rapidly at the location of near‐infrared‐light irradiation (NIR) on POS with suitable Fe3O4 nanoparticles content. Thus, various droplets (e.g., water, glycerol, ethylene glycol, propylene glycol, and ethanol) can be transported effectively and nimbly (e.g., along desired trajectories with controllable velocity and direction, even run uphill and deliver solid particles). This work reveals a synergistic effect between the asymmetrical droplet deformation and the inside Marangoni flows, which forms a unique driving force for droplet transport with high efficiency. This finding offers insight into the design of novel responsive interface materials for droplet transportation, which would be significant for laboratory‐on‐a‐chip contexts, mass transportation, and microengines.  相似文献   
35.
In an attempt to manipulate the biological features of nanomaterials via both anisotropic shape and ligand modification, four types of nanoparticulates with good morphological stability are designed and engineered, including hybrid nanospheres, nanodiscs, and nanodiscs with edge modification or plane modification of octa‐arginine (R8) sequence. It is found that the R8 modification anisotropy can trigger huge differences in the endocytosis, intracellular trafficking, and even tissue penetration of nanoparticulates. From plane modification to edge modification of R8, the maximum increase in cell uptake is up to 17‐fold, which is much more significant than shape anisotropy alone. On the other hand, six types of different cell lines are investigated to simulate biological microenvironment. It is demonstrated that the maximum difference in cell uptake among six cell lines is 12‐fold. Three main driving forces are found to contribute to such bio–nano interactions. Based on the findings of this study, it seems possible to manipulate the biointeraction mode of nanomaterials and its output by regulating their anisotropy in both shape and ligand modification.  相似文献   
36.
The direct-synthesis of conductive PbS quantum dot (QD) ink is facile, scalable, and low-cost, boosting the future commercialization of optoelectronics based on colloidal QDs. However, manipulating the QD matrix structures still is a challenge, which limits the corresponding QD solar cell performance. Here, for the first time a coordination-engineering strategy to finely adjust the matrix thickness around the QDs is presented, in which halogen salts are introduced into the reaction to convert the excessive insulating lead iodide into soluble iodoplumbate species. As a result, the obtained QD film exhibits shrunk insulating shells, leading to higher charge carrier transport and superior surface passivation compared to the control devices. A significantly improved power-conversion efficiency from 10.52% to 12.12% can be achieved after the matrix engineering. Therefore, the work shows high significance in promoting the practical application of directly synthesized PbS QD inks in large-area low-cost optoelectronic devices.  相似文献   
37.
We present a rollover prevention control law for wheeled mobile manipulators based on the invariance control framework, and that makes use of recursively calculated analytic gradients of the mobile manipulator’s zero moment point. Our controller relaxes many of the assumptions made in existing approaches, and enhances robustness through the use of exact gradient information. Numerical experiments demonstrate the improved performance of our controller vis-à-vis existing rollover prevention schemes.  相似文献   
38.
Fully electrical manipulation of magnetism, preferably through spin current, is highly desired to achieve energy-efficient, nonvolatile, and programmable spin logic devices. It is demonstrated in this study that in a single Pt/IrMn/Co/Ru/CoPt heterojunction, all 16 Boolean logic functions can be realized in a purely electrical way, relying on electrical manipulation of magnetic-field-free spin-orbit torque (SOT) switching. By applying current pulses along with two orthogonal directions, the exchange bias between IrMn and Co, and the SOT switching polarity (clockwise or counterclockwise) of perpendicularly magnetized CoPt, can be reversibly controlled, enabling complete spin logic within a single nonvolatile memory. This study makes a significant step towards practical electrical programmable spin logic devices.  相似文献   
39.
The geometrical accuracy of a machined feature on a workpiece during machining processes is mainly affected by the kinematic chain errors of multi-axis CNC machines and robots, locating precision of fixtures, and datum errors on the workpiece. It is necessary to find a way to minimize the feature errors on the workpiece. In this paper, the kinematic chain errors are transformed into the displacements of the workpiece. The relationship between the kinematic chain errors and the displacements of the position and orientation of the workpiece is developed. A mapping model between the displacements of workpieces and the datum errors, and adjustments of fixtures is established. The suitable sets of unit basis twists for each of the commonly encountered types of feature and the corresponding locating directions are analyzed, and an error elimination (EE) method of the machined feature is formulated. A case study is given to verify the EE method. Recommended by Prof. XIONG YouLun, Member of Editorial Committee of Science in China, Series E: Technological Sciences Supported by the National Natural Science Foundation of China (Grant Nos. 50475141, 50436010), the “973” Research Foundation of China (Grant No. 2005CB724103) and the Program for New Century Excellent Talents in University (Grant No. NCET-05-0651)  相似文献   
40.
模块化机器人双臂协调操作的实验研究   总被引:1,自引:0,他引:1  
提出了利用optotrak3020三维测量系统获得精确位置信息来进行双臂机器人协调操作的方法。通过对双臂协调操作的运动约束进行分析,确定双臂协调运动的约束条件,同时将三维测量系统获得的空间三维坐标信息反馈到控制计算机,调整机器人末端的位置和姿态,以装配螺栓为例从运动学角度完成协调操作的实验。实验证明,利用optotrak3020三维测量系统获得精确位置信息对双臂机器人进行协调操作是有效的。  相似文献   
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