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1.
Computing clusters (CC) consisting of several connected machines, could provide a high-performance, multiuser, timesharing environment for executing parallel and sequential jobs. In order to achieve good performance in such an environment, it is necessary to assign processes to machines in a manner that ensures efficient allocation of resources among the jobs. The paper presents opportunity cost algorithms for online assignment of jobs to machines in a CC. These algorithms are designed to improve the overall CPU utilization of the cluster and to reduce the I/O and the interprocess communication (IPC) overhead. Our approach is based on known theoretical results on competitive algorithms. The main contribution of the paper is how to adapt this theory into working algorithms that can assign jobs to machines in a manner that guarantees near-optimal utilization of the CPU resource for jobs that perform I/O and IPC operations. The developed algorithms are easy to implement. We tested the algorithms by means of simulations and executions in a real system and show that they outperform existing methods for process allocation that are based on ad hoc heuristics. 相似文献
2.
Recent advances in the realization of individual molecular‐scale devices [1,2] highlight the integration of individual devices into large‐scale functional circuits as the major challenge. DNA‐programmed assembly is a promising avenue in that direction due to the large amount of information that can be coded into the molecules and the ability to translate that information into physical constructs [3]. Large‐scale DNA‐templated electronics require, however, complex manipulation of double‐stranded DNA (dsDNA) molecules, as well as patterning of the electrical properties instilled to them by, e.g., metallization. To that end, sequence‐specific molecular lithography on single DNA molecules has been developed [4]. This was achieved by harnessing the exquisite homologous recombination process of the RecA protein. Sequence‐specific patterning of the metal coating of DNA molecules, localization of arbitrary labeled molecular objects at any desired dsDNA address without prior modifications, and generation of molecularly accurate stable dsDNA‐dsDNA junctions are demonstrated. The information encoded in the DNA molecules directs the lithographic process in analogy to the masks used in conventional microelectronics. The RecA protein provides the assembling capabilities, as well as the resist function. 相似文献
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Zhi Li Kaveh Ahadi Keren Jiang Behzad Ahvazi Peng Li Anthony O.Anyia Ken Cadien Thomas Thundat 《Nano Research》2017,(5):1847-1860
Nanocellulose is a sustainable and eco-friendly nanomaterial derived from renewable biomass.In this study,we utilized the structural advantages of two types of nanocellulose and fabricated freestanding carbonized hybrid nanocellulose films as electrode materials for supercapacitors.The long cellulose nanofibrils (CNFs) formed a macroporous framework,and the short cellulose nanocrystals were assembled around the CNF framework and generated micro/mesopores.This two-level hierarchical porous structure was successfully preserved during carbonization because of a thin atomic layer deposited (ALD) Al2O3 conformal coating,which effectively prevented the aggregation of nanocellulose.These carbonized,partially graphitized nanocellulose fibers were interconnected,forming an integrated and highly conductive network with a large specific surface area of 1,244 m2·g-1.The two-level hierarchical porous structure facilitated fast ion transport in the film.When tested as an electrode material with a high mass loading of 4 mg·cm-2 for supercapacitors,the hierarchical porous carbon film derived from hybrid nanocellulose exhibited a specific capacitance of 170 F.g-1and extraordinary performance at high current densities.Even at a very high current of 50 A·g-1,it retained 65% of its original specific capacitance,which makes it a promising electrode material for high-power applications. 相似文献
5.
This paper shows that shared-coin algorithms can be combined to optimize several complexity measures, even in the presence of a strong adversary. By combining shared coins of Bracha and Rachman (1991) [10] and of Aspnes and Waarts (1996) [7], this yields a shared-coin algorithm, and hence, a randomized consensus algorithm, with O(nlog2n) individual work and O(n2logn) total work, using single-writer registers. This improves upon each of the above shared coins (where the former has a high cost for individual work, while the latter reduces it but pays in the total work), and is currently the best for this model. 相似文献
7.
Keren Nitzan Leah Ellenbogen Ziv Bentulila Dekel David Motty Franko Emanuela P. Break Michal Zoharetz Alon Shamir Yosef Sarne Ravid Doron 《International journal of molecular sciences》2022,23(16)
Alzheimer’s disease (AD) is the most common form of dementia, but there is still no available treatment. Δ9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent. Using THC in conventional high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice. Here, 5xFAD AD model mice received a single treatment of ULD-THC (0.002 mg/kg) after disease onset and were examined in two separate experiments for cognitive functions, neurotropic, and inflammatory factors in the hippocampus. We show that a single injection of ULD-THC alleviated cognitive impairments in 6- and 12-month-old 5xFAD mice. On the biochemical level, our results indicate an imbalance between the truncated TrkB receptor isoform and the full receptor, with AD mice showing a greater tendency to express the truncated receptor, and ULD-THC improved this imbalance. We also investigated the expression of three AD-related inflammatory markers and found an ameliorating effect of ULD-THC. The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset. 相似文献
8.
本文在金属元素和组成固定的条件下 ,利用正交实验研究了催化剂的制备条件 (沉淀温度A、老化平衡时间B、干燥温度C、加料方式D)对大豆油加氢催化剂活性与选择性的影响 ,发现影响催化剂活性的顺序是D >A >B >C ,影响亚麻酸选择性指数SⅡ 的顺序是A >B >D >C ,亚油酸选择性指数SⅠ 的顺序是B >A >C >D ,其最佳制备条件是沉淀温度 70℃ ,老化平衡时间 4 0min ,干燥温度 1 0 5℃ ,加料方式为并加法。并利用线性回归方法建立了大豆油氢化时亚麻酸与亚油酸的选择性指数SⅡ 和SⅠ 与主要制备条件 (A/K、B/min、C/K)之间的关系 ,即SⅡ =-2 .6386 0 .0 1 0 4A 0 .0 0 55B 0 .0 0 31 33CSⅠ =0 .1 60 7 0 .0 0 0 8A 0 .0 0 1 89B 0 .0 0 53C 相似文献
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10.
利用傅里叶变换红外光谱仪(FTIR)在线追踪聚乙烯基苄基氯(PVBCl)与N,N,N′,N′-四甲基-1,6-己二胺(TMHDA)的交联反应历程,考察了反应时间与温度对交联程度的影响.实验结果表明,随着反应时间的延长,交联程度先迅速增大,而后趋于平缓直至不变;反应温度越高,交联程度越大.对反应进行动力学的研究计算结果显示,该交联反应的反应级数n=4,表观活化能Ea=97.2kJ/mol. 相似文献