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排序方式: 共有571条查询结果,搜索用时 31 毫秒
111.
K. Young T. Ouchi Y. Liu B. Reichman W. Mays M.A. Fetcenko 《Journal of Alloys and Compounds》2009,480(2):521-528
Simple ternary alloys with formula TixZr7−xNi10 (x between 0 and 2.5) were studied as a potential replacement for Laves phase alloys used in the negative electrodes of nickel metal hydride batteries. The samples were prepared by arc-melting and were not annealed. The samples retained a high degree of disorder, which contributed positively to activation and other electrochemical properties. Before hydrogenation, the alloys have a Zr7Ni10 orthorhombic structure mixed with some C15 and ZrO2 secondary phases. The amount of C15 secondary phase is important to the bulk diffusion of hydrogen and the surface electrochemical kinetics. That is, the diffusion coefficient and the exchange current both increase in the presence of C15 secondary phase. The proportion of C15 secondary phase is controllable by stoichiometry design. For instance, a slightly higher Zr content reduces the C15 content. Further, as the titanium substitution level increases: (1) the lattice constants decrease; (2) the PCT plateau pressure increases; (3) activation becomes easier; and (4) the high rate dischargeability improves. 相似文献
112.
Carolina A. Oliva Jimmy Stehberg Rafael Barra Trinidad Mariqueo 《International journal of molecular sciences》2022,23(13)
Neuropathic pain reduces GABA and glycine receptor (GlyR)-mediated activity in spinal and supraspinal regions associated with pain processing. Interleukin-1β (IL-1β) alters Central Amygdala (CeA) excitability by reducing glycinergic inhibition in a mechanism that involves the auxiliary β-subunit of GlyR (βGlyR), which is highly expressed in this region. However, GlyR activity and its modulation by IL-1β in supraspinal brain regions under neuropathic pain have not been studied. We performed chronic constriction injury (CCI) of the sciatic nerve in male Sprague Dawley rats, a procedure that induces hind paw plantar hyperalgesia and neuropathic pain. Ten days later, the rats were euthanized, and their brains were sliced. Glycinergic spontaneous inhibitory currents (sIPSCs) were recorded in the CeA slices. The sIPSCs from CeA neurons of CCI animals show a bimodal amplitude distribution, different from the normal distribution in Sham animals, with small and large amplitudes of similar decay constants. The perfusion of IL-1β (10 ng/mL) in these slices reduced the amplitudes within the first five minutes, with a pronounced effect on the largest amplitudes. Our data support a possible role for CeA GlyRs in pain processing and in the neuroimmune modulation of pain perception. 相似文献
113.
Xi He Ningchao Zheng Ruiting Hu Zhuofeng Hu Jimmy C. Yu 《Advanced functional materials》2021,31(7):2006505
Biomasses are very important natural products. Transferring biomass into catalysts for the advanced oxidation process (AOP) via heat treatment has attracted extensive attention. This review systematically introduces and summarizes two kinds of innovative biomass-based catalysts according to the treating temperature. At low temperature ( < 300 ° C), biomasses are converted into hydrothermal carbonation carbon (HTCC) with semiconductive properties for photocatalysis application. At high temperature ( > 300 ° C), by contrast, the products lose their semiconductive nature and become a conductive carbon-based conductor (biochar). They usually work as AOP catalysts by activating oxidant of O2, H2O2, and peroxysulfate for environmental treatment. This review summarizes and compares HTCC and biochar according to their formation process, structure, catalytic mechanism, and key points for the activity enhancement. The active units in HTCC are the sp2-hybridized polyfuran unit while those in biochar are the persistent free radicals, nitrogen-containing unit, or defects. HTCC converts water into OH radicals by using the photoexcited electron/hole pairs induced by solar illumination, while biochar activates oxidants via the active unit on its surface. More importantly, this review summarizes and demonstrates the key points to obtain high-efficiency HTCC and biochar catalysts. Finally, conclusions are drawn and the future aspects for biomass-based catalysis are given. 相似文献
114.
115.
John B. Braden DooHwan Won Laura O. Taylor Nicole Mays Allegra Cangelosi Arianto A. Patunru 《Journal of Great Lakes research》2008,34(4):649-660
This study estimates the economic benefits of remediation in the Sheboygan River, WI Area of Concern (AOC) using two distinct empirical methods. The methodology parallels that described by Braden et al. (2008). The results are mixed. Using hedonic analysis of property sales, for owner-occupied homes within a 5-mile radius of the Sheboygan River AOC, the overall estimated loss of value is $158 million (8% of market value). Of this total, only $49 million in losses for homes closest to the upper river segment has strong statistical support. The impacts are greatest proportionally for properties closest to the AOC. A survey-based method yields a mean estimate of $218 million (10% of property value) in willingness to pay for full cleanup of the AOC. If remediation were to induce recovery of property values, then the local communities could benefit through increased property tax revenues. 相似文献
116.
JJ Harrington G Van Bokkelen RW Mays K Gustashaw HF Willard 《Canadian Metallurgical Quarterly》1997,15(4):345-355
We have combined long synthetic arrays of alpha satellite DNA with telomeric DNA and genomic DNA to generate artificial chromosomes in human HT1080 cells. The resulting linear microchromosomes contain exogenous alpha satellite DNA, are mitotically and cytogenetically stable in the absence of selection for up to six months in culture, bind centromere proteins specific for active centromeres, and are estimated to be 6-10 megabases in size, approximately one-fifth to one-tenth the size of endogenous human chromosomes. We conclude that this strategy results in the formation of de novo centromere activity and that the microchromosomes so generated contain all of the sequence elements required for stable mitotic chromosome segregation and maintenance. This first-generation system for the construction of human artificial chromosomes should be suitable for dissecting the sequence requirements of human centromeres, as well as developing constructs useful for therapeutic applications. 相似文献
117.
Determination of the Optimal Location for Developments to Minimize Detention Requirements 总被引:1,自引:1,他引:0
A methodology is presented to determine the optimal locations to place various types of developments in a watershed to reduce the changes in flow rates and volume from natural to developed conditions. An optimization model is developed which incorporates the hydrology (based upon rational method computations and a lag routing method) as constraints. The non-linear programming (NLP) model can be solved using Microsoft Excel (generalized reduced gradient (GRG)) procedure, or other NLP software. This model is meant to serve as a planning tool to help develop best management practices for regulatory agencies and to reduce cost of drainage facilities for developers. The model was applied to two examples to show its applicability and usefulness using Excel NLP software, which should enhance the availability of the modeling approach. 相似文献
118.
David W. Payton David Keirsey Dan M. Kimble Jimmy Krozel J. Kenneth Rosenblatt 《Applied Intelligence》1992,2(3):225-250
This paper describes a highly distributed fault-tolerant control system capable of compensating for deficiencies in system-level performance even when the cause of a fault cannot be explicitly identified. Developed for an autonomous underwater vehicle that must remain operational for several weeks without human intervention, this system must be capable of dealing with events that cannot be anticipated at design time. A unique aspect of this system is that it handles such events by attempting to do whatever works if it is unable to diagnose and correct specific faults. The software architecture used in this approach is applicable to a wide range of complex autonomous control applications. 相似文献
119.
Differentiating Antiproliferative and Chemopreventive Modes of Activity for Electron‐Deficient Aryl Isothiocyanates against Human MCF‐7 Cells
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120.
GN Taylor RD Lloyd CW Mays SC Miller WS Jee S Mori L Shabestari XJ Li 《Canadian Metallurgical Quarterly》1997,73(4):679-683
A comparison of the risk coefficients for 239Pu- or 226Ra-induced bone cancer in two canine breeds, one with a relatively low (beagle) and the other with a very high (St. Bernard) natural incidence, indicated only slightly higher risk in the giant breed. The differences in risk for skeletal malignancy in 239Pu and 226Ra dogs were nonsignificant (p > 0.05). Likewise, the values of the 239Pu:226Ra "toxicity ratios" for these respective breeds, using bone cancer as the endpoint, were not significantly different at the 0.05 level. The anatomical distribution of the radiation-induced bone tumors tended to be a function of both the bone mass and the skeletal distribution of the radionuclide, not the site of predilection for naturally occurring bone neoplasia. Although the etiology of the higher natural incidence of bone cancer in the St. Bernard was not determined, several possible factors, including a higher osteoblastic activity level in the St. Bernards, are presented. These data suggest that making extrapolations of radiation-induced bone cancer risk from animals to humans is valid. 相似文献