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461.
Established helper-judged frequency and discomfort values for potentially challenging interaction situations between nonprofessional child aides and young maladapting school children. Ss were 49 child aides with 1-3 yrs intensive experience, under supervision, with 10-50 primary graders. Helper discomforts were found to cluster meaningfully. Child aggression, family problems, and limit-testing behavior produced greater helper discomfort than the child's need to have the aide for himself or to be dependent. Rarely experienced situations had the highest judged discomfort ratings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
462.
The question of the nature and stability of polar ordering in nanoscale ferroelectrics is examined with colloidal nanocrystals of germanium telluride (GeTe). We provide atomic-scale evidence for room-temperature polar ordering in individual nanocrystals using aberration-corrected transmission electron microscopy and demonstrate a reversible, size-dependent polar-nonpolar phase transition of displacive character in nanocrystal ensembles. A substantial linear component of the distortion is observed, which is in contrast with theoretical reports predicting a toroidal state.  相似文献   
463.
Scope : To identify genes involved in the susceptibility to iodine‐induced autoimmune thyroiditis. Methods and results : Diabetes, thyroiditis‐prone (BBdp) and ‐resistant (BBc) rats were fed either a control or a high‐iodine diet for 9 wk. Excess iodine intake increased the incidence of insulitis and thyroiditis in BBdp rats. BBdp rats fed the high‐iodine diet that did not develop thyroiditis had higher mRNA levels of Fabp4, Cidec, perilipin, Pparγ and Slc36a2 than BBdp rats fed the control diet and BBc rats fed either the control or the high‐iodine diet. BBdp rats fed the high‐iodine diet that did develop thyroiditis had higher mRNA levels of Cidec, Icam1, Ifitm1, and Slpi than BBdp rats fed the control diet and BBc rats fed either the control or the high‐iodine diet. BBdp rats that did develop thyroiditis had lower mRNA levels of Fabp4, perilipin and Slc36a2 but higher mRNA levels of Icam1, Ifitm1 and Slpi than BBdp that did not develop thyroiditis. Excess dietary iodine also increased the protein levels of Fabp4, Cidec and perilipin in BBdp rats. Conclusion : Differential expression of thyroid genes in BBdp versus BBc rats caused by excess dietary iodine may be implicated in autoimmune thyroiditis and insulitis pathogenesis.  相似文献   
464.
Many organisms provision offspring with antipredator chemicals. Adult blue-ringed octopuses (Hapalochlaena spp.) harbor tetrodotoxin (TTX), which may be produced by symbiotic bacteria. Regardless of the ultimate source, we find that females invest TTX into offspring and offspring TTX levels are significantly correlated with female TTX levels. Because diversion of TTX to offspring begins during the earliest stages of egg formation, when females are still actively foraging and looking for mates, females may face an evolutionary tradeoff between provisioning larger stores of TTX in eggs and retaining that TTX for their own defense and offense (venom). Given that total TTX levels appear to increase during development and that female TTX levels correlate with those of offspring, investment may be an active adaptive process. Even after eggs have been laid, TTX levels continue to increase, suggesting that offspring or their symbionts begin producing TTX independently. The maternal investment of TTX in offspring of Hapalochlaena spp. represents a rare examination of chemical defenses, excepting ink, in cephalopods.  相似文献   
465.
Variable emittance (ε) is a property vital for the increasing needs in thermal control of future microspacecraft. This article describes fabrication, function, and performance of thin‐film, flexible, variable‐emittance (V‐E) electrochromic skins that use a conducting polymer/‐Au/‐microporous membrane (CP/Au/µP) base, and a new, unique ionic liquid electrolyte (IonEl). Poly(aniline‐co‐diphenyl amine) with a long‐chain polymeric dopant is used as the CP. A unique, patented device design yields no barrier between the active, electrochromic CP surface and the external environment, except for a thin, infrared‐transparent semiconductor/polymer film that lowers solar absorptance [α(s)] and protects from atomic‐O/far‐UV. Use of the IonEl requires special activation methods. Data presented show tailorable ε variations from 0.19 to 0.90, Δε values of >0.50 (which is the highest reported thus far for any functional V‐E material, to our knowledge), α(s) < 0.35, and nearly indefinite cyclability. Extended space durability testing, including calorimetric thermal vacuum and continuous light/dark cycling over >7 months under space conditions (<10?5 Pa vacuum, far‐UV), show excellent durability. Other data show resistance to solar wind, atomic‐O, electrostatic discharge, and micrometeoroids. These lightweight, inexpensive, advanced polymeric materials represent the only technology that can work with micro‐ (<20 kg) and nano‐ (<2 kg) spacecraft, thus eventually allowing for much greater flexibility in their design and potentially “democratizing” the entire space industry, for example, allowing small firms to launch their own, dedicated satellites. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40850.  相似文献   
466.
467.
Small molecules inducing protein degradation are important pharmacological tools to interrogate complex biology and are rapidly translating into clinical agents. However, to fully realise the potential of these molecules, selectivity remains a limiting challenge. Herein, we addressed the issue of selectivity in the design of CRL4CRBN recruiting PROteolysis TArgeting Chimeras (PROTACs). Thalidomide derivatives used to generate CRL4CRBN recruiting PROTACs have well described intrinsic monovalent degradation profiles by inducing the recruitment of neo-substrates, such as GSPT1, Ikaros and Aiolos. We leveraged structural insights from known CRL4CRBN neo-substrates to attenuate and indeed remove this monovalent degradation function in well-known CRL4CRBN molecular glues degraders, namely CC-885 and Pomalidomide. We then applied these design principles on a previously published BRD9 PROTAC (dBRD9-A) and generated an analogue with improved selectivity profile. Finally, we implemented a computational modelling pipeline to show that our degron blocking design does not impact PROTAC-induced ternary complex formation. We believe that the tools and principles presented in this work will be valuable to support the development of targeted protein degradation.  相似文献   
468.
Six species of phytoplankton,Pseudoisochrysis paradoxa, Isochrysis galbana, Monochrysis lutheri, Platymonas suecica, Thalassiosira fluviatilis and aChaetoceros species, were cultured in the laboratory and their sterol contents analyzed utilizing digitonin precipitation, thin layer and gas chromatography and gas chromatography-mass spectrometry. A total of 7 sterols were found in phytoplankton. The occurrence of these sterols, cholest-5-en-3β-ol, cholest-5,22-dien-3β-ol, 24-methylcholesta-5,24(28)-dien-3β-ol, 24-methylcholest-5-en-3β-ol, 24-methylcholesta-5,22-dien-3β-ol, 24-ethylcholest-5-en-3β-ol and 24-ethylcholest-5,22-dien-3β-ol, differed significantly among the various phytoplankton species. Cultures ofP. paradoxa biosynthesized both of the sterols found in this species when incubated in the presence of14C- or3H-mevalonic acid for 0.5–9 days. These sterols were cholesterol and 24-methylcholesta-5,22-dien-3β-ol. Since 5 of the sterols found in the phytoplankton commonly occur in mollusks which feed on phytoplankton, it is likely that at least some of the tissue sterols in mollusks are of dietary origin. Research trainee, HL 07295-02, National Heart, Lung and Blood Insitute.  相似文献   
469.
Joint motion control of a powered lower limb orthosis for rehabilitation   总被引:6,自引:0,他引:6  
Many patients with spinal injures are confined to wheelchairs, leading to a sedentary lifestyle with secondary pathologies and increased dependence on a carer. Increasing evidence has shown that locomotor training reduces the incidence of these secondary pathologies, but the physical effort involved in this training is such that there is poor compliance. This paper reports on the design and control of a new "human friendly" orthosis (exoskeleton), powered by high power pneumatic Muscle Actuators (pMAs). The combination of a highly compliant actuation system, with an intelligent embedded control mechanism which senses hip, knee, and ankle positions, velocity, acceleration and force, produces powerful yet inherently safe operation for paraplegic patients. This paper analyzes the motion of ankle, knee, and hip joints under zero loading, and loads which simulate human limb mass, showing that the use of "soft" actuators can provide a smooth user friendly motion. The application of this technology will greatly improve the rehabilitative protocols for paraplegic patients.  相似文献   
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