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121.
Multi-frequency passive microwave remote sensing affords a unique opportunity to understand various phenomena; low-frequency microwaves penetrate clouds and are able to observe Earth surface conditions (~6–18 GHz), while the higher frequencies are strongly impacted by prevailing atmospheric conditions. By using these relationships, an atmospheric opacity index (AOI) using Advanced Microwave Scanning Radiometer on Earth Observing Satellite (AMSR-E) multi-frequency data is proposed. This index utilizes four AMSR-E frequencies spanning both high- and low-microwave frequency. This AOI can be used to discriminate cloudy atmosphere from clear-sky conditions. This index shows good agreement with current cloud indices. In this research, it is compared against the Moderate Imaging Spectroradiometer (MODIS) and the Geostationary Operational Environmental Satellite 9th series (GOES-9) atmosphere products. It offers the possibility of detecting convective clouds at all times (day and night) due to the advantage of the independence of the microwave sensors on the Sun for illumination. 相似文献
122.
Toshio Honda 《Sequential Analysis》2013,32(1):73-89
Let X1, X2... be i.i.d. observations with mean μ and variance σ2, and suppose that given a sample of size n one wishes to estimate μ by Xn, subject to the loss function Ln= A2(Xn-μ)2+n. When σ2 is unknown, the optimal sample size n0 for minimizing the risk Rn = E{Ln} cannotbe found. To resolve this problem, Robbins (1959) proposed a sequential procedure whenXi is normally distributed, and then the asymptotic properties have been extensively studied. In this paper, we apply Hall's three stage procedure to the problem without specifying the distribution of Xi and derive the second order asymptotic expansions of the expected sample size and the risk. 相似文献
123.
Toshio Honda 《Sequential Analysis》2013,32(3-4):239-251
Suppose that {Xn} is a strongly mixing process with unknow marginal density f(x) and that we estimate f(x) by a kernel estimator [fcirc]n(x|hn)and want to achive the MISE no larger than some preassigned postive number w. However,the appropriate sample size n*depends on a functional of the unknow density function. Therefore some sequential procedure is required and we adopt a fully sequential procedure. In this paper we investigate the asymptotic properties of the procedure and show that the producure is asymptotically efficient in a certain sense as w→0. The results are almost the same in the i.i.d. setting. our result extend a class of models to which the methodology can be applied. For example economic variable,experiments on a single subject in which obervation are not indepent, and so on. 相似文献
124.
Effect of Firing Temperature on the Thermal Stability of Low-Oxygen Silicon Carbide Fibers 总被引:1,自引:0,他引:1
Toshio Shimoo Ichiro Tsukada Tadao Seguchi Kiyohito Okamura 《Journal of the American Ceramic Society》1998,81(8):2109-2115
Low-oxygen SiC fibers which were fabricated by curing with electron-beam irradiation and firing at 1273 and 1573 K (fiber-A and fiber-B) were exposed at 1673 to 1973 K. Significant differences in surface composition, crystallinity, specific resistivity, and tensile strength were found between fiber-A and fiber-B. On exposing the fibers to high temperatures, they both crystallized nearly completely into intermixed β-SiC and free carbon, and consequently the resistivity decreased markedly. Deep voids were formed at the surface of fiber-A as a result of rapid dehydrogenation at the earliest stage of high-temperature exposure. On the other hand, fiber-B, which decomposed mildly, had a dense pore-free structure. The fiber strength was proportional to the reciprocal square root of SiC crystal size. At the same crystal size, the strength of fiber-A was lower because of the surface flaws. 相似文献
125.
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127.
When the excited triplet states of disperse azo dyes with nitro groups abstract hydrogen to generate hydrazinyl (from azo groups) and nitrosyl hydroxide radicals (from nitro groups), both the radicals as H‐acceptors carry out azo scission, conversion to nitrogen dioxide via disproportionation reactions and self‐decomposition via rearrangement. A kinetic equation was formulated by the sum of these reactions, which describes the initial rates (KPA) of reductive fading. The KPA values were controlled by the rate constants of the reactions of hydrazinyl and nitrosyl hydroxide radicals as H‐acceptors, which were estimated by thermochemical analyses of the reactants, intermediates and end products using the semiempirical molecular orbital PM5 method, and by the concentrations of the reactants: H‐acceptors and H‐donors. The KPA values observed for 12 dyes were explained semi‐quantitatively by multiple routes of reactions depending upon to what extent each radical reaction was thermochemically favoured. 相似文献
128.
The microstructure development in Sb2O3-doped ZnO was studied at doping levels up to 2.0 mol%. Dopant Sb2O3 reacted with ZnO to form inclusion particles,α-Zn7Sb2O12, and inhibited the grain growth of ZnO. With increasing doping level of Sb2O3, the growth rate of ZnO decreased whereas that of inclusion particles increased. Some inclusion particles were trapped in ZnO grains at low doping levels of Sb2O3, but the volume fraction of trapped inclusion particles decreased with increasing doping level. Stereological analysis of the size and number ratios of ZnO grains and inclusion particles indicated that a compatible assumption is needed to evaluate Zener effect in two-phase sintering. 相似文献
129.
This paper describes principles, analyses and experimental studies of a brushless and self-excited single-phase synchronous generator which was devised by one of the authors. The analyses and test results of performances of the generator system of which the armature winding is supplied with an exciting power from a transformer which is connected with the generator armature winding through a reactor or a condenser are presented. It can be found from the test results that the necessary exciting power is less in case of the armature winding supplied with DC exciting current from the transformer through the condenser. 相似文献
130.
The work described in this paper is a study of the high temperature corrosion reaction of iron in oils containing phosphorus compounds such as the phosphite, phosphate, thiosulphate, acid phosphate and acid phosphite, by using the hot-wire method. The neutral type esters show very little chemical reactivity towards iron in marked contrast to the very high reactivity of the acid type esters and thiophosphite. X-ray analysis revealed basic iron phosphate, 2FeFe4(PO4)(OH)5, and iron sulfide as the main reaction products for the neutral type and acid type esters and thiophosphite, respectively. The surface polishing action, peculiarly attributed to phosphorus compounds, could not be confirmed in the present work. The results from X-ray analysis seem to support the iron phosphate lubrication mechanism of phosphorus type EP additives. Some considerations are given for the correlations between the chemical reactivity, load carrying capacity and anti-wear property of oils containing phosphorus compounds. As to the lubrication characteristics of chloride, sulfide, phosphide and phosphate films, some postulations are made. 相似文献