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41.
Vladimír Špitalský 《Dynamical Systems: An International Journal》2019,34(1):53-70
Recurrence determinism, one of the fundamental characteristics of recurrence quantification analysis, measures predictability of a trajectory of a dynamical system. It is tightly connected with the conditional probability that, given a recurrence, following states of the trajectory will be recurrences. In this paper, we study recurrence determinism of interval dynamical systems. We show that recurrence determinism distinguishes three main types of ω-limit sets of zero entropy maps: finite, solenoidal without non-separable points, and solenoidal with non-separable points. As a corollary, we obtain characterizations of strongly non-chaotic and Li–Yorke (non-)chaotic interval maps via recurrence determinism. For strongly non-chaotic maps, recurrence determinism is always equal to one. Li–Yorke non-chaotic interval maps are those for which recurrence determinism is always positive. Finally, Li–Yorke chaos implies the existence of a Cantor set of points with zero determinism. 相似文献
42.
Kunesová M Hainer V Tvrzicka E Phinney SD Stich V Parízková J Zák A Stunkard AJ 《Lipids》2002,37(1):27-32
Fourteen pairs of obese female monozygotic twins were recruited for a study of genetic influences on serum and adipose fatty
acid (FA) composition. Following 1 wk of inpatient stabilization, fasting serum and adipose tissue obtained by surgical excision
were analyzed by thin-layer and gas chromatography. Intrapair resemblances (IPR) for individual FA were assessed by Spearman
rank correlation and by analysis of variance and were found in serum cholesteryl esters (CE), triglycerides (TG), and adipose
TG. With two exceptions (CE linoleate and adipose eicosapentaenoate), these IPR were limited to the nonessential FA. Palmitate
had significant IPR in four lipid fractions; in serum CE and adipose TG palmitate was strongly correlated with multiple measures
of adiposity. In contrast to other lipid fractions, serum phosphatidylcholine (PC) FA had 12 IPR, of which 6 were essential
FA including arachidonate (r=0.76, P<0.0005), eicosapentaenoate (r=0.78, P<0.0005), and docosahexaenoate (r=0.86, P<0.0001). The PC IPR could not be explained by analysis of preadmission 7-d food records. After dividing the pairs into two
groups differing and nondiffering according to fat intake of individuals in the pair, there was no evidence of a gene-environment
interaction between fat intake and FA composition. The IPR for nonessential FA indicate that there is active genetic control
of either food choices or postabsorptive metabolic processing. The high level of IPR in the PC fraction in contrast to the
other lipid fractions suggests strong genetic influence over selection of specific FA for this membrane fraction independent
of diet. 相似文献
43.
Milan Kubíček Hanns Hofmann Vladimír Hlaváček Jiří Sinkule 《Chemical engineering science》1980,35(4):987-996
An analysis of mass and enthalpy balances describing dynamic behavior of two homogeneous CSTR with recirculation is performed. Methods of investigation of regions of existence of multiple steady states and stability are described. Effect of recirculation ratio, Damköhler number, cooling parameter and cooling temperature on the exit temperature is followed. The dependence of the exit temperature on the residence time is analyzed and it is shown that bizarre situations may occur (deformated “mushrooms”, two isolas, etc.). Plots are given to show the influence of system parameters on the reactor behavior. 相似文献
44.
Jelínek Jaroslav Hlaváček Vladimír Křivský Zdeněk 《Chemical engineering science》1973,28(10):1833-1838
The relaxation procedure is used for solution of two interlinked distillation columns. Both approaches-sequential iterative method and the block relaxation technique are compared. A new algorithm making use of simultaneous solution of all equations is proposed. 相似文献
45.
Giorgio Pettinari Francesco Filippone Antonio Polimeni Giuseppe Mattioli Amalia Patanè Vladim Lebedev Mario Capizzi Aldo Amore Bonapasta 《Advanced functional materials》2015,25(33):5353-5359
Substitution of constituent atoms and/or changes of crystal structure are routinely used to tailor the fundamental properties of a semiconductor. Here, it is shown that such a tailoring can also be realized thanks to a novel hydrogen effect. Four hydrogen atoms can screen the effect the crystal potential has on a constituent cation, thus generating a solitary cation: an effectively isolated impurity, so chemically different from the unscreened constituent cations that it strongly perturbs the electronic properties of the material by increasing its fundamental band‐gap energy. Such a hydrogen‐induced screening effect is removed by thermal treatments, thus permitting reversible modifications of both the “crystal chemistry” and material's properties. This phenomenon, observed in InN and other topical nitrides, should permit the development of a new class of materials as well as the fabrication of photonic devices and optical integrated circuits with distinct, tailor‐made regions emitting or absorbing light, all integrated onto a monolithic semiconductor structure. 相似文献
46.
Jan Rathouský Vladimír Havlena 《International Journal of Adaptive Control and Signal Processing》2013,27(11):974-999
This paper proposes a method to approximate a dual controller by a computationally feasible algorithm. Dual control that optimally solves the problem of simultaneous control and identification of a system with uncertain parameters is known to be both analytically and computationally unsolvable. This paper proposes a multiple‐step active control algorithm that gives a suboptimal but tractable solution to the original dual control problem. The algorithm is based on model predictive control (MPC) and approximates persistent system excitation in terms of the increase of the lowest eigenvalue of the parameter estimate information matrix. The problem is formulated as a two‐phase optimization problem, where first an MPC solution is found and then the lowest eigenvalue of the information matrix is maximized in the next step within a given permitted input perturbation. Unlike similar methods, the proposed algorithm predicts the information matrix for more than one step of control, which makes it possible to uniformly excite the parameter space. The use of MPC in the first design phase instead of a cautious controller is justified by showing unfavorable properties of cautious control. The advantage of the multiple‐step prediction over single‐step prediction is shown by examples and simulations. The proposed algorithm is analyzed in terms of convergence and complexity, and stability issues are addressed. The formal proofs are included in the Appendix. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
47.
ABSTRACTIsogeometric analysis is a recently developed computational approach that integrates finite element analysis directly into design described by non-uniform rational B-splines (NURBS). In this paper, we show that price surfaces that occur in option pricing can be easily described by NURBS surfaces. For a class of stochastic volatility models, we develop a methodology for solving corresponding pricing partial integro-differential equations numerically by isogeometric analysis tools and show that a very small number of space discretization steps can be used to obtain sufficiently accurate results. Presented solution by finite element method is especially useful for practitioners dealing with derivatives where closed-form solution is not available. 相似文献
48.
49.
Eva Lorencová Leona Buňková Dagmar Matoulková Vladimír Dráb Pavel Pleva Vlastimil Kubáň František Buňka 《International Journal of Food Science & Technology》2012,47(10):2086-2091
The aim was to monitor production of eight biogenic amines (BAs) (histamine, tyramine (TYR), tryptamine, putrescine, cadaverine (CAD), phenylethylamine, spermine and spermidine) by selected 81 lactic acid bacteria (LAB) strains: Lactobacillus, Lactococcus, Leuconostoc, Enterococcus, Pediococcus, Tetragenococcus and Bifidobacterium. The tested LAB and bifidobacteria were isolated from dairy products and beer. The decarboxylase activity of the micro‐organisms was studied in growth medium after cultivation. The activity was monitored by HPLC after the pre‐column derivatisation with dansylchloride. Fifty LAB showed decarboxylase activity. Thirty‐one strains produced low concentrations of CAD (≤10 mg L?1). Almost 70% of beer isolates generated higher amounts of TYR (≤3000 mg L?1). Most of the tested LAB demonstrated decarboxylase activity. The above micro‐organisms can contribute to the increase of content of BAs in dairy products or beer and thereby threaten food safety and health of consumers. Production of BAs even by the representatives of some probiotic strains (Bifidobacterium and Lactobacillus rhamnosus) was detected in this research. This study has also proved that contaminating LAB can act as sources of higher amounts of CAD and TYR in beer. 相似文献
50.