全文获取类型
收费全文 | 209篇 |
免费 | 15篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 86篇 |
金属工艺 | 4篇 |
机械仪表 | 3篇 |
建筑科学 | 7篇 |
矿业工程 | 1篇 |
能源动力 | 1篇 |
轻工业 | 33篇 |
武器工业 | 1篇 |
无线电 | 7篇 |
一般工业技术 | 49篇 |
冶金工业 | 2篇 |
原子能技术 | 1篇 |
自动化技术 | 23篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 5篇 |
2013年 | 25篇 |
2012年 | 13篇 |
2011年 | 19篇 |
2010年 | 13篇 |
2009年 | 15篇 |
2008年 | 11篇 |
2007年 | 4篇 |
2006年 | 7篇 |
2005年 | 1篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 2篇 |
2001年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1993年 | 3篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1983年 | 5篇 |
1982年 | 3篇 |
1981年 | 8篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 3篇 |
1973年 | 5篇 |
1966年 | 2篇 |
排序方式: 共有224条查询结果,搜索用时 28 毫秒
41.
Koľveková Gabriela Raisová Manuela Zoričak Martin Gazda Vladimír 《Computational Economics》2021,58(1):57-81
Computational Economics - Population growth and greater human well-being imply increased use of scarce resources, which makes innovative proposals for fair redistribution policies necessary. The... 相似文献
42.
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
43.
Vijay Bijalwan Vladimír Prajzler Jiří Erhart Hua Tan Pavla Roupcová Dinara Sobola Pavel Tofel Karel Maca 《Journal of the European Ceramic Society》2021,41(4):2514-2523
This work shows for the first time the possibility to sinter BCZT powder compacts by rapid heating rates within one hour of sintering, while achieving good piezoelectric properties. The sintering was performed by rapid (heating rates 100 and 200 °C/min) pressure-less sintering (PLS) at 1550 °C/5-60 min and by SPS sintering (100 °C/min, 1450 °C/5?60 min and 1500 °C/15?45 min). The rapid PLS samples reached a relative density up to 94 % and grain sizes of 17–36 μm acquiring d33 up to 414 pC/N. Although the SPS samples reached full density at 1450 °C, their piezoelectric properties worsened due to smaller grains (10?15 μm) as well as formation of cracks at dwell times > 30 min. At elevated SPS temperature of 1500 °C/30 min, the d33 increased to 360 pC/N sustaining full density. Even higher increase in d33 (424 pC/N) of SPS samples was achieved by post-rapid PLS at 1550 °C/60 min resulting from further expansion in grain size. 相似文献
44.
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
45.
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
46.
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
47.
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
48.
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
49.
The effects of age, vegetation density (normalised difference vegetation index [NDVI]) and vegetation type on temperature fluctuations were studied in post-coal-mining sites in the Czech Republic. NDVI and surface temperature were obtained from an airborne multispectral aerial photograph and FLIR infrared camera. The difference between morning and afternoon temperature was assumed as a measure of the temperature buffering ability of the ecosystem. Buffering increased with increasing NDVI but also depended on the type of vegetation, reclaimed sites have significantly higher buffering than unreclaimed sites. In contrary to grasslands, woody vegetation gradually increased temperature buffering capacity with plot age. Topsoil application substantially increased buffering capacity. 相似文献
50.