全文获取类型
收费全文 | 768篇 |
免费 | 40篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 6篇 |
综合类 | 11篇 |
化学工业 | 265篇 |
金属工艺 | 8篇 |
机械仪表 | 10篇 |
建筑科学 | 30篇 |
矿业工程 | 5篇 |
能源动力 | 15篇 |
轻工业 | 90篇 |
水利工程 | 2篇 |
石油天然气 | 8篇 |
武器工业 | 3篇 |
无线电 | 57篇 |
一般工业技术 | 56篇 |
冶金工业 | 7篇 |
原子能技术 | 4篇 |
自动化技术 | 249篇 |
出版年
2024年 | 1篇 |
2023年 | 7篇 |
2022年 | 6篇 |
2021年 | 28篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 23篇 |
2017年 | 31篇 |
2016年 | 21篇 |
2015年 | 21篇 |
2014年 | 26篇 |
2013年 | 69篇 |
2012年 | 37篇 |
2011年 | 58篇 |
2010年 | 36篇 |
2009年 | 70篇 |
2008年 | 55篇 |
2007年 | 54篇 |
2006年 | 47篇 |
2005年 | 33篇 |
2004年 | 25篇 |
2003年 | 27篇 |
2002年 | 21篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 14篇 |
1998年 | 3篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 2篇 |
1994年 | 4篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有826条查询结果,搜索用时 0 毫秒
71.
Impact of zinc salts on heat-induced aggregation of natural actomyosin from yellow stripe trevally 总被引:2,自引:0,他引:2
Impact of zinc sulphate (ZnSO4) and zinc chloride (ZnCl2) on heat-induced aggregation of natural actomyosin (NAM) extracted from yellow stripe trevally (Selaroides leptolepis) was investigated. In the presence of ZnSO4 or ZnCl2, the transition temperature (Tmax) of myosin shifted from 47.83 ± 0.30 °C to 46.05 ± 0.36 and 46.49 ± 0.49 °C, with the coincidental decreases in ΔH from 1.07 ± 0.03 J/g to 0.63 ± 0.02 and 0.67 ± 0.04 J/g, respectively (P < 0.05). Additionally, Ca2+–ATPase activity of NAM decreased with increasing the concentrations of ZnSO4 or ZnCl2 during heating up to 40 °C. During heating from 20 to 75 °C, higher turbidity, surface hydrophobicity and disulphide bond formation were obtained in NAM added with ZnSO4 or ZnCl2 at temperatures ranging from 40 to 75 °C, compared with the control. Nevertheless, a higher aggregation was found in NAM added with ZnSO4, compared with ZnCl2. Zeta potential (ζ) analysis suggested that the surface of NAM added with ZnSO4 became less negatively charged, compared with that of ZnCl2 counterpart. Transmission electron microscopy showed that the structure of NAM was highly interconnected, finer and denser when zinc salts, especially ZnSO4 were incorporated. Therefore, ZnSO4 could be used to induce aggregation of fish muscle proteins, thereby improving gelling property of fish mince or surimi. 相似文献
72.
Review on multi-criteria decision analysis aid in sustainable energy decision-making 总被引:4,自引:0,他引:4
Jiang-Jiang Wang You-Yin Jing Chun-Fa Zhang Jun-Hong Zhao 《Renewable & Sustainable Energy Reviews》2009,13(9):2263-2278
Multi-criteria decision analysis (MCDA) methods have become increasingly popular in decision-making for sustainable energy because of the multi-dimensionality of the sustainability goal and the complexity of socio-economic and biophysical systems. This article reviewed the corresponding methods in different stages of multi-criteria decision-making for sustainable energy, i.e., criteria selection, criteria weighting, evaluation, and final aggregation. The criteria of energy supply systems are summarized from technical, economic, environmental and social aspects. The weighting methods of criteria are classified into three categories: subjective weighting, objective weighting and combination weighting methods. Several methods based on weighted sum, priority setting, outranking, fuzzy set methodology and their combinations are employed for energy decision-making. It is observed that the investment cost locates the first place in all evaluation criteria and CO2 emission follows closely because of more focuses on environment protection, equal criteria weights are still the most popular weighting method, analytical hierarchy process is the most popular comprehensive MCDA method, and the aggregation methods are helpful to get the rational result in sustainable energy decision-making. 相似文献
73.
Trimmed bagging 总被引:1,自引:0,他引:1
Bagging has been found to be successful in increasing the predictive performance of unstable classifiers. Bagging draws bootstrap samples from the training sample, applies the classifier to each bootstrap sample, and then averages over all obtained classification rules. The idea of trimmed bagging is to exclude the bootstrapped classification rules that yield the highest error rates, as estimated by the out-of-bag error rate, and to aggregate over the remaining ones. In this note we explore the potential benefits of trimmed bagging. On the basis of numerical experiments, we conclude that trimmed bagging performs comparably to standard bagging when applied to unstable classifiers as decision trees, but yields better results when applied to more stable base classifiers, like support vector machines. 相似文献
74.
海战场综合电子信息系统仿真测试技术 总被引:1,自引:0,他引:1
为了对海战场综合电子信息系统的功能和性能指标进行测试,迫切需要对海战场综合电子信息系统的测试内容、测试方法、测试环境构成、态势驱动方式等内容进行深入研究.文章介绍了海战场综合电子信息系统的组成、功能和评估指标体系,详细阐述了海战场综合电子信息系统仿真测试系统的类型、功能、成员设计、测试过程、主要模型及关键技术.该仿真测试系统已经用于某作战指挥系统和某指挥自动化系统应用软件的研究测试中,可以为海战场综合电子信息系统的研制提供全面的仿真测试环境. 相似文献
75.
《Information and Software Technology》2013,55(9):1590-1601
ContextAn accepted fact in software engineering is that software must undergo verification and validation process during development to ascertain and improve its quality level. But there are too many techniques than a single developer could master, yet, it is impossible to be certain that software is free of defects. So, it is crucial for developers to be able to choose from available evaluation techniques, the one most suitable and likely to yield optimum quality results for different products. Though, some knowledge is available on the strengths and weaknesses of the available software quality assurance techniques but not much is known yet on the relationship between different techniques and contextual behavior of the techniques.ObjectiveThis research investigates the effectiveness of two testing techniques – equivalence class partitioning and decision coverage and one review technique – code review by abstraction, in terms of their fault detection capability. This will be used to strengthen the practical knowledge available on these techniques.MethodThe results of eight experiments conducted over 5 years to investigate the effectiveness of three techniques – code reading by stepwise abstraction, equivalence class partitioning and decision (branch) coverage were aggregated using a less rigorous aggregation process proposed during the course of this work.ResultsIt was discovered that the equivalence class partitioning and the decision coverage techniques behaved similarly in terms of fault detection capacity (and type of faults caught) based on the programs and fault classification used in the experiments. They both behaved better than the code reading by stepwise abstraction technique.ConclusionOverall, it can be deducted from the aggregation results that the equivalence class partitioning and the decision coverage techniques used are actually equally capable in terms of the type and number of faults detected. Nevertheless, more experiments is still required in this field so that this result can be verified using a rigorous aggregation technique. 相似文献
76.
本文阐述了土壤有机质(SOM)稳定性的影响因素及其稳定性特征,包括有机物质化学稳定性、物理稳定性和生物化学稳定性,探讨了通过分子特征,即元素组成、功能团、分子构像;有机物、无机物质或其它有机物质之间的分子间相互作用;有机质与微生物和酶之间的作用;以及水热条件对SOM稳定性的影响。 相似文献
77.
石油沥青质的化学和物理:Ⅳ.石油沥青质溶液的胶体化学 总被引:13,自引:2,他引:13
本文从胶体化学的角度讨论了石油青质的性质,评述了自1924年以来提出的各种沥青胶体模型,探讨了石油胶粒的形状和尺寸,形成机制以及沥青质粒子聚集的动力学行为。 相似文献
78.
The induced generalized OWA operator 总被引:1,自引:0,他引:1
We present the induced generalized ordered weighted averaging (IGOWA) operator. It is a new aggregation operator that generalizes the OWA operator, including the main characteristics of both the generalized OWA and the induced OWA operator. This operator uses generalized means and order-inducing variables in the reordering process. It provides a very general formulation that includes as special cases a wide range of aggregation operators, including all the particular cases of the IOWA and the GOWA operator, the induced ordered weighted geometric (IOWG) operator and the induced ordered weighted quadratic averaging (IOWQA) operator. We further generalize the IGOWA operator via quasi-arithmetic means. The result is the Quasi-IOWA operator. Finally, we present a numerical example to illustrate the new approach in a financial decision-making problem. 相似文献
79.
The usefulness of Monte Carlo simulation of aggregation phenomena is discussed and applied in analysis of the structure of particle deposits. The structural properties of depositional aggregates in single and multiparticle regimes are obtained and expressed in terms of fractal geometrical concepts. These properties are related to the Peclet number and to the concentration in the non-aggregate (vapour) phase. The topological properties of the aggregates are obtained from random walk simulation, thus confirming the anomalous properties of these structures, even in the case of multiparticle simulations, i.e. for high values of the concentration in the vapour phase. 相似文献
80.
Rocío de Andrés José Luis García-Lapresta Luis Martínez 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2010,14(1):21-34
The performance appraisal is a relevant process to keep and improve the competitiveness of companies in nowadays. In spite
of this relevance, the current performance appraisal models are not sufficiently well-defined either designed for the evaluation
framework in which they are defined. This paper proposes a performance appraisal model where the assessments are modelled
by means of linguistic information provided by different sets of reviewers in order to manage the uncertainty and subjectivity
of such assessments. Therefore, the reviewers could express their assessments in different linguistic scales according to
their knowledge about the evaluated employees, defining a multi-granular linguistic evaluation framework. Additionally, the
proposed model will manage the multi-granular linguistic labels provided by appraisers in order to compute collective assessments
about the employees that will be used by the management team to make the final decision about them. 相似文献