全文获取类型
收费全文 | 1135篇 |
免费 | 91篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 12篇 |
化学工业 | 370篇 |
金属工艺 | 32篇 |
机械仪表 | 26篇 |
建筑科学 | 39篇 |
矿业工程 | 2篇 |
能源动力 | 43篇 |
轻工业 | 124篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 43篇 |
一般工业技术 | 265篇 |
冶金工业 | 12篇 |
原子能技术 | 9篇 |
自动化技术 | 242篇 |
出版年
2023年 | 9篇 |
2022年 | 15篇 |
2021年 | 58篇 |
2020年 | 25篇 |
2019年 | 36篇 |
2018年 | 70篇 |
2017年 | 51篇 |
2016年 | 81篇 |
2015年 | 57篇 |
2014年 | 66篇 |
2013年 | 130篇 |
2012年 | 50篇 |
2011年 | 68篇 |
2010年 | 78篇 |
2009年 | 69篇 |
2008年 | 55篇 |
2007年 | 39篇 |
2006年 | 21篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 8篇 |
2002年 | 15篇 |
2001年 | 6篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 10篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1974年 | 8篇 |
1973年 | 5篇 |
排序方式: 共有1229条查询结果,搜索用时 15 毫秒
71.
Jindřich Parus Ivana Kolingerová Martina Málková 《Advances in Engineering Software》2009,40(5):323-333
Morphing is a shape transformation where the shape of one object is deformed to the shape of the other object. It is used as an animation or a modeling technique. Classical morphing operates between two input objects but this concept can be extended to multiple input objects – the so called multimorphing. Shapes generated by the multimorphing form a space of shapes motivated by an affine space. Besides the analogy with an affine space we also introduce an inner product and a concept of an orthogonal projection. We also show how to explore space of shapes and how to systematically generate new shapes. The paper focuses on the boundary representation, although some ideas are more general and can be used for other representations, too. 相似文献
72.
A new equation is developed in this paper which is further used to divide sorption isotherms into classes which are connected to surface water effects and/or solution water effects and their combinations. It is shown that sorption isotherms can be successfully classified using the new equation into three basic classes I, II (most frequent) and III which roughly correspond to the original Brunauer’s classes. The equation is also used for further division of class II into three subclasses. Criteria for these classifications are presented. 相似文献
73.
V. ŠvorčíK K. Ročková B. Dvořánková L. Brož V. Hnatowicz R. Ochsner H. Ryssel 《Journal of Materials Science》2002,37(6):1183-1188
Polyethylene (PE) was irradiated with 10 and 63 keV Ar+ ions to fluences of 1 × 1017 to 3 × 1019 m–2 and then it was grafted with aminoacid (alanine). The changes of surface polarity, electrical conductivity, and oxygen concentration were examined on pristine, as-irradiated, and irradiated-grafted PE. The in vitro adhesion of mice fibroblasts on the modified PE was evaluated 24 hours after inoculation. It was proved that for the PE irradiated at 10 keV ion energy, the presence of chemically bound alanine increases cell adhesion and its homogenity. For PE irradiated with 63 keV ions, however, the alanine grafting leads to a reduction of the number of adhering cells. It was found that a rising surface polarity increases cell adhesion, but when its value is too high the cell adhesion starts to decrease. No correlation between electrical conductivity and cell adhesion was observed. In general, higher cell adhesion is observed on modified PE in comparison with pristine one. 相似文献
74.
Summary The evolution of scientific fields analyzed by co-word analysis and presented in strategic diagrams is simulated based on
the law of cumulative advantages - the probability of a new tie between two keywords depends positively on the frequencies
in which both keywords have taken part already. The results we get from simulations are compared with the results of real
scientific field evolution. We consider the high correspondence of both to be a proof of the working of the law of cumulative
advantages in the development of scientific fields and we believe that our research opens new possibilities for predictions
of the development of scientific fields. 相似文献
75.
76.
77.
The problem of computerized batch control of the silicon epitaxial layer deposition technological process has been solved using optimal stochastic control methods. A control algorithm is presented the main emphasis being given to the forecasting and compensating of disturbing processes which act on a process unit under real operation conditions. The method of multidimensional time series, stochastic model form identification for the process noise is developed based on multidimensional time series, correlation analysis results. The “maximum likelihood” identification method is applied in order to obtain efficient estimates of the model parameters. The identification of the model form and model parameters is carried out on the basis of a rather extensive set of data obtained from operation records of a high capacity epitaxial unit. The adequacy of the identified models is checked by means of a correlation analysis of the model residuals. It is demonstrated that results comparable to those with an intuitive process control by an experienced operator, can be achieved when using the algorithm presented in the present work for process computer control. This algorithm thus represents a reliable and rational basis for process control computer software development. 相似文献
78.
A finite element method often leads to large sparse symmetric and positive definite systems of linear equations. We consider parallel solvers based on the Schur complement method on homogeneous parallel machines with distributed memory. A finite element mesh is partitioned by graph partitioning. Such partitioning results in submeshes with similar numbers of elements and, consequently, submatrices of similar sizes. The submatrices are partially factorised. The time spent on the partial factorisation can be different, i.e., disbalanced, because methods exploiting the sparsity of submatrices are used. This paper proposes a Quality Balancing heuristic that modifies classic mesh partitioning so that the partial factorisation times are balanced, which saves overall computation time, especially for time dependent mechanical and nonstationary transport problems. 相似文献
79.
Temperature‐Dependent Exciton and Trap‐Related Photoluminescence of CdTe Quantum Dots Embedded in a NaCl Matrix: Implication in Thermometry 下载免费PDF全文
Sergii Kalytchuk Olga Zhovtiuk Stephen V. Kershaw Radek Zbořil Andrey L. Rogach 《Small (Weinheim an der Bergstrasse, Germany)》2016,12(4):466-476
Temperature‐dependent optical studies of semiconductor quantum dots (QDs) are fundamentally important for a variety of sensing and imaging applications. The steady‐state and time‐resolved photoluminescence properties of CdTe QDs in the size range from 2.3 to 3.1 nm embedded into a protective matrix of NaCl are studied as a function of temperature from 80 to 360 K. The temperature coefficient is found to be strongly dependent on QD size, with the highest sensitivity obtained for the smallest size of QDs. The emission from solid‐state CdTe QD‐based powders is maintained with high color purity over a wide range of temperatures. Photoluminescence lifetime data suggest that temperature dependence of the intrinsic radiative lifetime in CdTe QDs is rather weak, and it is mostly the temperature‐dependent nonradiative decay of CdTe QDs which is responsible for the thermal quenching of photoluminescence intensity. By virtue of the temperature‐dependent photoluminescence behavior, high color purity, photostability, and high photoluminescence quantum yield (26%–37% in the solid state), CdTe QDs embedded in NaCl matrices are useful solid‐state probes for thermal imaging and sensing over a wide range of temperatures within a number of detection schemes and outstanding sensitivity, such as luminescence thermochromic imaging, ratiometric luminescence, and luminescence lifetime thermal sensing. 相似文献
80.
Wan Norlinda Roshana Mohd Nawi Sharifah Rafidah Wan Alwi Zainuddin Abdul Manan Jiří Jaromír Klemeš 《Clean Technologies and Environmental Policy》2016,18(6):1769-1777
There has been growing interests to reduce the environmental impact caused by greenhouse gas emissions from process plants through various energy conservation strategies. CO2 emissions are closely linked to energy generation, conversion, transmission and utilisation. Various studies on the design of energy-efficient processes, optimal mix of renewable energy and hybrid power system are driven to reduce reliance on fossil fuel as well as CO2 emissions reduction. This paper presents a systematic technique in the form of graphical visualisation tool for cost-effective CO2 emission reduction strategies in industry. The methodology is performed in four steps. The first step involves calculating the energy consumption of a process plant. This is followed by identification of potential strategies to reduce CO2 emissions using the CO2 management hierarchy as a guide. In the third step, the development of “Investment” versus “CO2 Reduction” (ICO2) plot is constructed to measure the optimal CO2 emission reductions achieved from the implementation of possible CO2 reduction strategies. The Systematic Hierarchical Approach for Resilient Process Screening (Wan Alwi and Manan in AIChE J 11:3981–3988, 2006) method is used in the fourth step via substitution or partial implementation of the various CO2 reduction options in order to meet the cost-effective emission reduction within the desired investment limit or payback period (PP). An illustrative case study on a palm oil refinery plant has been used to demonstrate the implementation of the method in reduction of CO2 emissions. The developed graphical tool provides an insight-based approach for systematic CO2 emission reduction in the palm oil refinery considering both heat and power energy sources. Result shows that 31.2 % reduction in CO2 emissions can be achieved with an investment of USD 38,212 and PP of 10 months based on the present energy prices in Malaysia. 相似文献