全文获取类型
收费全文 | 746047篇 |
免费 | 12861篇 |
国内免费 | 2157篇 |
专业分类
电工技术 | 13477篇 |
综合类 | 867篇 |
化学工业 | 113729篇 |
金属工艺 | 27679篇 |
机械仪表 | 21726篇 |
建筑科学 | 18486篇 |
矿业工程 | 3182篇 |
能源动力 | 20098篇 |
轻工业 | 68297篇 |
水利工程 | 7376篇 |
石油天然气 | 12175篇 |
武器工业 | 108篇 |
无线电 | 85194篇 |
一般工业技术 | 141495篇 |
冶金工业 | 145798篇 |
原子能技术 | 14244篇 |
自动化技术 | 67134篇 |
出版年
2022年 | 4800篇 |
2021年 | 7443篇 |
2020年 | 5438篇 |
2019年 | 6936篇 |
2018年 | 11512篇 |
2017年 | 11340篇 |
2016年 | 12002篇 |
2015年 | 8295篇 |
2014年 | 13318篇 |
2013年 | 35341篇 |
2012年 | 21094篇 |
2011年 | 28301篇 |
2010年 | 22312篇 |
2009年 | 24654篇 |
2008年 | 25476篇 |
2007年 | 24891篇 |
2006年 | 21774篇 |
2005年 | 19917篇 |
2004年 | 19119篇 |
2003年 | 18758篇 |
2002年 | 17784篇 |
2001年 | 17490篇 |
2000年 | 16501篇 |
1999年 | 17338篇 |
1998年 | 45081篇 |
1997年 | 31664篇 |
1996年 | 24254篇 |
1995年 | 18163篇 |
1994年 | 15863篇 |
1993年 | 15579篇 |
1992年 | 11345篇 |
1991年 | 10567篇 |
1990年 | 10256篇 |
1989年 | 9893篇 |
1988年 | 9281篇 |
1987年 | 8243篇 |
1986年 | 8107篇 |
1985年 | 9135篇 |
1984年 | 8552篇 |
1983年 | 7604篇 |
1982年 | 7213篇 |
1981年 | 7363篇 |
1980年 | 6970篇 |
1979年 | 6736篇 |
1978年 | 6409篇 |
1977年 | 7888篇 |
1976年 | 10330篇 |
1975年 | 5672篇 |
1974年 | 5401篇 |
1973年 | 5555篇 |
排序方式: 共有10000条查询结果,搜索用时 296 毫秒
91.
Fermanelli Carla S. Galarza Emilce D. Pierella Liliana B. Renzini María S. Saux Clara 《Topics in Catalysis》2019,62(12-16):918-930
Topics in Catalysis - In this work, a simple thermal-catalytic system was used to valorize peanut shells (Arachis hypogaea), the residual biomass from the peanut industry. To accomplish this... 相似文献
92.
María D Torres Herminia Domínguez 《International Journal of Food Science & Technology》2020,55(6):2296-2304
Potato processing industry has a high degree of discarding, which currently has low added value being used primarily for animal feed. However, potato wastes offer a broad range of interesting components such as antioxidants, starch, protein or fibre with potential applications in the food and non-food industries. The recovery of these high valuable fractions using efficient multistage and multiproduct processes could be of great interest. This short review provides a general overview on the integral valorisation of potato wastes, offering an updated vision of the main residual parts generated during potato harvesting and processing, the high valuable obtained components focusing on the bioactive ones and the potential of the emerging extraction techniques over conventional ones. In addition, innovative applications are discussed to highlight the scientific and applied interest of these underutilised and undervalued fractions and to emphasise the integral valorisation of raw materials. 相似文献
93.
The role of the following factors in the selection of technological bases for manufacturing is considered: the accessibility of the machined surfaces; their parameters and dimensional relationships; their position relative to the forces acting; and the uniformity of the margin distribution. 相似文献
94.
Kobrakov K. I. Kurnetsov D. N. Ruchkina A. G. Sharpar N. M. 《Theoretical Foundations of Chemical Engineering》2020,54(5):1052-1056
Theoretical Foundations of Chemical Engineering - New research results, as well as those published earlier by the authors, on the synthesis of azo compounds based on nitroanilines obtained by the... 相似文献
95.
A method is proposed to generate categorical colour observer functions (individual colour matching functions) for any field size based on the CIE 2006 system of physiological observer functions. The method combines proposed categorical observer techniques of Sarkar et al with a physiologically-based individual observer model of Asano et al and a clustering technique to produce the optimal set of categorical observers. The number of required categorical observers varies depending on an application with as many as 50 required to predict individual observers' matches when a laser projector is viewed. However, 10 categorical observers are sufficient to represent colour-normal populations for personalized colour imaging. The proposed and recommended categorical observers represent a robust and inclusive technique to examine and quantify observer metamerism in any application of colorimetry. 相似文献
96.
Gomes A. C. S. A. Costa L. C. Brito D. C. Frana R. J. Marques Mnica R. C. 《Polymer Bulletin》2020,77(4):1969-1981
Polymer Bulletin - In this study, we synthesized a new ion-imprinted polymer (IIP) based on introduction of amidoxime groups in acrylonitrile, complexation with Cd2+ ions and polymerization with... 相似文献
97.
Nurullah Bulut Bahar Atmaca Gülsün Akdemir Evrendilek Sibel Uzuner 《Journal of Food Safety》2020,40(6):e12855
Seed processing technologies are essential for seed safety and functionality through protection of physicochemical quality, pathogen inactivation, aflatoxin detoxification and alleviation of mutagenicity. Design of a pilot-scale unit of pulsed electric fields (PEF) to treat sesame seeds with respect to quality parameters, Aspergillus parasiticus inactivation and aflatoxin reduction as well as alleviation of aflatoxin mutagenicity were prompted in this study. PEF energy ranged from 0.97 to 17.28 J achieved maximum reductions of peroxide value and acidity number of 67.4 and 85.7%, respectively, and did not change color L*, a*, b* and hue values. A 60% reduction of A. parasiticus counts occurred at the maximum PEF energy. Aflatoxins G1, G2, B1, and B2 contents decreased by 94.7, 92.7, 86.9, and 98.7%, respectively. Except for the samples treated by 2.16 J with 100 μg/plate and by 6.80 J with 10 μg/plate, PEF treatment provided elimination of aflatoxin mutagenity. It is concluded that PEF treatment can be used to treat sesame seeds with preservation of physicochemical properties, inactivation of A. parasiticus and decomposition of aflatoxins with reduced mutagenicity. 相似文献
98.
Bankov S. E. Vesnik M. V. Kravchenko V. F. 《Journal of Communications Technology and Electronics》2020,65(4):398-405
Journal of Communications Technology and Electronics - Abstract—The article presents a rigorous numerical solution, using the Wiener–Hopf method, to the problem of plane wave... 相似文献
99.
The proliferating need for sustainability intervention in food grain transportation planning is anchoring the attention of researchers in the interests of stakeholders and environment at large. Uncertainty associated with food grain supply further intensifies the problem steering the need for designing robust, cost-efficient and sustainable models. In line with this, this paper aims to develop a robust and sustainable intermodal transportation model to facilitate single type of food grain commodity shipments while considering procurement uncertainty, greenhouse gas emissions, and intentional hub disruption. The problem is designed as a mixed integer non-linear robust optimisation model on a hub and spoke network for evaluating near optimal shipment quantity, route selection and hub location decisions. The robust optimisation approach considers minimisation of total relative regret associated with total cost subject to several real-time constraints. A version of Particle Swarm Optimisation with Differential Evolution is proposed to tackle the resulting NP-hard problem. The model is tested with two other state-of the art meta-heuristics for small, medium, and large datasets subject to different procurement scenarios inspired from real time food grain operations in Indian context. Finally, the solution is evaluated with respect to total cost, model and solution robustness for all instances. 相似文献
100.
Durmuş Burhanettin Temurtaş Hasan Özyön Serdar 《Neural computing & applications》2020,32(22):17097-17113
Neural Computing and Applications - This study presents the design of a tenth-order multiple feedback Chebyshev low-pass filter (MF-C-LPF). Component selection and gain calculation of filters are... 相似文献