全文获取类型
收费全文 | 1478篇 |
免费 | 90篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 20篇 |
综合类 | 4篇 |
化学工业 | 522篇 |
金属工艺 | 37篇 |
机械仪表 | 44篇 |
建筑科学 | 29篇 |
矿业工程 | 2篇 |
能源动力 | 87篇 |
轻工业 | 141篇 |
水利工程 | 14篇 |
石油天然气 | 16篇 |
无线电 | 139篇 |
一般工业技术 | 231篇 |
冶金工业 | 73篇 |
原子能技术 | 7篇 |
自动化技术 | 210篇 |
出版年
2024年 | 5篇 |
2023年 | 23篇 |
2022年 | 47篇 |
2021年 | 85篇 |
2020年 | 59篇 |
2019年 | 64篇 |
2018年 | 84篇 |
2017年 | 82篇 |
2016年 | 69篇 |
2015年 | 49篇 |
2014年 | 71篇 |
2013年 | 124篇 |
2012年 | 93篇 |
2011年 | 87篇 |
2010年 | 66篇 |
2009年 | 60篇 |
2008年 | 53篇 |
2007年 | 41篇 |
2006年 | 27篇 |
2005年 | 29篇 |
2004年 | 19篇 |
2003年 | 21篇 |
2002年 | 26篇 |
2001年 | 11篇 |
2000年 | 9篇 |
1999年 | 13篇 |
1998年 | 24篇 |
1997年 | 10篇 |
1996年 | 13篇 |
1995年 | 12篇 |
1994年 | 7篇 |
1993年 | 16篇 |
1992年 | 11篇 |
1991年 | 8篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 6篇 |
1984年 | 12篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1980年 | 14篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 8篇 |
1975年 | 5篇 |
排序方式: 共有1576条查询结果,搜索用时 15 毫秒
1.
Felipe A. Perdomo Siti H. Khalit Claire S. Adjiman Amparo Galindo George Jackson 《American Institute of Chemical Engineers》2021,67(3):e17194
The SAFT-γ Mie group-contribution equation of state is used to represent the fluid-phase behavior of aqueous solutions of a variety of linear, branched, and cyclic amines. New group interactions are developed in order to model the mixtures of interest, including the like and unlike interactions between alkyl primary, secondary, and tertiary amine groups (NH2, NH, N), cyclic secondary and tertiary amine groups (cNH, cN), and cyclic methine-amine groups (cCHNH, cCHN) with water (H2O). The group-interaction parameters are estimated from appropriate experimental thermodynamic data for pure amines and selected mixtures. By taking advantage of the group-contribution nature of the method, one can describe the fluid-phase behavior of mixtures of molecules comprising those groups over broad ranges of temperature, pressure, and composition. A number of aqueous solutions of amines are studied including linear, branched aliphatic, and cyclic amines. Liquid–liquid equilibria (LLE) bounded by lower critical solution temperatures (LCSTs) have been reported experimentally and are reproduced here with the SAFT-γ Mie approach. The main feature of the approach is the ability not only to represent accurately the experimental data employed in the parameter estimation, but also to predict the vapor–liquid, liquid–liquid, and vapor–liquid–liquid equilibria, and LCSTs with the same set of parameters. Pure compound and binary phase diagrams of diverse types of amines and their aqueous solutions are assessed in order to demonstrate the main features of the thermodynamic and fluid-phase behavior. 相似文献
2.
Ankit Sachan Shyam Kamal Sorin Olaru Devender Singh Xiaogang Xiong 《国际强度与非线性控制杂志
》2020,30(6):2443-2460
》2020,30(6):2443-2460
This article presents a hands‐off control design for discrete‐time nonlinear system with a special type of nonlinear sector termed as “discrete‐time sector.” The design method to define the boundary of a discrete‐time sector is done with control‐Lyapunov function. The generalization of nonlinear system is viewed in the perspective of a comparison function. By means of a proposed sector, a switching control is designed such that no control action is experienced inside the sector thus, saving unnecessary control efforts. However, to study the robustness for discrete‐time system, a hands‐off control is modified to ensure the monotonic decrease in the energy of the system. Finally, the proposed approach is verified with the simulation results. 相似文献
3.
In this paper, we consider the classical finite mixture model, which is an effective tool for modeling lifetime distributions for random samples from heterogeneous populations. We discuss new results on stochastic comparison for two finite mixtures when each of them is drawn from one of the following semiparametric families, i.e., proportional hazards, accelerated lifetime and proportional reversed hazards. 相似文献
4.
5.
6.
M. Aamir I. Bibi S. Ata K. Jilani F. Majid S. Kamal N. Alwadai M.A.S. Raza M. Bashir S. Iqbal M. Aadil M. Iqbal 《Ceramics International》2021,47(12):16696-16707
In the present investigation, La1-xCoxCr1-yFeyO3 (x,y = 0.0, 0.12, 0.36, 0.60) perovskite was fabricated via a facile micro-emulsion route. The synthesized perovskites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) techniques to examine the effect of Co and Fe ions on the physico-chemical properties. The ferroelectric, dielectric, and magnetic properties of La1-xCoxCr1-yFeyO3 were changed significantly as a function of dopants contents (Co and Fe ions). Outcomes revealed that the dielectric, ferroelectric and magnetic properties of LaCrO3 perovskite can be tuned significantly via Co and Fe doping and La0.40Co0.60Cr0.40Fe0.60O3 have potential for photocatalytic dye removal under (visible) light expoure. The photocatalytic activity (PCA) of the pristine LaCrO3 and La0.40Co0.60Cr0.40Fe0.60O3 photocatalyst was evaluated under (visible) light irradiation for crystal violet (CV) dye. Experimental results revealed that La0.40Co0.60Cr0.40Fe0.60O3 photocatalyst degrdae almost 77.21% CV dye with the rate constant value of 0.01475 min?1. In the presence of isopropyl alcohol (IPA) scavenger, the PCA of the La0.40Co0.60Cr0.40Fe0.60O3 photocatalyst and rate constant value of the photocatalytic reaction decreased to 32.5% and 0.00491 min?1, suggesting the superoxide as main active specie. Results revealed that Co and Fe doping doped material is efficient for photocatalytic presentations under solar light expoure. 相似文献
7.
Hina Kamal Cheng Foh Le Andrew M. Salter Asgar Ali 《Comprehensive Reviews in Food Science and Food Safety》2021,20(3):2455-2475
The chief intent of this review is to explain the different extraction techniques and efficiencies for the recovery of protein from food waste (FW) sources. Although FW is not a new concept, increasing concerns about chronic hunger, nutritional deficiency, food security, and sustainability have intensified attention on alternative and sustainable sources of protein for food and feed. Initiatives to extract and utilize protein from FW on a commercial scale have been undertaken, mainly in the developed countries, but they remain largely underutilized and generally suited for low-quality products. The current analysis reveals the extraction of protein from FW is a many-sided (complex) issue, and that identifies for a stronger and extensive integration of diverse extraction perspectives, focusing on nutritional quality, yield, and functionality of the isolated protein as a valued recycled ingredient. 相似文献
8.
Dina Zidan Mohd Redzwan Sabran Nurul Shazini Ramli Siti Raihanah Shafie Mohammad Fikry 《International Journal of Food Science & Technology》2021,56(5):2175-2181
Wastes from agricultural industry are often disposed. Nevertheless, these wastes contain nutraceuticals and functional compounds. Xylooligosaccharide (XOS) was extracted from two sugarcane wastes (SW); rind (SR) and pith (SP), and the prebiotic properties of both XOS were examined. SR and SP had different mixture of XOS and were resistant towards α-amylase and gastric juice digestion in vitro. Although the growth of Lactobacillus casei Shirota (LcS) and Bifidobacterium animalis subsp. Lactis ATCC® 700541™ increased significantly in both XOS after 48 h of incubation, XOS from SR showed better enrichment of probiotics growth. Both XOS were found to be more fermentable by LcS and acetic acid was the predominant end product of the fermentation. Since XOS composition was different between SR and SP and such difference can affect their prebiotic properties, it is important to choose the appropriate parts of SW to extract XOS with high fermentable properties and obtain the best synbiotics combination. 相似文献
9.
10.
Wan-Mohtar Wan Abd Al Qadr Imad Ab Kadir Safuan Halim-Lim Sarina Abdul Ilham Zul Hajar-Azhari Siti Saari Nazamid 《Food science and biotechnology》2019,28(6):1747-1757
Food Science and Biotechnology - In submerged-liquid fermentation, seven key parameters were assessed using one-factor-at-a-time to obtain the highest GABA yield using an industrial soy sauce koji... 相似文献