全文获取类型
收费全文 | 400篇 |
免费 | 38篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 7篇 |
综合类 | 25篇 |
化学工业 | 85篇 |
金属工艺 | 21篇 |
机械仪表 | 15篇 |
建筑科学 | 21篇 |
矿业工程 | 5篇 |
能源动力 | 22篇 |
轻工业 | 46篇 |
水利工程 | 10篇 |
石油天然气 | 11篇 |
武器工业 | 1篇 |
无线电 | 40篇 |
一般工业技术 | 61篇 |
冶金工业 | 30篇 |
原子能技术 | 4篇 |
自动化技术 | 39篇 |
出版年
2023年 | 10篇 |
2022年 | 9篇 |
2021年 | 20篇 |
2020年 | 12篇 |
2019年 | 15篇 |
2018年 | 20篇 |
2017年 | 14篇 |
2016年 | 10篇 |
2015年 | 22篇 |
2014年 | 12篇 |
2013年 | 32篇 |
2012年 | 25篇 |
2011年 | 18篇 |
2010年 | 12篇 |
2009年 | 17篇 |
2008年 | 12篇 |
2007年 | 12篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 11篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 8篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1974年 | 2篇 |
1973年 | 3篇 |
1972年 | 3篇 |
1970年 | 1篇 |
1967年 | 1篇 |
1961年 | 1篇 |
排序方式: 共有443条查询结果,搜索用时 15 毫秒
71.
Adsorption of cationic polyacrylamide onto sepiolite 总被引:3,自引:0,他引:3
The adsorption of PAM onto sepiolite from aqueous solutions has been investigated systematically as a function of some parameters such as calcination temperature of sepiolite, pH, ionic strength and temperature. The adsorption of cationic polyacrylamide (PAM) increases with pH from 5.50 to 11.00, temperature from 25 to 55 degrees C and ionic strength from 0 to 0.1molL(-1). The sepiolite sample calcined at 200 degrees C has a higher adsorption capacity than the other calcined samples. Adsorption isotherms of PAM onto sepiolite have been determined and correlated with common isotherm equations such as Langmuir and Freundlich isotherm models. The Langmuir isotherm model appeared to fit the isotherm data better than the Freundlich isotherm model. The physical properties of this adsorbent are consistent with the parameters obtained from the isotherm equations. The zeta potentials of sepiolite suspensions have been measured in aqueous solutions of NaCl and different PAM concentrations and pH. From the experimental results: (i) pH strongly alters the zeta potential of sepiolite, (ii) sepiolite has an isoelectric point at about pH 6.6 in water and about pH 8 in 250mgL(-1) PAM concentration, (iii) PAM changes the interface charge from negative to positive for sepiolite. Effect of temperature on adsorption has been quantified by calculating various thermodynamic parameters such as Gibbs free energy, enthalpy and entropy. The dimensionless separation factor (R(L)) has shown that sepiolite can be used for adsorption of PAM from aqueous solutions. 相似文献
72.
Zuhaib F. Bhat James D. Morton Susan L. Mason Alaa El‐Din A. Bekhit Hina F. Bhat 《Comprehensive Reviews in Food Science and Food Safety》2019,18(4):1192-1208
Defined as meat cultured in a laboratory within a bioreactor under controlled artificial conditions, in vitro meat is a relatively recent area that has opened a whole universe of possibilities and opportunities for the meat sector. With improved chemical and microbial safety and varied options, in vitro meat has been proposed as a green, healthy, environmentally friendly, and nutritionally better product that is free from animal suffering and death. Cell culture and tissue culture are the most probable technologies for the development of this futuristic muscle product. However, there are many challenges in the production of a suitable product at an industrial scale under a sustainable production system and a great body of research is required to fill the gaps in our knowledge. Many materials used in the product development are novel and untested within the food industry and demand urgent regulatory and safety assessment systems capable of managing any risks associated with the development of cultured meat. The future of this product will depend on the actions of governments and regulatory agencies. This article highlights emerging biotechnological options for the development of cultured meat and suggests ways to integrate these emerging technologies into meat research. It considers the problems and possibilities of developing cultured meat, opportunities, ethical issues as well as emerging safety and regulatory issues in this area. 相似文献
73.
Semiconductors - This paper presents a finite-element-based two-dimensional numerical simulation study of the vertical channel engineering approaches for controlling the short-channel effects... 相似文献
74.
Chang Abeer Memon Tayab Din Hussain Zahir M. Kalwar Imtiaz Hussain Chowdhry Bhawani Shankar 《Wireless Personal Communications》2019,106(4):1915-1929
Wireless Personal Communications - Matched filtering has found its way in many diverse applications such as communication, signal processing and more. The emphasis of this paper is on the design... 相似文献
75.
Farida khan Naeem A Israf Ud Din T. Saeed Mshari A. Alotaibi Abdulrahman I. Alharthi Asad Habib Tabassum Malik 《Ceramics International》2021,47(4):4749-4757
In the present study, hexagonal boron nitride (h-BN) was synthesized from boric acid and melamine by thermal annealing method in a nitrogen atmosphere. The pure h-BN was used as an efficient sorbent for the uptake of Cd2+ ions from the solution phase. The kinetics and sorption studies of metal ions onto the h-BN were carried out in batch adsorption experiments at different temperature, time, pH, sorbent dosage, and concentration of metal ions. The optimum pH for the removal of the Cd2+ ions was found to be pH 7. The effect of temperature showed that the process of Cd2+ sorption remained endothermic in the range of 298 K–328 K. The Lagergren's first and Ho's second kinetic models were tested to interpret the adsorption kinetic data, however the present data was explained well by Ho's model for kinetics. The thermodynamic perameters ΔG, ΔS and ΔH were determined using the available adsorption data at different temperatures. The physicochemical properties of the synthesized product were also characterized before and after adsorption by different analytical techniques like FT-IR, TGA, XRD and Point of Zero Charge (PZC). The morphology of the surface was analyzed with the help of Scanning Electron Microscopy. The h-BN proved to be an efficient adsorbent for the uptake of the Cd2+ ions from aqueous media. 相似文献
76.
77.
Won-Chun Oh Yin Liu Kwang Youn Cho Md Rokon Ud Dowla Biswas 《Fullerenes, Nanotubes and Carbon Nanostructures》2020,28(11):945-958
AbstractPolyaniline/Bismuth Vanadate/Graphene Oxide (PANI-BiVO4-GO) or BGPA composite was prepared by sonochemical deposition of bismuth vanadate-graphene oxide (BiVO4) nanoparticles on the surface of polyaniline (PANI). The best photocatalytic degradation performance was obtained by 5wt% BGPA composites for MB, RhB, and SO dyes, which is approximately 4 times higher than that of 1% BGPA. Meanwhile, the photocatalytic stability of BiVO4 was significantly improved by introducing PANI into the PANI-BiVO4-GO composite. The dramatic promotion of the photocatalytic degradation performance and the photocatalytic stability can be attributed to the formation of a heterojunction free electron between PANI and BiVO4-GO. The existence of those extra free electrons can dramatically enhance the efficiency of the photogenerated electrons, which accelerate the transfer of photogenerated holes from BiVO4-GO to PANI, and therefore inhibit the self-oxidation of BiVO4. 相似文献
78.
Salah Ud‐Din Khan 《国际能源研究杂志》2019,43(13):6827-6839
Nuclear and hydrogen are considered to be the most promising alternatives energy sources in terms of meeting future demand and providing a CO?‐free environment, and interest in the development of more cost‐effective hydrogen production plants is increasing—and nuclear‐powered hydrogen generation plants may be a viable alternative. This paper is a report on investigating the application of new generation nuclear power plants to hydrogen production and development of an associated techno‐economic model. In this paper, theoretical and computational assessments of generations II, III+, and IV nuclear power plants for hydrogen generation scenarios have been reported. Technical analyses were conducted on each reactor type—in terms of the design standard, fuel specification, overnight capital cost, and hydrogen generation. In addition, a theoretical model was developed for calculating various hydrogen generation parameters, and it was then extended to include an economic assessment of nuclear power plant‐based hydrogen generation. The Hydrogen Economic Evaluation Program originally developed by the International Atomic Energy Agency was used for calculating various parameters, including hydrogen production and storage costs, as well as equity, operation and maintenance (O&M), and capital costs. The results from each nuclear reactor type were compared against reactor parameters, and the ideal candidate reactor was identified. The simulation results also verified theoretically proven results. The main objective of the research was to conduct a prequalification assessment for a cogeneration plant, by developing a model that could be used for technical and economic analysis of nuclear hydrogen plant options. It was assessed that high‐temperature gas‐cooled reactors (HTGR‐PM and PBR200) represented the most economical and viable plant options for hydrogen production. This research has helped identify the way forward for the development of a commercially viable, nuclear power‐driven, hydrogen generation plant. 相似文献
79.
Alaa El‐Din H. Sayed Usama M. Mahmoud Fatma Essa 《Microscopy research and technique》2019,82(4):443-451
The microstructure of the oral cavity and alimentary canal of herbivorous fish Siganus rivulatus collected from the Red Sea were investigated by using scanning electron microscope (SEM). The results showed that S. rivulatus has three types of teeth, tri‐cusped, bi‐cusped, and papilliform. A taste bud (Type I) was recorded in the oropharyngeal cavity. Characteristic styles of microridges on the cell's surface inside the buccal cavity were recorded. Also, the distribution of the mucous cells in the lining of the mouth cavity, alimentary canal was observed. Mucosal folds along the distinct parts of alimentary canal, showed characteristic pattern which was complex in the intestinal mucosa. The results concluded that there are characteristic microstructures according to feeding habitat compared with other bony fishes. 相似文献
80.
Microwave and pulsed electric field assisted extractions of polyphenols from defatted canola seed cake
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Sue‐Siang Teh Brian E. Niven Alaa El‐Din A. Bekhit Alan Carne Edward John Birch 《International Journal of Food Science & Technology》2015,50(5):1109-1115
The incorporation of microwave and pulsed electric field (PEF) technologies in optimising the extraction of polyphenols from defatted canola seed cake was determined by Box‐Behnken response surface methodology, using three parameters of microwave treatment (power, time and liquid: solid (L:S) ratio) and four parameters of PEF (ethanol concentration, time, frequency and voltage). After microwave and PEF pretreatments, the polyphenols of defatted canola seed cake were extracted by ultrasound treatment under fixed variables (200 W of ultrasonic power, 70 °C of water bath and 20 min of extraction time). The measured responses were total phenolics, total flavonoids, the DPPH˙ scavenging activity and ferric reducing antioxidant power (FRAP). The maximum yields of all responses were achieved under optimum conditions of microwave processing (5 min, L:S ratio of 6.0 and 633.3 W) and PEF‐assisted extraction (30 V, 30 Hz, 10% ethanol concentration and 10 s). 相似文献