全文获取类型
收费全文 | 482篇 |
免费 | 12篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 7篇 |
综合类 | 14篇 |
化学工业 | 116篇 |
金属工艺 | 28篇 |
机械仪表 | 16篇 |
建筑科学 | 34篇 |
矿业工程 | 22篇 |
能源动力 | 51篇 |
轻工业 | 12篇 |
水利工程 | 8篇 |
石油天然气 | 30篇 |
武器工业 | 2篇 |
无线电 | 72篇 |
一般工业技术 | 40篇 |
冶金工业 | 15篇 |
原子能技术 | 8篇 |
自动化技术 | 25篇 |
出版年
2023年 | 8篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 6篇 |
2017年 | 7篇 |
2016年 | 17篇 |
2015年 | 15篇 |
2014年 | 36篇 |
2013年 | 29篇 |
2012年 | 22篇 |
2011年 | 37篇 |
2010年 | 22篇 |
2009年 | 20篇 |
2008年 | 15篇 |
2007年 | 28篇 |
2006年 | 19篇 |
2005年 | 26篇 |
2004年 | 18篇 |
2003年 | 15篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 27篇 |
1999年 | 8篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 9篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 2篇 |
排序方式: 共有500条查询结果,搜索用时 15 毫秒
91.
含油污泥减量化处理现场中试试验 总被引:2,自引:0,他引:2
研究分析了某油田含油污泥的组分特点,针对性地进行了实验。根据室内研究结果,提出了脱稳—絮凝—固液分离的技术路线,设计出中试设备并进行中试试验。中试设备的核心是反应脱稳罐,有效容积为1 m3、配备调速搅拌器,可满足不同转速的搅拌要求。油泥脱稳后进入筛网过滤器进行固液分离,分离水送回原水池处理,脱水油泥含油量达20%以上,可用作燃料。设备运行稳定,在脱稳剂加量为3%,PAM加量为400 mg/L时,形成絮体较大,固液分离效果明显,过滤速度快,分离水清澈,过滤2 h,剩余含油污泥含水率在60%左右。经脱水后的含油污泥量减少到原来的1/3左右,为后续的资源化利用提供了条件。现场试验结果与室内研究结果相符。 相似文献
92.
93.
固定化酵母薯干原料酒精发酵中试研究 总被引:1,自引:0,他引:1
本文论述了固定化酵母薯干原料带渣酒精发酵的中试结果。中试生物反应器容积为1000L,采用改性海藻酸钙凝胶为固定化酵母细胞的载体。中试研究中设计了较合理的中试工艺流程,优选出较佳的发酵条件,并考察了生物反应器的性能。试验获得了如下结果:中试装置已运转192天,固定化酵母仍保持高活力,并可继续运转;发酵成熟醪酒精含量达6.5~8.0%(v),它比同期传统式酒精发酵高出0.3~0.4%;淀粉利用率达91~92%;固定化酵母生物反应器的乙醇生产能力为9.5KgEtOH/M ̄3·h,它可比传统式发酵罐的生产能力提高10~12倍。 相似文献
94.
《中国炼油与石油化工》2014,(3):76-76
正The first in China pilot unit for biological conversion of biomass,the 1 000 t/a succinic acid unit at the Yangzi Petrochemical Company(YPC),has accomplished its third test production target to deliver high-purity succinic acid,which has laid a good foundation to study and develop 相似文献
95.
Pekka Manninen Elina H?iv?l? Seppo Sarimo H. Kallio 《Zeitschrift für Lebensmitteluntersuchung und -Forschung A》1997,204(3):202-205
The distribution of vegetative microbial cells and their spores in a supercritical CO2 extraction process was studied. The seed and flesh/skin fractions of the press residue of sea buckthorn berries (Hippopha? rhamnoides) from a juice factory were used as raw materials. A pilot-scale extraction plant was operated at 30 MPa at temperatures of
40 and 60°C. The number of yeasts, moulds and bacteria in the pulp/skin fraction, in the extraction residues, in the extracted
oils as well as in the water phases separated from the extracted oils was estimated by the spread plate technique. The microbial
content of the flesh/skin material was increased in some extractions by the addition of bacterial spores. In general, the
extraction process led to a decrease in the bacterial count of the extracted material, whereas no microbial growth was detected
in the oils extracted or in the water phases separated from them. Neither yeasts nor moulds were found in any samples after
the extraction process. The microbial status of seed oil and flesh/skin oil obtained by industrial-scale CO2 extraction at 40°C and at 30 MPa before and after gelatine encapsulation remained unchanged. This proves that supercritical
CO2 can be used to manufacture edible oil products free of living micro-organisms and their spores.
Received: 14 May 1996 相似文献
96.
以导频总功率最小化为准则,提出了一种适用非连续正交频分复用系统的导频设计方法.与传统的子载波总功率受限的导频设计方法相比,对给定的导频辅助信道估计最小均方误差指标,需要较小的导频总功率,从而提高了数据传输的功率利用率,这也响应了当今社会提倡的节能减排的号召.仿真结果证明了该结论. 相似文献
97.
《Drying Technology》2013,31(9):2103-2129
A dynamic modelling methodology, which combines on-line variable estimation and parameter identification with physical laws to form an adaptive model for rotary sugar drying processes, is developed in this paper. In contrast to the conventional rate-based models using empirical transfer coefficients, the heat and mass transfer rates are estimated by using on-line measurements in the new model. Furthermore, a set of improved sectional solid transport equations with localized parameters is developed in this work to replace the global correlation for the computation of solid retention time. Since a number of key model variables and parameters are identified on-line using measurement data, the model is able to closely track the dynamic behaviour of rotary drying processes within a broad range of operational conditions. This adaptive model is validated against experimental data obtained from a pilot-scale rotary sugar dryer. The proposed modelling methodology can be easily incorporated into nonlinear model based control schemes to form a unified modelling and control framework. 相似文献
98.
99.
2013年9月29日,中国(上海)自由贸易试验区正式揭幕,对于从事进出口贸易的企业来说是一个非常好的契机,而对于集装箱运输行业来说,也提供了一次大力发展,与国外班轮公司竞争的机会。本文分析了集装箱多式联运的优点、自贸区为其带来的机会以及我国开展集装箱多式联运中的问题,初步探讨了如何利用物联网相关技术,结合集装箱多式联运的手段,来实现更低成本下的快速便捷物流。 相似文献
100.
J. M. L. N. de Moura Bell D. Maurer L. Yao T. Wang S. Jung L. A. Johnson 《Journal of the American Oil Chemists' Society》2013,90(7):1079-1088
The economic viability of enzyme-assisted aqueous extraction processing (EAEP) of soybeans depends on properties and potential applications of all fractions (skim and insolubles as well as oil). EAEP oil contained lower free fatty acid, phosphorus, and tocopherol contents, similar unsaponifiable matter levels, and higher degrees of oxidation (peroxide and p-anisidine values) than hexane-extracted oil. The phospholipid profile of EAEP fractions was mainly composed of phosphatidic acid, followed by phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine. Most of phospholipids were present in the skim, except for phosphatidic acid, which was the major phospholipid in the cream fraction. Skim and cream contained 55 and 3 % of the soluble carbohydrates in the original extruded flakes, respectively. Soluble carbohydrates of the skim were mainly composed of stachyose (5.8 ± 0.8 mg/mL) and sucrose (9.9 ± 0.8 mg/mL), which were hydrolyzed into glucose, galactose, and fructose after addition of α-galactosidase. Skim and cream peptides contained <20 kDa MW molecules. About 71 % of the skim peptides were <20 kDa MW, with 49 % being <1.35 kDa MW, 22 % being 17–1.35 kDa MW, and 29 % being 44–670 kDa MW. Skim protein and carbohydrate contents make this fraction suitable for replacing water in ethanol fermentations, thereby improving the fermentation rate/production and the nutritional quality of distiller’s dried grains with solubles. 相似文献