首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   244篇
  免费   15篇
电工技术   5篇
化学工业   63篇
金属工艺   2篇
机械仪表   4篇
建筑科学   4篇
矿业工程   1篇
能源动力   14篇
轻工业   71篇
石油天然气   3篇
无线电   23篇
一般工业技术   40篇
冶金工业   6篇
原子能技术   2篇
自动化技术   21篇
  2024年   2篇
  2023年   5篇
  2022年   12篇
  2021年   16篇
  2020年   11篇
  2019年   10篇
  2018年   8篇
  2017年   13篇
  2016年   12篇
  2015年   3篇
  2014年   9篇
  2013年   26篇
  2012年   13篇
  2011年   18篇
  2010年   9篇
  2009年   11篇
  2008年   12篇
  2007年   13篇
  2006年   8篇
  2005年   6篇
  2004年   6篇
  2003年   4篇
  2002年   5篇
  2001年   5篇
  2000年   1篇
  1999年   3篇
  1998年   2篇
  1997年   3篇
  1996年   1篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   4篇
  1988年   1篇
  1985年   1篇
  1984年   1篇
  1978年   1篇
排序方式: 共有259条查询结果,搜索用时 15 毫秒
51.
52.
In this paper we develop the language theory underpinning the logical framework PLF. This language features lambda abstraction with patterns and application via pattern-matching. Reductions are allowed in patterns. The framework is particularly suited as a metalanguage for encoding rewriting logics and logical systems where proof terms have a special syntactic constraints, as in term rewriting systems, and rule-based languages. PLF is a conservative extension of the well-known Edinburgh Logical Framework LF. Because of sophisticated pattern matching facilities PLF is suitable for verification and manipulation of HXML documents.  相似文献   
53.
Color tunable Tb3+ doped SrGd2Al2O7 nanophosphor is synthesized employing a facile and economic urea assisted solution combustion approach. XRD studies confirm the crystallization of single phased SrGd2(1-x)Tb2xAl2O7 nanophosphor in tetragonal lattice with I4/mmm (139) space group. Rietveld refinement is performed over SrGd1.9Tb0.1Al2O7 sample to execute qualitative as well as quantitative phase analysis. TEM analysis confirms the more or less spherical shaped phosphors in nano domain with average particle size ranging 45–80?nm. Photoluminescent investigation reveals that this nanophosphor can be successfully excited by ultraviolet light yielding significant luminescent properties arising due to radiative transitions from 5D3,4 levels to 7Fj levels. Dipole-dipole interactions are solely responsible for the energy transfer causing concentration quenching. Concentration controlled luminescent tendency can be employed to induce chromaticity from blue to green region. Findings of the study proclaim the application of this nanophosphor as one of the green component of tricolor based ultraviolet excited white LEDs.  相似文献   
54.
Vibrio parahaemolyticus is one of the most prevalent food-borne pathogens along the southwest coast of India, where marine foods are frequently consumed. Shrimp (Penaeus monodon) and environmental samples were collected from aquaculture farms located in and around Cochin. Confirmation of the biochemically identified strains with species-specific toxR gene and detection of virulent genes viz., tdh and trh was performed by polymerase chain reaction (PCR). The phenotypic markers for the presence of tdh and trh genes were assayed by Kanagawa phenomenon and urease activity, respectively. Protease activity was examined to identify other potential virulence factors. After phenotypic characterization of bacterial strains fingerprinting of genomic DNA was carried by various typing methods, viz., random amplified polymorphic DNA (RAPD), enterobacterial repetitive intergenic consensus sequence (ERIC), repetitive extragenic palindromic sequence (REP), and ribosomal gene spacer sequence (RS) PCR methods to assess the genetic diversity within the isolates. Eighteen percent of the samples were found positive for the incidence of V. parahaemolyticus by biochemical protocols and toxR (368 bp) targeted PCR. PCR analyses revealed 1% of the samples positive for tdh (269 bp) and trh (500 bp) gene. RAPD analysis revealed clustering of toxigenic strains into a single group. Cluster analysis revealed the conglomeration of isolates into two, five, and seven major groups using RS, ERIC, and REP PCR methods, respectively. RS PCR generated fewer amplified bands compared to REP and ERIC PCR methods, thus giving scope for higher discrimination. Moreover, RS PCR patterns were more discernible visually from other patterns, suggesting RS PCR as a considerably practical method for routine use.  相似文献   
55.
The present study deals with the energy and exergy analysis of a wavy fin radiator deploying various shapes of Al2O 3‐water as nanocoolant. The effects of radiator effectiveness, pumping power, heat transfer rate, and performance index with variously shaped nanoparticles, mainly spherical, brick, and platelet, on coolant flow rates and air velocities have been investigated. Also, the impacts of entropy, second law efficiency, entropy generation number, and irreversibility on radiator performance analysis have been considered with steady‐state assumptions. Theoretical analysis revealed that the spherical particle–based nanocoolant showed 21.9%, and 18.2% higher effectiveness than platelet and brick nanocoolants. However, minimization in the entropy generation is observed in the platelet shape of the nanoparticle. The second law efficiency is 13% higher for the spherical nanocoolant compared with the brick nanocoolant. An optimum entropy generation number is found at a coolant flow rate of 13 l/min and then gradually decreases with an increase in the coolant flow rate. For all the considered operating parameters, the spherical nanoparticle showed a better performance than brick and platelet nanofluids as a radiator coolant. Due to the enhanced overall performance for the spherical nanofluid, it may be considered as a potential candidate for a radiator coolant.  相似文献   
56.
57.

Tele health utilizes information and communication mechanisms to convey medical information for providing clinical and educational assistances. It makes an effort to get the better of issues of health service delivery involving time factor, space and laborious terrains, validating cost-efficiency and finer ingress in both developed and developing countries. Tele health has been categorized into either real-time electronic communication, or store-and-forward communication. In recent years, a third-class has been perceived as remote healthcare monitoring or tele health, presuming data obtained via Internet of Things (IOT). Although, tele health data analytics and machine learning have been researched in great depth, there is a dearth of studies that entirely concentrate on the progress of ML-based techniques for tele health data analytics in the IoT healthcare sector. Motivated by this fact, in this work a method called, Weighted Bayesian and Polynomial Taylor Deep Network (WB-PTDN) is proposed to improve health prediction in a computationally efficient and accurate manner. First, the Independent Component Data Arrangement model is designed with the objective of normalizing the data obtained from the Physionet dataset. Next, with the normalized data as input, Weighted Bayesian Feature Extraction is applied to minimize the dimensionality involved and therefore extracting the relevant features for further health risk analysis. Finally, to obtain reliable predictions concerning tele health data analytics, First Order Polynomial Taylor DNN-based Feature Homogenization is proposed that with the aid of First Order Polynomial Taylor function updates the new results based on the result analysis of old values and therefore provides increased transparency in decision making. The comparison of proposed and existing methods indicates that the WB-PTDN method achieves higher accuracy, true positive rate and lesser response time for IoT based tele health data analytics than the traditional methods.

  相似文献   
58.
Although breastmilk is adequate to meet the energy and nutrient requirements of an infant up to four to six months of age, thereafter it is insufficient to sustain normal growth and needs to be supplemented with other foods, such as weaning foods. However, the capacity of a weaning diet to meet the protein and energy requirements of infants depends on its nutritional quality as well as its dietary bulk. This review highlights varieties of weaning foods, blend formulations, nutrient requirements, process characteristics, physicochemical parameters, quality evaluation, and other important aspects of developing a weaning food that satisfies all the requirements of the infant during the vulnerable transitional stage. Traditional weaning foods of India are briefly summarized.  相似文献   
59.
The present work reports on the oil content of fried noodle-like products prepared from model individual blends of corn starch with casein, soy protein or their hydrolysates in ratios ranging from 80:20 to 20:80 of protein/hydrolysate:starch. In general, the oil content increased for all blends with an increase in the content of the protein/protein hydrolysate. However, there was a pronounced increase in oil uptake with an increase in the content of protein hydrolysates in the model blends. The Results are interpreted with respect to possible differences in surface tension and hydrophobicity, which are known to influence oil content in fried foods. © 1999 Society of Chemical Industry  相似文献   
60.
Reduction of oil content in deep fat fried foods would be welcome by both the food manufacturers and the consumers. Among the many approaches that have been evaluated for this purpose, use of hydrocolloid additives is believed to be most promising. Work in this area is restricted mostly to cellulose derivatives. The mechanism of action of these derivatives is attributed to formation of an oil resistant barrier film, an alteration in surface hydrophobicity of the product being fried, and the thermal gelation. However, most hydrocolloids would alter the surface hydrophobicity, and many of them have the ability to form films. Furthermore, the presence of other food constituents can alter all these properties. Hence, hydrocolloids at 0.25— 2.00 % (on the basis of chickpea flour) were screened for their ability to reduce oil uptake in sev, a model deep fat fried product prepared from chickpea flour. Results obtained indicate that the ability to reduce oil uptake in this product decreases in the following order: gum arabic > carrageenan > gum karaya > guar gum > carboxymethylcellulose > hydroxypropylmethyl cellulose. Hydrocolloids such as xanthan, gum ghatti, gum tragacanth, and locust bean gum were found to be ineffective (<10 % reduction in the oil content) for this purpose.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号