全文获取类型
收费全文 | 311篇 |
免费 | 12篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 56篇 |
金属工艺 | 12篇 |
机械仪表 | 15篇 |
建筑科学 | 4篇 |
矿业工程 | 1篇 |
能源动力 | 11篇 |
轻工业 | 32篇 |
石油天然气 | 2篇 |
无线电 | 23篇 |
一般工业技术 | 83篇 |
冶金工业 | 32篇 |
原子能技术 | 4篇 |
自动化技术 | 44篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 7篇 |
2019年 | 5篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 11篇 |
2015年 | 6篇 |
2014年 | 15篇 |
2013年 | 23篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 18篇 |
2009年 | 11篇 |
2008年 | 16篇 |
2007年 | 10篇 |
2006年 | 18篇 |
2005年 | 10篇 |
2004年 | 10篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 5篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有323条查询结果,搜索用时 250 毫秒
91.
Catootjie L Nalle Ganesharanee Ravindran Velmurugu Ravindran 《Journal of the science of food and agriculture》2010,90(7):1227-1231
BACKGROUND: Removal of hulls may be an effective means of reducing the level of some antinutritional factors and improving the feeding value of grain legumes. Published data on the effects of dehulling on the energy utilisation and amino acid digestibility of grain legumes are limited. This study was designed to investigate the influence of dehulling on the nitrogen‐corrected apparent metabolisable energy (AMEn) and apparent ileal amino acid digestibility of faba beans, Australian sweet lupins and peas for broilers. RESULTS: The non‐starch polysaccharide contents of all three legume species were decreased by the removal of hulls. Dehulling increased (P < 0.05) the content and ileal digestibility of starch in faba beans but had no effect (P > 0.05) on those in peas. Dehulling increased (P < 0.05) the AMEn of faba beans and lupins but had no effect (P > 0.05) on that of peas. Removal of hulls increased the amino acid concentrations in all three legume species, but the apparent ileal digestibility coefficients of most amino acids were unaffected (P > 0.05). CONCLUSION: Dehulling of grain legumes is nutritionally beneficial in view of the improved amino acid concentrations and metabolisable energy values. Copyright © 2010 Society of Chemical Industry 相似文献
92.
Preetha CR Gladis JM Rao TP Venkateswaran G 《Environmental science & technology》2006,40(9):3070-3074
Major quantities of uranium find use as nuclear fuel in nuclear power reactors. In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to remove uranium from nuclear power reactor effluents before discharge into environment. Ion imprinted polymer (IIP) materials have traditionally been used for the recovery of uranium from dilute aqueous solutions prior to detection or from seawater. We now describe the use of IIP materials for selective removal of uranium from a typical synthetic nuclear power reactor effluent. The IIP materials were prepared for uranyl ion (imprint ion) by forming binary salicylaldoxime (SALO) or 4-vinylpyridine (VP) or ternary SALO-VP complexes in 2-methoxyethanol (porogen) and copolymerizing in the presence of styrene (monomer), divinylbenzene (cross-linking monomer), and 2,2'-azobisisobutyronitrile (initiator). The resulting materials were then ground and sieved to obtain unleached polymer particles. Leached IIP particles were obtained by leaching the imprint ions with 6.0 M HCl. Control polymer particles were also prepared analogously without the imprint ion. The IIP particles obtained with ternary complex alone gave quantitative removal of uranyl ion in the pH range 3.5-5.0 with as low as 0.08 g. The retention capacity of uranyl IIP particles was found to be 98.50 mg/g of polymer. The present study successfully demonstrates the feasibility of removing uranyl ions selectively in the range 5 microg - 300 mg present in 500 mL of synthetic nuclear power reactor effluent containing a host of other inorganic species. 相似文献
93.
Aarthi Ahgilan Vikineswary Sabaratnam Vengadesh Periasamy 《International Journal of Food Properties》2016,19(5):1173-1181
Riboflavin or B2, isolated from a wide variety of animals and plant products is an important vitamin commonly found in the diets of various cultures. This vitamin has been generally known to impart antimicrobial properties when exposed to ultra-violet A irradiation. In the current work, we investigated the possibility of preventing or reducing pathogenic infections using both ultra-violet A assisted and stand-alone riboflavin solutions on selected strains of bacteria. The antimicrobial properties of riboflavin were determined by the effective inhibition of the growth of pathogens through the disc diffusion method. Zones of inhibition studies indicated that riboflavin on its own was found to be quite effective and was able to inhibit the pathogens when diffused at a concentration of 50.0 µL. Stand-alone riboflavin solution successfully inhibited Staphylococcus aureus, Enterococcus faecalis, Salmonella typhi, and Pseudomonas aeruginosa with an inhibition range of (18.7 ± 0.6) mm; (17.7 ± 0.6) mm; (17.3 ± 0.6) mm, and (15.7 ± 0.6) mm, respectively. Intermediate zones of inhibition were observed for Escherichia coli and Candida albicans with a range of (11.7 ± 0.6) mm and (11.7 ± 0.6) mm, respectively. Klebsiella pneumoniae was the only resistant pathogen at (7.7 ± 0.6) mm for the riboflavin concentration used in this work. These results may indicate the exciting prospects of the applications of riboflavin as a complementary approach toward inactivation of pathogenic infections. 相似文献
94.
Effect of alloying elements on the segregation and dissolution of CuAl2 phase in Al-Si-Cu 319 alloys
Z. Li A. M. Samuel F. H. Samuel C. Ravindran S. Valtierra 《Journal of Materials Science》2003,38(6):1203-1218
The hypoeutectic 319 aluminum alloy (Al-7%Si-3.5%Cu) was used in the present study to investigate the effect of diverse alloying elements on the dissolution of the copper phase (CuAl2) during solution heat treatment. Elements such as Sr, Fe and P were added to the base alloy individually and in various combinations. The cooling curves of these alloys were obtained by solidifying the alloy melts in a preheated graphite mold (600°C, cooling rate 0.8°C/s). From these the first derivate curves were plotted and used to determine the effect of the additives on the precipitation temperature of the Al-CuAl2 eutectic reaction. Microstructural examination was carried out using optical microscopy, image analysis, and electron probe microanalysis (EPMA), with energy dispersive X-ray (EDX) and wavelength dispersive spectroscopic (WDS) analysis facilities. Samples from different alloys were solution heat treated at 505°C for various times up to 100 hours. The results explicitly reveal that solution heat treatment plays a critical role on the dissolution of the CuAl2 phase. It is found that Sr leads to segregation of the CuAl2 phase away from the Al-Si eutectic regions, which slows down its dissolution during solution heat treatment. The -Al5FeSi phase platelets act as preferred precipitation sites for the copper phase and hence lessen the degree of segregation. Thus, addition of Fe can accelerate the copper phase dissolution. However, phosphorus addition has a negative effect on CuAl2 dissolution due to (i) its solubility in the CuAl2 phase particles, and (ii) the formation of (Al,P)O2 oxide particles which act as nucleation sites for the precipitation of the block-like CuAl2 phase. It retards the complete dissolution of this copper phase even after 100 hr solution treatment. In the case when phosphorus and iron are added together, the negative effect of phosphorus can be neutralized to some extent. 相似文献
95.
Karthik Subramani Balu Kolathupalayam Shanmugam Suriyaprabha Rangaraj Manivasakan Palanisamy Prabu Periasamy Rajendran Venkatachalam 《IET nanobiotechnology / IET》2018,12(4):459
Nanomaterials play a vital role in textile industries due to their unique properties and applications. There is an increase in the use of nanoscale phyto products in textiles to control the bacterial infection in fabrics. Here, natural herbal nanoparticles of different sizes were prepared from shade‐dried Aloe vera plant leaves using ball milling technique without any additives. The amorphous herbal A. vera nanoparticles possess an average particle size of 40 ± 2 nm and UV‐absorption maximum at 269 nm. A. vera nanopowders–chitosan nanocomposites were prepared and coated on cotton fabrics using pad‐dry cure method. The evaluation of antibacterial activity against Escherichia coli (22.05 ± 0.06 mm) and Staphylococcus aureus (27.17 ± 0.02 mm), UV‐protection properties (UV‐protection factor = 57.2 ± 0.1), and superhydrophobic nature (155 ± 3°) of the prepared herbal nanoparticles and their composites were analysed by disc diffusion, UV–visible spectral analysis, and contact angle analysis. Understanding the functional properties of herbal nanoparticles, coated particles on fabrics highlights their potential applications in protective clothing with better antimicrobial properties, hydrophobicity, and UV‐protection properties. This study of using A. vera herbal nanoparticles in textiles significantly enhances the fabric performance to develop protective textile fabrics in defence and biomedical fields.Inspec keywords: nanoparticles, particle size, nanofabrication, nanomedicine, antibacterial activity, biomedical materials, hydrophobicity, ultraviolet spectra, visible spectra, radiation protection, textile fibres, cotton fabrics, ball milling, X‐ray diffraction, light scattering, scanning electron microscopy, X‐ray fluorescence analysis, fluorescence, amorphous state, nanocomposites, filled polymers, protective coatings, curing, microorganisms, biodiffusion, contact angle, surface morphology, protective clothingOther keywords: UV‐blocking, antimicrobial properties, disc diffusion, UV‐visible spectral analysis, contact angle analysis, morphological characteristics, protective clothing, protective textile fabrics, biomedical fields, superhydrophobic nature, UV‐protection factor, UV‐protection properties, Staphylococcus aureus, Escherichia coli, pad‐dry cure method, cotton fabrics, A. vera nanopowders‐chitosan nanocomposites, UV‐absorption maximum, average particle size, amorphous herbal A. vera nanoparticles, X‐ray fluorescence spectrometry, scanning electron microscopy, dynamic light scattering, UV‐visible spectrophotometry, X‐ray diffraction, ball milling, shade‐dried Aloe vera plant leaves, natural herbal nanoparticle size, bacterial infection, nanoscale phyto products, textile industries, nanomaterials, textile applications 相似文献
96.
Multi-criteria mathematical model for designing the distribution network of a consumer goods company
Aixa Cintron A. Ravi Ravindran Jose A. Ventura 《Computers & Industrial Engineering》2010,58(4):584-593
This paper describes a multiple criteria mixed-integer linear program used for designing the best possible supply chain distribution network for a consumer goods company. The model determines the optimal configuration of the manufacturing plants, distributors and customers in the distribution network. The model is intended for making tactical decisions for designing distribution networks, or more specifically, for designing the flow of products from the manufacturing plants to the customers. The customers have four options for receiving products in this model. Products can be supplied from (1) the regional distribution center (DC), (2) the manufacturing plant, (3) an independent distributor who is supplied from the regional DC, or (4) an independent distributor who is supplied directly from a manufacturing plant. The model selects the best option for each customer/distributor based on several criteria: profit, lead time, power, credit performance, and distributors’ reputation. The model is validated with real data from a consumer goods company to show its functionality. To account for variability in demand, the model is run under multiple scenarios and the results are analyzed to obtain the best solution. The company uses two DC’s located in the same region, but the model assumes only one regional DC with infinite capacity. With the proposed network, we show that one of the regional DC’s could be eliminated and distribution costs would be reduced from 12% to 3% of the Net Sales (approximately a monthly reduction of $574,000 in distribution expenses). 相似文献
97.
Hyeonjoong Cho Binoy Ravindran E. Douglas Jensen 《Journal of Parallel and Distributed Computing》2010
We consider optimal real-time scheduling of periodic tasks on multiprocessors—i.e., satisfying all task deadlines, when the total utilization demand does not exceed the utilization capacity of the processors. We introduce a novel abstraction for reasoning about task execution behavior on multiprocessors, called T–L plane and present T–L plane-based real-time scheduling algorithms. We show that scheduling for multiprocessors can be viewed as scheduling on repeatedly occurring T–L planes, and feasibly scheduling on a single T–L plane results in an optimal schedule. Within a single T–L plane, we analytically show a sufficient condition to provide a feasible schedule. Based on these, we provide two examples of T–L plane-based real-time scheduling algorithms, including non-work-conserving and work-conserving approaches. Further, we establish that the algorithms have bounded overhead. Our simulation results validate our analysis of the algorithm overhead. In addition, we experimentally show that our approaches have a reduced number of task migrations among processors when compared with a previous algorithm. 相似文献
98.
A labeled-tree approach to semantic and structural data interoperability applied in hydrology domain
The issues of data integration and interoperability pose significant challenges in scientific hydrological and environmental studies, due largely to the inherent semantic and structural heterogeneities of massive datasets and non-uniform autonomous data sources. To address these data integration challenges, we propose a unified data integration framework, called Hydrological Integrated Data Environment (HIDE). HIDE is based on a labeled-tree data integration model referred to as DataNode tree. Using this framework, characteristics of datasets gathered from diverse data sources - with different logical and access organizations - can be extracted and classified as Time-Space-Attribute (TSA) labels and are subsequently arranged in a DataNode tree. The uniqueness of our approach is that it effectively combines the semantic aspects of the scientific domain with diverse datasets having different logical organizations to form a unified view. Further, we also adopt a metadata-based approach for specifying the TSA-DataNode tree in order to achieve flexibility and extensibility. The search engine of our HIDE prototype system evaluates a simple user query systematically on the TSA-DataNode tree, presenting integrated results in a standardized format that facilitates both effective and efficient data integration. 相似文献
99.
Thispaper presents resource management techniques that achieve thequality of service (QoS) requirements of dynamic real-time systemsusing open architectures and commercial off-the-shelf technologies(COTS). Dynamic real-time systems are subject to constant changessuch as a varying external environment, overload of internalsystems, component failure, and evolving operational requirements.Examples of such systems include the emerging generation of computer-based,command and control systems of the U.S. Navy. To enable the engineeringof such systems, we present adaptive resource management middlewaretechniques that achieve the QoS requirements of the system. Themiddleware performs QoS monitoring and failure detection, QoSdiagnosis, and reallocation of resources to adapt the systemto achieve acceptable levels of QoS. Experimental characterizationsof the middleware using a real-time benchmark illustrate itseffectiveness for adapting the system for achieving the desiredreal-time and survivability QoS during overload situations. 相似文献
100.
S.K. Gupta Y. Aikawa N.V. Gopalakrishnan Y. Hayashi N. Ikeda N. Ito A. Jain A.V. John S. Karthikeyan S. Kawakami T. Matsuyama D.K. Mohanty P.K. Mohanty S.D. Morris T. Nonaka A. Oshima B.S. Rao K.C. Ravindran M. Sasano K. Sivaprasad B.V. Sreekantan H. Tanaka S.C. Tonwar K. Viswanathan T. Yoshikoshi 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2005,540(2-3):311-323
The change in the spectral index from about -2.7 to -3.1 at 3×1015 eV in the all-particle energy spectrum of primary cosmic rays is very significant for learning about the nature of cosmic sources of ultra-high energy particles and their acceleration and propagation in the galactic disk. Any observation of a fine structure in the spectrum would be important for improving our understanding of these physical processes. The GRAPES-3 air shower array has been designed to achieve higher precision in determination of various shower parameters to enable observation of any fine structure in the energy spectrum, if it exists. The details of the shower detectors, shower trigger and the data acquisition system are presented here along with estimates of trigger efficiencies from Monte Carlo simulations for primary photons (γ-rays) and several nuclei. 相似文献