全文获取类型
收费全文 | 955篇 |
免费 | 43篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 233篇 |
金属工艺 | 19篇 |
机械仪表 | 19篇 |
建筑科学 | 17篇 |
能源动力 | 49篇 |
轻工业 | 64篇 |
水利工程 | 2篇 |
石油天然气 | 4篇 |
无线电 | 121篇 |
一般工业技术 | 193篇 |
冶金工业 | 151篇 |
原子能技术 | 12篇 |
自动化技术 | 106篇 |
出版年
2023年 | 8篇 |
2022年 | 26篇 |
2021年 | 19篇 |
2020年 | 22篇 |
2019年 | 13篇 |
2018年 | 36篇 |
2017年 | 32篇 |
2016年 | 29篇 |
2015年 | 18篇 |
2014年 | 30篇 |
2013年 | 76篇 |
2012年 | 31篇 |
2011年 | 31篇 |
2010年 | 29篇 |
2009年 | 48篇 |
2008年 | 21篇 |
2007年 | 22篇 |
2006年 | 31篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 13篇 |
2001年 | 8篇 |
2000年 | 20篇 |
1999年 | 16篇 |
1998年 | 38篇 |
1997年 | 23篇 |
1996年 | 34篇 |
1995年 | 15篇 |
1994年 | 18篇 |
1993年 | 22篇 |
1992年 | 18篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 11篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 14篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 8篇 |
1980年 | 16篇 |
1979年 | 14篇 |
1978年 | 12篇 |
1977年 | 9篇 |
1976年 | 10篇 |
1975年 | 7篇 |
1974年 | 5篇 |
排序方式: 共有998条查询结果,搜索用时 15 毫秒
121.
Rakesh Kumar Gupta Raghwesh Mishra Kingsuk Mukhopadhyay Rajesh Kumar Tiwari Ashok Ranjan Arvind Kumar Saxena 《SILICON》2009,1(2):125-129
Multiwalled carbon nanotubes (MWCNTs) have been coated with silicon carbide (SiC) using polycarbosilane as precursor in order
to improve their thermo oxidative stability. The polycarbosilane coated MWCNTs were heated to ~1300°C under an inert atmosphere
to generate the SiC coating. X-ray diffraction, energy dispersive X-ray analysis and scanning electron microscopy have confirmed
the formation of SiC on the MWCNTs. The retention of the tubular structure of the MWCNTs has been confirmed by transmission
electron microscopy. Thermogravimetric analysis has been performed to evaluate the thermo oxidative stabilities of coated
and virgin MWCNTs. Sonication studies have shown that the mechanical strength of the MWCNTs was increased after coating with
SiC. 相似文献
122.
Alka D. Kamble Vinod K. Saxena Prakash D. Chavan Bhagwan D. Singh Vinod A. Mendhe 《能源学会志》2019,92(4):982-1004
The reactivity of coal and biomass has been evaluated by comparing the optical and chemical changes in feed material prior and after the co-gasification. The proximate, ultimate, GCV, low-pressure N2 sorption isotherm, micropetrography, SEM and EDX spectroscopy analyses are carried out to assess the reactivity of blends of high ash Indian coal and biomass. The relative changes in parameters like surface area, pore size, and pore volume have been correlated with reacted percentage area of coal macerals and cellulose-lignin cellular structures of biomass. The Optimas image processing software is being used to mark the reacted portion of organic constituents and calculated the reactivity percentage. The bottom ash of pure coal has shown the least reacted organic matters, indicating inefficiency of high ash coal due to a large amount of inorganic and inertinite contents that is resisting the oxidation. The reactivity percentage is determined by the petrographic and SEM images, and varies from 36.34 to 99.64% and 6.61–96.22%, respectively. It is summarised that the estimation of percentage alteration of macerals and other micro-organic constituents can be used as one of the practical approaches for the assessment of the reactivity of coal and biomass. The blending ratio 6:4 of coal and press mud has shown the highest reactivity (>99.64%). The values of petrographic and SEM reactivity have shown good correlations with the carbon contents, unreacted vitrinites, mineral matters and biomass remnants. These relations have been taken into account to formulate the proposed petrographic empirically calculated reactivity (RPEC). The focus has also been made to investigate the influence of feed composition on carbon conversion and heating value of the product gas. 相似文献
123.
Walia Gurjit Singh Kumar Ashish Saxena Astitwa Sharma Kapil Singh Kuldeep 《Pattern Analysis & Applications》2020,23(3):1439-1455
Pattern Analysis and Applications - Particle filter is used extensively for estimation of target nonlinear and non-Gaussian state. However, its performance suffers due to its inherent problem of... 相似文献
124.
125.
Mrinal Kanti Kundu Goutam Hatui Vineeta Nigam Arvind Kumar Saxena 《Polymer-Plastics Technology and Engineering》2015,54(7):691-702
A tubelike, naturally occurring halloysite clay mineral (HNTs) incorporated polyphosphazene (PPZ) elastomeric nanocomposites had been electron beam radiated and thermally treated for certain applications. To improve the dispersion of raw HNTs (H), an organosilane modifier had been exploited. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) technique were utilized for plausible interaction and intercalation. The efficiency of electron beam radiation over chemical initiation for intra and inter chain network formation within the resin was substantiated through oil and solvent resistance studies. Effective delay in mass transport as compared to the virgin elastomer was observed through thermal analysis. 相似文献
126.
Nina Kubatova Dr. Hendrik R. A. Jonker Dr. Krishna Saxena Dr. Christian Richter Verena Vogel Sandra Schreiber Prof. Dr. Anita Marchfelder Prof. Dr. Harald Schwalbe 《Chembiochem : a European journal of chemical biology》2020,21(1-2):149-156
Past sequencing campaigns overlooked small proteins as they seemed to be irrelevant due to their small size. However, their occurrence is widespread, and there is growing evidence that these small proteins are in fact functionally very important in organisms found in all kingdoms of life. Within a global proteome analysis for small proteins of the archaeal model organism Haloferax volcanii, the HVO_2922 protein has been identified. It is differentially expressed in response to changes in iron and salt concentrations, thus suggesting that its expression is stress-regulated. The protein is conserved among Haloarchaea and contains an uncharacterized domain of unknown function (DUF1508, UPF0339 family protein). We elucidated the NMR solution structure, which shows that the isolated protein forms a symmetrical dimer. The dimerization is found to be concentration-dependent and essential for protein stability and most likely for its functionality, as mutagenesis at the dimer interface leads to a decrease in stability and protein aggregation. 相似文献
127.
Energy crisis and the global impetus to “go green” have encouraged the integration of renewable energy resources, plug-in electric vehicles, and energy storage systems to the grid. The presence of more than one energy source in the grid necessitates the need for an efficient energy management system to guide the flow of energy. Moreover, the variability and volatile nature of renewable energy sources, uncertainties associated with plug-in electric vehicles, the electricity price, and the time-varying load bring new challenges to the power engineers to achieve demand-supply balance for stable operation of the power system. The energy management system can effectively coordinate the energy sharing/trading among all available energy resources, and supply loads economically in all the conditions for the reliable, secure, and efficient operation of the power system. This paper reviews the framework, objectives, architecture, benefits, and challenges of the energy management system with a comprehensive analysis of different stakeholders and participants involved in it. The review paper gives a critical analysis of the distributed energy resources behavior and different programs such as demand response, demand-side management, and power quality management implemented in the energy management system. Different uncertainty quantification methods are also summarized. This review paper also presents a comparative and critical analysis of the main optimization techniques used to achieve different energy management system objectives while satisfying multiple constraints. Thus, the review offers numerous recommendations for research and development of the cutting-edge optimized energy management system applicable for homes, buildings, industries, electric vehicles, and the whole community. 相似文献
128.
Subhash Wadhwa Madhawanand Mishra Avneet Saxena 《International Journal of Flexible Manufacturing Systems》2007,19(4):410-442
Agility can be viewed as a need to encourage the enterprise-wide integration of flexible and core competent resources so as to offer
value-added product and services in a volatile competitive environment. Since flexibility is considered a property that provides change capabilities of different enterprise-wide resources and processes in time and
cost dimensions, supply chain flexibility can be considered a composite state to enterprise-wide resources to meet agility needs. Enterprise modeling frameworks depicting
these composite flexibility states are difficult to model because of the complex and tacit interrelationship among system
parameters and also because agility thrives on many business objectives. In view of this, the modeling framework presented
in this paper is based on analytical network process (ANP) since this methodology can accommodate the complex and tacit interrelationship
among factors affecting enterprise agility. The modeling framework forms a three-level network with the goal of attaining
agility from the perspective of market, product, and customer as the actors. The goal depends on substrategies that address
the characteristics of the three actors. Each of these substrategies further depends on manufacturing, logistic, sourcing,
and information technology (IT) flexibility elements of the enterprise supply chain (SC). The research highlights that, under
different environmental conditions, enterprises require synergy among appropriate supply chain flexibilities for practising
agility. In the present research, the ANP modeling software tool Super Decisions™ has been used for relative prioritization
of the supply chain flexibilities. We demonstrate through sensitivity analysis that dynamic conditions do require adjustments
in the enterprise-wide flexibility spectrum.
相似文献
Avneet SaxenaEmail: |
129.
S. Swarupa Tripathy Swati Gupta Divya Mishra Praveen Kumar Yadav Sunita Raina Rajiv K. Saxena Niranjan Singh Nahar Singh Monika J. Kulshrestha V. N. Ojha R. K. Kotnala 《Mapan》2020,35(1):111-115
Breath alcohol analyser is used to detect alcohol content in end-expiratory breaths in order to enforce driving regulations under the influence of alcohol legislation. The accuracy and reliability of the routine measurements of alcohol content performed with breath alcohol analyser can be achieved by the calibration of the breath alcohol analyser using standards traceable to SI reference material. Proper calibration is essential for transparency in legal verification for which reference material is needed. At international level, a number of NMIs are active to address this important measurement issue of providing accurate measurements. Several international key comparison programs have been organized so far for the determination of ethanol content in aqueous and in nitrogen/air matrix. NIST, USA; BAM, Germany; IRMM, Belgium, Portugal, INMETRO, Brazil, LGC, UK etc. have developed certain reference materials of ethanol in water solution/air with different concentration ranges. However, no such reference material is introduced in India as an indigenous standard, rather, being procured from abroad or using high purity alcohol for calibration purposes. CSIR-NPL, India, being the NMI is now focusing on establishing the calibration facility and development of SI traceable aqueous alcohol standard to provide test reliability for the testing in breath alcohol analyser. This program has a societal impact which contributes to human health and regulatory needs for the nation. 相似文献
130.
Das Apurba Rabha Susmita Saxena Varun Bhardwaj Aman Pandey Lalit M. Emmanuel K. A. Dobbidi Pamu 《Journal of Materials Science》2022,57(28):13586-13602
Journal of Materials Science - The exploration of exquisite electrical properties of biomaterials for clinical applications is driven by natural design. Inspired by the idea, composite thin films... 相似文献