全文获取类型
收费全文 | 1014篇 |
免费 | 44篇 |
专业分类
电工技术 | 8篇 |
化学工业 | 254篇 |
金属工艺 | 19篇 |
机械仪表 | 20篇 |
建筑科学 | 17篇 |
能源动力 | 52篇 |
轻工业 | 79篇 |
水利工程 | 4篇 |
石油天然气 | 4篇 |
无线电 | 129篇 |
一般工业技术 | 197篇 |
冶金工业 | 151篇 |
原子能技术 | 12篇 |
自动化技术 | 112篇 |
出版年
2023年 | 10篇 |
2022年 | 31篇 |
2021年 | 26篇 |
2020年 | 27篇 |
2019年 | 15篇 |
2018年 | 43篇 |
2017年 | 37篇 |
2016年 | 34篇 |
2015年 | 18篇 |
2014年 | 33篇 |
2013年 | 81篇 |
2012年 | 34篇 |
2011年 | 34篇 |
2010年 | 30篇 |
2009年 | 49篇 |
2008年 | 22篇 |
2007年 | 23篇 |
2006年 | 31篇 |
2005年 | 17篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 14篇 |
2001年 | 9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1058条查询结果,搜索用时 0 毫秒
61.
Effect of Controlled Atmosphere Storage and Chitosan Coating on Quality of Fresh-Cut Jackfruit Bulbs 总被引:2,自引:0,他引:2
Alok Saxena Tanushree Maity Saxena P. S. Raju A. S. Bawa 《Food and Bioprocess Technology》2013,6(8):2182-2189
Fresh-cut jackfruit bulbs were evaluated for quality changes as effect of an additive pretreatment with CaCl2, ascorbic acid, citric acid, and sodium benzoate followed by chitosan coating. Different types of samples such as pretreated and coated, only pretreated, only coated, and untreated were subjected to controlled atmosphere (CA) storage (3 kPa O2?+?6 or 3 kPa CO2; N2 balance) or normal air at 6 °C. CA conditions, pretreatment, as well as chitosan coating in synergy with each other, could significantly minimize the loss in total phenolics and ascorbic acid content of the samples to the levels of around 5% and 17%, respectively, during extended storage up to 50 days. Chitosan coating could also restrict the changes in microbial load. The CA condition of 3 kPa O2?+?6 kPa CO2 was found to render higher efficacy in retaining quality attributes of the samples. 相似文献
62.
The effect of technology scaling (0.5-0.09 /spl mu/m) on single event upset (SEU) phenomena is investigated using full two-dimensional device simulation. The SEU reliability parameters, such as critical charge (Q/sub crit/), feedback time (T/sub fd/) and linear energy transfer (LET), are estimated. For L/sub g/<0.18 /spl mu/m, the source node collects a significant fraction of radiation-induced charge resulting in an increase of LET, despite the lower critical charge at the sensitive drain node. The effect of striking location on LET confirms this finding. 相似文献
63.
A few aluminum containing polycarbosilanes named AlOR-PCS and Alac-PCS have been synthesized by the reaction of aluminum isopropoxide (AlOR) and aluminum acetylacetonate (Alac) with polycarbosilane (PCS), respectively. These materials were characterized by Fourier Transform Spectroscopy (FTIR), Thermo gravimetric Analysis (TGA) and Gel Permeation Chromatography (GPC). The rheological properties of these compounds were studied with respect to time, temperature and atmosphere (inert & air). It has been observed that the increase in metal content enhances the crosslinking of the PCS chains. Under similar conditions, the crosslinking of AlOR-PCS derivatives was found slower than Alac-PCS. GPC analysis of the samples showed the increase in molecular weight of these compounds compared to virgin PCS. TGA showed improved ceramic yield with increasing metal content. Alac-PCS gave higher ceramic yield than AlOR-PCS for similar molar ratios of metal complexes. 相似文献
64.
Yogi Priyanka Poonia Deepika Yadav Pooja Mishra Suryakant Saxena Shailendra K. Roy Swarup Sagdeo Pankaj R. Kumar Rajesh 《SILICON》2018,10(6):2801-2807
Silicon - Nano-metal/semiconductor junction dependent porosification of silicon has been studied here. The silicon nanostructures (SiNSs) have been textured on n- and p- type silicon wafers using... 相似文献
65.
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
66.
Akanksha Singh Wilhelm Pfleging Markus Beiser Chantal Khan Malek 《Microsystem Technologies》2013,19(3):445-453
Recently microfluidic devices have emerged as a viable technology for the miniaturization of high throughput tools for analytical tasks related to structural biology such as screening of crystallization conditions and structural analysis. This work reports the manufacture of microfluidic chips in transparent thermoplastic polymers [poly(methylmethacrylate) (PMMA), and cyclic olefin copolymer (COC)] using two complementary technologies, injection moulding for the fabrication of the fluidic level and laser transmission welding for the sealing of the cover. A steel mould insert was produced by laser micro caving using a solid state laser radiation source (Nd:YAG, wavelength 1,064 nm). Fluidic chips of ~670 μm thickness comprising channels of 50 μm depth and width down to 50 μm were injection moulded in PMMA and COC. Joining of transparent thin cover film to the micro-injected fluidic level was performed by laser transmission welding using high power diode laser radiation (wavelength 940 nm) and an intermediate thin absorbing layer with a thickness of about several nanometers. 相似文献
67.
Swanand J. Deodhar K.B.C. Saxena Rajen K. Gupta Mikko Ruohonen 《The Journal of Strategic Information Systems》2012,21(4):274-294
The open source approach to software development has been used by software organizations in tandem with their existing business models, which are based on proprietary software licensing. This led to the creation of hybrid business models that merge open source and proprietary paradigms. This paper explores the practices used by software product vendors using hybrid business models and proposes strategies emerging out of these practices using interpretive, single case study research design. 相似文献
68.
R. C. Sharma R. K. Saxena K. S. Verma 《International journal of remote sensing》2013,34(17):3209-3218
The Indo-Gangetic alluvial plain is subjected to large scale soil alkalization. In order to map and characterize salt-affected soils, with the aim of applying management techniques, Etah district in Uttar Pradesh, located between 26oo45' to 28o02' N and 78o15' to 79o20' E was selected. Multidate, high resolution, IRS-LISS II, geocoded FCC images on 1550 000 scale were used. Integrating visual image interpretation, physiographic analysis, ground data and laboratory analysis of soil samples, a legend for mapping salt-affected soils (SAS) was formulated. Based on variations in physicochemical properties: nature, intensity and depth wise distribution of salts, five categories of SAS requiring specific reclamation measures were identified. Soil categories S2, S3 and S4 have a gypsum requirement (GR) of 20, 12 and 4t/ha-1 respectively. Reclamation of medium to heavy textured highly alkali soils requires the addition of amendments and a rice-wheat rotation for the initial 3-4 years. Under resource constraints, pit planting of Prosopis juliflora can bring about slow but effective reclamation. The soil category S5 is slightly alkali in the substratum, needing only biological reclamation by growing salt tolerant varieties of rice and wheat crops. Soils of category S1 are saline and need management by hydrological treatments. Incorporation of village boundaries on a map showing SAS would facilitate decision taking in planning reclamation projects and accelarate management operations directly at village level. 相似文献
69.
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
70.
Design and development of guided four beam cantilever type MEMS based piezoelectric energy harvester
Microsystem Technologies - MEMS devices have found applicability in remote area of operation such as temperature monitoring in extreme climates, structural health monitoring, and car tire pressure... 相似文献