全文获取类型
收费全文 | 212篇 |
免费 | 11篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 47篇 |
金属工艺 | 7篇 |
机械仪表 | 9篇 |
建筑科学 | 31篇 |
能源动力 | 4篇 |
轻工业 | 32篇 |
水利工程 | 2篇 |
无线电 | 22篇 |
一般工业技术 | 35篇 |
冶金工业 | 7篇 |
原子能技术 | 1篇 |
自动化技术 | 19篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 5篇 |
2016年 | 14篇 |
2015年 | 8篇 |
2014年 | 8篇 |
2013年 | 21篇 |
2012年 | 7篇 |
2011年 | 21篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 8篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 1篇 |
2003年 | 1篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1986年 | 2篇 |
1984年 | 2篇 |
1983年 | 2篇 |
1982年 | 1篇 |
排序方式: 共有223条查询结果,搜索用时 15 毫秒
11.
A mannose-binding protein from the cell surface of flocculent Saccharomyces cerevisiae (NCIM 3528): its role in flocculation 总被引:1,自引:0,他引:1
A cell surface lectin was isolated and purified to homogeneity from the cell walls of a highly flocculent strain of Saccharomyces cerevisiae (NCIM 3528) by chromatography on DEAE-cellulose, phenyl Sepharose and Sephacryl S-300. It showed a molecular mass of 40 kDa on SDS-PAGE. It is an acidic protein with a pI of 4.0 and contains 44% hydrophobic amino acids. The N-terminal sequence up to 10 amino acid residues showed at least 70% homology with the predicted N-terminal sequence of the putative FLO1 as well as FLO5 gene products. The mannose-binding nature of the lectin was indicated by its high affinity and specificity towards the branched trisaccharide of mannose, a ligand which also inhibits the flocculation of yeast cells. Immunofluorescence studies confirmed the presence of lectin on the yeast cell surface and lectin-specific IgGs prevented flocculation of the cells. This cell surface mannose-specific lectin probably plays an important role in flocculation, with the branched trimannoside on the cell wall being the apparent carbohydrate receptor. The N-terminal sequence data gives a primary indication that the lectin could be a product of one of the FLO genes. 相似文献
12.
Chandra S. Sharma Mukund D. Behera Atmaram Mishra Sudhindra N. Panda 《Water Resources Management》2011,25(13):3219-3246
Natural hazards such as flooding can cause changes in land-cover. The present study deals with the changes in land-cover in
three worst affected districts (Anand, Vadodara and Kheda) of Gujarat state in India due to severe flood during 2005. The
Indian Remote Sensing (IRS) P6 Linear Imaging Self Scanning (LISS) III satellite imageries of pre- and post-flooding periods
were used as sources of information for the study area. Three classification approaches (unsupervised ISODATA, supervised
Maximum Likelihood Classifier, and fuzzy rule based) were used to extract flood induced land-cover information. Results obtained
from the above classification approaches were compared. Soft computing technique such as fuzzy based image classification
gave better separability amongst classes as compared to hard classification techniques. The accuracy assessment showed that
the fuzzy approach can predict land-cover more accurately than traditional approach and also showed great potential for dealing
with mapping of flood induced land-cover. Unsupervised classification results for the period October 2004 to October 2005
revealed decrease in inland water bodies (14.49%) and agricultural area (6.42%) while increase in remaining land-cover. During
February 2005 to February 2006, all land-cover classes decreased except agricultural fallow and sparse vegetation. In case
of supervised classification, decreasing trend was observed only in case of agricultural area (6.78%) during October 2004
to October 2005. Similarly, during February 2005 to February 2006, increase in coastal water bodies (0.73%) and sparse vegetation
(1.7%) was observed where as decreasing trend was noticed in the remaining land-cover classes. In fuzzy based classification,
only decrease in agricultural area (7.09%) was observed from October 2004 to October 2005, whereas during February 2005 to
February 2006, decrease in area was exhibited in all land-cover classes except coastal water bodies and sparse vegetation.
Change detection indicated interchange of areas between inland and coastal water bodies and decrease in agricultural area
leading to increase in area of agricultural fallow and sparse vegetation. 相似文献
13.
Serafim Bakalis & Mukund V. Karwe 《International Journal of Food Science & Technology》1997,32(3):241-253
Velocity measurements inside the screw channels of a co-rotating, self-wiping, twin-screw extruder were carried out. A laser Doppler anemometer (LDA) system was used to measure tangential and axial velocity components in the translational region of one of the screws of a twin-screw extruder. The velocity measurements were carried out using heavy corn syrup at different screw speeds and for two forwards conveying elements differing in their pitch. It was found that velocity profiles in the translational region were substantially affected by the pitch of the screw element, however, screw speed (30–90 r.p.m.) did not have a significant effect on the shape of the velocity profiles. The range of velocity values in a 14 mm pitch screw element was wider than that in a 28 mm pitch screw element. Experimentally measured velocity profiles were compared with predictions of a one-dimensional model, which showed that the model underpredicted the velocity values, for the 14 mm pitch element. 相似文献
14.
Sarabmeet Kaur Asit B Mandal Kunwer B Singh Mukund M Kadam Arumbackam V Elangovan 《Journal of the science of food and agriculture》2007,87(5):751-759
The effect on egg production of graded levels of ideal amino acids, combined with reduced protein in the diet, was investigated in 312 laying quails aged 6–18 weeks. The quails were offered six diets, each of which contained one of three levels of amino acids (85, 100 and 115% of essential amino acids (EAAs)) together with 5% or without fishmeal (FM) (3 × 2 factorial design). Each diet was offered to 26 replicated groups of two quails each. Hen‐day and hen‐housed egg production did not differ as a result of EAA level, protein type or their interaction during the overall period of egg production. Egg weight improved linearly (P < 0.01) with increased EAA levels, while egg mass output per bird per day remained similar at the 100 and 115% EAA levels. Quails fed higher (100 and 115%) EAA levels had an improved feed conversion ratio (P < 0.01) compared to birds fed 85% EAA. The gain in body weight during the laying period was higher (P < 0.01) at the 100 or 115% than at 85% EAA levels The ratio of egg mass or egg mass and live weight gain, together, to protein intake improved (P < 0.01) linearly with a decrease in EAA levels in the diets, while better (P < 0.01) energy efficiency (EE, energy intake: egg mass) and net EE (energy intake: egg mass plus gain) was obtained in higher EAA levels (100 or 115%). Protein and energy efficiencies remained similar due to protein type or interaction. Shape index, albumen index, yolk index, yolk colour and relative shell weight did not differ due to EAA levels, protein type or their interaction. Eggs laid from quails fed diets with 100% EAAs without FM and 115% EAAs with or without FM had higher shell thickness than those on 85% EAAs irrespective of protein type. The retention of nitrogen and calcium retention was higher (P < 0.01) at the 115% EAA level. The results indicated a dietary level of 100% EAA (185 g kg?1 crude protein (CP)) with 12.13 MJ kg?1 was suitable for laying quails of 6–18 weeks of age. Copyright © 2007 Society of Chemical Industry 相似文献
15.
Kang Huang Yuyang Tian Deepti Salvi Mukund Karwe Nitin Nitin 《Food and Bioprocess Technology》2018,11(3):621-633
Washing and sanitation of fresh produce are critical for detachment and inactivation of pathogenic and spoilage microorganisms. The overall goal of this study was to evaluate the influence of processing conditions such as washing time, shear stress, and a food grade surfactant on the detachment of Escherichia coli O157:H7 from lettuce leaf surfaces during a simulated washing process. A benchtop scale rotating disk washing device was designed to simulate the processing conditions used in commercial washing systems. Numerical simulations were carried out to calculate the flow profile and shear stress near the leaf surface. Removal of E. coli O157:H7 as a function of processing conditions in the rotating disk washing device was evaluated by enumeration of bacterial population using plate counting and changes in bioluminescence intensity and further confirmed by bioluminescence imaging. The results showed that shear stress was necessary to remove attached bacteria from inoculated leaf samples and simple incubation of inoculated leaves with wash water was not effective. Furthermore, detachment of bacteria from inoculated leaf samples increased with increasing shear stress and incubation time. Shear stress values in the range of 0 – 300 mPa were adequate to induce removal of approximately 1.5 log CFU/cm2 of bacteria from inoculated samples. The addition of a surfactant increased the removal of bacteria from inoculated leaf samples by 0.5 log CFU/cm2. Overall, these results may guide the design of new produce wash systems as well as current industrial practice related to flow conditions and use of surfactants during washing of fresh produce. 相似文献
16.
Punyasloka Bal Bahniman Ghosh Partha Mondal M. W. Akram Ball Mukund Mani Tripathi 《Journal of Computational Electronics》2014,13(1):230-234
This paper proposes a junctionless tunnel field effect transistor (JLTFET) with dual material gate (DMG) structure and the performance was studied on the basis of energy band profile modulation. The two-dimensional simulation was carried out to show the effect of conduction band minima on the abruptness of transition between the ON and OFF states, which results in low subthreshold slope (SS). Appropriate selection of work function for source and drain side gate metal of a double metal gate JLTFET can also significantly reduce the subthreshold slope (SS), OFF state leakage and hence gives improved I ON/I OFF. 相似文献
17.
Syed Ubaid Ahmed Panneerselvam Ranganathan Ashok Pandey Savithri Sivaraman 《Journal of Bioscience and Bioengineering》2010,109(6):588-597
In the present study, experiments have been carried out to identify various flow regimes in a dual Rushton turbines stirred bioreactor for different gas flow rates and impeller speeds. The hydrodynamic parameters like fractional gas hold-up, power consumption and mixing time have been measured. A two fluid model along with MUSIG model to handle polydispersed gas flow has been implemented to predict the various flow regimes and hydrodynamic parameters in the dual turbines stirred bioreactor. The computational model has been mapped on commercial solver ANSYS CFX. The flow regimes predicted by numerical simulations are validated with the experimental results. The present model has successfully captured the flow regimes as observed during experiments. The measured gross flow characteristics like fractional gas hold-up, and mixing time have been compared with numerical simulations. Also the effect of gas flow rate and impeller speed on gas hold-up and power consumption have been investigated. 相似文献
18.
Meenakshisundaram Ramanathan Biswadeep Saha Chai Ren Sivaraman Guruswamy Michael McCarter 《Journal of Materials Engineering and Performance》2013,22(4):1028-1034
Presence of hydrogen in materials is known to affect their mechanical properties due to hydrogen embrittlement problem. Steels used in various applications are prone to be exposed to aqueous electrochemical environments, which may introduce hydrogen into the alloy. These alloys are also prone to be simultaneously exposed to magnetic field, which may affect the hydrogen embrittlement susceptibility of these alloys. Therefore, it is important to examine the effect of hydrogen and magnetic field on the mechanical behavior of iron-based alloys. In this work, the effect of hydrogen and magnetic field on the fracture behavior of high strength AISI 4340 steel was examined. Three-point bend test was used to study the fracture behavior. In all the cases, the samples tested with hydrogen charging show a drastic reduction in ductility and fracture stress values. The effect of magnetic field was seen to be negligible. The hydrogen embrittlement was characterized by a change in the fracture surface from a ductile-type fracture to a brittle cleavage-type fracture. Acoustic emission signals collected during the test corresponds to the fracture behavior. 相似文献
19.
In this paper, we propose a double aperture double-gate AlGaN/GaN vertical high-electron-mobility transistor (HEMT) to improve the device characteristics, such as the current and the ON resistance (\(\hbox {\textit{R}}_{\mathrm{ON}}\)). The proposed vertical HEMT results are compared to the conventional single aperture single-gate vertical HEMT of equal dimensions, and increased drain current and lower \(\hbox {\textit{R}}_{\mathrm{ON}}\) are shown. A comprehensive simulation study has also been carried out for the proposed device, to analyse the impact of thickness and doping concentration of aperture, drift region, and current blocking layer. In addition, the effect of different materials in current blocking layer on device characteristics is also studied. The obtained results and their effect on device characteristics have been thoroughly analysed and explained accordingly. 相似文献
20.
S. Basavarajappa G. Chandramohan M. Prabu K. Mukund M. Ashwin 《International Journal of Machine Tools and Manufacture》2007,47(1):92-96
The main concern in the present study is the surface roughness variations on the drilled surface and extension of surface and sub-surface deformation due to drilling. The influence of different tools and cutting conditions on Al2219/15%SiCp and Al2219/15%SiCp-3%Graphite (hybrid) composites is investigated experimentally. The composites are fabricated by liquid metallurgy method. The drilling tests are conducted with carbide and coated carbide tools. The surface roughness decreases with the increase in cutting speed and increases with the increase in feed rate. The surface is analyzed using scanning electron microscope (SEM). Microhardness profiles indicate that the subsurface deformation extends up to a maximum of 120 μm below the machined surface for Al2219/15SiCp-3Gr composite when compared to 150 μm in Al2219/15SiCp composite. 相似文献