全文获取类型
收费全文 | 429篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 87篇 |
金属工艺 | 14篇 |
机械仪表 | 16篇 |
建筑科学 | 10篇 |
矿业工程 | 5篇 |
能源动力 | 10篇 |
轻工业 | 27篇 |
石油天然气 | 2篇 |
无线电 | 66篇 |
一般工业技术 | 102篇 |
冶金工业 | 46篇 |
原子能技术 | 6篇 |
自动化技术 | 45篇 |
出版年
2024年 | 4篇 |
2023年 | 11篇 |
2022年 | 19篇 |
2021年 | 15篇 |
2020年 | 12篇 |
2019年 | 20篇 |
2018年 | 27篇 |
2017年 | 20篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 32篇 |
2012年 | 23篇 |
2011年 | 13篇 |
2010年 | 14篇 |
2009年 | 21篇 |
2008年 | 13篇 |
2007年 | 11篇 |
2006年 | 7篇 |
2005年 | 6篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 10篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 12篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 7篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1969年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有440条查询结果,搜索用时 390 毫秒
11.
12.
Prabhjot Kaur A.K. Soni Anjana Gosain 《Engineering Applications of Artificial Intelligence》2013,26(2):833-847
A new data clustering algorithm Density oriented Kernelized version of Fuzzy c-means with new distance metric (DKFCM-new) is proposed. It creates noiseless clusters by identifying and assigning noise points into separate cluster. In an earlier work, Density Based Fuzzy C-Means (DOFCM) algorithm with Euclidean distance metric was proposed which only considered the distance between cluster centroid and data points. In this paper, we tried to improve the performance of DOFCM by incorporating a new distance measure that has also considered the distance variation within a cluster to regularize the distance between a data point and the cluster centroid. This paper presents the kernel version of the method. Experiments are done using two-dimensional synthetic data-sets, standard data-sets referred from previous papers like DUNN data-set, Bensaid data-set and real life high dimensional data-sets like Wisconsin Breast cancer data, Iris data. Proposed method is compared with other kernel methods, various noise resistant methods like PCM, PFCM, CFCM, NC and credal partition based clustering methods like ECM, RECM, CECM. Results shown that proposed algorithm significantly outperforms its earlier version and other competitive algorithms. 相似文献
13.
Amit K. Jaiswal Hemlata Chhabra Sachin S. Kadam Kishore Londhe Vivek P. Soni Jayesh R. Bellare 《Materials science & engineering. C, Materials for biological applications》2013,33(5):2926-2936
The aim of this study was to compare physico-chemical and biological properties of hydroxyapatite (HA) and hardystonite (HS) based composite scaffolds. Hardystonite (Ca2ZnSi2O7) powders were synthesized by a sol–gel method while polycaprolactone–hardystonite (PCL–HS) and polycaprolactone–hydroxyapatite (PCL–HA) were fabricated in nanofibrous form by electrospinning. The physico-chemical and biological properties such as tensile strength, cell proliferation, cell infiltration and alkaline phosphatase activity were determined on both kinds of scaffolds. We found that PCL–HS scaffolds had better mechanical strength compared to PCL–HA scaffolds. Addition of HA and HS particles to PCL did not show any inhibitory effect on blood biocompatibility of scaffolds when assessed by hemolysis assay. The in vitro cellular behavior was evaluated by growing murine adipose-tissue-derived stem cells (mE-ASCs) over the scaffolds. Enhanced cell proliferation and improved cellular infiltrations on PCL–HS scaffolds were observed when compared to HA containing scaffolds. PCL–HS scaffolds exhibited a significant increase in alkaline phosphatase (ALP) activity and better mineralization of the matrix in comparison to PCL–HA scaffolds. These results clearly demonstrate the stimulatory role of Zn and Si present in HS based composite scaffolds, suggesting their potential application for bone tissue engineering. 相似文献
14.
A Combinatorial Approach for Assessing the Magnetic Properties of High Entropy Alloys: Role of Cr in AlCoxCr1–xFeNi
下载免费PDF全文
![点击此处可从《Advanced Engineering Materials》网站下载免费的PDF全文](/ch/ext_images/free.gif)
15.
This article reports the application of ozone for the selective oxidation of cyclohexane over 13X molecular sieve supported various metal oxides at ambient temperatures. From the SEM, XRD and HR-TEM results, the impregnated metal oxides are highly dispersed on the support. The activity results reveal that Co/MS, Mo/MS, Cu/MS, and Ag/MS catalysts produce cyclohexanone/cyclohexanol as selective oxidation products, whereas Ce/MS, Mn/MS, and V/MS catalysts yield, predominantly, CO and CO2. Among them, Co/MS catalyst exhibits better conversion of 12.2% with selectively of 58% to cyclohexanone/cyclohexanol, which is attributed to the simultaneous activation of ozone and cyclohexane (-C-H bond) at ambient conditions. 相似文献
16.
P. L. Soni H. W. Sharma S. S. Bisen H. C. Srivastava M. M. Gharia 《Starch - St?rke》1987,39(12):411-413
Starch from sal seeds cake was isolated, bleached and purified. Scanning electron microscopy of the starch showed round to oval shaped granules of the size 3.5 to 12.3 μm. The starch has more nitrogen, phosphorus, lipids, amylose and water binding capacity in comparison to the other starches of forest origin. Despite its low and seemingly restricted swelling, the sal starch is much more soluble at any particular degree of swelling. Paste viscosity curve showed no drop in viscosity after full gelatinisation had taken place, i. e. the paste is stable on continued cooking. 相似文献
17.
Synergistic effect of some antiscalants as corrosion inhibitor for industrial cooling water system 总被引:2,自引:0,他引:2
Harish Kumar Moudgil S. Yadav R. S. Chaudhary Dheeraj Kumar 《Journal of Applied Electrochemistry》2009,39(8):1339-1347
In order to study synergistic effect, various combinations of antiscalants 1-hydroxyethane-1,1-diphosphonic acid (HEDP), sodium
hexametaphosphate (SHMP), sodium tripolyphosphate (STPP), and trisodium phosphate (TSP), were investigated as corrosion inhibitors
for carbon steel. Corrosion rate and percentage inhibition efficiency of various combinations of antiscalants as corrosion
inhibitors (20/80, 40/60, 60/40, 50/50, 80/20, and 100 ppm of different combinations of HEDP, SHMP, STPP, and TSP) in synthetic
cooling water VI (692 ppm of Cl− ions) was determined by weight loss, electrochemical polarization technique, and metallurgical microscopy technique. It was
observed that a 50/50 ppm combination of HEDP and SHMP gave 98% corrosion inhibition efficiency and maximum synergistic effect.
The percentage inhibition efficiency of HEDP when mixed with other antiscalants as corrosion inhibitors at 50/50 ppm concentration
was found in the following order HEDP/SHMP > HEDP/STPP > HEDP/TSP. The synergistic effect of HEDP/SHMP combination is due
to intermolecular hydrogen bonding between the molecules of HEDP and SHMP, which results in the adsorption of uniform multilayered
two-dimensional film of –HEDP–SHMP– molecules on carbon steel surface. 相似文献
18.
Chander Shekhar Sharma Amanda Ates Poulson Joseph Kamlesh A. Soni M. Wes Schilling Aaron Kiess 《International Journal of Food Science & Technology》2013,48(7):1410-1415
The efficacy of lauric arginate (LAE) on Salmonella survivability in ground chicken containing 9.8% fat was determined under refrigerated storage. The effect of LAE treatments on total aerobes, pH and objective colour were also assessed in ground chicken. LAE was highly effective against Salmonella in 0.1% peptone with no detectable survivors following treatment with 200 ppm and 400 ppm of LAE. No difference existed (P > 0.05) in the growth of Salmonella and total aerobes after treatment with 200 and 400 ppm of LAE in ground chicken inoculated with a four strain mixture of Salmonella. At these concentrations, LAE did not exhibit any treatment effect on the pH and colour of ground chicken (P > 0.05). In conclusion, although LAE possesses strong inhibitory (P < 0.05) effect against Salmonella in suspension in 0.1% peptone water, no inhibitory (P > 0.05) effect on growth of Salmonella was observed in ground chicken at the currently approved levels of 200 ppm of LAE. 相似文献
19.
The energy of sunlight falling on surface of the earth can be directly converted into electricity by means of the solar cells. Among the various materials used for photovoltaics, the chalcopyrite compounds CuXSe2 (X=Al, Ga, In) are very promising as semiconductors and have received much attention in the recent years. To check the applicability of these materials in solar cells, we have computed the energy bands, density of states, optical dielectric tensors, reflectivity, refraction and absorption coefficients using the full potential linearized augmented plane wave method. It is seen that the energy bandgap reduces from X=Al→In. The dielectric property of these materials is discussed in terms of interband transitions. The absorption coefficients of these materials in the region of solar radiation (0–5 eV energy) are discussed to explore their use in the fabrication of solar cells. 相似文献
20.
Biplab Kumar Paul Dheeraj Mondal Solanky Das Debasis Roy Papiya Nandy Sukhen Das 《Journal of Electronic Materials》2018,47(12):7075-7084
In this communication, the formation mechanism of the electroactive β phase, morphology and the dielectric activities of increasing doping concentration (0–1.2 M.W % of mullite) of Fe2+ ion-doped, mullite-impregnated polyvinylidene fluoride (PVDF) nanocomposite have been investigated. Differential thermal analysis (DTA) confirms the formation of an electroactive β phase, and Fourier transform infrared spectroscopy (FTIR) showed that the β phase increases simultaneously and attains the maximum increment of 2.6 times compared to pristine PVDF. X-ray diffraction (XRD) spectra also agreed well with the β-phase increment behaviour and also confirmed the presence of required mullite phases. Field emission scanning electron microscopy (FESEM) images indicate the strong interaction between the polymer matrix and different concentrations of Fe2+ ion-doped mullite particles, resulting in enhanced electroactive β phase formation and large dielectric constant of the nanocomposite films followed by significant low dielectric loss with high ac conductivity compared to pristine PVDF films at room temperature. This doped polymer composite can be used as a high dielectric separator and, using this separator, we have successfully fabricated a high-charge-storage device. This paper also demonstrates that the loading of conductive Fe2+ ions within the highly insulating mullite matrix has a critical concentration for the enhancement and nucleation of the electroactive β phase of the PVDF polymer. In this critical concentration, the highest formation of a β network and maximum numbers of homogeneously distributed iron-doped mullite (FeM) particles in PVDF matrix improves the effective interfacial polarization by Maxwell–Wagner–Sillar (MWS) polarization effect which is responsible for the enhancement of dielectric constant and ac conductivity followed by significant tangent loss. So, it can be concluded that the incorporation of Fe2+-doped mullite into PVDF matrix is an effective way to fabricate a high dielectric separator of high-charge-storage electronic devices. 相似文献