全文获取类型
收费全文 | 397篇 |
免费 | 11篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 72篇 |
金属工艺 | 6篇 |
机械仪表 | 4篇 |
建筑科学 | 3篇 |
矿业工程 | 2篇 |
能源动力 | 22篇 |
轻工业 | 20篇 |
水利工程 | 6篇 |
石油天然气 | 4篇 |
无线电 | 46篇 |
一般工业技术 | 86篇 |
冶金工业 | 59篇 |
原子能技术 | 6篇 |
自动化技术 | 67篇 |
出版年
2024年 | 3篇 |
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 10篇 |
2019年 | 17篇 |
2018年 | 18篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 8篇 |
2014年 | 18篇 |
2013年 | 23篇 |
2012年 | 23篇 |
2011年 | 25篇 |
2010年 | 15篇 |
2009年 | 23篇 |
2008年 | 22篇 |
2007年 | 21篇 |
2006年 | 12篇 |
2005年 | 4篇 |
2004年 | 15篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 1篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1979年 | 1篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1973年 | 2篇 |
排序方式: 共有410条查询结果,搜索用时 15 毫秒
71.
The effect of citrate, oxalate, acetate, silicate and phosphate on stability of synthetic arsenic-loaded ferrihydrite and Al-ferrihydrite 总被引:2,自引:0,他引:2
Mohapatra D Singh P Zhang W Pullammanappallil P 《Journal of hazardous materials》2005,124(1-3):95-100
The effect of the organic species oxalate, citrate and acetate and the inorganic species silicate and phosphate on release of As(V) from synthetic arsenic-loaded ferrihydrite and Al-ferrihydrite in the pH range 4-8 was investigated. For ferrihydrite, the organic species increased %As(V) extraction in the order: acetatePO4(3-). Competitive adsorption of the investigated organic and inorganic species on ferrihydrite and Al-ferrihydrite could explain the enhanced release of As(V) into solution. However, disproportionate adsorption of other species relative to amount of As(V) release occurs, suggesting that mechanisms other than competitive adsorption are also operative. The results could best be explained in terms of combination of competitive adsorption and processes involving pH-dependent dissolution of ferrihydrite/Al-ferrihydrite, formation of various complex ionic species involving Al(III), Fe(III), As(V), SiO3(2-), PO4(3-), OH-, H+ and organic species: acetate, oxalate and citrate. 相似文献
72.
Evaluation of Dielectric Properties of CCTO-BT/Epoxy Composites for Electronic Applications
下载免费PDF全文
![点击此处可从《哈尔滨工业大学学报(英文版)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Swagatika Mishr Punyapriya Mishr Punyatoya Mishr Dinesh Kumar Mishr KH-/HJJZ 《哈尔滨工业大学学报(英文版)》2024,31(1):69-77
In the current study, the calcium copper titanate (CCTO)/epoxy, barium titanate (BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression moulding process. The composite samples are characterized for the frequency dependence on dielectric properties, conductivity, impedance spectroscopy and electrical modulus. X-ray diffraction (XRD) representation of CCTO-BT/epoxy composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric characteristics of hybrid CCTO-BT/epoxy composite samples with CCTO∶BT ratio of 40∶60, 60∶40, and 50∶50 was found relatively better than those of single ceramic filler reinforced epoxy composites. AC conductivity analysis shows improvement in the results of hybrid filler-filled CCTO-BT/epoxy composites in comparison with single filler-filled epoxy composite. 50∶50 CCTO-BT/epoxy composite shows the best AC conductivity value of ~2.2×10-5 ohm-1·m-1 at a higher frequency of 1 MHz. The impedance analysis confirms the higher insulating properties for hybrid 40∶60 and 60∶40 CCTO-BT/epoxy composites with respect to the single and other hybrid ceramic epoxy composites. The analysis suggests the hybrid CCTO-BT/epoxy composites to be adopted as a potential dielectric material for energy storage devices and other electronic applications. 相似文献
73.
Ryan Green Roukiah Khalil Shyam S. Mohapatra Subhra Mohapatra 《International journal of molecular sciences》2022,23(21)
There is currently a growing interest in the use of cannabidiol (CBD) to alleviate the symptoms caused by cancer, including pain, sleep disruption, and anxiety. CBD is often self-administered as an over-the-counter supplement, and patients have reported benefits from its use. However, despite the progress made, the mechanisms underlying CBD’s anti-cancer activity remain divergent and unclear. Herein, we provide a comprehensive review of molecular mechanisms to determine convergent anti-cancer actions of CBD from pre-clinical and clinical studies. In vitro studies have begun to elucidate the molecular targets of CBD and provide evidence of CBD’s anti-tumor properties in cell and mouse models of cancer. Furthermore, several clinical trials have been completed testing CBD’s efficacy in treating cancer-related pain. However, most use a mixture of CBD and the psychoactive, tetrahydrocannabinol (THC), and/or use variable dosing that is not consistent between individual patients. Despite these limitations, significant reductions in pain and opioid use have been reported in cancer patients using CBD or CBD+THC. Additionally, significant improvements in quality-of-life measures and patients’ overall satisfaction with their treatment have been reported. Thus, there is growing evidence suggesting that CBD might be useful to improve the overall quality of life of cancer patients by both alleviating cancer symptoms and by synergizing with cancer therapies to improve their efficacy. However, many questions remain unanswered regarding the use of CBD in cancer treatment, including the optimal dose, effective combinations with other drugs, and which biomarkers/clinical presentation of symptoms may guide its use. 相似文献
74.
Shivani Chaturvedi Ayesha Sadaf Amrik Bhattacharya Prasant Kumar Rout Lata Nain Sunil Kumar Khare 《European Journal of Lipid Science and Technology》2021,123(11):2000376
The microbial lipids isolated from oleaginous yeasts are a potential alternative to tree borne oils. There is a need to optimize and enhance the production of lipid by various stress approaches. In the present study, yeasts are subjected to physico-chemical stresses, and growth, as well as lipid concentration at different time intervals are monitored. It is found that the nanoparticles (NP) such as Ag-NP and Zn-NP have an inhibitory effect on yeast growth. Most yeast strains show an increase in growth and lipid accumulation when ionic liquid (1-ethyl-3-methylimidazolium acetate) ([EMIM][OAc]) and table salt (NaCl) stress are applied. Lipid is chemically characterized using gas chromatography furnished with flame ionization detector (GC-FID), GC/MS, and NMR techniques. It contains a higher percentage of saturated fatty acids (SFA: 74.3%), monounsaturated fatty acids (19.1%) with low amounts of polyunsaturated fatty acids (1.9%). The thermo-stability study reveals that the lipid have higher volatility (380–410 °C) as closely compared with coconut oil, and much lower with respect to the winged bean oil (430–470 °C). The melting point of the lipids (37 °C) is determined through differential scanning calorimetry (DSC). The DSC and physico-chemical properties are supported that the yeast lipids may use as a cocoa-butter substitute. Production of lipid under NaCl stress (200 × 10−3 m ) is more than 60.4% higher as compared to the control. However, the combined stress effect of NaCl (200 × 10−3 m ) and 15 × 10−3 m of [EMIM][OAc] results in more than 96.4% yield of lipid. The exchange of inorganic and organic ions in combined treatment forces the microbial cells to accumulate more amounts of lipid, which may form a lipid-emulsion layer to protect the cell from osmosis. It is interestingly observed that the stress cells shift the flux to accumulate a significantly improved percentage of SFA, which could be provided better protection cover due to its expanded structure, less reactive characteristics, and completely insoluble nature in ionic-aqueous solvent. Practical applications: Oleaginous yeast is multiplied in a very limited space, and easily scalable for sustainable production of lipid to meet its commercial demand. This novel approach for enhancing the yield of lipid with the application of synergistic stress in between NaCl and the green solvent (ionic liquid) is being reported for the first time. This lipid has potential alternative applications as cocoa-butter. 相似文献
75.
Akshey Marwaha Amit Dhir Sunil Kumar Mahla Saroj Kumar Mohapatra 《Catalysis Reviews》2018,60(4):594-628
The alcoholysis process requires high activity catalysts for biodiesel production. Heterogeneous catalysts have been proven to possess highly active nature and are environment-friendly. The present article emphasizes on various types of solid base catalysts that have been used in the recent past for the production of biodiesel by transesterification of oils. The parameters and conditions affecting the transesterification reaction and biodiesel yield have also been mentioned in the article. Heterogeneous catalysts have the capability to be recycled for many runs in the process without greatly abating the biodiesel yield. Also, such catalysts possess noncorrosive nature, thus making the biodiesel safe to be used in engine without any damage. The exploitation of waste materials as catalysts would reduce the overall production cost of biodiesel. Calcium-based catalysts in the reviewed literature have shown promising outcomes for the future use and would make the process economical for large-scale industrial applications. 相似文献
76.
77.
78.
A nine-point degree five rule for the numerical approximation of double integrals of analytic functions of complex variables and its error bound have been derived. 相似文献
79.
Mohapatra N.R. Nair D.R. Mahapatra S. Ramgopal Rao V. Shukuri S. Bude J.D. 《Electron Devices, IEEE Transactions on》2003,50(10):2104-2111
The impact of programming biases, device scaling and variation of technological parameters on channel initiated secondary electron (CHISEL) programming performance of scaled NOR Flash electrically erasable programmable read-only memories (EEPROMs) is studied in detail. It is shown that CHISEL operation offers faster programming for all bias conditions and remains highly efficient at lower biases compared to conventional channel hot electron (CHE) operation. The physical mechanism responsible for this behavior is explained using full band Monte Carlo simulations. CHISEL programming efficiency is shown to degrade with device scaling, and various technological parameter optimization schemes required for its improvement are explored. The resulting increase in drain disturbs is also studied and the impact of technological parameter optimization on the programming performance versus drain disturb tradeoff is analyzed. It is shown that by judicious choice of technological parameters the advantage of CHISEL programming can be maintained for deeply scaled electrically erasable programmable read-only memory (EEPROM) cells. 相似文献
80.
Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献