全文获取类型
收费全文 | 506篇 |
免费 | 16篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 2篇 |
综合类 | 32篇 |
化学工业 | 93篇 |
金属工艺 | 9篇 |
机械仪表 | 7篇 |
建筑科学 | 11篇 |
矿业工程 | 42篇 |
能源动力 | 44篇 |
轻工业 | 25篇 |
石油天然气 | 3篇 |
武器工业 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 70篇 |
冶金工业 | 155篇 |
原子能技术 | 40篇 |
自动化技术 | 2篇 |
出版年
2023年 | 7篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 19篇 |
2019年 | 9篇 |
2018年 | 15篇 |
2017年 | 35篇 |
2016年 | 26篇 |
2015年 | 22篇 |
2014年 | 31篇 |
2013年 | 94篇 |
2012年 | 22篇 |
2011年 | 36篇 |
2010年 | 18篇 |
2009年 | 14篇 |
2008年 | 21篇 |
2007年 | 21篇 |
2006年 | 17篇 |
2005年 | 9篇 |
2004年 | 12篇 |
2003年 | 8篇 |
2002年 | 10篇 |
2001年 | 9篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 9篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 1篇 |
排序方式: 共有538条查询结果,搜索用时 15 毫秒
1.
《Ceramics International》2022,48(9):12014-12027
The formed deposits wear out of refractory wall linings in the rotary kiln and may cause production disturbances. This study describes the chemical composition and mineralogical phase components at the deposit/refractory interface in the rotary kiln for fluxed iron ore pellets production. The main phases of refractory bricks are corundum and mullite, while the deposits mainly contain hematite and silicates. The main phases in the deposit/refractory brick contact zone are hematite, anorthite (CaAl2Si2O8), mullite, corundum, and silicates. Moreover, the hematite phases in the deposit/brick interface averagely contain 6.98 wt% Al and 1.38 wt% Ti. The silicates in the contact zone contain higher aluminium content and lower iron content than the silicates in the deposits. Finally, the thermodynamic analysis indicates that the main phases in the deposits can react with the refractory to form Al2Fe2O6, CaAl2Si2O8, feldspar, and liquid phases lead to the degradation of bricks in the kiln during the iron ore pellets production. 相似文献
2.
C. R. Copeland S. K. Kawatra 《Mineral Processing and Extractive Metallurgy Review》2019,40(3):218-223
Both straight-grate and grate-kiln furnaces have been accepted in the iron ore industry. Both are considered to be roughly equal when comparing overall costs and expenses versus the final product production rate. However, the product quality of these two systems is not equal. This is shown by critically examining the dust generation of pellets from several facilities. The dustiness of pellets is associated with overall pellet strength, and is an important quality measure of fired pellets on its own. A clear distinction between the dustiness of grate-kiln and straight-grate fired pellets is established. We conclude that grate-kiln-cooler systems provide superior pellet quality, but at the cost of some pellet production rate. 相似文献
3.
Air pollution is a major health problem in developing countries and has adverse effects on human health and the environment. Non-thermal plasma is an effective air pollution treatment technology. In this research, the performance of a dielectric barrier discharge (DBD) plasma reactor packed with glass and ceramic pellets was evaluated in the removal of SO2 as a major air pollutant from air in ambient temperature. The response surface methodology was used to evaluate the effect of three key parameters (concentration of gas, gas flow rate, and voltage) as well as their simultaneous effects and interactions on the SO2 removal process. Reduced cubic models were derived to predict the SO2 removal efficiency (RE) and energy yield (EY). Analysis of variance results showed that the packed-bed reactors (PBRs) studied were more energy efficient and had a high SO2 RE which was at least four times more than that of the non-packed reactor. Moreover, the results showed that the performance of ceramic pellets was better than that of glass pellets in PBRs. This may be due to the porous surface of ceramic pellets which allows the formation of microdischarges in the fine cavities of a porous surface when placed in a plasma discharge zone. The maximum SO2 RE and EY were obtained at 94% and 0.81 g kWh−1, respectively under the optimal conditions of a concentration of gas of 750 ppm, a gas flow rate of 2 l min−1, and a voltage of 18 kV, which were achieved by the DBD plasma packed with ceramic pellets. Finally, the results of the model's predictions and the experiments showed good agreement. 相似文献
4.
1-脱氧野尻霉素控释微丸采用挤出滚圆和流化床方法进行制备。首先使用羟丙基甲基纤维素和微晶纤维素等辅料制备分散体、丸芯,再使用羟丙基甲基纳米纤维素邻苯二甲酸酯作为主要包衣材料进行包衣,并装入胶囊。采用SEM观察微丸的微观形态,以及测定其产率、脆碎度、密度、水分含量和粒径分布等物理性质,研究结果显示微丸性质符合中国药典标准规定。在体外释药试验中,溶出介质和放置方式对药物释放无显著影响,释放过程符合Baker-Lonsdale模型。对比研究1-脱氧野尻霉素原料药、分散体微丸和控释微丸在比格犬体内的控释特性,结果表明:与1-脱氧野尻霉素原料药相比,分散体微丸和控释微丸分别使1-脱氧野尻霉素的生物利用度提高了183.37%和243.87%。此外,1-脱氧野尻霉素控释微丸的体内-体外研究的相关性分析可知体外溶出和体内吸收之间呈现良好的线性关系。 相似文献
5.
外墙外保温施工质量控制的探讨(上) 总被引:2,自引:1,他引:2
文章首先叙述了外墙外保温的分类,然后从施工的角度,对目前应用较多的胶粉聚苯颗粒外墙外保温系统和粘贴膨胀聚苯板薄抹灰外墙外保温系统的施工质量控制进行了阐述,最后对目前外墙外保温市场提出了几点建议,以便工程实际中参考。 相似文献
6.
对几种玻璃纤维织物增强酚醛树脂复合材料进行了双向滑动摩擦试验,考察织物结构和基体树脂对复合材料的摩擦磨损性能的影响。研究结果表明:通过添加自润滑颗粒可提高复合材料的摩擦磨损性能,其中石墨的耐摩擦磨损效果比聚四氟乙烯(PTFE)显著;织物结构对复合材料摩擦性能的影响,主要受控于织物的表面粗糙度和织物结构对复合材料树脂体积分数的影响。此外,复合材料存在一个较优的树脂体积分数范围,在此范围内,复合材料的摩擦磨损性能较为优异。 相似文献
7.
Purpose: Salvianolic acid B micro-porous osmotic pump controlled release pellets (SalB-CRPs) with suitable in vitro release profiles and good in vitro and in vivo correlation (IVIVC) were developed.Method: Extrusion-spheronization was used to prepare the starter cores containing SalB/MCC/Kollidon®CL-SF/Flowlac®100 of 30:40:15:15 [w/w, The formulation composition of SalB immediate-release pellets (SalB-IRPs)] and complexed with lactose. The pellets were subsequently coated with Surelease aqueous dispersion to achieve controlled-release properties. Furthermore, a single-dose pharmacokinetics study was carried out in New Zealand White (NZW) rabbits.Results: In the starter cores, the lactose content was 25% based on the SalB-IRPs constituent. The optimal coating polymer ratio of Surelease aqueous dispersion and polyvinyl alcohol–polyethylene glycol (PVA–PEG) graft copolymer (EC/PVA–PEG) was found to be 70:30 (w/w, %) with a coating weight of 5%. The prepared SalB-CRPs had similar in vitro release under three different pH release mediums. A good IVIVC was characterized by a high coefficient of determination (r?=?0.9801). The in vivo study indicated that the maximum plasma concentration (Cmax) of SalB-CRPs was decreased, peak concentration time (Tmax) and mean residence time (MRT) were all prolonged, as that of SalB-IRPs. In addition, the area under concentration–time curve from 0 to 24?h (AUC0–24?h) and 0 to infinity (AUC0–∞) were significantly higher, compared with those of SalB-IRPs.Conclusion: Collectively, these results manifested that SalB-CRPs were likely to be a more suitable formulation in treating cardiovascular disease with improved in vivo retention, decreased plasma drug concentration fluctuation. 相似文献
8.
Jinlong Ma Juan Wang Zhibo Cheng Tian Yin Huan Teng Hui Xu 《Drug development and industrial pharmacy》2015,41(2):307-314
The purpose of this study was to prepare sustained-release pellets of nifedipine (NSPs) based on MCC matrix. Wet-milling and extrusion-spheronization techniques were employed to prepare the microcrystals and pellets, respectively. The drug release mechanism and the influencing factors were investigated. After milled with HPMC (E5), the mean particle size of nifedipine in co-grinding mixture (CGM) was 5?μm, which is 15-fold smaller than that of raw material. DSC, X-ray powder diffraction and microscopic observation confirmed the microcrystals of drug were maintained in the CGM. With increased milling time and the content of HPMC, the dissolution rate was greatly enhanced compared with the raw material. The NSPs prepared by MCC and the CGM, which was obtained by cogrinding nifedipine with 5% HPMC solution for 210?min, exhibited sustained release pattern within 8?h. Nifedipine release from MCC-based NSPs followed the Korsmeyer model and closely related to the microstructure of pellet. High stability of NSPs was confirmed after 6 months of accelerated stability test. Using commercially available sustained product as reference, bioequivalence study in beagle dogs was executed and two formulations were bioequivalent. This sustained release pellet formulation of nifedipine was advantageous with convenient and easy scaled-up preparation process. 相似文献
9.
10.
The phenomena of spontaneous combustion and thermal runaway in wood pellets storage were investigated using lab-scale experiments in the temperature range of 100–200 °C. The critical temperatures were determined for four sizes of reactors. The kinetic parameters of the self-heating were determined using three methods, the Frank-Kamenetskii's method, crossing point method, and numerical curve fitting method. Mean values of activation energy (E) of 78.7 ±0.8 kJ/mol and self-heating rate constant (∆ rhA) of (4.22 ±2.5) × 10 6 kJ/(kg s) were obtained for four type of wood pellets (made from whitewood) samples from different pellet producers in British Columbia. Finally, a two-dimensional numerical model was developed to predict the temperature development during self-heating and the critical temperature for known sizes of reactors. 相似文献