全文获取类型
收费全文 | 1260篇 |
免费 | 33篇 |
国内免费 | 32篇 |
专业分类
电工技术 | 10篇 |
综合类 | 46篇 |
化学工业 | 244篇 |
金属工艺 | 104篇 |
机械仪表 | 48篇 |
建筑科学 | 56篇 |
矿业工程 | 19篇 |
能源动力 | 43篇 |
轻工业 | 155篇 |
水利工程 | 3篇 |
石油天然气 | 86篇 |
武器工业 | 13篇 |
无线电 | 52篇 |
一般工业技术 | 137篇 |
冶金工业 | 80篇 |
原子能技术 | 16篇 |
自动化技术 | 213篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 20篇 |
2021年 | 11篇 |
2020年 | 18篇 |
2019年 | 16篇 |
2018年 | 19篇 |
2017年 | 17篇 |
2016年 | 26篇 |
2015年 | 23篇 |
2014年 | 54篇 |
2013年 | 53篇 |
2012年 | 54篇 |
2011年 | 84篇 |
2010年 | 50篇 |
2009年 | 60篇 |
2008年 | 74篇 |
2007年 | 68篇 |
2006年 | 83篇 |
2005年 | 48篇 |
2004年 | 51篇 |
2003年 | 56篇 |
2002年 | 45篇 |
2001年 | 37篇 |
2000年 | 34篇 |
1999年 | 33篇 |
1998年 | 70篇 |
1997年 | 69篇 |
1996年 | 35篇 |
1995年 | 37篇 |
1994年 | 25篇 |
1993年 | 8篇 |
1992年 | 9篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1981年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1325条查询结果,搜索用时 18 毫秒
51.
“空间”是中国现代建筑中一个非常重要的话语.从“空间构图”这个开启中国现代建筑“空间”话语的关键词入手,文章试图展现“空间”概念怎么与“布杂”体系的构图原理相结合,目的在于呈现“空间”概念是如何对中国现代建筑产生影响的. 相似文献
52.
This study investigated the catalytic ozonation of p-chloronitrobenzene (p-CNB) in aqueous solution by using different pumice surface compositions as catalysts. The results indicate that the surface hydroxyl groups of metal oxides on pumice play an important role in ozone decomposition to generate the hydroxyl radical (?OH). An increase in the mass ratio of SiO2/metal oxides results in the acceleration of ozone adsorption on the catalyst surface. The synergistic mechanism confirms that SiO2 induced ozone enrichment on the pumice surface and increased the probability of reaction between surface hydroxyl groups on metal oxides and ozone molecules to initiate ?OH from ozone decomposition and to stimulate p-CNB degradation. 相似文献
53.
《Journal of the European Ceramic Society》2022,42(13):5432-5437
In recent years, the demand for gradient porous ceramics is increasing in engineering field. By traditional process, the disadvantage of prepared gradient porous ceramics is its low porosity and uncontrollable pore gradient, which limits the wide application of gradient porous ceramics. In this study, the gradient porous ceramic skeleton (GPCS) was prepared by combining liquid crystal display (LCD) 3D printer with liquid silicon infiltration (LSI). Experimental results showed that the mass of ceramic powder in the ceramic slurry with optimal printing performance accounts for 45% of the mass of photosensitive resin, and the thermal decomposition rate of photosensitive resin is faster in the range of 300–450 °C. Furthermore, the effect of LSI temperature on the composition, microstructure and mechanical properties of GPCS was investigated. The GPCS is expected to be applied in the fields of energy storage, heat transfer and biofouling, among others. 相似文献
54.
乳脂肪以脂肪球的形式存在,乳脂肪球膜是包裹在乳脂肪球周围的三层生物薄膜,具有很高的营养价值。随着食品科学研究的深入和分离技术的发展,乳脂肪球膜中的活性成分及其功能作用正在逐渐被揭示。乳脂肪球膜是含有蛋白质、磷脂、鞘脂、神经节苷脂、胆碱、唾液酸和胆固醇的混合物,这些成分是具有重要功能的食品成分,应用于配方食品生产。本文综述了乳脂肪球膜中常见的蛋白质、脂质及其生物活性,综述了近年来乳脂肪球膜及其成分在改善肠道健康、改善大脑发育、改善肥胖及相关并发症、改善老年人虚弱、抗癌、抗氧化和缓解疲劳等方面的体内研究和临床研究进展,并讨论了其可能的作用机制,以期为乳脂肪球膜配料的研发及其在配方食品中的应用提供借鉴和参考。 相似文献
55.
56.
基于XML的具有性能约束构件的组装技术 总被引:2,自引:1,他引:1
采用在软总线TAO(The ACE ORB)上利用XML文档中所包含的语义化的抽象数据类型对构件对象进行操作,从而实现语义化的性能约束构件组装。建构的XML模式描述了构件组装相关的构件接口、交互及配置规约,并通过接口显式地表达构件对环境的依赖,使得能在一个分布式的网络环境里,将多个处于不同节点、提供紧密相关服务的构件在运行时动态地组装成功能系统。在给出的示例中,实现了将三个分布在不同节点的性能约束构件通过它们接口的交互及配置,实现在运行时开放的松散式组装。最后给出了下一步研究工作的重点及方向。 相似文献
57.
《Journal of the European Ceramic Society》2020,40(8):3122-3128
Lanthanum zirconate is a promising thermal barrier coating material owing to its excellent thermophysical properties and La plays the key role in its corrosion resistance. Here, an amorphous precursor is used as raw feedstock material so as to synthesize lanthanum zirconate coatings with tailorable composition by atmospheric plasma spray (APS). Three lanthanum zirconate coatings of La1.7Zr2.3O7.15, La2.0Zr2.0O7.0 and La2.3Zr1.7O6.85 are fabricated. Furthermore, the corrosion resistance of the as-sprayed coatings against CaO-MgO-Al2O3-SiO2 at 1250℃ is investigated. The increased La content promotes the formation of a sealing layer of the crystalline Ca2La8(SiO4)6O2 apatite, which slows down the penetration of molten CaO-MgO-Al2O3-SiO2. Therefore, the infiltration rate of the La2.3Zr1.7O6.85 coating decreased up to 42.6 % compared with the other two coatings. This work develops a feasible preparation strategy to control the La composition for the improved corrosion resistance, which is expected to guide the future coating design and synthesis for the materials with big composition changes during the APS process. 相似文献
58.
Can Shi Ruijie Liu Ming Chang Qingzhe Jin Xingguo Wang 《Journal of the American Oil Chemists' Society》2016,93(6):869-877
In this study, we evaluated the composition of rice bran stearin (RBS) from various refineries across China. Here, we report the physicochemical parameters of RBS. The slip melting point ranged from 20.8 to 35.3 °C. The free fatty acid content (0.05–0.27 %) and peroxide value (0.34–3.70 mequiv oxygen/kg) was quite low, indicating that the RBS was of good quality. The iodine value ranged from 85.8–102.9 g/100 g, indicating a high unsaturated bond content. There was a significant difference in the unsaponifiable matter content (1.20–3.87 %) among RBS samples. The oxidative stability index (OSI) ranged from 0.56 to 5.85 h. The palmitic acid content in RBS refined by molecular distillation was significantly higher than the RBS that was refined physically and chemically. The major triacylglycerol was LLO/OLL, PLL/LPL, OLO, PLP, OOO and POO (L, linoleic acid; O, oleic acid; P, palmitic acid). RBS contained high levels of micronutrients, including total tocopherols (23.3–117.9 mg/100 g), oryzanol (0.1–2.1 %), and total sterols (682.9–1787.3 mg/100 g). Moreover, three different kinds of solid fat curves were distinguished. The results presented here are probably the first report regarding RBS on an industrial scale, meanwhile the potential utilization of RBS is discussed. 相似文献
59.
60.
Polycyclic aromatic hydrocarbons (PAHs) in urban surface dust of Guangzhou, China: Status, sources and human health risk assessment 总被引:7,自引:0,他引:7
Wang W Huang MJ Kang Y Wang HS Leung AO Cheung KC Wong MH 《The Science of the total environment》2011,409(21):4519-4527
Ninety-six urban surface dust samples collected from Guangzhou, a typical urban center in South China, were analyzed for 16 PAHs (2-6 rings). ∑ PAHs concentrations in the urban surface dust ranged from 0.84 to 12.3 μg/g with a mean of 4.80 μg/g. High molecular weight compounds (4-6 rings) contributed to 62 to 94% of ∑ PAHs mass in the surface dust samples. Four hotspots with highest ∑ PAHs were identified via kriging prediction mapping, representing the highly-urbanized regions: central downtown, highway and industrial area. Two major origins of PAHs inputs to urban surface dust were identified as vehicle emissions (51.9%) and coal combustion (26.8%). The 95% UCL of Incremental Lifetime Cancer Risk (ILCR) due to human exposure to urban surface dust PAHs in central South China was 3.03 × 10−6 for children and 2.92 × 10−6 for adults. 相似文献