全文获取类型
收费全文 | 109篇 |
免费 | 10篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 17篇 |
综合类 | 1篇 |
化学工业 | 25篇 |
金属工艺 | 4篇 |
机械仪表 | 8篇 |
建筑科学 | 4篇 |
能源动力 | 4篇 |
轻工业 | 15篇 |
一般工业技术 | 18篇 |
冶金工业 | 4篇 |
原子能技术 | 5篇 |
自动化技术 | 20篇 |
出版年
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 26篇 |
2012年 | 3篇 |
2011年 | 8篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 9篇 |
1995年 | 2篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1976年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有125条查询结果,搜索用时 15 毫秒
1.
The transient temperature and stress fields in a quenched rectangular bar were computed and used to determine the stress intensity factors for midside and corner-edge cracks. The stress intensity factors, K 1 , are presented as a function of time, flaw size, and aspect ratio. The variations of AT, along the crack edge are given and the self-limiting growth of the crack depth is discussed in relation to the nonlimited surface growth. 相似文献
2.
Quadrupole interactions of 11 B and 27 Al in SiO2 -B2 O3 -Al2 O3 -R2 O glass systems were investigated to determine the structure of these glasses, which should be amenable to chemical strengthening. The ratio of BO4 units to BO3 units approached unity as the R2 O/Al2 O3 ratio for compounds having fixed B2 O3 contents approached unity. Nuclear quadrupole coupling constants ( e2 Qq/h =2.73 to 2.93 MHz) were measured for the NMR spectra of 11 B triangles. The line shapes of 27 Al spectra varied with chemical composition, but a few glasses exhibited 27 Al line shapes similar to those of the AlO4 triclusters in SiO2 -Al2 O3 -Na2 O glasses. Compositional trends in the formation of BO4 and AlO4 were deduced from the NMR spectra. 相似文献
3.
Atsuko SHINOHARA Takehisa MATSUKAWA Momoko CHIBA Toshio KUMASAKA Jun KOBAYASHI Kenji TAKAMORI Shozo ICHINOSE Kazuhito YOKOYAMA 《中国稀土学报(英文版)》2010,(Z1):507-509
Distribution of Sm and Ce in mice was investigated after inhalation exposure to their oxide particles of 5 μm diameter and 15 mg/m3.Sm and Ce were mainly distributed in lung,their concentrations decreased with passing time,and their concentrations in lung were correlated with exposure periods.Concentrations of Ce were lower than that of Sm in each point.Sm was also distributed in the other organs and bone but Ce was scarcely detected.These results suggest that the behaviors of Sm and Ce inhaled were different,although their chemical properties are similar. 相似文献
4.
TAKETOSHI TAKEMURA MASAHIRO KOBAYASHI YOSHIO TAKADA KEN SATO 《Journal of the American Ceramic Society》1987,70(4):237-241
The breakdown voltage, the upturn voltage, and the nonlinearity of the ZnO varistors are significantly influenced by the Sb2 O3 and SiO2 contents, as well as by the β→γ transition of the Bi2 O3 phase. The lattice parameter of spinel is influenced by the coexisting Bi2 O3 phase. Antimony oxide disperses into the powders of ZnO and other additives in the early stage of sintering, and finally gathers again as particles of spinel which may play an important role in the improvement of the nonlinearity by stressing the interfaces of two ZnO grains. 相似文献
5.
KEIJI KOBAYASHI 《Journal of the American Ceramic Society》1976,59(1-2):9-11
Chromium centers in isolated Cr ions and Cr(III)-Cu(II) redox interactions were investigated by optical and EPR spectra. Line shapes and intensities of high-field Cr(III)-Cu(II) superimposed EPR absorption lines were sensitive to alkali content of host glasses. High-field chromium g values (1.94 to 1.99) and intensities (190 to 3600) were calculated. The increase in g values from 1.96 to 1.98 is related to an increase in Cr(V) and to a conversion from Cu(I) to Cu(II) with increased alkali content. Two components of Cr powder spectra near g = 2.0 and g = 5.0 correspond to isolated octahedral Cr centers described by Landry et al. Cr-Cr pair structure was not observed for low Cr2 O3 concentrations. Three components of optical absorption bands near 340 nm, 430 to 460 nm, and 600 nm were measured in Cr(III)-Cu(II) redox systems. Electronic interactions of Cr(III)-Cu(II) redox systems and the structure of Cr centers are discussed. 相似文献
6.
高灰熔点煤高温下煤焦CO2/水蒸汽气化反应特性的实验研究 总被引:1,自引:2,他引:1
我国煤炭年产量中,1400℃以上的高灰熔点煤约占50%以上。为探索固态排渣方式的高灰熔点煤气流床气化,本文选出具有代表性的三种高灰熔点煤种和一种低灰熔点煤种,在TGA-51H型高温热天平上进行了煤焦-CO2和煤焦-水蒸汽气化反应特性的实验研究,并利用SEM考察了气化条件下煤焦及灰的微观结构。实验结果表明:在煤焦-CO2、H2O反应过程中,反应速度明显表现出高温区域的扩散反应和低温区域的化学反应;无论在1273K~1573K的低温区域,还是在高于1573K的高温区域,反应速率随燃料比(FC/V)的增加而减小。 相似文献
7.
由于大部分的生物体都具有相对的自发性、功能性和有效率性,模仿生物体动作的机械研究在工程领域是非常重要的。根据这个观点,我们研究了一种基于水中微生物动作的微型推进机构。 相似文献
8.
TAKETOSHI TAKEMURA MASAHIRO KOBAYASHI YOSHIO TAKADA KEN SATO 《Journal of the American Ceramic Society》1986,69(5):430-436
The nonlinearity of ZnO varistors is significantly influenced by the Bi2 O3 and Sb2 O3 contents, as well as by the phase composition of the Bi2 O3 . Degradation of the current-voltage characteristics due to the applied voltage is not always lowered by the β—γ transition of the Bi2 O3 phase. Lattice parameter determinations and stress analyses suggest that the Bi2 O3 -rich phase in multigrain junctions causes mechanical strain at the grain boundary which may play an important role in the current-voltage characteristics of ZnO varistors. 相似文献
9.
Abstracts are not published in this journal 相似文献
10.
依据美国开发的BEES软件,选择张家港当地某一栋具体的多层住宅建筑(6层,每层大约750 m2)进行了生命周期评价.把建筑的全生命周期范围确定为建材准备阶段(包括原材科开采、运输、原材料加工等)、建造阶段、运行阶段(运行70年)、拆毁阶段和建筑垃圾处理阶段.依据确定的范围进行了清单分析.根据建筑的结构形式,计算得到各种建材的需求量和建造、运行、拆毁、建筑垃圾处理时的各种输入输出,以统一的功能单位(一栋建筑)合并各种输入输出数据,得到总的数据清单.采用BEES分类表征方法进行影响评价.根据我国的具体情况确定环境影响因子和类别(酸雨、全球变暖、资源枯竭等),将不同的环境影响因子分配到一个或多个环境影响类别中,再根据具体情况确定各指标的权重系数进行加权,得到综合的评价结果.找出了建筑物全生命周期阶段中产生环境影响最大的阶段,即运行阶段. 相似文献