全文获取类型
收费全文 | 318篇 |
免费 | 8篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 161篇 |
金属工艺 | 8篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 25篇 |
轻工业 | 15篇 |
水利工程 | 3篇 |
石油天然气 | 12篇 |
无线电 | 1篇 |
一般工业技术 | 48篇 |
冶金工业 | 26篇 |
原子能技术 | 1篇 |
自动化技术 | 14篇 |
出版年
2023年 | 4篇 |
2022年 | 37篇 |
2021年 | 31篇 |
2020年 | 11篇 |
2019年 | 13篇 |
2018年 | 20篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 10篇 |
2014年 | 20篇 |
2013年 | 18篇 |
2012年 | 25篇 |
2011年 | 13篇 |
2010年 | 11篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有327条查询结果,搜索用时 15 毫秒
51.
Kokhanchik LS Borodin MV Burimov NI Shandarov SM Shcherbina VV Volk TR 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2012,59(6):1076-1084
We report the results of fabrication and investigations of surface periodic domain structures created by a set of quasi-point e-beam irradiations both on the Y- and X-cuts of LiNbO(3), and on Ti:LiNbO(3) and Zn:LiNbO(3) planar waveguides. Domain gratings with spatial periods from 4.75 to 7.25 μm were formed by a 25-keV e-beam. Doses from 500 to 2000 μC/cm(2) were used for different structures to estimate optimal fabrication conditions. The investigations allowed the visualization of the formed surface domain structures, estimation of their uniformity, and determination of waveguide generation of the second optical harmonic. The surface structures can be used in optical devices for the realization of quasi-phase-matched frequency conversion, which includes the creation of compact radiation sources based on waveguides. 相似文献
52.
53.
Nina N. Makhova Igor V. Ovchinnikov Alexandr S. Kulikov Dmitriy V. Khakimov Marina S. Molchanova Tatyana S. Pivina 《Propellants, Explosives, Pyrotechnics》2012,37(5):549-557
Different approaches to synthesize diaminofuroxan are presented herein. Mathematical and quantum chemical methods were used to study the possible reasons for failures in the syntheses of diaminofuroxan. Additionally, structural isomers of this compound were generated. With the help of the results of quantum chemical calculations at levels of DFT B3LYP 6‐31G(d) and MP2 6‐31G(d), screening of the most stable isomeric forms in the gaseous phase and in water was performed. It was shown that diaminofuroxan is not the thermodynamically most stable isomer among its structural analogues. 相似文献
54.
Tatyana Pivina Vyacheslav Korolev Dmitriy Khakimov Tatyana Petukhova Victor Ivshin David Lempert 《Propellants, Explosives, Pyrotechnics》2012,37(4):502-509
An approach to simulate thermal destruction processes of energetic materials has been developed. It is based on the classification of structural features for nitro compounds and the experimental data regarding their decomposition mechanisms. This approach consists of the mathematical simulation of thermal decomposition mechanisms to predict the likely reactions that may occur during the destruction of organic compounds. On the basis of contemporary experimental data on the decomposition of energetic materials from various chemical classes, a set of semi‐empirical rules for modeling possible reaction pathways has been formulated. These rules allow the generation of a whole set of possible decomposition mechanisms for substances at different steps of their destruction. In this study, the suggested methodology is applied to 2,4,6,8,10,12‐hexanitro‐2,4,6,8,10,12‐hexaazaisowurtzitane (CL‐20) and hydrazine and to their binary energetic mixture. It has been shown that thermal decomposition of the binary system consists in decompositions of the separate compounds at the initial stage with subsequent collisions and interactions of the resultant intermediates and decomposition products at different stages. In addition to some experimentally found decomposition products, our simulation showed some other possible compounds among the final products. 相似文献
55.
Aibassov Erkin Zhakenovich Yemelyanova Valentina Stepanovna Shakieva Tatyana Vladimirovna TussupbaevNessipbay Kuandykovich Blagikh Evgeniy Vladimirovich 《化学与化工:英文版》2014,(4):428-432
It is discovered a new three-, four-component Petasis, Passerini, Hantzsch, Kabachnic-Fields, Ugi reactions with of arsine, stibine and bismuthine in organometallic chemistry. Modifications were replaced to a nitrogen atom of classical reactions of atoms of phosphorus, arsenic, antimony and bismuth. It has been proposed a new mechanism for possible reactions. 相似文献
56.
Surface Structure,Spectroscopic and Photocatalytic Activity Study of Polyaniline/TiO2 Nanocomposites
Maksim Zagorny Igor Bykov Andrey Melnyk Tatyana Lobunets Alexander Zhygotsky Anatoliy Pozniy Alexander Shirokov Andrey Ragulya 《化学与化工:英文版》2014,(2):118-127
PANI (polyaniline) as a promising conducting polymer and photosensitizer has been used to prepare PANI/TiO2 (polyaniline/TiO2) nanocomposite as photocatalyst. TiO2 nanoparticles with size of 5-100 nm were encapsulated by PANI via the "in situ" polymerization of aniline on the surface of TiO2 nanoparticles. IR, SEM, EPR techniques were used to characterize the mechanism of electron interaction in PANI/TiO2 nanocomposite. The resulting PANI-modified TiO2 composites exhibit significantly higher photocatalytic activity than that of neat PANI on degradation of MB (methylen blue) aqueous solution under UV irradiation. 相似文献
57.
Yurkevich Nataliya Olenchenko Vladimir Bortnikova Svetlana Saeva Olga Korneeva Tatyana 《Mine Water and the Environment》2021,40(4):943-955
Mine Water and the Environment - Geochemical and geophysical investigations were performed in an area of the Darasun ore cyanidation tailings impoundment, which is located in a permafrost region.... 相似文献
58.
59.
60.
Anatolii Ustinov Yury Falchenko Tatyana Melnichenko Andrey Shishkin Gennady Kharchenko Lidia Petrushinets 《Journal of Materials Processing Technology》2013,213(4):543-552
In the diffusion welding (DW) of difficult-to-deform materials (such as composites and intermetallics), the application of intermediate multilayer foils (MF), which have alternating layers of elements that form intermetallics, allows for production of a permanent joint under milder conditions. In this paper, the processes occurring in the joint zone (JZ) during DW of Al–5 wt.%Mg+27 wt.%Al2O3 composite material through the Al/Cu interlayer were studied. It was shown that, while heating of such a foil, phase transformations that are due to the reaction diffusion of elements, run in it. At MF heating under a continuously applied external load, the materials are plastically deformed. It is established that the intensity of foil plastic deformation at a specified load non-monotonically depends on temperature. It is shown that welding temperature is determined by the temperature at which MF can undergo superplastic flow under the impact of applied pressure. A mechanism of formation for a solid-phase joint of high-strength materials through interlayers based on the MF of intermetallic-forming elements is proposed. 相似文献