首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   4篇
  免费   0篇
化学   1篇
数学   3篇
  2022年   1篇
  2009年   1篇
  2008年   2篇
排序方式: 共有4条查询结果,搜索用时 15 毫秒
1
1.
The toxicity of phosgene (COCl2) combined with its extensive use as a reactant and building block in the chemical industry make its fast and accurate detection a prerequisite. We have developed a carboxylic derivative of 5,6-pinenepyridine which is able to act as colorimetric and fluorimetric sensor for phosgene in air and solution. For the first time, the formation of a pyrido-[2,1-a]isoindolone was used for this purpose. In solution, the sensing reaction is extremely fast (under 5 s), selective and highly sensitive, with a limit of detection (LOD) of 9.7 nM/0.8 ppb. When fixed on a solid support, the sensor is able to detect the presence of gaseous phosgene down to concentrations of 0.1 ppm, one of the lowest values reported to date.  相似文献   
2.
The paper presents the study of the human body, as a mechanical system, seated inside an autovehicle and exposed under the vertical harmonic vibration action during the auto vehicle motion time. The human body may be roughly approximated by a linear lumped parameter at low frequencies and low vibration levels. Therefore, the model has 5 DOFs in translation, where 4 DOFs represents the human body and 1 DOF is for the seat cushion The mechanical model of the human body, in sitting position on the seat cushion of a vehicle seat, consists of four parts: pelvis, upper torso, viscera and head.. The eigenvalues for the human body – seat system and the damping ratio for the system was been calculate. The system stability analysis is given by the existence of a Lyapunov function for the system. The stability of a system can also be characterized by the eigenvalues of the system. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
3.
The traffic of autovehicles in pilot zone of great city of Cluj-Napoca is presented in the work. There are established the noise measuring locations for the fixed station and successive positions of the mobile station in pilot zone. Noise pollution measurements are done on the mentioned locations. The “Sound plan” programme pack is used to fulfill the sound map of the great city of Cluj-Napoca; its graphic representation is compared to the real measurement results. Present paper represents a part of research activity of T.U.C.N. researchers in studying for fulfilling of E.U. tasks of environment protection. This research is made for the application of the EU legislation on the Romanian cities. First we worked in the great city of Cluj-Napoca, but the extensions will be to all the urban agglomerations having greater than 100000 people. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
4.
Mariana Arghir  Geamilia Solea  Dan Borza 《PAMM》2008,8(1):10397-10398
Longitudinal elasticity modulus, E, is a material specific feature, which,. in general, is establish on the pieces by longitudinal stress. This procedure is possible to apply to the compact material but not to the sintered power parts (or porous material test pieces). For sintered parts, the establishing of Young's modulus, in this paper, it is proposed by transmition of mechanical vibrations along to the test pieces. The test pieces of compact or porous material were strained at longitudinal vibrations. It was establish the linkage between vibration and density, respective between the density and the value of the longitudinal elasticity modulus. Using the test pieces of compact material we realized the methodology to obtain the longitudinal elasticity modulus regarding the compact material, and in this way can be establish the possibility to measure with a good result the longitudinal elasticity modulus for the pieces of sintered powders or of porous material. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   
1
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号