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排序方式: 共有1513条查询结果,搜索用时 15 毫秒
91.
Sub‐Terahertz Frequency‐Domain Spectroscopy Reveals Single‐Grain Mobility and Scatter Influence of Large‐Area Graphene 下载免费PDF全文
92.
New efficient intermetallide catalysts for hydrogen storage in reversible processes of aromatics hydrogenation and naphthene dehydrogenation were studied. These catalysts provide an enhanced activity in the dehydrogenation of saturated organic molecules, with no side reactions like cracking, hydrogenolysis, ring opening, or coke formation occurring on these catalysts. The use of intermetallides provides some hydrogen storage capacity in the low-temperature region, while their catalytic activity in the dehydrogenation affords the hydrogen supply in the high-temperature range. 相似文献
93.
Rafael Davalos Yong Huang Boris Rubinsky 《Nanoscale and Microscale Thermophysical Engineering》2013,17(3):147-159
This article provides a brief review of the field of electroporation and introduces a new microdevice that facilitates studies to test theories, gain understanding, and control this important biomedical technology. Electroporation, a bio-electrochemical process whose fundamentals are not yet understood, is a means of permeating the cell membrane by applying a voltage across the cell and forming nano-scale pores in the membrane. It has become an important field in biotechnology and medicine for the controlled introduction of macromolecules, such as gene constructs and drugs, into various cells. It is viewed as an engineering alternative to biological techniques for the genetic engineering of cells. To study and control electroporation, we have created a low-cost microelectroporation chip that incorporates a live biological cell with an electric circuit. The device revealed an important behavior of cells in electrical fields. They produce measurable electrical information about the electroporation state of the cell that may enable precise control of the process. The device can be used to facilitate fundamental studies of electroporation and can become useful in providing precise control over biotechnological processes. 相似文献
94.
Vanya B. Kurteva Liudmil M. Antonov Daniela V. NedeltchevaAurélien Crochet Katharina M. FrommRositsa P. Nikolova Boris L. ShivachevMaya S. Nikiforova 《Dyes and Pigments》2012,92(3):1266-1277
A series of azo dyes, possessing amide fragments with restricted flexibility tethered to 4-(phenyldiazenyl)naphthalen-1-ol, was obtained from 1-hydroxy-2-naphthoic acid by subsequent conversion to amides and diazo coupling. It was shown that the position of the tautomeric equilibrium in solution strongly depends on the solvent in both UV and NMR concentration scale. The compounds exist as pure enol forms in chloroform and hydrocarbons, while in polar solvents (acetone, acetonitrile, alcohols) a tautomeric mixture is observed. According to the quantum-chemical calculations the aggregation of the keto tautomer is the possible reason for this shift in the position of the tautomeric equilibrium. To support the theoretical predictions, it was found that from acetone the keto form crystallizes as a dimer with hydrogen bonding between N1-H in the one molecule and amide CO in the other forming a three-dimensional structure. The importance of the side-chain nitrogen atom on the dimer formation was confirmed by solution and solid state study of 4-(phenyldiazenyl)-2-acetylnaphthalen-1-ol. The results indicate that the new azo-dyes obtained could be suitable candidates for switching and sensing applications in non-polar solvents. 相似文献
95.
Boris Mahltig Dr. 《真空研究与实践》2010,22(2):25-28
Vacuum impregnation of porous metal materials with inorganic nanosol The sealing of porous metal pieces is possible by application of inorganic nanosols. For suitable sealing it is necessary that the nansols are applied by vacuum impregnation. For sealing useful nanosols contain particles of silicon/aluminium‐oxide with a modification of organic methyl groups. The nanosol particles are smaller than 100nm and the maximum of the particle size distribution is around 10nm. Beside sealing of the metal pieces, also their stability against corrosion can be improved by this nanosol application. The further development of this technology is especially promising for applications in machine factory or automobile. 相似文献
96.
97.
Csomor Philipp A.; Yee Benjamin K.; Vollenweider Franz X.; Feldon Joram; Nicolet Tiana; Quednow Boris B. 《Canadian Metallurgical Quarterly》2008,122(4):885
Prepulse inhibition (PPI) of the startle reflex refers to the reduction of the reflexive startle response to an intense pulse stimulus when its presentation is shortly preceded by a weak prepulse stimulus. PPI is considered as a cross-species translational model of sensorimotor gating, and deficient PPI has been reported in a number of neuropsychiatric disorders. Although a part of the literature is based on the assumption that PPI is independent of the baseline startle reaction, there is accumulating evidence (Csomor et al., 2006; Sandner & Canal, 2007; Yee, Chang, Pietropaolo, & Feldon, 2005) that argues against such an independency. The authors systematically investigated whether PPI indexed as percentage or difference score is dependent on the magnitude of baseline startle reactivity in healthy human volunteers and in C57BL/6 mice. The results revealed that both indexations of PPI were affected by the magnitude of the baseline startle. The authors highlight the pitfalls of different methods to index PPI, especially when startle reactivity differs considerably between groups under comparison, and offer practical recommendations to satisfactorily deal with such baseline differences. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
98.
Abdeslam Et Taouil Fabrice Lallemand Jean-Marie Melot Jérôme Husson Jean-Yves Hihn Boris Lakard 《Synthetic Metals》2010,160(9-10):1073-1080
Two functionalized polypyrrole films, poly(11-N-pyrrolylundecanoic) acid and poly(N-undecylpyrrole), were used as sensitive layers for pH sensors. The functionalized pyrrole monomers were first synthesized before carrying out their electropolymerization onto non-oxidizable electrodes. The deposits were characterized by SEM imaging, XPS and PM-IRRAS to study surface structure and composition. Poly(11-N-pyrrolylundecanoic) acid coating yielded very promising results as sensitive layer in pH sensors. Indeed, the potentiometric responses from pH 4.0 to 9.0 appeared linear, reversible, stable in time over a period of 1 month and highly selective for H+ ions. This behavior was attributed to carboxylic acid groups which are sensitive to proton concentration changes. This was confirmed by the fact that poly(N-undecylpyrrole) film led to potentiometric responses being pH dependent only from pH 6.0 to 9.0 with low sensitivity. Poly(11-N-pyrrolylundecanoic) acid is thus promoted to be used as sensitive layer in pH sensors. 相似文献
99.
van Schie Hein T.; van Waterschoot Boris M.; Bekkering Harold 《Canadian Metallurgical Quarterly》2008,34(6):1493
A robust finding in imitation literature is that people perform their actions more readily if they are congruent with the behavior of another person. These action congruency effects are typically explained by the idea that the observation of someone else acting automatically activates our motor system in a directly matching way. In the present study action congruency effects were investigated between an imitation task and a complementary action task. Subjects imitated or complemented a virtual actor's grasp on a manipulandum. In both tasks, a color-cue could be presented forcing subjects to ignore the task rule and execute a predefined grasp. Reaction times revealed a reversal of congruency effects in the complementary action task, suggesting that subjects were able to circumvent the automatic tendency to copy actions or postures of another person. In 2 additional control experiments, congruency effects were replicated, and a Simon effect was identified to underlie faster responses in the imitation task. These results make a case against current theoretical views on imitation and direct matching in favor of more flexible models of perception-action coupling. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Boris Beizer 《Annals of Software Engineering》2000,10(1-4):293-310
The reliability notions that have worked so well for hardware do not work for software. It is not just reliability issues
that makes software engineering different than most traditional engineering disciplines, but fundamental, usually unrecognized
paradigms. Twelve assumptions that are rarely questioned in traditional engineering fields are explored and each is shown
not to hold in software engineering. These differences between software engineering and traditional engineering are often
at the core of misunderstandings between their practitioners.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献