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排序方式: 共有289条查询结果,搜索用时 15 毫秒
281.
Jahn E. Agrawal N. Arbert M. Ehrke H.-J. Franke D. Ludwig R. Pieper W. Weber H.G. Weinert C.M. 《Electronics letters》1995,31(21):1857-1858
The authors demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s to 5 Gbit/s data signals by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor laser amplifiers 相似文献
282.
283.
284.
J. Jahn 《OR Spectrum》1982,3(4):239-243
Zusammenfassung Bei der hier vorgestellten Methode wird bei jeder Iteration, die in der Bildmenge verläuft, vom Entscheidungsträger die Angabe erwartet, welche Zielfunktionskomponente verbessert werden muß. Nach der interaktiven Phase wird ein effizienter Punkt über ein nichtlineares Optimierungsproblem bestimmt.
Summary For the method presented here at each iteration point which lies in the criteria set the decision maker is asked to give the preference information which component of the objective function must be improved. After the interactive phase an efficient point is determined by solving a nonlinear optimization problem.相似文献
285.
M. T. Jahn 《Journal of Low Temperature Physics》1978,30(3-4):529-534
The resistive transitions and the temperature dependence of the current-voltage (I–V) characteristics of Nb-powder bulk granular superconductors near the transition temperature are investigated. Experimental results on the resistive transition are explained in terms of Anderson's theory as thermally activated phase slippage, and the I–V characteristics are compared with the effects of thermal fluctuations on an array of Josephson weak links in a simplified model based on Ambegaokar and Halperin's theory of thermal noise in the Josephson effect. 相似文献
286.
Jannik Jahn Antonia Bollensdorf Christopher Kalischer Robin Piecha Jana Weiß-Müller Phani Sankar Potru Tamara Ruß Bjrn Spittau 《International journal of molecular sciences》2022,23(18)
Simple SummaryIn the present study, we provided evidence that TGFβ signaling regulated the expression of the microglia activation marker CD74. Our data demonstrated that TGFβ1 inhibited LPS-induced upregulation of CD74. Moreover, inhibition of microglial TGFβ signaling in vitro and silencing of TGFβ signaling by deletion of Tgfbr2 in vivo resulted in marked upregulation of microglial CD74.AbstractMicroglia play important roles during physiological and pathological situations in the CNS. Several reports have described the expression of Cd74 in disease-associated and aged microglia. Here, we demonstrated that TGFβ1 controled the expression of Cd74 in microglia in vitro and in vivo. Using BV2 cells, primary microglia cultures as well as Cx3cr1CreERT2:R26-YFP:Tgfbr2fl/fl in combination with qPCR, flow cytometry, and immunohistochemistry, we were able to provide evidence that TGFβ1 inhibited LPS-induced upregulation of Cd74 in microglia. Interestingly, TGFβ1 alone was able to mediate downregulation of CD74 in vitro. Moreover, silencing of TGFβ signaling in vivo resulted in marked upregulation of CD74, further underlining the importance of microglial TGFβ signaling during regulation of microglia activation. Taken together, our data indicated that CD74 is a marker for activated microglia and further demonstrated that microglial TGFβ signaling is important for regulation of Cd74 expression during microglia activation. 相似文献
287.
288.
Max Stevenson Sebastian Weiß Gihoon Cha Maximilian Schamel Leonard Jahn Daniel Friedrich Michael A. Danzer Jun Young Cheong Josef Breu 《Small (Weinheim an der Bergstrasse, Germany)》2023,19(39):2302617
To ensure the safety and performance of lithium-ion batteries (LIBs), a rational design and optimization of suitable cathode materials are crucial. Lithium nickel cobalt manganese oxides (NCM) represent one of the most popular cathode materials for commercial LIBs. However, they are limited by several critical issues, such as transition metal dissolution, formation of an unstable cathode-electrolyte interphase (CEI) layer, chemical instability upon air exposure, and mechanical instability. In this work, coating fabricated by self-assembly of osmotically delaminated sodium fluorohectorite (Hec) nanosheets onto NCM (Hec-NCM) in a simple and technically benign aqueous wet-coating process is reported first. Complete wrapping of NCM by high aspect ratio (>10 000) nanosheets is enabled through an electrostatic attraction between Hec nanosheets and NCM as well as by the superior mechanical flexibility of Hec nanosheets. The coating significantly suppresses mechanical degradation while forming a multi-functional CEI layer. Consequently, Hec-NCM delivers outstanding capacity retention for 300 cycles. Furthermore, due to the exceptional gas barrier properties of the few-layer Hec-coating, the electrochemical performance of Hec-NCM is maintained even after 6 months of exposure to the ambient atmosphere. These findings suggest a new direction of significantly improving the long-term stability and activity of cathode materials by creating an artificial CEI layer. 相似文献
289.
Lukas Gericke Dr. Dipali Mhaindarkar Dr. Lukas C. Karst Sören Jahn Marco Kuge Michael K. F. Mohr Jana Gagsteiger Dr. Nicolas V. Cornelissen Xiaojin Wen Prof. Dr. Silja Mordhorst Prof. Dr. Henning J. Jessen Prof. Dr. Andrea Rentmeister Prof. Dr. Florian P. Seebeck Prof. Dr. Gunhild Layer Prof. Dr. Christoph Loenarz Prof. Dr. Jennifer N. Andexer 《Chembiochem : a European journal of chemical biology》2023,24(9):e202300133
S-Adenosylmethionine (SAM) is an enzyme cofactor involved in methylation, aminopropyl transfer, and radical reactions. This versatility renders SAM-dependent enzymes of great interest in biocatalysis. The usage of SAM analogues adds to this diversity. However, high cost and instability of the cofactor impedes the investigation and usage of these enzymes. While SAM regeneration protocols from the methyltransferase (MT) byproduct S-adenosylhomocysteine are available, aminopropyl transferases and radical SAM enzymes are not covered. Here, we report a set of efficient one-pot systems to supply or regenerate SAM and SAM analogues for all three enzyme classes. The systems’ flexibility is showcased by the transfer of an ethyl group with a cobalamin-dependent radical SAM MT using S-adenosylethionine as a cofactor. This shows the potential of SAM (analogue) supply and regeneration for the application of diverse chemistry, as well as for mechanistic studies using cofactor analogues. 相似文献