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排序方式: 共有3450条查询结果,搜索用时 15 毫秒
941.
942.
Achieving Nearly 30% External Quantum Efficiency for Orange–Red Organic Light Emitting Diodes by Employing Thermally Activated Delayed Fluorescence Emitters Composed of 1,8‐Naphthalimide‐Acridine Hybrids
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Weixuan Zeng Hsin‐Yu Lai Wei‐Kai Lee Min Jiao Yi‐Jiun Shiu Cheng Zhong Shaolong Gong Tao Zhou Guohua Xie Monima Sarma Ken‐Tsung Wong Chung‐Chih Wu Chuluo Yang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(5)
The combination of rigid acridine donor and 1,8‐naphthalimide acceptor has afforded two orange–red emitters of NAI‐DMAC and NAI‐DPAC with high rigidity in molecular structure and strongly pretwisted charge transfer state. Endowed with high photoluminescence quantum yields (ΦPL), distinct thermally activated delayed fluorescence (TADF) characteristics, and preferentially horizontal emitting dipole orientations, these emitters afford record‐high orange–red TADF organic light‐emitting diodes (OLEDs) with external quantum efficiencies of up to 21–29.2%, significantly surpassing all previously reported orange‐to‐red TADF OLEDs. Notably, the influence of microcavity effect is verified to support the record‐high efficiency. This finding relaxes the usually stringent material requirements for effective TADF emitters by comprising smaller radiative transition rates and less than ideal ΦPLs. 相似文献
943.
Acute kidney injury in a postpartum woman with paroxysmal nocturnal hemoglobinuria: A case report and literature review
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Masatoshi Nishimoto Masaru Matsui Hideo Tsushima Kaori Tanabe Miho Tagawa Ken‐ich Samejima Yasuhiro Akai Yoshihiko Saito 《Hemodialysis international. International Symposium on Home Hemodialysis》2018,22(1):E6-E10
Paroxysmal nocturnal hemoglobinuria is a rare clonal hematopoietic stem cell disorder characterized by intravascular hemolysis, hemoglobinuria, and inflammatory thrombotic state. Intravascular hemolysis in paroxysmal nocturnal hemoglobinuria (PNH) can lead to acute and chronic renal injury through hemoglobin‐mediated toxicity. A 32‐year‐old pregnant woman with myelodysplastic syndrome was admitted to our hospital with severe preeclampsia. Shortly after an urgent caesarean section, she became obtunded and showed signs of acute kidney injury (AKI) with anuria, severe intravascular hemolysis, and hypermagnesemia. She was diagnosed with PNH with a positive Ham test and flow cytometry analysis. Renal magnetic resonance imaging revealed decreased signal intensity in the renal cortex due to hemosiderin deposition. Hemodialysis, plasma exchange, and administration of corticosteroids ameliorated her clinical condition and renal function. This case illustrates that careful management is required to prevent postpartum AKI in pregnant women with PNH. 相似文献
944.
This paper discusses design tradeoffs for mixedsignal radio frequency integrated circuit (RF IC) transceivers for wireless applications in terms of noise, signal power, receiver linearity, and gain. During air wave transmission, the signal is corrupted by channel noise, adjacent interfering users, image signals, and multipath fading. Furthermore, the receiver corrupts the incoming signal due to RF circuit nonlinearity (intermodulation), electronic device noise, and digital switching noise. This tutorial paper gives an overview of the design tradeoffs needed to minimize RF noise in an integrated wireless transceiver. Fundamental device noise and the coupling of switching noise from digital circuits to sensitive analog sections and their impact on RF circuits such as frequency synthesizers are examined. Methods to minimize mixedsignal noise coupling and to model substrate noise effects are presented. 相似文献
945.
Shin Takahashi Satoshi Matsuoka Ken Miyashita Hiroshi Hosobe Tomihisa Kamada 《Constraints》1998,3(1):61-86
TRIP systems are tools for visualization and animation. They are based on a constraint-based model of bi-directional translation between abstract data and pictorial data. Using these systems, programmers can visualize abstract data, and animate various algorithms and processes, simply by providing a declarative mapping rule. This paper presents this model for visualization and animation, focusing on the use of constraints, and also presents the TRIP systems with examples of visualization and animation. 相似文献
946.
Ishihara Ken Katayama Seiichi Watanabe Takeji Seto Makoto Matsuyama Isamu 《Industry Applications, IEEE Transactions on》1985,(1):147-153
Recently, adjustable-speed ac drive systems have been employed successfully for blowers, pumps, table rollers, etc., in steel plants instead of the more conventional dc drives. In processing lines many drives require speed and tension control. To confirm the suitability of an ac drive for tension control, the tension reel of an existing pilot processing line has been equipped with an adjustable-speed ac drive. An ac drive system for tension reel control, its characteristics, and performance are described and compared with a dc tension control. 相似文献
947.
Automatic debugging of UML class diagrams helps in the visual specification of software systems because users cannot detect errors in logical consistency easily. This study focuses on the tractable consistency checking of UML class diagrams. We accurately identify inconsistencies in these diagrams by translating them into first-order predicate logic that is generalized by counting quantifiers and classify their expressivities by eliminating certain components. We introduce optimized algorithms that compute the respective consistencies of class diagrams of different expressive powers in P, NP, PSPACE, or EXPTIME with respect to the size of the class diagrams. In particular, owing to the restrictions imposed on attribute value types, the complexities of consistency checking of class diagrams decrease from EXPTIME to P and PSPACE in two cases: (i) when the class diagrams contain disjointness constraints and overwriting/multiple inheritances and (ii) when the class diagrams contain both these components along with completeness constraints. Additionally, we confirm the existence of a restriction of class diagrams that prevents any logical inconsistency. 相似文献
948.
Jeremy Roschelle Ken Rafanan Gucci Estrella Miguel Nussbaum Susana Claro 《Computers & Education》2010
The field of Computer Supported Collaborative Learning (CSCL) includes designers who emphasize effectiveness, measured via experiments, as well as designers who emphasize context and conduct qualitative research on teaching and learning practices. We conjectured that these two different emphases could be fruitful combined in a research and development process aimed at producing effective CSCL practices. We explored this possibility in a project that adapted a CSCL tool from Chile to serve as the basis of an effective 3-week classroom module for primary school mathematics in the United States. To go from tool to module, we addressed curricular fit, training materials, pedagogical guidance, formative and summative assessments, and logistical support. In conducting the project, we found that effectiveness and contextual research could be conducted simultaneously and yielded complementary insight to this design process, which enabled our project to rapidly move from the base tool towards complete classroom modules. An experiment we conducted after our design iterations showed that students who used the modules learned more about the target content, fractions. A retrospective analysis of our design process suggests that the Integrative Learning Design framework is useful for organizing the complementary components of effectiveness and contextual research in our design process. 相似文献
949.
This paper presents supervisory control of a total molten-metal pouring system to improve the productivity of the factory, the safety of workers, and the quality of the product. Through the pouring processes model, a forward tilting control input was calculated by an adaptive feedforward control system to hold the liquid in the sprue cup at a constant level considering the change effected by the accumulating slag in the ladle. A backward tilting input was obtained by means of the hybrid shape approach applied to suppress the slosh. The supervisory control system reasonably switches from the forward tilting motion to the backward tilting motion by using model predictive control to achieve the accurate poured quantity. The validity of the proposed total control system was demonstrated through experiments. 相似文献
950.