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排序方式: 共有153条查询结果,搜索用时 15 毫秒
1.
本文通过“1 4-1 5”智力玩具和最优戴断切割问题两个实例 ,讨论了逆序数在解决实际问题中的应用  相似文献   
2.
Developing stable, readily‐synthesized, and solution‐processable transparent conducting polymers for interfacial modifying layers in organic photovoltaic (OPV) devices has become of great importance. Here, the radical polymer, poly(2,2,6,6‐tetramethylpiperidinyloxy methacrylate (PTMA), is shown to not affect the absorption of the well‐studied poly(3‐hexylthiophene) (P3HT) and [6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM) active layer when incorporated into inverted OPV devices, as it is highly transparent in the visible spectrum due to the non‐conjugated nature of the PTMA backbone. The inclusion of this radical polymer as an anode‐modifying layer enhanced the open‐circuit voltage and short‐circuit current density values over devices that did not contain an anodic modifier. Importantly, devices fabricated with the PTMA interlayer had performance metrics that were time‐independent over the entire course of multiples days of testing after exposing the OPV devices to ambient conditions. Furthermore, these high performance values were independent of the metal used as the top electrode contact in the inverted OPV devices. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53, 311–316  相似文献   
3.
基于经典的马克思两大部类社会再生产公式,建立了离散确定型的持续扩大再生产的优化问题的动态规划模型.在生产资料部类的不变资本产出率高于另一部类的条件下,动态规划的指标函数是作为决策变量的生产资料部类积累率的单调函数,因而可以使用逆序解法或者顺序解法,获得唯一的最优策略和最优指标函数.借助《资本论》中的一个举例,计算验证了最优解.  相似文献   
4.
Two hydrophilic conjugated polymers, PmP‐NOH and PmP36F‐NOH, with polar diethanol­amine on the side chains and main chain structures of poly(meta‐phenylene) and poly(meta‐phenylene‐alt‐3,6‐fluorene), respectively, are successfully synthesized. The films of PmP‐NOH and PmP36F‐NOH show absorption edges at 340 and 343 nm, respectively. The calculated optical bandgaps of the two polymers are 3.65 and 3.62 eV, respectively, the largest ones so far reported for hydrophilic conjugated polymers. PmP‐NOH and PmP36F‐NOH also possess deep‐lying highest occupied molecular orbital levels of −6.19 and −6.15 eV, respectively. Inserting PmP‐NOH and PmP36F‐NOH as a cathode interlayer in inverted polymer solar cells with a PTB7/PC71BM blend as the active layer, high power conversion efficiencies of 8.58% and 8.33%, respectively, are achieved, demonstrating that the two hydrophilic polymers are excellent interlayers for efficient inverted polymer solar cells.

  相似文献   

5.
The involvement of silver in two-electron AgI/AgIII processes is currently emerging. However, the range of stability of the required and uncommon AgIII species is virtually unknown. Here, the stability of AgIII towards the whole set of halide ligands in the organosilver(III) complex frame [(CF3)3AgX] (X=F, Cl, Br, I, At) is theoretically analyzed. The results obtained depend on a single factor: the nature of X. Even the softest and least electronegative halides (I and At) are found to form reasonably stable AgIII−X bonds. Our estimates were confirmed by experiment. The whole series of nonradiative halide complexes [PPh4][(CF3)3AgX] (X=F, Cl, Br, I) has been experimentally prepared and all its constituents have been isolated in pure form. The pseudohalides [PPh4][(CF3)3AgCN] and [PPh4][(CF3)3Ag(N3)] have also been isolated, the latter being the first silver(III) azido complex. Except for the iodo compound, all the crystal and molecular structures have been established by single-crystal X-ray diffraction methods. The decomposition paths of the [(CF3)3AgX] entities at the unimolecular level have been examined in the gas phase by multistage mass spectrometry (MSn). The experimental detection of the two series of mixed complexes [CF3AgX] and [FAgX] arising from the corresponding parent species [(CF3)3AgX] demonstrate that the Ag−X bond is particularly robust. Our experimental observations are rationalized with the aid of theoretical methods. Smooth variation with the electronegativity of X is also observed in the thermolyses of bulk samples. The thermal stability in the solid state gradually decreases from X=F (145 °C, dec.) to X=I (78 °C, dec.) The experimentally established compatibility of AgIII with the heaviest halides is of particular relevance to silver-mediated or silver-catalyzed processes.  相似文献   
6.
Marcus电子转移理论的主要成果之一是预言了电子转移反应反转区的存在.从实验上 验证Marcus反转区仍是一个热点问题.通过对γ-MnO2/K3[Fe(CN)6]溶液界面平带电位、极 化曲线的测量,计算了在极化条件下,γ-MnO2导带的电子直接转移到溶液中氧化态物种[F e(CN)6]3-空电子能级上的速率常数ket,logket对外加电位作图,观察到了Marcus反转区. 从理论上也论证了在半导体/溶液界面上的直接电子转移反转区的存在.  相似文献   
7.
基于反中值滤波的红外焦平面自适应非均匀性校正方法   总被引:1,自引:0,他引:1  
分析了红外焦平面阵列非均匀性的噪声特性,提出了一种用反中值滤波为核心的红外焦平面自适应校正的方法。针对实际的图像进行了实验,实验证明该方法在校正效果、收敛速度、对静止目标保持能力及可硬件化等方面都有较好的表现。  相似文献   
8.
张启义 《中国物理 B》2009,18(2):658-663
The pair interaction between bilayer membrane-coated nanosized particles has been explored by using the self-consistent field (SCF) theory. The bilayer membranes are composed of amphiphilic polymers. For different system parameters, the pair-interaction free energies are obtained. Particular emphasis is placed on the analysis of a sequence of structural transformations of bilayers on spherical particles, which occur during their approaching processes. For different head fractions of amphiphiles, the asymmetrical morphologies between bilayers on two particles and the inverted micellar intermediates have been found in the membrane fusion pathway. These results can benefit the fabrication of vesicles as encapsulation vectors for drug and gene delivery.  相似文献   
9.
Expressions are derived for the tunnel electric current between two metals produced by the adiabatic transitions of the electrons through a bridge electron level. A new possible physical phenomenon is discussed, viz. electronically driven oscillations of the electron bridge level between two molecular wires.  相似文献   
10.
郭鹏飞  王建中  施家栋 《应用声学》2016,24(7):253-255, 261
为提高点着地四足机器人在匀速对角小跑过程中的动态稳定性,将对角小跑过程简化为一个倒立摆模型。针对四足机器人对角小跑过程中由于重心无法始终处于支撑对角线上所引起的翻转,在此模型中转换为由于重心引起的摆动角误差。采用虚位移原理对机器人摆动角的变化进行分析,确定不同重心运动变化对摆动角误差的影响并找到合适的重心起始位置,理论上能够使摆动角的误差为零。动态仿真实验验证了所提出的对角步态规划能够使四足机器人实现稳定的对角小跑的有效性。  相似文献   
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