Study on Conductivity Properties of PEDOT Prepared through a Modified LB Film Method

Adopting LB film method, an arachidic acid (AA)/PEDOT multilayer LB film was chosen, and polymerized EDOT monomers in hydrophilic group of LB to prepare arachidic acid (AA)/PEDOT multilayer LB film. UV‐Vis, FT‐IR and XPS analyses implied that EDOT was effectively polymerized in film, and thus PEDOT conducting polymer was produced. Analyses of XRR and SIMS indicated that film had a well‐arranged lamella structure, and further research showed that polymerization of EDOT in AA film destroyed the orderliness of the original LB film. This phenomenon could be related to the destructive effect of polymerization on layered structure. We used four‐point probe and semiconductor instrument to study the conductivity property of the film, and observed that the conductivity of AA/PEDOT film had sudden changes with the processing time of changes in effective conduction network. That was caused by "permeability" in conducting channel of multilayer film. The test results also indicated that the conductivity of AA/PEDOT film was obviously better than that of spin‐coating PEDOT/PSS film or that of ODA‐SA/PEDOT‐PSS film, which was due to the higher π structure of PEDOT structure and ordered film structure.     

Research on stochastic control of networked control systems

A new control mode is proposed for networked control systems whose network-induced delay is longer than a sampling period. Under the control mode, the mathematical model of networked control systems is obtained. Markov characteristic of the network-induced delay is discussed. Based on Markov chain theory, the optimal controller is designed. One example is given for illustration.     

红色长余辉发光材料Ca2Zn4Ti15O36∶Pr3+的合成和发光性质

分别采用高温固相法和溶胶-凝胶法合成了新型红色长余辉发光材料Ca2Zn4Ti15O36∶Pr. 高温固相法合成Ca2Zn4Ti15O36需要在1200 ℃灼烧96 h才能形成纯物相. 热重分析曲线和X射线衍射分析结果表明 溶胶-凝胶法制得的前驱体在700 ℃灼烧12 h开始形成Ca2Zn4Ti15O36物相; 在1000 ℃灼烧24 h得到Ca2Zn4Ti15O36纯物相; 最佳反应温度为1000 ℃, 激活剂Pr3+的最佳浓度为0.6mol%, 发光强度比高温固相法增强了510%.     

Synthesis and asymmetric polymerization of (S)‐N‐maleoyl‐L‐leucine propargyl ester

A kind of N‐substituted maleimide (RMI), chiral (S)‐N‐maleoyl‐L ‐leucine propargyl ester ((S)‐PLMI) with a specific rotation of [α]₄₃₅ = ?27.5° was successfully synthesized from maleic anhydride, L ‐leucine, and propargyl alcohol. (S)‐PLMI was polymerized by three polymerization methods to obtain the corresponding optically active polymers. Asymmetric anionic, radical, and transition‐metal‐catalyzed polymerizations were carried out using organometal/chiral ligands, 2,2′‐azobisisobutyronitrile (AIBN) and (bicyclo [2,2,1]hepta‐2,5‐diene) chloro rhodium (I) dimer ([Rh(nbd) Cl]₂), respectively. Poly((S)‐PLMI) obtained by [Rh(nbd)Cl]₂ in DMF showed the highest specific rotation of ?280.6°. Chiroptical properties and structures of the polymers obtained were investigated by GPC, CD, IR, and NMR measurements. Two types of poly((S)‐PLMI)‐bonded‐silica gels as the chiral stationary phase (CSP) were prepared for high‐performance liquid chromatography (HPLC). Their optical resolution abilities were also elucidated. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3722–3738, 2007     

Observer-based fault detection for networked discrete-time infinite-distributed delay systems with packet dropouts

This paper addresses the problem of fault detection for networked discrete-time infinite-distributed delay systems with packet dropouts. Both sensor-to-controller and controller-to-actuator packet dropouts are described by two different Bernoulli distributed white sequences, respectively. The problem addressed is to design an observer-based fault detection filter (FDF) such that the error between the residual and the fault is made as small as possible. Unlike most of the existing literature, we have noted that the control input of the observer is different from that of the plant because of packet dropouts in the controller-to-actuator link. Sufficient condition for the existence of the FDF is derived in terms of some linear matrix inequalities (LMIs). When these LMIs are feasible, the explicit expression of the desired FDF can also be characterized. A numerical example is exploited to show the effectiveness of the obtained results.     

Reduction features of NO over a potassium-doped C12A7-O- catalyst

The NO reduction features over a noble-metal-free NO(x) storage/reduction catalyst ([Ca24Al28O64](4+*)4O-/K, defined as C12A7-O-/K), including the NO conversion, the N2 selectivity, and sulfur tolerance, were investigated with hydrogen and C3H6 as the reducing agents in a fixed-bed continuous flow reactor. The NO conversion and the N2 selectivity on the C12A7-O-/K catalyst mainly depends on the sample temperature, the percentage of potassium, the reducing agents, and the composition of the mixture of gases. The C12A7-O-/10%K catalyst possessed the highest selective reduction ability (to N2) among the catalysts C12A7-O-/x%K. Over 50% of NO can be reduced to N2 with H2 as the reduction agent at 550-700 degrees C. The C12A7-O-/K catalyst also shows higher NO(x) storage capacity (183.9 micromol/g at about 550 degrees C) as well as sulfur tolerance for both the NO(x) storage and the reduction processes. The catalyst characteristics and the intermediate species formed in the NO storage and reduction processes were investigated by the X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and time-of-flight mass spectrometry. The mechanism of NO(x) reduction was addressed according to the above investigations.     

固结系数的空间变异性对一维固结的影响分析

采用空间均值的方差的两种算法分析了自相关距离对固结系数的变异性的影响。结果表明,随着自相关距离的增大,固结系数的变异性增大。分析了不同土层的固结系数的不同,变异性对一维平均固结度的影响是不同的。结果表明分析一维固结,应视土层情况和工程性质考虑是否用随机场来模拟土的固结。     

An accurate theoretical study of energy barriers of alkaline hydrolysis of carboxylic esters

Hydrolysis of esters is one of the most important and frequently used reactions in both organic synthesis and biochemistry. While the reaction mechanism in solution is reasonably well understood, many questions still remain to be answered. In the present study, the combination method, MPW1B95/6-311++G(3df,2p)//B3LYP/6-31+G(d)//HF//CPCM/UA0, was found to be reliably predict the energy barriers of alkaline hydrolysis of various esters. The MAD and RMSE were equal to 1.03 and 1.06?kcal/mol, respectively. With this authorized theoretical protocol in hand, we systematically studied the mechanisms of alkaline hydrolysis of ethyl benzoate. The acyl-oxygen cleavage B_AC2 route is preferred over the alkyl-oxygen cleavage B_AL2 route. Then, the total activation energy barriers of B_AC2 and B_AL2 routes of over 40 esters have been calculated. And this large body of data allows us to systematically study the various effects controlling the alkaline ester hydrolysis, including the polar effect, the steric effect, and the remote substituent effect. Also, the solvent effect has been extensively studied in this work. Furthermore, the differences between B_AC2 and B_AL2 routes of these effects are also discussed. The results enable us to predict the energy barrier of the hydrolysis of cyhalofop-butyl in aquatic solution.     

木质素二聚体模型物裂解历程的理论研究

木质素作为生物质的主要成分之一, 是生物油的重要组分, 在工业生产中有着重要的应用. 生物质高温裂解液化制备生物油的过程伴随着木质素的裂解, 因此研究木质素高温裂解历程, 对生物油的制备有很大的帮助. 利用密度泛函方法对木质素在高温条件下的裂解历程进行理论研究, 并通过对各步反应的热力学焓变计算, 确定了初次裂解的路径为Cα—Cβ和β-O-4热裂解路径. 根据进一步的研究预测了裂解反应的主要产物.     

Monitoring molecular vibronic coherences in a bichromophoric molecule by ultrafast X-ray spectroscopy

The role of quantum-mechanical coherences in the elementary photophysics of functional optoelectronic molecular materials is currently under active study. Designing and controlling stable coherences arising from concerted vibronic dynamics in organic chromophores is the key for numerous applications. Here, we present fundamental insight into the energy transfer properties of a rigid synthetic heterodimer that has been experimentally engineered to study coherences. Quantum non-adiabatic excited state simulations are used to compute X-ray Raman signals, which are able to sensitively monitor the coherence evolution. Our results verify their vibronic nature, that survives multiple conical intersection passages for several hundred femtoseconds at room temperature. Despite the contributions of highly heterogeneous evolution pathways, the coherences are unambiguously visualized by the experimentally accessible X-ray signals. They offer direct information on the dynamics of electronic and structural degrees of freedom, paving the way for detailed coherence measurements in functional organic materials.

Coherences during the non-adiabatic dynamics of a bichromophoric molecules are probed via stimulated X-ray Raman signals. They survive for several hundred femtoseconds, despite highly heterogeneous contributions across the molecular sampling space.