Asymmetric Hydrogenation of Ketones-Design of Chiral Catalysts

1Introduction Asymmetric hydrogenation of ketones is one of the most reliable methods for obtaining chiral secondary alcohols. This transformation is not only of academic interest, but also of industrial significance because of its simplicity, environmental friendliness, and economic viability. Chiral RuXY(binap)(1,2-diamine) complexes (BINAP = 2,2'-bis(diphenyl-phosphino)-1, 1'-binaphthyl,X = Y = C1 or X = H, Y = BH4) with[1] or without[2] a strong base catalyze rapid, highly productive asymmetric hydrogenation of various simple ketones in 2-propanol. This reaction, unlike conventional hydrogenation, proceeds selectively at a C = O bond leaving coexisting C = C linkages intact. A range of chiral alcohols are accessible in high enantiomeric purity from aromatic,heteroaromatic, olefinic, and amino ketones by this method[1,2]. However, no universal chiral catalysts exist due to the structural diversity of ketonic substrates. Thus, tert-alkyl ketones and 1-tetralones have remained difficult to be hydrogenated with high reactivity and enantioselectivity. We here report that this problem can be resolved by the use of BINAP/PICA-Ru (PICA = α-picolylamine)[3] or BINAP/1,4-diamine-Ru[4] complexes as catalysts.     

Language and Gender

The definitions of gender in Oxford Advmlced Learner＇s Dictionary. （on line） are as follows： 1. the fact of being male or female. 2. （Grammar） （in some languages） each of the classes （masculine. feminine and sometimes neuter） into which nouns, pronouns and adjectives are divided. It is hardly a matter of dis- pute that male and female are different. One major genetic difference is that females have two X chromosomes while males have an X and a Y. The book, Men are from Mars and Women are from Venus. asserts the notion that men and women are as different as beings from other planets.     

Effective Palladium（Ⅱ） Catalyst for Oxypalladation of Alkene

A variety of Pd（ Ⅱ ）-catalyzed oxidative transformations ot allcenes with oxygen nucleophiles are catalyzed by PdXa（X=OAc, Cl, etc） with CuX.（ n = 1 or 2） under O2. In the so-called Wacker catalyst of such,Pd（OAe）2 is less reactive compared to PdCl2. In an attempt to increase the reactivity of Pd（OAe）2, we have now found that tuning of Cu site with catechol gives an intriguing reactivity to Pd（OAc）2, which is unprecedented in the chemistry of palladium.     

Real-time rapid prediction of variations of Earth’s rotational rate

Real-time rapid prediction of variations of the Earth＇s rotational rate is of great scientific and practical importance. However, due to the complicated time-variable characteristics of variations of the Earth＇s rotational rate （i.e., length of day, LOD）, it is usually difficult to obtain satisfactory predictions by con- ventional linear time series analysis methods. This study employs the nonlinear artificial neural net-works （ANN） to predict the LOD variations. The topology of the ANN model is determined by minimizing the root mean square errors （RMSE） of the predictions. Considering the close relationships between the LOD variations and the atmospheric circulation movement, the operational prediction series of axial atmospheric angular momentum （AAM） is incorporated into the ANN model as an additional input in the real-time rapid prediction of LOD variations with 1-5 days ahead. The results show that the LOD prediction is significantly improved after introducing the operational prediction series of AAM into the ANN model.     

Some Results about the Sample Path Properties of Markov Processes with Independent Self-Similar Components

This paper considers a special class of operator self-similar processes Markov processes {X（t）, t≥0} with independent self-similar components, that is, X （ t ） =（X^1（t）,…,X^d（t））, where {X^i（t）,t≥0}, i=1,2,…,d are d independent real valued self-similar Markov processes. By means of Brel-Cantelli lemma, we give two results about asymptotic property as t→∞ of sample paths for two special classes of Markov processes with independent self-similar components.     

Numerical Simulations on Geometrical Properties of Wall-attaching Transonic Jet

Effects of operating conditions and device＇ s geometrical sizes on geometrical properties of wall-attaching transonic jet between two parallel plat plates are numerically simulated. Conclusions are as follows ： 1 ） Upriver part of the wall-attaching jet＇s center streamline is in good accordance with parabola; 2） When both gas inlet pressure and outlet pressure as well as their ratio are not too high （ the outlet pressure is less than 10 MPa and the pressure ratio is less than 3 ）, the center streamlines of the wall-attaching jet with the same pressure ratio coincide with each other very well, and the deflection degree of the center streamline decreases with rise of the pressure ratio ; 3 ） The deflection degree of the jet＇ s center streamline decreases with either broadening of nozzle＇ s throat or rise of wall offset ; 4） With rise of the pressure ratio, attachment distance of the jet increases, but the increase rate descends ; 5 ） The attachment distance ascends with rise of either the nozzle＇ s throat or the wall offset.     

On Features of EST and Its Translation

The study of translation has always been emphasizing the translation of literature, therefore, the translation of EST （English for science and technology）, which is a special style or genre of English, doesn＇t get enough attention yet. This thesis attempts to discuss the translation of English for science and technology, and its features.     

Modeling of Operators’ Workload in a Nuclear Power Plant

Accidents in a nuclear power plant are coped with by operators in the main control room （MCR）. An analysis of the workload of operators in a MCR after the happening of initiating events is helpful to the alleviation of human errors and to the promotion of training efficiency. This paper establishes a framework of how man is located in a man-ma- chine interface of a nuclear power plant （NPP） as well as a simulation of the man-machine scenario in accidents in NPPs, including the simulation of the operators＇ task and cognitive work and the establishment of task analysis. On the basis of the above, a model of the dynamic changes of the operators＇ tasks is constructed and a computation of operators＇ workload is conducted.     

A matrix version of the Wielandt inequality and its application to statistics

Suppose that A is an n × n positive definite Hemitain matrix. Let X and Y be n × p and n × q matrices (p+ q≤n), such that X* Y = 0. The following inequality is proved X*AY( Y* AY)-Y Y*AX≤( (λ1-λn)/(λ1+λn))2 X*AX, where λ1 and λn are respectively the largest and smallest eigenvalues of A, and M- stands for a generalized inverse of M. This inequality is an extension of the well-known Wielandt inequality in which both X and Y are vectors. The inequality is utilized to obtain some interesting inequalities about covari-ance matrix and various correlation coefficients including the canonical correlation, multiple and simple correlation.     

Corrosion Protection Properties of Organofunctional Silanes——An Overview

The aim of this paper is to review the development and state of the art in the application of certain organosilicon compounds known as trialkoxysilanes （or simply silanes） to the problems of the metal finishing industry. The ultimate goal of this work is the replacement of chromate passivation and paint pretreatments, as well as overcoming the shortcomings of organic coatings formulated in the modern environmentally friendly world, thus without chromate or chromated pigments, volatile organic carbon （VOC） containing compounds or harazardous air pollutants （HAPs）.     

Depression and Emancipation——Two Representative Images of Victorian Women in View of Ernestina and Sarah

In the novel The French Lieutenant＇s Woman,the two major female role--Ernestina and Sarah,can be the representative images of Victorian women. Sarah＇s speech and behaviors reveal the spirit of emancipation and freedom,while Ernestina is the conservative and depressed women in that period. Through the analysis of them,the social values of Victorian period are presented clearly. This also reflects John Fowles＇attitude towards women.     

Interacting domains of the HN and F Proteins of paramyxovirus

Binding sialates to hemagglutinin-neuraminidase （HN） activates （triggers） the fusion protein （F） to start the membrane fusion process of paramyxovirus, but the mechanism by which the HN and F associate with each other to induce membrane fusion is still unclear. It is noteworthy to study the interaction domains of HN and F of paramyxovirus. To screen interacting domains of the HN and F proteins of Avian parainfluenza virus-2 （APIV-2） and identify the structure of binding proteins, the GST pull-down assay and mass spectroscopy （MS） and circular dichroism （CD） experiments were performed in this study. The study revealed that the globular head region of HN protein tends to form a complex with either the heptad repeat 1 （HR1） or the heptad repeat 2 （HR2） of F protein respectively. This paper discusses the novel fusion mechanism induced by paramyxovirus HN and F proteins.     

Recent advances in catalytic asymmetric hydrogenation： Renaissance of the monodentate phosphorus ligands

The history for the development of chiral phosphorus ligands in catalytic asymmetric hydrogenation is briefly highlighted. This review focuses on the recent advances in the synthesis of the monodentate phosphorus ligands and their applications in catalytic asymmetric hydrogenation. The examples highlighted in this article clearly demonstrated the importance and advantages of monodentate phosphorus ligands, which had been ignored for 30 a and experienced a renaissance at the very beginning of this millennium, particularly in the area of asymmetric hydrogenation.     

How to Foster Students＇ Ability of Studying Independently——English Study for Example

Among students＇ abilities,the important one is the ability of studying independently.It is the teachers＇ indispensable task to foster students＇ ability of studying independently.This essay deals with the problem that how a teacher can foster the ability of student self-study,especially English study,from these perspectives：the nature,the characteristics,the conditions and the structure of the ability of independent study.The appropriate methods that the teacher should take in the process of fostering the ability are discussed in the last part of this essay.     

A combination of influence from Confucianism and Taoism upon Chinese culture and literature

Preface
The mixture of various cultures including those deep rooted in Chinese history and those imported in the ancient time has led to the profoundness, uniqueness and colorfulness of Chinese culture, among which the combination of two of them---Confucianism and Taoism has fundamental influence in the way Chinese think and behave. This may sometimes confuse the western world when it comes to the characteristics of the nation, as stated in the equation R4D1H3S3 （R=realism, D=dreams or idealism, H=humor, S=sensitivity） by Lin Yutang. The western world is surprised to see a nation with the greatest sense of realism among several peoples including Japanese, British, French, American and German）, yet the Chinese also demonstrate a great level of humor toward life, how can that be if a nation is characterized both for its realism and its light attitude toward reality. To reply to these questions, we will have to trace back to the wellsprings of Chinese wisdom in the combination of Confucianism（realism） and Taoism（idealism）.     

Reversal Efficacy of SDZ-PSC833 and Verapamil on Drug-Resistant Human Cervical Carcinoma Cells Line

This article discusses the characteristics of the drugresistant human cervical carcinoma cell line HeLa/MMC and investigates reversal effect of SDZ-PSC833（PSC833） and Verapamil （Ver） upon HeLa/MMC. Relative content of cell DNA detection, H3-TdR incorporation test and drug-resistance have been experimented, meanwhile a tumor transplant model in the nude mice for Hela/MMC has been established. Then the volume of cancer, tumor weight, curve line of growing up in tumor -bearing nude mouse and its morphological variation of carcinoma organism are observed to evaluate the reversal effect of PSC833 and VER. It has been found that： （1） Compared with HeLa cells,subline HeLaJ MMC Cells＇ drug-resistant capability against Mitomycin（MMC） or cisplatin（DDP） is as 5.02 folds or 2 folds as that of the former, respectively. The Hela/MMC cell line has characteristics of multi- drug resistance and stronger multiplication; （2） PSC833 and VER can reverse resistance of HeLa/MMC to Mitomycin in vivo.PSC833 will be a better candidate for reversing multidrug resistant than verapamil in clinic application.     

The Loss of Weight and Release of Formaldehyde in Acid Treatment of Basofil Fiber

The Basofil fiber is a new type of hightemperature fiber. Its Limiting Oxygen Index （LOI） value reaches 32. It does not melt, drop down or smolder when it contacts fire. The fiber is condensed from melamine and formaldehyde into a cross-linked with methylene-ether and methylene bridge bond. This thesis discusses the change of fiber structure and performance after the acid treatment.     

Dependence of magnetic properties of HDDR Nd-Fe-B bonded magnet on intergranular phase

Using proposed different anisotropy expressions K1^Ⅰ（r） and K1^Ⅱ（r） at the grain boundary, we investigate the effect of intergranular phase （IP） on the average anisotropy 〈K1〉 of grain boundary and the coercivity Hc of HDDR （hydrogenation, disproportionation, desorption and recombination） Nd-Fe-B bonded magnet. The results indicate that when the IP＇s thickness d is zero, 〈K1〉 and Hc based on K1^Ⅰ（r） are equal to the corresponding ones based on K1^Ⅱ（r）. While dtakes nonzero values, 〈K1〉 and Ho based on K1^Ⅱ（r） falls and rises more rapidly, respectively, with increasing d. When d is 1 nm and the structure defect thickness r0 is close to the thickness of domain wall （-4 nm）, the calculated coercivity is consistent well with the avaiable experimental data.     

Analysis of PROFIBUS-DP Network Delay and Its Influence on the Performance of Control Systems

This paper analyzes PROFIBUS-DP network delay in detail and presents the calculational formula of its maximum time-delay, which is significant to the research of PROFIBUS-DP. At the same time, the paper puts forward a method of simplifying the network induced time-varying indeterminate system according to the features of the network. Through the analysis of a pump-control-motor system which is composed of PROFIBUS-DP network, it illustrates the network＇s influence on the performance of control systems. This method helps to design and analyze the network＇s influence on the performance of control systems, which is of considerable practical value in a time when network control systern is widely used.