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Reinvestigation of the Henry's law constant for hydrogen peroxide with temperature and acidity variation

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Journal of Environmental sciences 2010年第4期22卷 570-574页

作者： Daoming Huang,Zhongming Chen The state key laboratory of Environmental Simulation and Pollution Control,College of Environmental sciences and Engineering,Peking university,beijing 100871,china. [a] The state key laboratory of Environmental Simulation Pollution Control College of Environmental Sciences Engineering Peking University Beijing 100871 China

Hydrogen peroxide is not only an important oxidant in itself; it also serves as both sink and temporary reservoir for other important oxidants including HOx （OH and HO2） radicals and O3 in the atmosphere. Its partitioning between gas and aqueous phases in the atmosphere, usually described by its Henry＇s law constant （KH）, significantly influences its role in atmospheric processes. Large discrepancies between the KH values reported in previous work, however, have created uncertainty for atmospheric modelers. Based on our newly developed online instrumentation, we have re-determined the temperature and acidity dependence of KH for hydrogen peroxide at an air pressure of （0.960 ± 0.013） atm （1 atm = 1.01325 × 10^5 Pa）. The results indicated that the temperature dependence of KH for hydrogen peroxide fits to the Van＇t Hoff equation form, expressed as lnKH = a/T - b, and a = -△H/R, where KH is in M/atm （M is mol/L）, T is in degrees Kelvin, R is the ideal gas constant, and AH is the standard heat of solution. For acidity dependence, results demonstrated that the KH value of hydrogen peroxide appeared to have no obvious dependence on decreasing pH level （from pH 7 to pH 1）. Combining the dependence of both temperature and acidity, the obtained a and b were 7024 ± 138 and 11.97 ± 0.48, respectively, AH was （58.40 ± 1.15） kJ/（***）, and the uncertainties represent σ. Our determined KH values for hydrogen peroxide will therefore be of great use in atmospheric models.

关键词： hydrogen peroxide Henry's law constant atmosphere acidity

Threshold quantum secure direct communication without entanglement

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Science china(Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3 & WEN QiaoYan2 1 College of Computer Science and Technology, beijing university of Technology, beijing 100022, china 2 school of Science, beijing university of Posts and Telecommunications, beijing 100876, china 3 state key laboratory of Information Security (Graduate school of Chinese Academy of sciences), beijing 100049, china 1. College of Computer Science and Technology Beijing University of Technology Beijing 100022 China 3. state key laboratory of Information Security (Graduate school of Chinese Academy of sciences) Beijing 100049 China 2. school of Science Beijing University of Posts and Telecommunications Beijing 100876 China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing

Logical verification of scientific discovery

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Science china(Information sciences) 2010年第4期53卷 677-684页

作者： LI Wei state key laboratory of Software Development Environment, school of Computer Science and Engineering, Beihang university, beijing 100191, china 1. state key laboratory of Software Development Environment School of Computer Science and Engineering Beihang University Beijing 100191 China

This paper shows that the discovery processes of Einstein’s special theory of relativity and Darwin’s theory of evolution of species can be formally verified by R-calculus which is a logical inference system. The aim of R-calculus is to delete the principles of scientific theories which contradict empirical evidence. The paper shows that the special theory of relativity is the only and correct choice for physics to meet the experimental evidence given at the time. As far as the biology of Darwin’s time is concerned, however, the R-calculus has derived three logically correct but different theories, which are all consistent with the empirical evidence provided by Darwin and his principle of natural selection. Darwin’s theory of evolution matches one of the three theories derived by R-calculus. This theory has a logical consequence that is "each species has been independently created is erroneous". But the other two theories support the negation of the above statement. The existence of the other two theories may be a reason of the controversies over Darwin’s theory.

关键词： R-calculus theory of relativity theory of evolution

INFINITE ELEMENT METHOD FOR THE EXTERIOR PROBLEMS OF THE HELMHOLTZ EQUATIONS

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Journal of Computational Mathematics 2000年第6期18卷 657-672页

作者： Lung-an Ying (school of Mathematical sciences, Peking university, beijing 100871, china) 北京大学北京 100871

There are two cases of the exterior problems of the Helmholtz equation. If λ ≥ 0 the bilinear form is coercive, and if λ < 0 it is the scattering problem. We give a new approach of the infinite element method, which enables us to solve these exterior problems as well as corner problems. A numerical example of the scattering problem is given. [ABSTRACT FROM AUTHOR]

关键词： Helmholtz equation exterior problem infinite element method

PTEN,a general negative regulator of cyclin D expression

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Cell Research 2007年第4期17卷 291-292页

作者： Eirong Diao~1 Ye-Guang Chen ~1state key laboratory of biomembrane and membrane biotechnology,Department of Biological sciences and biotechnology Tsing-hua Universiry,beijing 100084,china statekeylaboratoryofbiomembraneandmembranebiotechnology DepartmentofBiologicalSciencesandBiotechnologyTsing-huaUniversityBeijing100084China

The tumor-suppressor phosphatase with tensin homol-ogy(PTEN)is frequently mutated in many malignanciesand is one of the most well studied tumor suppressor genes[1,2].PTEN,a lipid and protein dual phosphatase,plays avital role in embryonic development,cell growth,apoptosisand cell *** well-known function of PTEN isphosphatidylinositol-3(PI)-phosphatase,which functionsas a negative regulator of the PIkinase(PI3K)*** well established that PTEN regulates the G1-S transitionby modulating the expression of cyclin D1 and *** passage of any cell through cell cycles is subtlymodulated by a series of proteins,among which the mainplayers in animal cells include cyclins,CDKs(cyclin-de-pendent kinases,positive regulators)and CDK inhibitors(negative regulators such as p21and *** Dsare key regulators during the G1 phase and there are threetypes of cyclin Ds,D1,D2 and D3 in mammalian cells[3].Although the phenotypic analyses of single cyclin Dknockout mice revealed that each of the D type cyclinsis sufficient to drive normal development of the majority

关键词： PTEN,a general negative regulator of cyclin D expression

A HIGH-ORDER-ACCURATE DIFFERENCE SCHEME WITH UNCONDITIONAL STABILITY FOR THE DIFFUSION EQUATION ON NONUNIFORM GRIDS

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Journal of Hydrodynamics 2001年第1期13卷 92-98页

作者： Wang Xuan, Yang Zhi-feng state key laboratory of Environment Simulation and Pollution Control, Institute of Environmental sciences, beijing Normal university, beijing 100875, china[WT5”HZ] beijing Normal Univ. Beijing 100875 China

WT5”BZ]A high-order-accurate difference scheme with unconditional stability is developed for the diffusion equation on nonuniform grids. The theoretical analysis shows that the accuracy of this scheme is between third order and fourth order, and fourth-order accuracy is achieved in the case of the same grid steps being used within the computational domain. Two numerical examples are given to demonst ate the advantages of the proposed scheme. Compared with the conventional difference scheme, more accurate numerical solution can be obtained by using the proposed scheme even with relatively larger grid sizes. It is also pointed out that the appropriate structure of the nonuniform grid can not only make the proposed scheme more practical, but lead to a solution superior to that for a uniform grid structure. [WT5”HZ]

关键词： ]finite difference scheme diffusion equation nonuniform grid high accuracy computational fluid dynamics

Multi-dimensional project management models for mega-construction companies and their applications

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Science china(Technological sciences) 2011年第S1期54卷 118-124页

作者： LIN ZhengHang 1,2,QIANG MaoShan 1,2,TANG WenZhe 1,2,FAN QiXiang 3 &LIU Qiang 4 1 Institute of Project Management and Construction Technology,Tsinghua university,beijing 100084,china 2 state key laboratory of Hydraulic and Engineering,Tsinghua university,beijing 100084,china 3 china Three Gorges Corporation,Yichang 443002,china 4 school of Software,Tsinghua university,beijing 100084,china 1. Institute of Project Management and Construction Technology Tsinghua University Beijing 100084 China2. State Key Laboratory of Hydraulic and Engineering Tsinghua University Beijing 100084 China3. China Three Gorges Corporation Yichang 443002 China4. School of Software Tsinghua University Beijing 100084 China

china is undertaking an increasing number of mega-infrastructure projects along with its rapid economic *** participants in these projects,understand how to adapt the proper and efficient management strategies is *** this paper,we propose three distinct models for companies under various background and management requirements,based on sophisticated data analysis and model ***,we successfully committed these models with hydropower development projects and achieved a great progress in enhancing management efficiency.

关键词： project management models mega-construction companies applications hydropower development companies

PII,the key regulator of nitrogen metabolism in the cyanobacteria

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Science china(life sciences) 2008年第12期51卷 1056-1065页

作者： ZHANG Ying & ZHAO JinDong state key laboratory of Protein and Plant Genetic Engineering, College of life Science, Peking university, beijing 100871, china 1. state key laboratory of Protein and Plant Genetic Engineering College of Life Science Peking University Beijing 100871 China

PII proteins are a protein family important to signal transduction in bacteria and plants. PII plays a critical role in regulation of carbon and nitrogen metabolism in cyanobacteria. Through conformation change and covalent modification, which are regulated by 2-oxoglutarate, PII interacts with different target proteins in response to changes of cellular energy status and carbon and nitrogen sources in cyanobacteria and regulates cellular metabolism. This article reports recent progress in PII research in cyanobacteria and discusses the mechanism of PII regulation of cellular metabolism .

关键词： carbon metabolism cyanobacteria nitrogen metabolism PII protein

THE GLOBAL ARTIFICIAL BOUNDARY CONDITIONS FOR NUMERICAL SIMULATIONS OF THE 3D FLOW AROUND A SUBMERGED BODY

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Journal of Computational Mathematics 2003年第4期21卷 435-450页

作者： Hou-de Han Xin Wen (Department of Mathematical sciences, Tsinghua university, beijing 100084, china) Department of Mathematical sciences Tsinghua University Beijing 100084 China

We consider the numerical approximations of the three-dimensional steady potential flow around a body moving in a liquid of finite constant depth at constant speed and distance below a free surface in a channel. One vertical side is introduced as the upstream artificial boundary and two vertical sides are introduced as the downstream artificial boundaries. On the artificial boundaries, a sequence of high-order global artificial boundary conditions are given. Then the original problem is reduced to a problem defined on a finite computational domain, which is equivalent to a variational problem. After solving the variational problem by the finite element method, we obtain the numerical approximation of the original problem. The numerical examples show that the artificial boundary conditions given in this paper are very effective.

关键词： Ship wave Potential flow Global artificial boundary condition Finite element method.