On Dirichlet Characters of Polynomials

The main purpose of this paper is to use the properties of Gaussiansums and the analytic method to study the problem of calculatingone kind of character sums modulo q, and to give an interestingidentity. 2000 Mathematics Subject Classification 11L10, 11L40.     

On a Generalized Cochrane Sum and Its Hybrid Mean Value Formula

The main purpose of this paper is to use a mean value theorem of Dirichlet L-functions to study the asymptotic property of a hybrid mean value of a generalized Cochrane sum, and give an interesting mean value formula.2000 Mathematics Subject Classification: Primary—11F20; Secondary—11F99     

On the even power mean of a sum analogous to Dedekind sums

Summary Our purpose is to extend results due to P. Chandra and L. Leindler concerning the order of approximation by means of Fourier series for functions belonging to generalized Lipschitz-classes.     

Sums of Two Exact Powers

An asymptotic formula is obtained for the number of representations of an element of a finite field as a weighted sum of two prescribed powers of primitive elements. This generalises previous work on sums of primitive elements, including that relating to some conjectures of Golomb.     

Pd-Rh型国Ⅲ排放三效催化剂的研制

对满足欧Ⅲ排放限值的Pd-Rh型三效催化剂进行研究开发,测试了新鲜催化剂的空燃比特性和起燃温度特性,并与市场上的欧Ⅲ催化剂在同等条件下老化后的性能进行了比较.对研制的催化剂进行封装总成后,按照GB18352.3-2005标准进行了常温冷起动Ⅰ型和低温冷起动IV型试验,测试结果完全能满足该标准的限值要求.     

Fast protein analysis enabled by high-temperature hydrolysis

While the bottom-up protein analysis serves as a mainstream method for biological studies, its efficiency is limited by the time-consuming process for enzymatic digestion or hydrolysis as well as the post-digestion treatment prior to mass spectrometry analysis. In this work, we developed an enzyme-free microreaction system for fast and selective hydrolysis of proteins, and a direct analysis of the protein digests was achieved by nanoESI (electrospray ionization) mass spectrometry. Using the microreactor, proteins in aqueous solution could be selectively hydrolyzed at the aspartyl sites within 2 min at high temperatures (∼150 °C). Being free of salts, the protein digest solution could be directly analyzed using a mass spectrometer with nanoESI without further purification or post-digestion treatment. This method has been validated for the analysis of a variety of proteins with molecular weights ranging from 8.5 to 67 kDa. With introduction of a reducing agent into the protein solutions, fast cleavage of disulfide bonds was also achieved along with high-temperature hydrolysis, allowing for fast analysis of large proteins such as bovine serum albumin. The high-temperature microreaction system was also used with a miniature mass spectrometer for the determination of highly specific peptides from Mycobacterium tuberculosis antigens, showing its potential for point-of-care analysis of protein biomarkers.

A high-temperature microreaction system is developed for fast and selective hydrolysis of proteins, enabling direct analysis of protein biomarkers by mass spectrometry.     

The application of scanning electrochemical microscopy to the discovery of Pd–W electrocatalysts for the oxygen reduction reaction that demonstrate high activity, stability, and methanol tolerance

An array of Pd–W alloys was fabricated, and the electrocatalytic activity of the alloys for the oxygen reduction reaction (ORR) in acidic media was screened by scanning electrochemical microscopy. The Pd_0.7W_0.3 showed the highest activity for the ORR, close to that for Pd_0.8Co_0.2 and Pt. A Pd–W electrocatalyst loaded on carbon black was formed by the NaBH₄-reduction method, exhibiting high activity and stability, suggesting that it is a good candidate for the proton exchange membrane fuel cell cathode.     

三(4-硝基苯基)甲烷衍生物的结构和振动光谱的理论研究（英文）

用密度泛函理论优化了三苯甲烷(1)和一系列三(4-硝基苯基)甲烷衍生物2,3和4的几何结构,并计算了其红外光谱和拉曼光谱;通过与实验光谱的对比,对实验光谱中的谱峰进行了指认,并从理论上纠正了部分对3和4红外光谱谱峰不合适的实验指认;同时预测了2,3和4的拉曼光谱.结果表明,几种化合物的振动光谱计算结果与相应的实验结果吻合良好;且化合物2,3和4的拉曼光谱具有相似性.     

A problem of D.H. Lehmer and its mean square value formula

Let q be an odd positive integer and let a be an integer coprime to q. For each integer b coprime to q with 1?b<q, there is a unique integer c coprime to q with 1?c<q such that . Let N(a,q) denote the number of solutions of the congruence equation with 1?b,c<q such that b,c are of opposite parity. The main purpose of this paper is to use the properties of Dedekind sums, the properties of Cochrane sums and the mean value theorem of Dirichlet L-functions to study the asymptotic property of the mean square value , and give a sharp asymptotic formula.     

DNA Structural Changes Under Different Stretching Methods Studied By Molecular Dynamics Simulations

We present a molecular dynamics simulation study of 22‐mer DNA conformational variations obtained by stretching both 3′‐termini and both 5′‐termini. Stretching 3′‐termini by 3.5 nm required 142 kJ mol^?1 and the force plateau was ～80 pN, whereas stretching 5′‐termini by the same length required 190 kJ mol^?1 and the force plateau was ～100 pN. Stretching 3′‐termini led to a larger untwisting of the double helix and the successive base pairs rolled to the side of the DNA minor groove, while stretching 5′‐termini resulted in the base pairs rolling to the major groove side and reducing of the diameter of DNA molecule. The most distinctive difference between stretching 3′‐termini and 5′‐termini was that at the force plateau region stretching the 5′‐termini resulted in breakage of the base pairs, which considerably disturbed the structure of the DNA double helix. All of the variations of base rotation and translation for both stretching methods took place when the relative length of DNA l was longer than 1.2, which was the point the force plateau appeared.