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Search Results: 1 - 10 of 10678 matches for " Zhongyan Du "
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Preparation of Silica Powder in Epoxy Resin Wear-Resistant Coating  [PDF]
Dongdong Zhang, Jihu Wang, Shaoguo Wen, Pengzhu Wang, Changle Yin, Zhongyan Du
Advances in Materials Physics and Chemistry (AMPC) , 2015, DOI: 10.4236/ampc.2015.52009
Abstract: Silicon powders possess good thermal stability and rub resistance and can be used as the filler of high temperature wear-resistant coating; it can possess good wettability and dispersibility in the organic polymer by surface modification of silane coupling agent. Organic silicon has good thermal stability, which can modify the frangibility and thermal stability of epoxy resin. A certain proportion of modified silica powder, curing agent and additives were dispersed to modified epoxy resin can compound wear-resistant coating. The results show that: the modification effect can be the best if the dosage of silane coupling agent is 1.5% of silicon powder. If the methyl triethoxy silane is 50 phr and modified silica powder is 200 phr, then various performances of coating tend to be the best.
Study on the Properties of UHMW-PE Film  [PDF]
Zhongyan Du, Jihu Wang, Shaoguo Wen, Pengzhu Wang, Dongdong Zhang, Changle Yin
Advances in Materials Physics and Chemistry (AMPC) , 2015, DOI: 10.4236/ampc.2015.58033
Abstract: Some physicochemical properties of UHMW-PE film such as gas permeability, tensile strength, and corrosion resistance in acid with different immersion time, various concentrations and various solutions and rattler testing were studied. The obtained results showed that the values of gas permeability, tensile strength, elongation at break, and the temperature of dissociation at weight loss 5% was 546.57 cm3·m﹣2·24 h·0.1 MPa, 37.22 MPa, 368.00%, 360°C, respectively. In different concentration acid, the surface resistance of film accumulated to some extent with immersion time increasing, together with that the higher acid concentration was, the lower the surface resistance of film was. Moreover, the contact angle of films gradually increased with the acid concentration decreasing and the increase of immersion time. After wear testing, the mass of UHMW-PE film did not nearly change, while the contact angle became larger with the number of turning increasing and the value was more than 90°.
The Review of Powder Coatings  [PDF]
Zhongyan Du, Shaoguo Wen, Jihu Wang, Changle Yin, Dayang Yu, Jian Luo
Journal of Materials Science and Chemical Engineering (MSCE) , 2016, DOI: 10.4236/msce.2016.43007
Abstract: With the environmental regulations becoming more stringent and awareness of consumers increasing to protect environment, an urgent problem is to reduce the use of volatile organic compounds (VOCs). Powder coating is a kind of solid powder coating without any solvent. Due to its excellent application performance and environment-friendly, it is widely used in the field of metal coating, especially appliances of offices and home. In recent years, the use of powder coatings has been developed very fast and the requirements of functional powder coatings are also gradually strengthened. According to resin of the film forming, powder coatings can be divided into two types: thermosetting powder coatings and thermoplastic powder coatings. Each kind of powder coatings has its own advantages and disadvantages, and they will be applied in different fields. In order to improve the properties of powder coatings, there are many reports and studies about them. The compositions of powder coatings were extruded, crushed and screened to gain powder of coating. The powder always was stored at room temperature. The powder coatings often operated by two kinds which were electrostatic spraying method and fluidized bed dipping method. After that, the powder was heated to melt and cure. Finally, a smooth bright permanent film on articles was formed to achieve the purpose of decoration and corrosion. The process flow preparation of powder coatings always separated into dry process production and wet process production. The development courses of powder coatings about resins, pigments and fillers are summarized. The future development trends of powder coatings are illustrated.
Preparation, Drug Releasing Property and Pharmacodynamics of Soy Isoflavone-Loaded Chitosan Microspheres
Zhongyan Du, Xiaobing Dou, Chenyun Huang, Jia Gao, Linfeng Hu, Jiazhen Zhu, Ying Qian, Minhua Dou, Chunlei Fan
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0079698
Abstract: Soybean isoflavone (SIF) has anti-aging properties and many other biological functions; however, SIF is difficult to reach higher blood concentration due to its rapid metabolism. Therefore, it is of great value to design and produce a sustained-release formulation that is able to maintain a stable level of plasma concentrations. In this paper, soybean isoflavone sustained-release microsphere from chitosan and sodium alginate was prepared successfully. The important factors that determined the quality of the microspheres were the sodium alginate concentration in solution B, the ratio of soybean isoflavone to chitosan and the mixing speed. The relative yield, encapsulation efficiency and drug loading capability of SIF were much higher than the existing commercial formulations. In real gastrointestinal conditions, compared with the non-sustained release group, the release rate of SIF slowed down and the reaction time was prolonged. Animal experiments showed that sustained-release microspheres intensified the anti-aging potentials of SIF. Compared with the Non-sustained release (NSR) group mice, oral SIF/CHI microsphere treated mice were better in the Morris Water Maze Test (MWMT), the MDA level in the both plasma and brain of the sustained release(SR) group mice decreased, and SOD content was remarkably improved.
A congruence involving alternating harmonic sums modulo $p^αq^β$
Zhongyan Shen,Tianxin Cai
Mathematics , 2015,
Abstract: In 2014, Wang and Cai established the following harmonic congruence for any odd prime $p$ and positive integer $r$, \begin{equation*} \sum\limits_{i+j+k=p^{r}\atop{i,j,k\in \mathcal{P}_{p}}}\frac{1}{ijk}\equiv-2p^{r-1}B_{p-3} ~(\bmod ~ p^{r}), \end{equation*} where $\mathcal{P}_{n}$ denote the set of positive integers which are prime to $n$. In this note, we obtain the congruences for distinct odd primes $p,~q$ and positive integers $\alpha,~\beta$, \begin{equation*} \sum\limits_{i+j+k=p^{\alpha}q^{\beta}\atop{i,j,k\in\mathcal{P}_{pq}\atop{i\equiv j\equiv k\equiv 1\pmod{2}}}}\frac{1}{ijk}\equiv\frac{7}{8}(2-q)(1-\frac{1}{q^{3}})p^{\alpha-1}q^{\beta-1}B_{p-3}\pmod{p^{\alpha}} \end{equation*} and \begin{equation*} \sum\limits_{i+j+k=p^{\alpha}q^{\beta}\atop{i,j,k\in \mathcal{P}_{pq}}}\frac{(-1)^{i}}{ijk} \equiv \frac{1}{2}(q-2)(1-\frac{1}{q^{3}})p^{\alpha-1}q^{\beta-1}B_{p-3}\pmod{p^{\alpha}}. \end{equation*} Finally, we raise a conjecture that for $n>1$ and odd prime power $p^{\alpha}||n$, $\alpha\geq1$, \begin{eqnarray} \nonumber \sum\limits_{i+j+k=n\atop{i,j,k\in\mathcal{P}_{n}}}\frac{(-1)^{i}}{ijk} \equiv \prod\limits_{q|n\atop{q\neq p}}(1-\frac{2}{q})(1-\frac{1}{q^{3}})\frac{n}{2p}B_{p-3}\pmod{p^{\alpha}} \end{eqnarray} and \begin{eqnarray} \nonumber \sum\limits_{i+j+k=n\atop{i,j,k\in\mathcal{P}_{n}\atop{i\equiv j\equiv k\equiv 1\pmod{2}}}}\frac{1}{ijk} \equiv \prod\limits_{q|n\atop{q\neq p}}(1-\frac{2}{q})(1-\frac{1}{q^{3}})(-\frac{7n}{8p})B_{p-3}\pmod{p^{\alpha}}. \end{eqnarray}
Super congruences involving alternating harmonic sums modulo prime powers
Zhongyan Shen,Tianxin Cai
Mathematics , 2015,
Abstract: In 2014, Wang and Cai established the following harmonic congruence for any odd prime $p$ and positive integer $r$, \begin{equation*} \sum\limits_{i+j+k=p^{r}\atop{i,j,k\in \mathcal{P}_{p}}}\frac{1}{ijk}\equiv-2p^{r-1}B_{p-3} (\bmod p^{r}), \end{equation*} where $\mathcal{P}_{n}$ denote the set of positive integers which are prime to $n$. In this note, we establish a combinational congruence of alternating harmonic sums for any odd prime $p$ and positive integers $r$, \begin{equation*} \sum\limits_{i+j+k=p^{r}\atop{i,j,k\in \mathcal{P}_{p}}}\frac{(-1)^{i}}{ijk} \equiv \frac{1}{2}p^{r-1}B_{p-3} (\bmod p^{r}). \end{equation*} For any odd prime $p\geq 5$ and positive integers $r$, we have \begin{align} &4\sum\limits_{i_{1}+i_{2}+i_{3}+i_{4}=2p^{r}\atop{i_{1}, i_{2}, i_{3}, i_{4}\in \mathcal{P}_{p}}}\frac{(-1)^{i_{1}}}{i_{1}i_{2}i_{3}i_{4}}+3\sum\limits_{i_{1}+i_{2}+i_{3}+i_{4}=2p^{r}\atop{i_{1}, i_{2}, i_{3}, i_{4}\in \mathcal{P}_{p}}}\frac{(-1)^{i_{1}+i_{2}}}{i_{1}i_{2}i_{3}i_{4}} \nonumber\\&\equiv\begin{cases} \frac{216}{5}pB_{p-5}\pmod{p^{2}}, if r=1, \\ \frac{36}{5}p^{r}B_{p-5}\pmod{p^{r+1}}, if r>1. \\ \end{cases}\nonumber \end{align} For any odd prime $p> 5$ and positive integers $r$, we have \begin{align} &\sum\limits_{i_{1}+i_{2}+i_{3}+i_{4}+i_{5}=2p^{r}\atop{i_{1}, i_{2}, i_{3}, i_{4}, i_{5}\in \mathcal{P}_{p}}}\frac{(-1)^{i_{1}}}{i_{1}i_{2}i_{3}i_{4}i_{5}}+2\sum\limits_{i_{1}+i_{2}+i_{3}+i_{4}+i_{5}=2p^{r}\atop{i_{1}, i_{2}, i_{3}, i_{4}, i_{5}\in \mathcal{P}_{p}}}\frac{(-1)^{i_{1}+i_{2}}}{i_{1}i_{2}i_{3}i_{4}i_{5}} \nonumber\\&\equiv\begin{cases} 12B_{p-5}\pmod{p}, if r=1,\\ 6p^{r-1}B_{p-5}\pmod{p^{r}}, if r>1. \end{cases}\nonumber \end{align}
An Improved Simultaneous-Revelation Resolution Procedure that Induces Truthfulness  [PDF]
Linlan Zhang, Chunmei Wu, Zhongyan Wang, Zefang Li
Journal of Service Science and Management (JSSM) , 2009, DOI: 10.4236/jssm.2009.22012
Abstract: Alternating-offer bargaining protocol is the most predominant way for solving bilateral bargaining problem in daily life. However, alternating-offer consumed more time and caused a lower efficiency in some cases. One proposed solution is called simultaneous-revelation resolution by which both parties reveal their reservation prices at the same time. But most simultaneous-revelation resolution procedures are inefficient because they encourage exaggerations. But it is fast and uncomplicated, this resolution procedure still has merit—especially if the parties can refrain from undue exaggera-tion. The paper designs a truthful mechanism for simultaneous-offer bargaining negotiation. In this mechanism, a rule manipulator can induce buyer and seller both to reveal their real prices by introducing suitable adjustment functions. And we show the honest revelations are in Nash equilibrium.
Research on Torque-Angle Characteristic of Large Gap Magnetic Drive System  [PDF]
Yan XU, Jianping TAN, Yunlong LIU, Zhongyan ZHU
Journal of Electromagnetic Analysis and Applications (JEMAA) , 2010, DOI: 10.4236/jemaa.2010.21004
Abstract: The principle and design method of the large gap magnetic drive system is studied in this work. The calculation model of the torque-angle characteristic in the large gap magnetic drive system driven by traveling wave magnetic field is established. The calculation model is computed by using MATLAB software, and the pattern of the system’s torque-angle characteristic is obtained by analyzing study results. These results indicate that: torque-angle characteristic and the driving torque of the system can be adjusted by changing the electric current of coil, the magnetization of permanent magnetic gear, the inner diameter of permanent magnetic gear, the coupling distance between electromagnet and permanent magnetic gear, the outer diameter of permanent magnetic gear, and the axial length of permanent magnetic gear.
Hydrothermal Characteristics of the Land-Atmospheric System in an Alpine Area of West Nyainqentanglha Mountains
念青唐古拉山西段高海拔陆—气系统水热特征

XIE Jian,LIU Jingshi,DU Mingyuan,KANG Shichang,JIA Shugang,WANG Zhongyan,
谢健
,刘景时,杜明远,康世昌,贾书刚,王忠彦

地理科学进展 , 2010,
Abstract: A preliminary study was carried out on the hydrothermal characteristics in the Nyainqentanglha mountainous region,using one-year observation data of air temperature,three layers of soil temperature and moisture from two sites at 4800 m a.s.l. and 5333 m a.s.l. on the southern slope,and one site at 5400 m a.s.l. on the northern slope. The results indicated that the differences between soil and air temperatures were greater in winter than in summer,and they were generally larger compared to the nearby areas. ...
Coesite eclogite facies metamorphic tectonite: Evidence for ultrahigh pressure deformation
Zhongyan Zhao,Aiming Fang,Liangjun Yu
Chinese Science Bulletin , 2002, DOI: 10.1360/02tb9306
Abstract: An ultrahigh pressure ductile shear mélange crops out on the beach of Yangkou Bay near Qingdao City. The mélange is composed of weakly deformed blocks in a highly ductilly flow mylonites. Ultrahigh pressure metamorphic (UHPM) tectonite includes strongly deformed eclogite and mylonitized eclogite. Coesite occurs in the tectonite as both interstitial mineral and inclusions in garnet and omphacite, indicating that the deformation took place in the stability field of coesite (800–850°C, >30 GPa) in the upper mantle. Coesite is rounded or short prismatic grains with undulatory extinction, and often fractured, suggesting brittle deformation. Garnet is also characterized by brittle fractures and sometimes necked and slightly elongated. Omphacite is elongated, with long axis preferred orientation. Undulatory extinction, subgrains and dynamically recrystallized grains suggest plastic flow of omphacite. Ultrahigh pressure metamorphic tectonite was probably formed in the ductile shear zone during the early stage of exhumation of the ultrahigh pressure metamorphic rocks. Its kinematic indicators point to the transport direction of the UHPM slab during the early stage of exhumation.
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