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ASYMPTOTIC BEHAVIOR FOR RANDOM WALK IN RANDOM ENVIRONMENT WITH HOLDING TIMES

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Acta Mathematica Scientia 2010年第5期30卷 1696-1708页

作者：毛明志李志民 school of Mathematics and physics China University of Geosciences Department of Applied Mathematics and physics Anhui Institute of Science and Technology

In this article, we mainly discuss the asymptotic behavior for multi-dimensional continuous-time random walk in random environment with holding times. By constructing a renewal structure and using the point ＂environment viewed from the particle＂, under General Kalikow＇s Condition, we show the law of large numbers （LLN） and central limit theorem （CLT） for the escape speed of random walk.

关键词： random walk random environment central limit theorem law of large numbers renewal structure

A novel 2.2.wavelength selective cross-connect based on Mach-Zehnder interferometer

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Optoelectronics Letters 2008年第1期4卷 15-18页

作者： FENG Yong-hua,LUO Feng-guang, and YUAN Jing school of Optoelectronic Science and technology, Huazhong {2. of Science and technology, {4., 4.0074. China school of Optoelectronic Science and technology Huazhong University of Science and Technology Wuhan China

A novel 2.2.wavelength selective cross-connect (WSXC) module, which is composed of a Bragg-grating-based Mach- Zehnder interferometer (MZI), a pair of optical waveguides, a pair of 1×2.optical switches (OSWs) and a pair of Y-model combiners is proposed. The mathematical description of the proposed 2.2.WSXC module is given and explained. Multi- channel multi-wavelength selective cross-connect can be fabricated with the proposed 2.2.WSXC module, together with multistage interconnection networks (MINs). A four-wavelength 4.4.WSXC is demonstrated by simulation to validate the flexibility of the proposed WSXC.

关键词：波长选择正交连接 Mach-Zehnder干涉计布拉格光栅光学转换

Individualization of Head Related Impulse Responses Using Division Analysis

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China Communications 2018年第5期15卷 92-103页

作者： Wei Chen Ruimin Hu Xiaochen Wang Cheng Yang Lian Meng National Engineering Research Center for Multimedia Software School of Computer Science.Wuhan UniversityWuhan 430072China hubei Key Laboratory of Multimedia and Network Communication Engineering Wuhan UniversityWuhan 430072China Collaborative Innovation Center of Geospatial technology Wuhan 430079China school of physics and Electronic Science Guizhou Normal UniversityGuiyang 550001China

For Virtual Reality(VR) to be truly immersive, it needs convincing sound to match. Due to the diversity of individual's anthropometric measurements, the individualized customization technology is needed to get convincing sound. In this paper, we proposed a simple and effective method for modeling relationships between anthropometric measurements and Head-related Impulse Response(HRIR). Considering the relationship between anthropometric measurements and different HRIR parts is complicated, we divided the HRIRs into small segments and carried out regression analysis between anthropometric measurements and each segment to establish relationship model. The results of objective simulation and subjective test indicate that the model can generate individualize HRIRs from a series of anthropometric measurements. With the individualized HRIRs, we can get more accurate acoustic localization sense than using non-individualized HRIRs.

关键词： HRIR Individualization Division analysis

Role of melatonin in Alzheimer-like neurodegeneration

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Acta Pharmacologica Sinica 2006年第1期27卷 41-49页

作者： Jian-zhi WANG~(2.4. Ze-fen WANG~(2.3)2.Pathophysiology Department,Key Laboratory of Neurological Diseases of hubei Province,Tongji Medical {4.,Huazhong {2. of Science and technology,{4. 4.0030,China 3 Department of Physiology,Medical College,{4. {2. {4. 4.0071,China PathophysiologyDepartment KeyLaboratoryofNeurologicalDiseasesofHubeiProvinceTongjiMedicalSchoolHuazhongUniversityoJScienceandTechnologyWuhan430030China DepartmentofPhysiology MedicalCollegeWuhanUniversityWuhan

Alzheimer disease (AD),an age-related neurodegenerative disorder with progres-sive loss of memory and deterioration of comprehensive cognition,is character-ized by extracellular senile plaques of aggregated β-amyloid (Aβ),and intracellularneurofibrillary tangles that contain hyperphosphorylated tau *** showed that melatonin,an indoleamine secreted by the pineal gland,mayplay an important role in aging and AD as an antioxidant and *** decreases during aging and patients with AD have a more profoundreduction in this *** from clinical trials indicate that melatonin supple-mentation improves sleep,ameliorates sundowning,and slows down the progres-sion of cognitive impairment in Alzheimer's *** efficiently pro-tects neuronal cells from Aβ-mediated toxicity via antioxidant and anti-amyloidproperties:it not only inhibits Aβ generation,but also arrests the formation ofamyloid fibrils by a structure-dependent interaction with Aβ.Our recent studieshave demonstrated that melatonin efficiently attenuates Alzheimer-like *** the exact mechanism is still not fully understood,a direct regulatory influence of melatonin on the activities of protein kinases andprotein phosphatases is ***,melatonin also plays a role inprotecting cholinergic neurons and in ***,the neuroprotectiveeffects of melatonin and the underlying mechanisms by which it exerts its effectsare *** capacity of melatonin to prevent or ameliorate tau and Aβpathology further enhances its potential in the prevention or treatment of AD.

关键词： Alzheimer disease melatonin tau,beta amyloid

Friction-reducing and antiwear behavior of metal halide-stabilized linear phosphazene derivatives as lubricants for a steel-on-steel contact

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Science China(Technological Sciences) 2005年第3期48卷 282-291页

作者： ZHU Jiamei 1,2., LIU Weimin 2.& LIANG Yongmin 2.1. school of Chemical Engineering and {4., China {2. of Mining and {4., Xuzhou 2.1008, China 2. State Key Laboratory of Solid Lubrication, Lanzhou Institute of Chemical {4., Chinese Academy of Sciences, Lanzhou 730000, China 1. school of Chemical Engineering and technology China University of Mining and Technology 221008 Xuzhou China 2. State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical Physics Chinese Academy of Sciences 730000 Lanzhou China

A series of novel metal halide-stabilized linear phosphazene derivatives were synthesized. The friction-reducing and antiwear abilities of the resulting products as the lubricants for a steel-on-steel contact were comparatively investigated on an Optimol SRV oscillating friction and wear tester. The morphology of the worn steel surface was observed on a scanning electron microscope, while the chemical states of some typical elements on the worn steel surface were examined by means of X-ray photoelectron spectroscopy. It was found that both the side branch structures and central metals influenced the friction-reducing and antiwear behaviors of the synthetic derivatives as the lubricants, which was related to the different adsorption activities of the organic compounds composed of different organic ingredients and metallic ions on a nascent metal surface. All the synthetic lubricants except for the iron (III) derivative showed increased antiwear abilities with increasing metallic ionic radius. A protective layer originated from the tribochemical reaction together with the adsorbed boundary lubricating layer containing organic fluorine compounds, nitrogen oxide, and Fe 3 (PO 4.) 2.plays an important role in improving the friction and wear behavior of the steel-on-steel system.

关键词： metal halide-stabilized linear phosphazene derivatives,lubricant,steel,tribological properties.

Archean relic body at lower crust in Sulu area:Evidence from magnetic data

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Chinese Science Bulletin 2003年第6期48卷 589-593页

作者： WU Qifan1,2. LU Fengxiang3, LIU Qingsheng3, ZHENG Jianping3, WANG Maoji2.& WU Wenli4.1. Department of Engineering physics, Tsinghua university, Beijing 100084. China 2. Aero Geophysical Survey & Remote Sensing Center, Beijing 100083, China 3. China university of Geosciences, wuhan 4.0074. China 4. Institute of Geophysical & Geochemical Exploration, Langfang 065000, China Aero Geophysical Survey & Remote Sensing Center Beijing 100083 China China university of Geosciences Wuhan 430074 China Institute of Geophysical & Geochemical Exploration Langfang 065000 China Department of Engineering physics Tsinghua University Beijing 100084 China

After the new 1︰1000000 aero magnetic data were processed and the three-dimensional inversion work was carried out, a vast high magnetic body northwestward was discovered. The magnetic body is located at the depth of about 2. km on the west side of Tanlu fault and at about 2. km on the east side of Tanlu fault beneath the Sulu area. There is a difference of vertical distance of 3—5 km in depth between both sides. We think that the magnetic body is an Archean metamorphic plate and belongs to the North China block. The discovery of the magnetic body is significant for us to reconstruct the structure model of the Sulu orogenic belt, delineate the suture of collision between the North China block and the Yangtze block, and estimate the depth of slipping surface when the eastside of Tanlu fault moved northward.

关键词：苏鲁地区地壳下层太古代残余体地球物理调查区域性磁场三维反演苏鲁造山带郯鲁断裂带大别-苏鲁超高压变质带

Formation of bulk ferromagnetic nanostructured Fe_(4.)Ni_(4.)P_(14.B_6 alloys by metastable liquid spinodal decomposition

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Science China(Technological Sciences) 2009年第7期52卷 1919-1922页

作者： LI Qiang1,2.1 school of physics Science and {2., Xinjiang {4., Urumqi 83004., China 2.Department of physics, The Chinese {4. of HongKong, Shatin N.T., HongKong, China school of physics Science and {2. Xinjiang University Urumqi 830046 China Department of physics The Chinese University of HongKong Shatin N.T. HongKong China

Nanostructured Fe4.Ni4.P14.6 alloy ingots of 3―5 mm in diameter could be synthesized by a metastable liquid state spinodal decomposition method. For undercooling T> 2.0 K, the microstructure of the undercooled specimen had exhibited liquid state spinodal decomposition in the undercooled liquid state. The microstructure could be described as two intertwining networks with small grains dispersed in them. For undercooling T>2.0 K, the overall microstructure of the specimen changed into a granular morphology. The average grain sizes of the small and large grains are 30 nm and 80 nm, respectively. These prepared samples are soft magnets with saturation magnetization Bs 0.74. T.

关键词： nanomaterials magnetic materials solidification bulk nanostructured alloy Fe4.Ni4.P14.6 metastable liquid spinodal decomposition

Photocatalytic Activity of TiO_2.Sensitized by CdS Quantum Dots under Visible-Light Irradiation

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wuhan university Journal of Natural Sciences 2011年第4期16卷 313-318页

作者： MAO Liangliang JIANG Wuzhou HE Lijuan FANG Pengfei school of physics and {2. Wuhan University Wuhan 430072 Hubei China

In this paper, CdS quantum dots sensitized TiO2.composite powders （QD-CdS/TiO2. were synthesized by impregnating TiO2.powder into CdS sol with different concentrations. X-ray diffraction pattern （XRD） shows the crystal structures of CdS and TiO2.are cubic phase and anatase phase separately in QD- CdS/TiO2.powder samples; the crystal size of CdS in QD- CdS/TiO2.is about 3-7 nm, while TiO2.crystal size is about 2. nm. With increasing CdS content in QD-CdS/TiO2.composite, the UV-Vis absorption spectrum shifted to the longer wavelength lines, exhibiting obvious quantum size effect. The fluorescence intensity of QD-CdS/TiO2.irradiated by blue light is weaker than that of pure CdS. When the molar ratio of CdS and TiO2.is about 1∶2. the QD-CdS/TiO2.powder has the best catalytic properties under visible-light irradiation, and the degradation rate of rhodamine B （RhB） is up to 92.2. within 60 min.

关键词： TiO2 CdS quantum-dots photocatalysis

Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science China Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2. WANG Jin3, WU Yishi1, YUAN Gu3, AI Xicheng1, WANG Li4.& ZHANG Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China 2. school of Life Science and technology, Beijing Institute of technology, Beijing 100081, China 3. College of Chemistry and Molecular Engineering, Peking university, Beijing 100080, China 4. Center for Condensed Matter {4., Institute of {4., Chinese Academy of Sciences, Beijing 100080, China Correspondence should be addressed to Ai Xicheng and Zhang Jianping 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. school of Life Science and technology Beijing Institute of Technology Beijing 100081 China 3. College of Chemistry and Molecular Engineering Peking University Beijing 100080 China 4. Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 32.ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.