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Effects of virtual agents on interaction efficiency and environmental immersion in MR environments

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虚拟现实与智能硬件（中英文） 2024年第2期6卷 169-179页

作者： Yihua BAO Jie GUO Dongdong WENG Yue LIU Zeyu tian Beijing Engineering Research Center of Mixed Reality and Advanced Display Beijing Institute of TechnologyBeijing 100081China Pengcheng Laboratory Shenzhen 518038China

Background Physical entity interactions in mixed reality(MR)environments aim to harness human capabilities in manipulating physical objects,thereby enhancing virtual environment(VEs)*** MR,a common strategy is to use virtual agents as substitutes for physical entities,balancing interaction efficiency with environmental ***,the impact of virtual agent size and form on interaction performance remains *** Two experiments were conducted to explore how virtual agent size and form affect interaction performance,immersion,and preference in MR *** first experiment assessed five virtual agent sizes(25%,50%,75%,100%,and 125%of physical size).The second experiment tested four types of frames(no frame,consistent frame,half frame,and surrounding frame)across all agent ***,utilizing a head mounted display,performed tasks involving moving cups,typing words,and using a *** completed questionnaires assessing aspects such as the virtual environment effects,interaction effects,collision concerns,and *** Results from the first experiment revealed that agents matching physical object size produced the best overall *** second experiment demonstrated that consistent framing notably enhances interaction accuracy and speed but reduces *** balance efficiency and immersion,frameless agents matching physical object sizes were deemed *** Virtual agents matching physical entity sizes enhance user experience and interaction ***,familiar frames from 2D interfaces detrimentally affect interaction and immersion in virtual *** study provides valuable insights for the future development of MR systems.

关键词： Mixed reality Virtual agents Interaction performance Environmental immersion Virtual environments

Study on the Properties of Esterified Corn Starch/Polylactide Biodegradable Blends

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Journal of Renewable Materials 2022年第11期10卷 2949-2959页

作者： Yongjie Zheng Mingjian Xu Jingzhi tian Meihong Yu BinTan Hong Zhao YinTang College of Chemistry and Chemical Engineering Qiqihar UniversityQiqihar161006China Engineering Research Center of Flax Processing Technology Ministry of Education P.R.CQiqihar UniversityQiqihar161006China College of Light Industry and Textile Qiqihar UniversityQiqihar161006China Department of Chemical Engineering and Materials Science Michigan State UniversityEast Lansing48824USA

Fully bio-based and biodegradable starch/polylactic acid blends have received increasing attentions for their biodegradability and potential to offset the use of unsustainable fossil resources,specifically,their application in ***,corn starch was first esterified with maleic anhydride and then compounded with polylactide(PLA)to prepare esterified corn starch/polylactic acid blends with starch content up to 35 wt%.The structures,morphologies,thermal and mechanical properties of starch or blends were *** results showed that corn starch was successfully grafted with maleic anhydride,which showed increased crystallinity and particle size than native *** corn starch/polylactic acid blends showed good surficial compatibility and good thermal stability with main decomposition temperature in the range of 300℃to 400℃.Additionally,incorporation of corn starch increased the hydrophilicity and water uptake of ***,the tensile and flexural strengths of blends decreased with increasing esterified starch amount.

关键词： Biodegradable polymers corn starch polylactide composite

The　θ－Methods　in　Numerical　Solution　of　Systems　of　Differential　Equations　with　Two　Delay　Terms

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Journal of Systems Engineering and Electronics 1994年第3期5卷 32-40页

作者： tian Hongjiong & Kuang Jiaoxun (Department of Mathematics, Shanghai Normal University, Shanghai 200234, China) Department of Mathematics Shanghai Normal University Shanghai 200234 China

This paper deals with the numerical solution of initial value problems for systems of differential equations with two delay terms. We investigate the stability of adaptations of the θ-methods in the numerical solution of test equations u'(t) = a 11 u(t) + a12v(t) + b11 u(t - τ1) + b12v(t-τ2,v'(t) = a21 u(t) + a22 v(t) + b21 u(t -τ1,) + b22 v(t -τ2), t>0,with initial conditionsu(t)=u0(t),v(t) =v0(t), t≤*** aij, bij∈C, τj >0, i,j = 1,2,, and u0(t), v0(t)are continuous and complex valued. Sufficient conditions for the asymptotic stability of test equation are derived. Furthermore, with respect to an appropriate definition of stability for the numerical method, it is proved that the linear θ-method is stable if and only if 1/2≤θ≤1 and the one-leg θ-method is stable if and only if θ= 1.

关键词： Delay differential equations Numerical solution θ-methods Asymptotic stability Schur polynomial.

Axisymmetric Waves in Isothermal Accretion Discs with Vertical Self-Gravity

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Communications in Theoretical Physics 2001年第12期36卷 743-748页

作者： LIU Xiao-Ci YANG Lan-tian WU Shao-Ping DING Shi-Xue Department of Physics Hainan Normal College Haikou 571158 Hainan Province Chinat Department of Physics and Institute of Astrophysics Huazhong Normal University Wuhan 430079 China Department of Physics and Institute of Astrophysics Huazhong Normal University Wuhan 430079 China Department of Physics and Institute of Astrophysics Huazhong Normal University Wuhan 430079 China Department of Physics and Institute of Astrophysics Huazhong Normal University Wuhan 430079 China Department of Physics Xiangfan Normal College Xiangfan 441053 Hubei Province China

We extend the research of axisymmetric waves in accretion discs with three-dimensional structure to the case that vertical self-gravity of the discs is included. We derive and analyze the dispersion relation and solve the eigenfunctions numerically. The following results have been reached: vertical self-gravity expands the forbidden region of the wave propagation. As the influence of the vertical self-gravity increases, the group velocities of the waves get smaller and the vertical nodes of the wave shrink to the middle plane of the disc.

关键词： accretion, accretion discs, hydrodynamics, waves

Geothermal data analysis at the high-temperature hydrothermal area in Western Sichuan

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Science China Earth Sciences 2017年第8期60卷 1507-1521页

作者： ZHANG Jian LI WuYang TANG XianChun tian Jiao WANG YingChun GUO Qi PANG ZhongHe Key Laboratory of Computational Geodynamics Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Geology and Geophysics Chinese Academy of Sciences

The western Sichuan hydrothermal area is located at the northeastern margin of the eastern syntaxis of the Qinghai-Tibet Plateau, which is also the eastern end of the Mediterranean-Himalayan geothermal activity zone. There are 248 warm or hot springs in this area, and 11 have temperatures beyond the local boiling temperature. Most of these hot springs are distributed along the Jinshajiang, Dege-Xiangcheng, Ganzi-Litang, and Xianshuihe faults, forming a NW-SE hydrothermal belt. A geothermal analysis of this high-temperature hydrothermal area is an important basis for understanding the deep geodynamic process of the eastern syntaxis of the Qinghai-Tibet Plateau. In addition, this study offers an a priori view to utilize geothermal resources, which is important in both scientific research and application. We use gravity, magnetic, seismic, and helium isotope data to analyze the crust-mantle heat flow ratio and deep geothermal structure. The results show that the background terrestrial heat flow descends from southwest to northeast. The crustal heat ratio is not more than 60%. The high temperature hydrothermal active is related to crustal dynamics processes. Along the Batang-Litang-Kangding line, the Moho depth increases eastward, which is consistent with the changing Qc/Qm(crustal/mantle heat flow) ratio trend. The geoid in the hydrothermal zone is 4–6 km higher than the surroundings, forming a local "platform". The NW-SE striking local tensile stress zone and uplift structure in the upper and middle crust corresponds with the surface hydrothermal active zone. There is an average Curie Point Depth(CPD) of 19.5–22.5 km in Batang, Litang, and Kangding. The local shear-wave(S-wave) velocity is relatively low in the middle and lower crust. The S-wave shows a low velocity trap(Vs<3.2 km s.1) at 15–30 km, which is considered a high-temperature partial melting magma, the crustal source of the hydrothermal active zone. We conclude that the hydrothermal system in this area can

关键词： Western Sichuan Plateau Fracture zone and thermally conductive structure Deep thermal structure Heat flow estimation

Resveratrol, an activator of SIRT1, restores erectile function in streptozotocin-induced diabetic rats

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Asian Journal of Andrology 2013年第5期15卷 646-651页

作者： Wen Yu Zan Wan Xue-Feng Qiu Yun Chen Yu-tian Dai Department of Urology Affiliated Drum Tower Hospital School of Medicine Nanjing University Nanjing 210008 China

The high incidence of erectile dysfunction （ED） in diabetes highlights a need for effective treatment strategies. Resveratrol, an activator of silent information regulator 2-related enzymes 1 （sirtuinl, SIRT1）, has received attention for its valuable effects in cancer, neurodegenerative diseases, longevity and cardiovascular disease. To explore the effects of resveratrol in diabetes-induced ED, resveratrol was administered to rats with streptozocin （65 mg kg-1）-induced diabetes. Erectile function, cavernous structure, tissue protein expression of silent information regulator 2-related enzymes 1 （sirtuinl, SIRT1）, p53 and forkhead transcription factor 0 3a （FOXO3a）, superoxide dismutase （SOD） activity and malondialdehyde （MDA） levels in the corpora cavernosa were studied. We found that SIRT1 was expressed in cavernosal tissue, and it was downregulated in the corpora of diabetic rats. The administration of resveratrol upregulated the expression of SI RT1 and restored erectile function. In contrast, resveratrol downregulated the expression of p53 and FOXO3a, which regulate apoptosis and oxidative stress. Furthermore, the resveratrol-treated group showed an improvement in smooth muscle content, SOD activity and MDA levels when compared with the diabetic group. Therefore, the ability of resveratrol to improve diabetes-induced ED is likely related to its activation of SIRT1 expression, thus causing the suppression of apoptosis and resistance towards oxidative stress.

关键词： apoptosis erectile dysfunction oxidative stress resveratrol

Theoretical Study of Electronic Structures and Charge Transport Properties of 9,10-Bis（（E）-2-（pyrid-n-yl） vinyl）（n=2, 3, 4） Anthracene

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Chinese Journal of Chemistry 2015年第8期33卷 974-980页

作者： Qing Guo Lijuan Wang Yuanfei Jiang Jing Guo Bin Xu Wenjing tian State Key Laboratory of Supramolecular Structure and Materials Jilin University Changchun Jilin 130012 China School of Materials Science and Engineering Harbin Institute of Technology at Weihai Weihai Shandong 264209 China Institution of Atomic and Molecular Physics Jilin University Changchun Jilin 130012 China

Charge carrier mobility is one of the most significant properties for organic semiconductors. In this work, the electronic structures and charge transport properties of 9,10-bis（（E）-2-（pyrid-n-yl）vinyl）（n=2, 3, 4） anthracene （BP2VA, BP3VA and BP4VA） were investigated via the analysis of the molecular geometry, the reorganization en- ergy, the frontier orbital and density of state, as well as the electronic coupling and the charge mobility. The results indicated that the linkage between 9,10-divinyl anthracene unit and pyridine （ortho-, meta- and para-） influenced not only the intra-molecular conformation （i.e., the reorganization energies）, but also the intermolecular interaction （i.e., transfer integrals）, and finally the charge mobility of the molecules. It is also found that：（1） The calculated charge mobilties of holes are dozens of times higher than those of electrons for the three molecules. （2） The charge mobilities of hole and electron of the three molecules display the trend： μBP4VA〉μBPZVA〉μBP3VA, and the hole mobility of BP4VA is as high as as-cm^2/（V·s）.

关键词： charge mobility reorganization energy electronic structure

Development of SV2A Ligands for Epilepsy Treatment:A Review of Levetiracetam,Brivaracetam,and Padsevonil

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Neuroscience Bulletin 2024年第5期40卷 594-608页

作者： Peng-Peng Wu Bi-Rong Cao Fu-Yun tian Zhao-Bing Gao Center for Neurological and Psychiatric Research and Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing100049China Zhongshan Institute for Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of SciencesZhongshan528400China

Epilepsy is a common neurological disorder that is primarily treated with antiseizure medications(ASMs).Although dozens of ASMs are available in the clinic,approximately 30%of epileptic patients have medically refractory seizures;other limitations in most traditional ASMs include poor tolerability and drug-drug ***,there is an urgent need to develop alternative ***(LEV)is a first-line ASM that is well tolerated,has promising efficacy,and has little drug-drug *** it is widely accepted that LEV acts through a unique therapeutic target synaptic vesicle protein(SV)2A,the molecular basis of its action remains *** so,the next-generation SV2A ligands against epilepsy based on the structure of LEV have achieved clinical *** review highlights the research and development(R&D)process of LEV and its analogs,brivaracetam and padsevonil,to provide ideas and experience for the R&D of novel ASMs.

关键词： Levetiracetam Epilepsy Antiseizure medications Synaptic vesicle protein 2A Brivaracetam Padsevonil

Synthesis of new heterocycles 1,3,2,6-dioxaphosphaselenacyclooctanes

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Chinese Journal of Chemistry 1997年第5期15卷 450-458页

作者： Li, JL tian, B Zhao, CQ Wang, YM Meng, JB Wang, HG Nankai Univ Dept Chem Tianjin 300071 Peoples R China Nankai Univ Cent Lab Tianjin 300071 Peoples R China

New phosphorus-and selenium containing heterocyclyes, 1,3,2,6-dioxaphosphaselena-cyclooctanes (1a-1h), were synthesized by the reaction of bis(2-hydroxyethyl)selenide with RP(X)Cl-2 where R=alkoxyl, aroxyl, aryl. and X=O or lone pair. Their structures were determined by spectroscopies and elemental analyses and finally confirmed by the X-ray crystallographic analysis of 1c. The molecular structures of the heterocycles were discussed in term of conformational analysis.

关键词： heterocycles synthesis structure