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STABILITY OF EQUILIBRIA OF NEMATIC LIQUID CRYSTALLINE POLYMERS

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Acta Mathematica Scientia 2011年第6期31卷 2289-2304页

作者： Hong Zhou hongyun wang Department of Applied MathematicsNaval Postgraduate School Monterey CA 93943 USA Department of Applied Mathematics and StatisticsUniversity of California Santa Cruz CA 95064 USA

We provide an analytical study on the stability of equilibria of rigid rodlike nematic liquid crystalline polymers （LCPs） governed by the Smoluchowski equation with the Maier-Saupe intermolecular potential. We simplify the expression of the free energy of an orientational distribution function of rodlike LCP molecules by properly selecting a coordinate system and then investigate its stability with respect to perturbations of orientational probability density. By computing the Hessian matrix explicitly, we are able to prove the hysteresis phenomenon of nematic LCPs： when the normalized polymer concentration b is below a critical value b＊（6.T314863965）, the only equilibrium state is isotropic and it is stable; when b＊〈 b 〈 15/2, two anisotropic （prolate） equilibrium states occur together with a stable isotropic equilibrium state. Here the more aligned prolate state is stable whereas the less aligned prolate state is unstable. When b 〉 15/2, there are three equilibrium states： a stable prolate state, an unstable isotropie state and an unstable oblate state.

关键词： equilibria stability nematic liquid crystalline polymers hysteresis phenomenon

Effects of Driving Mode on the Performance of Multiple-Chamber Piezoelectric Pumps with Multiple Actuators

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Chinese Journal of Mechanical Engineering 2015年第5期28卷 954-963页

作者： ZHANG Zhonghua KAN Junwu wang Shuyun wang hongyun MA Jijie JIANG Yonghua Institute of Precision Machinery Zhejiang Normal University

Due to the limited output capability of piezoelectric diaphragm pumps, the driving voltage is frequently increased to obtain the desired output. However, the excessive voltage application may lead to a large deformation in the piezoelectric ceramics, which could cause it to breakdown or become damaged. Therefore, increasing the number of chambers to obtain the desired output is proposed. Using a check-valve quintuple-chamber pump with quintuple piezoelectric actuators, the characteristics of the pump under different driving modes are investigated through experiments. By changing the number and connection mode of working actuators, pump performances in terms of flow rate and backpressure are tested at a voltage of 150 V with a frequency range of 60 Hz -400 Hz. Experiment results indicate that the properties of the multiple-chamber pump change significantly with distinct working chambers even though the number of pumping chambers is the same. Pump performance declines as the distance between the working actuators increases. Moreover, pump performance declines dramatically when the working piezoelectric actuator closest to the outlet is involved. The maximum backpressures of the pump with triple, quadruple, and quintuple actuators are increased by 39%, 83%, and 128%, respectively, compared with the pump with double working actuators; the corresponding maximum flow rates of the pumps are simply increased by 25.9%, 49.2%, and 67.8%, respectively. The proposed research offers practical guidance for the effective utilization of the multiple-chamber pumps under different driving modes.

关键词： piezoelectric pump multiple chambers multiple actuators driving mode flow rate backpressure

F-box proteins in flowering plants

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Chinese Science Bulletin 2002年第18期47卷 1497-1501页

作者： hongyun wang Jian Huang Zhao Lai Yongbiao Xue Chinese Acad Sci Inst Genet & Dev Biol Beijing 100080 Peoples R China

In eukaryotes, the ubiquitin-mediated protein degradation pathway has been shown to control several key biological processes such as cell division, development, metabolism and immune response. F-box proteins, as a part of SCF (Skp1-Cullin (or Cdc53)-F-box) complex, functioned by interacting with substrate proteins, leading to their subsequent degradation by the 26S proteasome. To date, several F-box proteins identified in Arabidopsis and Antirrhinum have been shown to play important roles in auxin signal transduction, floral organ formation, flowering and leaf senescence. Arabidopsis genome sequence analysis revealed that it encodes over 1000 predicted F-box proteins accounting for about 5% of total predicted proteins. These results indicate that the ubiquitin-mediated protein degradation involving the F-box proteins is an important mechanism controlling plant gene expression. Here, we review the known F-box proteins and their functions in flowering plants.

关键词： SCF complex F-box protein proteolysis auxin signal transduction.

Mechanism of floral scent production in Osmanthus fragrans and the production and regulation of its key floral constituents,β-ionone and linalool

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Horticulture Research 2019年第1期6卷 432-443页

作者： Yuanji Han hongyun wang Xiaodan wang Ke Li Meifang Dong Yong Li Qian Zhu Fude Shang School of Life Sciences State Key Laboratory of Cotton BiologyState Key Laboratory of Crop Stress Adaptation and ImprovementKey Laboratory of Plant Stress BiologyLaboratory of Plant Germplasm and Genetic EngineeringHenan UniversityKaifeng 475004 HenanChina

Sweet osmanthus(Osmanthus fragrans Lour.)is among the top ten most well-known flowers in China and is recognized as both an aromatic plant and ornamental ***,manual sectioning,scanning electron microscopy,and transmission electron microscopy of sweet osmanthus petals revealed that large amounts of lipids are present inside the petal cells and on the cell ***,no secretory structures were ***,the petal cells protrude slightly outward,and the surfaces of the cells are adorned with highly regular brush-shaped *** surfaces of the‘Yingui’petals possessed mostly curled and more numerous hairs,whereas the‘Dangui’petals possessed fewer brush-shaped and more sparsely arranged *** addition,many granular substances were attached to the brush-shaped hairs,and the granules were denser on the hairs of the‘Yingui’petals compared to the hairs on the‘Dangui’***,35 aromatic components in the‘Yingui’petals and 30 aromatic components in the‘Dangui’petals were detected via *** main aromatic component of the‘Yingui’petals wasβ-ionone,whereas that of the‘Dangui’petals was linalool and its *** sequencing and qRT-PCR indicated that the highβ-ionone content in the‘Yingui’petals was due to the overexpression of CCD1 and CCD4 and that the high linalool content in the‘Dangui’petals was due to the overexpression of MECS,HDR,IDI1,and LIS1,which function upstream of the linalool synthetic *** particular,the expression levels of CCD4 and LIS1 were upregulated by 5.5-and 5.1-fold in the‘Yingui’and‘Dangui’petals,*** transcription factor(ERF61)was cloned and named,and the expression pattern of ERF61 in sweet osmanthus petals was found to be generally consistent with that of *** transformation experiments,yeast one-hybrid experiments,and electrophoretic mobility shift assays indicated that ERF61 binds to the CCD4 promoter and stimulates CCD4 expression,thereby regulating the synthesis ofβ-iono

关键词： shaped flowers attached

Absorption Rate into a Small Sphere for a Diffusing Particle Confined in a Large Sphere

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Applied Mathematics 2016年第7期7卷 709-720页

作者： hongyun wang Hong Zhou Department of Applied Mathematics and Statistics Baskin School of Engineering University of California Santa Cruz CA USA Department of Applied Mathematics Naval Postgraduate School Monterey CA USA

We study the problem of a diffusing particle confined in a large sphere in the n-dimensional space being absorbed into a small sphere at the center. We first non-dimensionalize the problem using the radius of large confining sphere as the spatial scale and the square of the spatial scale divided by the diffusion coefficient as the time scale. The non-dimensional normalized absorption rate is the product of the physical absorption rate and the time scale. We derive asymptotic expansions for the normalized absorption rate using the inverse iteration method. The small parameter in the asymptotic expansions is the ratio of the small sphere radius to the large sphere radius. In particular, we observe that, to the leading order, the normalized absorption rate is proportional to the (n - 2)-th power of the small parameter for .

关键词： Diffusion Equation Brownian Diffusion Asymptotic Solutions Absorption Rate

Analysis on Tourism Carrying Capacity of Tourist Destination

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Journal of Landscape Research 2016年第4期8卷 119-121页

作者： wang hongyun Shandong Jiaotong University

Tourist overload brings enormous economic benefits to tourist destinations,but more negative effect,thus control of tourism carrying capacity is a serious problem in tourism destination *** on the analysis of previous researches on tourism carrying capacity and its influence factors,the paper explored the influence of the overloaded tourism carrying capacity and put forward the corresponding regulation measures.

关键词： Tounsm carrying capacity Impact Controlling measures

Non-Detection Probability of a Diffusing Target by a Stationary Searcher in a Large Region

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Applied Mathematics 2016年第3期7卷 250-266页

We revisit one of the classical search problems in which a diffusing target encounters a stationary searcher. Under the condition that the searcher’s detection region is much smaller than the search region in which the target roams diffusively, we carry out an asymptotic analysis to derive the decay rate of the non-detection probability. We consider two different geometries of the search region: a disk and a square, respectively. We construct a unified asymptotic expression valid for both of these two cases. The unified asymptotic expression shows that the decay rate of the non-detection probability, to the leading order, is proportional to the diffusion constant, is inversely proportional to the search region, and is inversely proportional to the logarithm of the ratio of the search region to the searcher’s detection region. Furthermore, the second term in the unified asymptotic expansion indicates that the decay rate of the non-detection probability for a square region is slightly smaller than that for a disk region of the same area. We also demonstrate that the asymptotic results are in good agreement with numerical solutions.

关键词： Detection of a Random Target Asymptotic Solutions Decay of the Non-Detection Probability

Performance of Stochastically Intermittent Sensors in Detecting a Target Traveling between Two Areas

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American Journal of Operations Research 2016年第2期6卷 199-212页

We study the problem of detecting a target that moves between a hiding area and an operating area over multiple fixed routes. The research is carried out with one or more cookie-cutter sensors with stochastic intermission, which turn on and off stochastically governed by an on-rate and an off-rate. A cookie-cutter sensor, when it is on, can detect the target instantly once the target comes within the detection radius of the sensor. In the hiding area, the target is shielded from being detected. The residence times of the target, respectively, in the hiding area and in the operating area, are exponentially distributed and are governed by rates of transitions between the two areas. On each travel between the two areas and in each travel direction, the target selects a route randomly according to a probability distribution. Previously, we analyzed the simple case where the sensors have no intermission (i.e., they stay on all the time). In the current study, the sensors are stochastically intermittent and are synchronized (i.e., they turn on or off simultaneously). This happens when all sensors are affected by the same environmental factors. We derive asymptotic expansions for the mean time to detection when the on-rate and off-rate of the sensors are large in comparison with the rates of the target traveling between the two areas. Based on the mean time to detection, we evaluate the performance of placing the sensor(s) to monitor various travel route(s) or to scan the operating area.

关键词： Stochastically Intermittent Sensors Moving Target with Constrained Pathways Mean Time to Detection Optimal Search Design

Computational Studies on Detecting a Diffusing Target in a Square Region by a Stationary or Moving Searcher

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American Journal of Operations Research 2015年第2期5卷 47-68页

作者： hongyun wang Hong Zhou Department of Applied Mathematics and Statistics Baskin School of Engineering University of California Santa Cruz USA Department of Applied Mathematics Naval Postgraduate School Monterey USA

In this paper, we compute the non-detection probability of a randomly moving target by a stationary or moving searcher in a square search region. We find that when the searcher is stationary, the decay rate of the non-detection probability achieves the maximum value when the searcher is fixed at the center of the square search region;when both the searcher and the target diffuse with significant diffusion coefficients, the decay rate of the non-detection probability only depends on the sum of the diffusion coefficients of the target and searcher. When the searcher moves along prescribed deterministic tracks, our study shows that the fastest decay of the non-detection probability is achieved when the searcher scans horizontally and vertically.

关键词： Diffusing Target Non-Detection Probability Search Theory Optimal Search Path