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Largely reduced cross-plane thermal conductivity of nanoporous In0.1Ga0.9N thin films directly grown by metal organic chemical vapor deposition

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Frontiers in Energy 2018年第1期12卷 127-136页

作者： Dongchao xu Quan WANG xuewang WU Jie ZHU Hongbo ZHAO Bo XIAO Xiaojia WANG xiaoliang WANG Qing HAO Aerospace & Mechanical Engineering University of Arizona 1130 NMountain Ave Tucson AZ 85721 USA Key laboratory of Semiconductor Materials Science Institute ofSemiconductors Chinese Academy of Sciences Beijing 100083 China Department of Mechanical Engineering University of Minnesota IllChurch St. SE Minneapolis MN 55455 USA

In recent year, nanoporous Si thin films have been widely studied for their potential applications in thermoelectrics, in which high thermoelectric performance can be obtained by combining both the dramatically reduced lattice thermal conductivity and bulk-like elec- trical properties. Along this line, a high thermoelectric figure of merit （ZT） is also anticipated for other nanoporous thin films, whose bulk counterparts possess superior electrical properties but also high lattice thermal conductivities. Numerous thermoelectric studies have been carried out on Si-based nanoporous thin fills, whereas cost-effective nitrides and oxides are not systematically studied for similar thermoelectric benefits. In this work, the cross-plane thermal conductivities of nanoporous Ino.lGao.9N thin films with varied porous patterns were measured with the time-domain thermoreflectance techni- que. These alloys are suggested to have better electrical properties than conventional SixGel x alloys; however, a high ZT is hindered by their intrinsically high lattice thermal conductivity, which can be addressed by introdu- cing nanopores to scatter phonons. In contrast to previous studies using dry-etched nanopores with amorphous poreedges, the measured nanoporous thin films of this work are directly grown on a patterned sapphire substrate to minimize the structural damage by dry etching. This removes the uncertainty in the phonon transport analysis due to amorphous pore edges. Based on the measurement results, remarkable phonon size effects can be found for a thin film with periodic 300-nm-diameter pores of different patterns. This indicates that a significant amount of heat inside these alloys is still carried by phonons with -300 nm or longer mean flee paths. Our studies provide important guidance for ZT enhancement in alloys of nitrides and similar oxides.

关键词： nanoporous film thermoelectrics phonon,mean free path diffusive scattering

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Electroacupuncture relieves irritable bowel syndrome by increasing expression of nucleotide-binding oligomerization domain protein-like receptor family pyrin domain containing 6 in water-avoidance stress mice

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Journal of Traditional Chinese Medicine 2020年第3期40卷 407-413页

作者： Song Yafang Geng Hao Chen Lu Wu xiaoliang Yuan Mengqian xu Wanli Guo Jing Sun Jianhua Pei Lixia Department of acupuncture The Affiliated Hospital of Nanjing University of Chinese MeidicneNanjing 210029China Department of the First Clinical Medical College Nanjing University of Chinese MedicineNanjing 210023China

OBJECTIVE: To investigate the effect of electroacupuncture(EA) on irritable bowel syndrome(IBS) in mice through regulating nucleotide-binding oligomerization domain protein-like receptor family pyrin domain containing 6(NLRP6).METHODS: Water-avoidance stress(WAS) mice model was used to investigate the effects and the mechanism of EA. Abdominal withdrawal reflex test, open field test, and intestinal motility test were used to evaluate visceral sensitivity, anxiety,and intestinal motility in mice. The expressions of NLRP6, Mucin-2(MUC2) and E-cadherin were determined using immunofluorescence and Western blotting assays.RESULTS: EA significantly upregulated the expression of NLRP6 in the intestine of mice. Moreover, EA increased the expressions of MUC2 and E-cadherin in WAS mice.CONCLUSION: Our study found that the relief of IBS symptoms by EA may involve the increase in the expression of NLRP6 in WAS mice.

关键词： Electroacupuncture Nod signaling adaptor proteins Irritable bowel syndrome

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Cell apoptosis in perihematomal brain regions and expression of Caspase-3 protein in patients with hypertensive intracerebral hemorrhage

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Neural Regeneration Research 2006年第5期1卷 420-423页

作者： Xinqing Zhang xiaoliang Yin Kun Zhang Zhimin Zhang Hui Cai Honglan xu Department of Neurosurgery Beijing Chuiyangliu Hospital Beijing 100022 China Department of Pathology Beijing Chuiyangliu Hospital Beijing 100022 China

BACKGROUND： In patients with intracerebral hemorrhage （ICH）, besides the space-occupying effect of hematoma, hematomal component also causes the pathological changes of perihematomal region, including the death of neurons and glial cells, vasogenic brain edema, the destruction of blood brain barrier and so on, which are the important factors to influence the prognosis of patients. Therefore, it is necessary to perform further investigation and study on the pathological characteristics of injury and death of brain nerve cells. OBJECTIVE： To observe the pathological changes of apoptosis and Caspase-3 expression in perihematomal brain regions in patients with hypertensive ICH （HICH） in different stages of onset, and analyze their relationship. DESIGN ： Case-control observation. SETTING： Departments of Neurosurgery and Pathology of Beijing Chuiyangliu Hospital.PARTICIPANTS： Totally 19 patients with HICH, including 12 male, 7 female, aged （58.3±12.8） ranging from 49 to 78 years, whose mean volume of hemorrhage was （48.6±16.4） mL, were involved . All the cases conformed to the diagnostic criteria of intracerebral hemorrhage formulated in the 4^th National Cerebrovascular Diseases Conference and were confirmed by skull CT scanning. Informed consents of operation and specimens were obtained from the patients and relatives. METHODS： ①Patients with HICH who had undergone surgical evacuation of an intracerebral hematoma by traverse temporal lobe approach in the Department of Neurosurgery, Beijing Chuiyangliu Hospital from January 2004 to July 2005 were involved. Nineteen specimens of brain tissue from perihematomal region of HICH patients in different phases served as patient group. Five specimens were obtained from distant regions of patients in the super-early phase as the control group. According to the time from onset to operation, the 19 cases were divided into 3 groups： 6 cases in super-early phase（onset 〈 8 hours）, 8 cases in early phase （onset about 8 to 24 hours） and 5 cases in delayed phase（onset 〉 24 ho

关键词： intracerebral hemorrhage cell apoptosis correlation analysis pathological characteristics immunohistochemical staining visual field signal transduction diagnostic criteria blood brain barrier protein expression measurement data temporal lobe nerve cells CT scanning brain edema

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Longitudinal non-vascular transport pathways originating from acupuncture points in extremities visualised in human body

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Chinese Science Bulletin 2014年第35期59卷 5090-5095页

作者： Hongyi Li Jiabin Tong Weiguo Cao Min Chen Hua Li Hong Dai Liang xu xiaoliang Chen Beijing Hospital of the Ministry of Health Institute of Computing Technology Chinese Academy of Sciences

A subcutaneous transport pathway in humans has been previously visualised by injection of a paramagnetic tracer into the specific region of skin.In the current study,we further investigated the behaviours of imaging tracers in the transport pathways using imaging techniques.Three types of imaging tracers,including Gd-DTPA,iodised oil,and fluorescein sodium,were hypodermically injected into different acupuncture points of healthy volunteers to visualise the transport pathways by magnetic resonance imaging(MRI),X-ray,CT,and a digital fluorescein camera.Several longitudinal transport pathways in the arms and feet,which represent venous vessels and subcutaneous transport pathways(STPs) without well-defined boundaries,were visualised by MRI.Among the visualised veins,the partial walls of a few veins were enhanced by Gd-DTPA.The fluorescent images further indicated that STPs likely represent boundless pathways.The findings in this study suggested that specific anatomical structures within the subcutaneous tissues or the partial walls of certain veins werenot vascular conduits but rather represented unique transport pathways in humans that warrant extensive future studies.

关键词：运输途径可视化血管穴位污水处理厂四肢成像技术荧光素钠

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Boron nitride microsphere/epoxy composites with enhanced thermal conductivity

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High Voltage 2017年第3期2卷 147-153页

作者： Jiajia Sun De Wang Yimin Yao xiaoliang Zeng Guiran Pan Yun Huang Jiantao Hu Rong Sun Jian-Bin xu Ching-Ping Wong Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055People's Republic of China Department of Nano Science and Technology Institute University of Science and Technology of ChinaSuzhou 215123People's Republic of China Department of Chemical Engineering Ordos College of Inner Mongolia UniversityOrdos 017000People's Republic of China Shenzhen College of Advanced Technology University of Chinese Academy of SciencesShenzhen 518055People's Republic of China Department of Chemical Engineering China University of PetroleumBeijing 102249People's Republic of China Department of Electronics Engineering The Chinese University of Hong KongHong Kong 999077People's Republic of China School of Materials Science and Engineering Georgia Institute of TechnologyAtlantaGeorgia 30332USA

As modern electronics are developed towards miniaturisation,high-degree integration and intelligentisation,a large amount of heat will be generated during the operation of devices.How to efficiently remove needless heat is becoming more and more crucial for the lifetime and performance of electronic devices.Many efforts have been made to improve the thermal conductivity of polymer composites,which is an important component of electronics.Herein,the authors report on preparation of boron nitride micosphere/epoxy composites.The cross-plane thermal conductivity of the resultant composites is up to 1.03 Wm‒1K‒1.This is attributed to the thermally conductive network formed by the peeled hexagonal boron nitride flakes.Thanks to the superior thermal stability of boron nitride micosphere,the boron nitride micosphere/epoxy composite shows a decreased coefficient of thermal expansion(53.47 ppm/K)and an increased glass transition temperature(147.2℃)compared with the pure epoxy resin.In addition,the boron nitride micosphere/epoxy composite exhibits a lower dielectric constant compared with that of the hexagonal boron nitride/epoxy composite.This strategy can potentially pave the way for the design and fabrication of materials with high cross-plane thermal conductivity and lower dielectric properties.

关键词： composites composite conductivity

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Physics-data-driven intelligent optimization for large-aperture metalenses

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Opto-Electronic Advances 2023年第11期6卷 5-15页

作者： Yingli Ha Yu Luo Mingbo Pu Fei Zhang Qiong He Jinjin Jin Mingfeng xu Yinghui Guo Xiaogang Li Xiong Li xiaoliang Ma Xiangang Luo National Key Laboratory of Optical Field Manipulation Science and Technology Chinese Academy of SciencesChengdu 610209China State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China Research Center on Vector Optical Fields Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China School of Optoelectronics University of Chinese Academy of SciencesBeijing 100049China Tianfu Xinglong Lake Laboratory Chengdu 610299China

Metalenses have gained significant attention and have been widely utilized in optical systems for focusing and imaging,owing to their lightweight,high-integration,and exceptional-flexibility capabilities.Traditional design methods neglect the coupling effect between adjacent meta-atoms,thus harming the practical performance of meta-devices.The existing physical/data-driven optimization algorithms can solve the above problems,but bring significant time costs or require a large number of data-sets.Here,we propose a physics-data-driven method employing an“intelligent optimizer”that enables us to adaptively modify the sizes of the meta-atom according to the sizes of its surrounding ones.The implementation of such a scheme effectively mitigates the undesired impact of local lattice coupling,and the proposed network model works well on thousands of data-sets with a validation loss of 3×10^(−3).Based on the“intelligent optimizer”,a 1-cm-diameter metalens is designed within 3 hours,and the experimental results show that the 1-mm-diameter metalens has a relative focusing efficiency of 93.4%(compared to the ideal focusing efficiency)and a Strehl ratio of 0.94.Compared to previous inverse design method,our method significantly boosts designing efficiency with five orders of magnitude reduction in time.More generally,it may set a new paradigm for devising large-aperture meta-devices.

关键词： intelligence method physics-data-driven method inverse design large-aperture metalenses

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Clean water generation with switchable dispersion of multifunctional Fe3O4-reduced graphene oxide particles

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Progress in Natural Science:Materials International 2018年第4期28卷 422-429页

作者： Ruijie Zhao Jiale xu Peng Tao Fenglei Shi Fan Yu xiaoliang Zeng Chengyi Song Jianbo Wu Wen Shang Tao Deng State Key Laboratory of Metal Matrix Composites School of Materials Science and Engineering Shanghai Jiao Tong University Guangdong Provincial Key Laboratory of Materials for High Density Electronic Packaging Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences

With the increased need for clean water and decreased supply of fresh water, purification of contaminated water can provide clean water that supplements the fresh water from nature. Physical adsorption, photo-degradation and solar-driven evaporation processes are promising ways to generate clean water with minimum environmental impact. However, different purification process requires different dispersion state of the treating agent to maximize its performance. Herein, we demonstrate that Fe3O4-reduced graphene oxide(MrGO) particles with switchable dispersion can be used as the multifunctional water treating agents to efficiently purify contaminated water through different processes. Under homogenously dispersed nanofluid mode, the MrGO particles have large exposed surface areas and can efficiently remove organic dye pollutants through physical adsorption. The uniform dispersion state also favors high contact efficiency facilitating decontamination of high concentration of organic compounds through solar-driven photocatalytic degradation by the MrGO particles. The excellent magnetic response of MrGO particles not only allows for easy collection of the treating agent from water but also enables assembly of MrGO at the air-water interface with external magnets. Under such interfacial assembled mode, clean water can be distilled out of the contaminated solution with high evaporation efficiency of 74.7% under simulated natural solar radiation. This work demonstrates that dispersion state can be used as another important means to optimize water purification performances.

关键词： Adsorption Photo-degradation Evaporation Dispersion state Water treatment

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Fabrication and characterization of AlGaN/GaN HEMTs with high power gain and efficiency at 8 GHz

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Journal of Semiconductors 2021年第12期42卷 48-55页

作者： Quan Wang Changxi Chen Wei Li Yanbin Qin Lijuan Jiang Chun Feng Qian Wang Hongling Xiao Xiufang Chen Fengqi Liu xiaoliang Wang Xiangang xu Zhanguo Wang State Key Laboratory of Crystal Materials Shandong University Institute of Novel Semiconductors Shandong University Key Lab of Semiconductor Materials Science Institute of Semiconductors Chinese Academy of Sciences Center of Materials Science and Optoelectronics Engineering and School of Microelectronics University of Chinese Academy of Sciences Beijing Key Laboratory of Low Dimensional Semiconductor Materials and Devices

State-of-the-art AIGaN/GaN high electron mobility structures were grown on semi-insulating 4 H-SiC substrates by MOCVD and X-band microwave power high electron mobility transistors were fabricated and characterized.Hall mobility of2291.1 cm~2/(V·s) and two-dimensional electron gas density of 9.954×1012cm-2were achieved at 300 K.The HEMT devices with a 0.45-μm gate length exhibited maximum drain current density as high as 1039.6 mA/mm and peak extrinsic transconductance of 229.7 mS/mm.The fT of 30.89 GHz and fmaxof 38.71 GHz were measured on the device.Load-pull measurements were performed and analyzed under(-3.5,28) V,(-3.5,34) V and(-3.5,40) V gate/drain direct current bias in class-AB,respectively.The uncooled device showed high linear power gain of 17.04 dB and high power-added efficiency of 50.56% at 8 GHz when drain biased at(-3.5,28) V.In addition,when drain biased at(-3.5,40) V,the device exhibited a saturation output power density up to 6.21 W/mm at 8 GHz,with a power gain of 11.94 dB and a power-added efficiency of 39.56%.Furthermore,the low fmax/fTratio and the variation of the power sweep of the device at 8 GHz with drain bias voltage were analyzed.

关键词： AlGaN/GaN heterostructure MOCVD HEMTs power amplifier

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Crosstalk-free achromatic full Stokes imaging polarimetry metasurface enabled by polarization-dependent phase optimization

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Opto-Electronic Advances 2022年第11期5卷 16-28页

作者： Yaxin Zhang Mingbo Pu Jinjin Jin Xinjian Lu Yinghui Guo Jixiang Cai Fei Zhang Yingli Ha Qiong He Mingfeng xu Xiong Li xiaoliang Ma Xiangang Luo State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China Research Center on Vector Optical Fields Institute of Optics and ElectronicsChinese Academy of SciencesChengdu 610209China School of Optoelectronics University of Chinese Academy of SciencesBeijing 100049China Key Laboratory of Optoelectronic Technology and System Ministry of EducationChongqing UniversityChongqing 400030China

Imaging polarimetry is one of the most widely used analytical technologies for object detection and analysis.To date,most metasurface-based polarimetry techniques are severely limited by narrow operating bandwidths and inevitable crosstalk,leading to detrimental effects on imaging quality and measurement accuracy.Here,we propose a crosstalkfree broadband achromatic full Stokes imaging polarimeter consisting of polarization-sensitive dielectric metalenses,implemented by the principle of polarization-dependent phase optimization.Compared with the single-polarization optimization method,the average crosstalk has been reduced over three times under incident light with arbitrary polarization ranging from 9μm to 12μm,which guarantees the measurement of the polarization state more precisely.The experimental results indicate that the designed polarization-sensitive metalenses can effectively eliminate the chromatic aberration with polarization selectivity and negligible crosstalk.The measured average relative errors are 7.08%,8.62%,7.15%,and 7.59%at 9.3,9.6,10.3,and 10.6μm,respectively.Simultaneously,the broadband full polarization imaging capability of the device is also verified.This work is expected to have potential applications in wavefront detection,remote sensing,light-field imaging,and so forth.

关键词： metasurface broadband achromatic crosstalk-free full polarization imaging polarimetry

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Study on the targets and mechanisms of traditional Chinese medicine in inhibiting platelet aggregation

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Asian Journal of Pharmaceutical Sciences 2016年第1期11卷 26-27页

作者： xiaoliang Wang Yiying Li Hongyan Yang Jiang Li Shaofeng xu Ling Wang Department of Pharmacology Institute of Materia Medica Chinese Academy of Medical Sciences

Platelets aggregation and thrombosis formation are major reasons of cardiovascular and cerebral vascular diseases.To develop novel,effective and safe agents for inhibiting platelet aggregation and preventing above diseases is urgently needed.Some traditional Chinese medicines for“Houxue Huayu”have been shown to inhibit platelet aggregation potently.They are used frequently in China and also in Asian countries.Recently,the major effective components of Pueraria lobata,Salvia miltiorrhiza Bunge,Apium graveolens L.and so on were studied.The mechanisms and the molecular targets of puerarin,salvianolic acid B and the analogue of 3-n-butylphthalide,dl-PHPB were investigated.Four platelet aggregation inducers,ADP,arachidonic acid(AA),collagen(Col)and thrombin,were used in the study.

关键词： Platelet aggregation Traditional Chinese medicine ADP P2Y1 P2Y12

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