检索结果-南通市图书馆

Plasma Science and Technology 2020年第11期22卷 23-35页

作者： Lingfeng LU Ying LIU Huizong DUAN Yuanze JIANG hsien-chi yeh TianQin Research Center for Gravitational Physics and School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082People's Republic of China MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics PGMF and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074People's Republic of China

Plasma turbulence may lead to additional wavefront distortion of inter-spacecraft laser beams during the operation of spaceborne gravitational wave(GW)observatories,*** *** making use of the Space Weather Modelling Framework(SWMF)model and realistic orbit data for the Tian Qin constellation,the characteristic parameters of the plasma turbulence present at the Tian Qin orbit are *** a first step,this work is based on the assumptions that the cold plasma approximation is valid and that the effects of the electromagnetic field induced by charge separation within the Debye length on the laser's wavefront can be *** atmospheric turbulence-laser interaction model is then applied to analyze the effects of the plasma turbulence on the inter-spacecraft laser's *** preliminary results show that the wavefront distortion caused by the plasma turbulence is 10^-9 rad,which is significantly less than the designated error budget,i.e.10^-6 rad,and thus will not affect the laser interferometry.

关键词： plasma turbulence gravitational wave detection laser interferometry

Manufacture of a hollow corner cube retroreflector for next generation of lunar laser ranging

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2018年第11期18卷 55-62页

作者： Yun He Qi Liu Hui-Zong Duan Jing-Jing He Yuan-Ze Jiang hsien-chi yeh TIANQIN Research Center for Gravitational Physics School of Physics and Astronomy Sun Yat-sen University MOE Key Laboratory of Fundamental Quantities Measurement School of Physics Huazhong University of Science and Technology Key Laboratory of Gravitation and Quantum Physics of Hubei Province School of Physics Huazhong University of Science and Technology

Lunar laser ranging has made significant contributions to the study of gravitational physics and the Earth-Moon system. The best results for fundamental gravitational experiments have been achieved using lunar laser ranging data accumulated so far. However, corner cube retroreflector arrays placed on the Moon currently set a limit on the laser-ranging precision, which is approximately several centimeters for a single photon received. To achieve millimeter precision, next generation of lunar laser ranging using a single hollow retroreflector with a large aperture has been proposed. We developed a prototype hollow retroreflector with a 100-mm aperture using silicate bonding together with a new fabrication method. Dihedral angle offsets of 0.5′′, 0.8′′and 1.9′′were realized, which partly come close to meeting the requirements(offset of 0.6′′for each dihedral angle) for lunar laser ranging. Fluctuation of the wavefront is approximately 1.038λ at 633 nm. A thermal cycle test ranging from -40℃ to +75℃ was carried out for 18.5 periods(approximately 5 d). After this test, the dihedral angle offsets were measured to be 0.39′′, 1.00′′and 2.06′′. The results indicate the potential application of our method for manufacturing a hollow retroreflector with a large aperture to realize lunar laser ranging.

关键词： gravitation: instrumentation miscellaneous: Moon

Development of a 170-mm hollow corner cube retroreflector for the future lunar laser ranging

在线全文

学校读者我要写书评

暂无评论

chinese Physics B 2018年第10期27卷 266-270页

作者： Yun He Qi Liu Jing-Jing He Ming Li Hui-Zong Duan hsien-chi yeh Jun Luo TianQin Research Center for Gravitational Physics Sun Yat-sen UniversityZhuhai 519000China MOE Key Laboratory of Fundamental Physical Quantities Measurement School of PhysicsHuazhong University of Science and TechnologyWuhan 430074China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519000China DFH Satellite Co. Ltd.Beijing 100094China

Over the past 50 years, lunar laser ranging has made great contributions to the understanding of the Earth–Moon system and the tests of general relativity. However, because of the lunar libration, the Apollo and Lunokhod corner-cube retroreflector（CCR） arrays placed on the Moon currently limit the ranging precision to a few centimeters for a single photon received. Therefore, it is necessary to deploy a new retroreflector with a single and large aperture to improve the ranging precision by at least one order of magnitude. Here we present a hollow retroreflector with a 170-mm aperture fabricated using hydroxide-catalysis bonding technology. The precisions of the two dihedral angles are achieved by the mirror processing with a sub-arc-second precision perpendicularity, and the remaining one is adjusted utilizing an auxiliary optical configuration including two autocollimators. The achieved precisions of the three dihedral angles are 0.10 arcsecond,0.30 arc-second, and 0.24 arc-second, indicating the 68.5% return signal intensity of ideal Apollo 11/14 based on the far field diffraction pattern simulation. We anticipate that this hollow CCR can be applied in the new generation of lunar laser ranging.

关键词： lunar laser ranging comer cube retroreflector diffraction alignment

Analysis and suppression of thermal effect of an ultra-stable laser interferometer for space-based gravitational waves detection

在线全文

学校读者我要写书评

暂无评论

chinese Optics Letters 2022年第1期20卷 43-48页

作者： Guanfang Wang Zhu Li Jialing Huang Huizong Duan Xiangqing Huang Hongfan Liu Qi Liu Shanqing Yang Liangcheng Tu hsien-chi yeh MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational Physics&School of Physics and AstronomyFrontiers Science Center for TianQinCNSA Research Center for Gravitational WavesSun Yat-sen University(Zhuhai Campus)Zhuhai 519082China Shenhe Middle School Heyuan 517000China

In this paper,we present a suppression method for the thermal drift of an ultra-stable laser *** detailed analysis on the Michelson interferometer indicates that the change in optical path length induced by temperature variation can be effectively reduced by choosing proper thickness and/or incident angle of a *** the optical bench of the Laser Interferometer Space Antenna Pathfinder as an example,we analyze the optical bench model with a compensator and show that the temperature coefficient of this laser interferometer can be reduced down to 1 pm/K with an incident angle of 0.267828 *** method presented in this paper can be used in the design of ultra-stable laser interferometers,especially for space-based gravitational waves detection.

关键词： gravitational waves detection laser interferometer temperature compensation optical path calculation

Ultraprecision intersatellite laser interferometry

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2020年第2期2卷 54-66页

作者： Min Ming Yingxin Luo Yu-Rong Liang Jing-Yi Zhang Hui-Zong Duan Hao Yan Yuan-Ze Jiang Ling-Feng Lu Qin Xiao Zebing Zhou hsien-chi yeh Tianqin Research Center for Gravitational Physics and School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082People’s Republic of China MOE Key Laboratory of Fundamental Physical Quantities Measurement&Hubei Key Laboratory of Gravitation and Quantum Physics PGMF and School of PhysicsHuazhong University of Science and TechnologyWuhan 430074People’s Republic of China

Precision measurement tools are compulsory to reduce measurement errors or machining errors in the processes of calibration and *** laser interferometer is one of the most important measurement tools invented in the 20th ***,it is commonly used in ultraprecision machining and manufacturing,ultraprecision positioning control,and many noncontact optical sensing *** far,the state-of-the-art laser interferometers are the ground-based gravitational-wave detectors,*** Laser Interferometer Gravitational-wave Observatory(LIGO).The LIGO has reached the measurement quantum limit,and some quantum technologies with squeezed light are currently being tested in order to further decompress the noise *** this paper,we focus on the laser interferometry developed for space-based gravitational-wave *** basic working principle and the current status of the key technologies of intersatellite laser interferometry are introduced and discussed in *** launch and operation of these large-scale,gravitational-wave detectors based on space-based laser interferometry is proposed for the 2030s.

关键词： laser interferometry gravitational-wave detection inter-satellite laser ranging transponder laser interferometer

A concise review about fracture assessments of brittle solids with V-notches

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2019年第2期13卷 478-485页

作者： hsien-Yang yeh Bin YANG Department of Mechanical and Aerospace Engineering California State UniversityLong BeachCA 90801USA Department of Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

A concise review of recent studies about the fracture assessments of elastic brittle solid materials containing V-notches is presented. In this preliminary and brief survey, elastic stress distributions in V-notched solids are discussed first. The concept of notch stress intensity factor is introduced. Combine the digital image correlation method with numerical computation techniques to analyze the stress distribution near the notches. Fracture criteria such as strain energy density, J-integral, theory of critical distance are used. However, various new materials are developed in different engineering fields, thus, the establishment of reliable and accurate material strength theory or failure criterion is imperative. Therefore, predicting fracture for various modem materials would require more experiments to infer material dependent parameters in the local fracture model.

关键词： fracture assessment brittle solids V-notches review

The experimental study for the allocation of ground-sills downstream of check dams

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Sediment Research 2008年第1期23卷 28-43页

作者： Bing-Shyan LIN Chao-hsien yeh Hui-Pang LIEN Candidate Department of Civil and Hydraulic Engineering Institute and Construction and Disaster Prevention Research Center Feng-Chia University Department of Water Resources Engineering Feng-Chia University

The main purpose of this study is to understand the stabilizing effect of ground-sills on the riverbed through a series of flume model experiments. From results, although check dams have the ability to control upstream sediment transport, the mass energy produced by the free fall of the overtopping discharge still causes strong local scour downstream of the structure, and this scour leads to the instability of the check dam. Therefore, this study conducted model experiments on various types of serial ground-sills to determine the appropriate spacing to best protect the downstream bed. Based on the observations and analysis of channel geomorphology and sedimentation, this study concluded the following results: 1) Serial ground-sills reduces the sediment transport ability perfectly, especially under a mild channel gradient equipped with 2-4 times the average channel width interval. But for steep slopes, it is suggested that the proper spacing should be shortened to 1-2 times the average channel width. 2) Ground-sills can effectively protect the streambed from scouring under a suitable equipped condition and the concepts of guiding scour and riverbed inertia were used in the analysis of optimal ground-sill spacing.

关键词： Serial ground-sills Sedimentation Strong scour area Riverbed inertia Guiding scour

Microstructures and properties of cancellous bone of avascular necrosis of femoral heads

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2010年第1期26卷 13-19页

作者： Xuefeng Yao Peng Wang Ruchun Dai hsien Yang yeh Dai Department of Engineering Mechanics AML Tsinghua University 100084 Beijing China Institute of Metabolism and Endocrinology The Second Xiang-Ya Hospital Central South University410011 Changsha China Department of Mechanical and Aerospace Engineering California State University Long Beach CA 90840-8305 USA

The aim of this study is to investigate microscopic structure and characterize cancellous bone of avascular necrosis of the femoral head （ANFH）. The rabbit model of the ANFH is established. The histopathologic features are studied successfully. The differences between the steroidinjection group （S.G.） and the controlled group （C.G.） are examined, including the weight of rabbits, the hematological examination and the three-dimensional stnactures. It is found that the plasma levels of cholesterol （CHO）, high-density lipoprotein （HDL） and low-density lipoprotein （LDL） in S.G. are lower than those in C.G. when the triglyceride （TG） increased in the S.G.; but the bone mineral content （BMC） and the structural model index （SMI） of the organ and tissue decreased significantly in S.G. Three-dimensional structures of the femoral head are obtained using micro-computed tomography （CT） scanning and the mechanical model is established to analyze the influences of these structural changes on the mechanical properties of the cancellous bone.

关键词： Avascular necrosis of the femoral head Cancellous bone Microstructure Mechanical properties

Effect of transcutaneous electrical nerve stimulation through acupoints of Pucan (BL 61) and Shenmai (BL 62) on intraocular pressure in patients with glaucoma： a randomized controlled trial

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional chinese Medicine 2016年第1期36卷 51-56页

作者： yeh Tsui-Yun Lin Jen-chien Liu chi-Feng Graduate Institute of Integration of Traditional chinese Medicine with Western Nursing National Taipei University of Nursing and Health Sciences Taipei City Hospital Taipei 10065 China Department of Ophthalmology Taipei CityHospitaI Taipei 10065 China

OBJECTIVE： To investigate the effects of transcutaneous electrical nerve stimulation （TENS） through acupoints on the intraocular pressure （lOP） in patients with glaucoma. METHODS： A single-blinded, randomized experimental design study was conducted. Patients from the North of Taipei Ophthalmology outpatient department diagnosed with intraocular hypertension were selected and were further enrolled if they met the research subject criteria. The patients who met all criteria, and who met no exclusion criteria became the participants. Participants were randomly assigned into the treated group, wherein the TENS electrodes （Qing Ming Medical Device Co., Ltd., New Taipei City, china） were applied with direct current （DC） on the acupoints Pucan （BL 61） and Shenmai （BL 62） for 20 min. The control group received no TENS electrode treatments. Measurements of lOP were taken four times using a pneumotonometer （Clinico Co., Ltd., New Taipei City, china）, before, immediately after, 30 min after, and 60 min after TENS electrode treatments. RESULTS： Eighty-two participants completed the experiment, lOP decreased more in the group treated with DC （P 〈 0.01） than in the control *** lOPs were not affected by the age of the patients and their usage of medications. CONCLUSION： TENS of acupoints of Pucan （BL 61） and Shenmai （BL 62） could significantly reduce the lOP in patients with glaucoma.

关键词： Glaucoma Intraocular pressure Ocularhypertension Acupuncture points Transcutaneous electrical nerve stimulation Randomized con-trolled trial

Effects of glutamine-containing total parenteral nutrition on phagocytic activity and anabolic hormone response in rats undergoing gastrectomy

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2005年第6期11卷 817-822页

作者： Chen-hsien Lee Wan-Chun chiu Soul-chin Chen chih-Hsiung Wu Sung-Ling yeh Institute of Nutrition and Health Sciences Department of Surgery

AIM: To investigate the effect of glutamine (Gln)-containing parenteral nutrition on phagocytic activity and to elucidate the possible roles of Gln in the secretion of anabolic hormones and nitrogen balance in rats undergoing a gastrectomy. METHODS: Rats with an internal jugular catheter were divided into 2 experimental groups and received total parenteral nutrition (TPN). The TPN solutions were isonitrogenous and identical in nutrient compositions except for differences in amino acid content. One group received conventional TPN (control), and in the other group, 25% of the total amino acid nitrogen was replaced with Gin. After receiving TPN for 3 d, one-third of the rats in each experimental group were sacrificed as the baseline group. The remaining rats underwent a partial gastrectomy and were killed 1 and 3 d, respectively, after surgery. Plasma, peritoneal lavage fluid (PLF), and urine samples were collected for further analysis. RESULTS: The Gln group had fewer nitrogen losses 1 and 2 d after surgery (d1, 16.6±242.5 vs-233.4±205.9 mg/d, d2, 31.8±238.8 vs-253.4±184.6 mg/d, P<0.05). There were no differences in plasma growth hormone (GH) and insulin-like growth factor-1 levels between the 2 groups before or after surgery. The phagocytic activity of peritoneal macrophages was higher in the Gln group than in the control group 1 d after surgery (A 1185±931 vs323±201, P<0.05). There were no differences in the phagocytic activities of blood polymorphonuclear neutrophils between the 2 groups at the baseline or on the postoperative days. No significant differences in interleukin-1β or interleukin-6 concentrations in PLF were observed between the 2 groups. However, tumor necrosis factor-α level in PLF was significantly lower in the Gln group than in the control group on postoperative d 3. CONCLUSION: TPN supplemented with Gln can improve the nitrogen balance, and enhance macrophage phagocytic activity at the site of injury. However, Gin supplementation has no effect on p

关键词： Parenteral Nutrition Glutamine Phagocytosis Gastrectomy