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Effect of particle size on the preparation and microwave absorption properties of FeSiAl magnetically soft alloy hollow microspheres

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Defence Technology（防务技术） 2018年第5期14卷 477-483页

作者： Xu-dong Cai xiao-jun Jiang Wei Xie Jing-yang mu De-fei Yin 63983 Troops Wuxi214035China

FeSiAl magnetically soft alloy hollow microspheres(mSAHms) were prepared by self-reactive quenching technology based on Fe + Si + AI + KNO_3 reactive systems, in order to obtain absorbents with light weight, low frequency and high efficiency. Firstly, twice-balling adhesive precursor method was used to obtain FeSiAl magnetically soft alloy agglomerate powders. Then agglomerate powders with the mesh number of 150-240, 240-325 and 325-400 were sprayed through the flame field into the quenching water. At last, FeSiAl mSAHms with coarse(average at 86.97 μm), medium(average at 52.16 μm) and fine particles(average at 31.80 μm) were got. Effect of particle size on the phases and microwave absorption properties in low frequency band was studied by XRD and vector network analyzer. The results show that,Fe_3 Si_(0.7)Al_(0.3) and Fe_3 Si_(0.5)Al_(0.5) appear in the phase components of FeSiAl mSAHms,which is important to improve the microwave absorption properties in low frequency. In addition, the real part(ε′) and imaginary part(ε″) of complex permittivity, the real part(μ′) and imaginary part(μ″) of complex permeability of FeSiAl mSAHms all present the trend of fine particles > medium particles > coarse particles. The microwave absorption properties in low frequency are improved with the increasing of particle size, and the absorption peak moves to lower frequency range. The properties of fine particles are the best. Their matching thickness of samples is at 5 mm, and the minimum reflectivity is-43 dB at this thickness. The absorption frequency band lower than-10 dB is 4.6-7.6 gHz with a bandwidth of 3 gHz.

关键词： FeSiAl magnetically soft alloy Hollow microspheres Particle size microwave absorption properties Low frequency

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Botulinum toxin A inhibits salivary secretion of rabbit submandibular gland

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International Journal of Oral Science 2013年第4期5卷 217-223页

作者： xiao-Feng Shan Hui Xu Zhi-gang Cai Li-Ling Wu guang-Yan Yu Department of Oral and maxillofacial Surgery Peking University School and Hospital of Stomatology Department of Physiology and Pathophysiology Peking University Health Science Center

Botulinum toxin A （BTXA） has been used in several clinical trials to treat excessive glandular secretion; however, the precise mechanism of its action on the secretory function of salivary gland has not been fully elucidated. In this study, we aimed to investigate the effect of BTXA on secretion of submandibular gland in rabbits and to identify its mechanism of action on the secretory function of salivary gland. At 12 weeks after injection with 5 units of BTXA, we found a significant decrease in the saliva flow from submandibular glands, while the salivary amylase concentration increased. morphological analysis revealed reduction in the size of acinar cells with intracellular accumulation of secretory granules that coalesced to form a large ovoid structure. Expression of m3-muscarinic acetylcholine receptor （m3 receptor） and aquaporin-5 （AQP5） mRNA decreased after BTXA treatment, and distribution of AQP5 in the apical membrane was reduced at 1, 2 and 4 weeks after BTXA injection. Furthermore, BTXA injection was found to induce apoptosis of acini. These results indicate that BTXA decreases the fluid secretion of submandibular glands and increases the concentration of amylase in saliva. Decreased expression of m3 receptor and AQP5, inhibition of AQP5 translocation, and cell apoptosis might involve in BTXA-reduced fluid secretion of submandibular lands.

关键词： aquaporin-5 apoptosis botulinum toxin A m3-muscarinic acetylcholine receptor submandibular gland

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Radiological environmental impact analysis of a 2-mW thorium molten salt reactor during an accident

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Nuclear Science and Techniques 2019年第5期30卷 70-81页

作者： Chang-Qi Chen xiao-Bin Xia Zhi-Hong Zhang Jun Cai Chang-Yuan Li Shanghai Institute of Applied Physics Chinese Academy of Sciences University of Chinese Academy of Sciences

The thorium molten salt reactor–liquid fuel(TmSR-LF1) has inherent safety features. The accident occurrence possibility and their consequences are much lower for the TmSR-LF1 than that of traditional *** on accident analysis, the maximum credible accident and the radioactive source terms of the TmSR-LF1 were first estimated. Then, the total effective dose of the maximum credible accident was calculated. Based on calculations, the cover gas flow rate can significantly affect the radiation consequences of the maximum credible accident when it changes from 0 to 10 L/min. If no cover gas is flowing, a site-area emergency would be required within the range of 50–73 m from the reactor. In the case of cover gas flow, only an abnormal notification and an alert two emergency class would be required within the range of 50 m.

关键词： TmSR-LF1 Accident classification and description maximum credible accident Emergency class

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Research on the influence of machining introduced sub-surface defects and residue stress upon the mechanical properties of single crystal copper

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Science China(Technological Sciences) 2010年第12期53卷 3161-3167页

作者： CHEN mingJun, xiao gaoBo, CHEN JiaXuan & WU ChunYa Harbin Institute of Technology, Harbin 150001, China Harbin Institute of Technology

Large scale molecular dynamics simulations of nanomachining and stretching of single crystal copper are performed to analyze the machining process’ influence on the material’s mechanical properties. The simulation results show that the machining process will introduce interfacial defects inside the specimen and enhance the compressive stress beneath the surface. gener- ally speaking, interfacial defects lead to the decrease of the strength limit, while residue compressive stress can enhance the elastic limit and even the strength limit. Various machining parameters are adopted to investigate their influence on the me- chanical behavior of machined specimen. Lower cutting speed and smaller cutting depth lead to less defects and greater residue compressive stress, which brings about better mechanical properties. The elastic limit increases by 36.8% under the cutting depth of 0.73 nm and decreases by 21.1% under the cutting depth of 1.46 nm. The strength limit increases by 7.7% under the cutting speed of 100 m/s and decreases by 28.2% under the cutting speed of 300 m/s.

关键词： nanomachining deformation residue stress molecular dynamics dislocations

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年轻原发性慢性闭角型青光眼周边虹膜切除术与小梁切除术的疗效比较

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眼科 2024年第4期33卷 261-266页

作者：林树芬苏毅华钟毅敏肖辉朱颖婷方蕾陈立明刘杏中山大学中山眼科中心眼病防治全国重点实验室/广东省眼科视觉科学重点实验室/广东省眼部疾病临床医学研究中心广州510060 中山大学附属第一医院眼科广州510080

目的比较周边虹膜切除术(surgical peripheral iridectomy,SPI)与小梁切除术(trabeculectomy,Trab)治疗进展期和晚期年轻原发性慢性闭角型青光眼(chronic primary angle-closure glaucoma,CPACg)的疗效与安全性。设计回顾性比较性病例系列。研究对象2012年1月至2022年12月首次在中山大学中山眼科中心行Trab或SPI、年龄≤40岁的进展期或晚期CPACg连续病例48例(67眼)。方法按手术方式分为Trab组与SPI组,其中Trab组15例(22眼),SPI组33例(45眼)。记录视力、goldmann眼压、影像学及视野检查的结果,比较两组手术成功率及手术并发症发生率、术前与术后的眼部参数情况。主要指标最佳矫正视力、眼压、中央前房深度、降眼压药物种类、房角开放距离、前房夹角、手术成功率。结果48例CPACg患者中位数年龄为32.0(24.3,36.0)岁。Trab组术后平均随访19.6±22.2月;SPI组术后平均随访39.1±20.9个月。Trab组手术成功率为45.5%(10/22眼);SPI组手术成功率80.0%(36/45眼)。SPI组的手术成功率高于Trab组(χ^(2)=15.528,Pg患者行Trab手术成功率较低且手术并发症较多;SPI联合降眼压药物治疗成功率较高且手术并发症较少。对≤40岁的CPACg患者即使是进展期或晚期患者,首次手术可以考虑选择SPI。

关键词：闭角型青光眼小梁切除术周边虹膜切除术

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超声耦合TiO_(2)/UV光催化处理对玉米秸秆组分影响研究

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化学工程师 2024年第2期38卷 9-12,37页

作者：陆佳苏小红尤宏梅刘泽黑龙江省能源环境研究院黑龙江哈尔滨150027

本文采用超声耦合Ti O_(2)/UV光催化处理玉米秸秆,探究处理条件对玉米秸秆组分及结构的影响。研究结果表明,在Ti O_(2)投加量为0.25g·L^(-1)、pH值为8.25、超声强度为0.625W·m L^(-1)、处理1h的条件下,玉米秸秆中木质素和半纤维素含... 详细信息

本文采用超声耦合Ti O_(2)/UV光催化处理玉米秸秆,探究处理条件对玉米秸秆组分及结构的影响。研究结果表明,在Ti O_(2)投加量为0.25g·L^(-1)、pH值为8.25、超声强度为0.625W·m L^(-1)、处理1h的条件下,玉米秸秆中木质素和半纤维素含量分别由未处理前的26.06%、20.58%降低到22.85%、18.39%,纤维素含量由37.67%增加到40.39%。超声耦合Ti O_(2)/UV光催化处理可以破坏玉米秸秆的结构,玉米秸秆断裂破碎成细小碎片,表面粗糙有褶皱。本研究可为超声耦合Ti O_(2)/UV光催化技术在玉米秸秆预处理中的应用提供技术参考。

关键词：超声耦合 TiO_(2)/UV光催化玉米秸秆组分变化

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growth of Black Holes and Their Host Spheroids in (Sub)mm-loud High-Redshift QSOs

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Chinese Journal of Astronomy and Astrophysics 2008年第1期8卷 12-24页

作者： Cai-Na Hao xiao-Yang Xia Shu-De mao Zu-gan Deng Hong Wu Tianjin Astrophysics Center Tianjin Normal University Tianjin 300384 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Institute of Astronomy University of Cambridge Madingley Road Cambridge CB3 0HA UK Jodrell Bank Observatory University of Manchester Macclesfield Cheshire SK11 9DL UK graduate School of Chinese Academy of Sciences Beijing 100049

We study the growth of black holes and stellar population in spheroids at high redshift using several （sub）mm-loud QSO samples. Applying the same criteria established in an earlier work, we find that, similar to IR QSOs at low redshift, the far-infrared emission of these （sub）mm-loud QSOs mainly originates from dust heated by starbursts. By combining low-z IR QSOs and high-z （sub）mm-loud QSOs, we find a trend that the star formation rate （m＊） increases with the accretion rate （mace）. We compare the values of m＊/macc for submm emitting galaxies （Smgs）, far-infrared ultraluminous/hypeduminous QSOs and typical QSOs, and construct a likely evolution scenario for these objects. The （sub）mm-loud QSO transition phase has both high macc and m＊ and hence is important for establishing the correlation between the masses of black holes and spheroids.

关键词： galaxies active - galaxies evolution - galaxies high-redshift - galaxies interactions - quasars general - galaxies starburst

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magnetostratigraphy and provenance of the Qingzhou loess in Shandong province

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Journal of Arid Land 2011年第3期3卷 184-190页

作者： ShuZhen PENg LiJun ZHU guoQiao xiao YanSong QIAO ZhiDong gAO DongDong CHEN Department of Tourism Resources and Environment Taishan University Taian 271021 China College of Urban and Environment Sciences of Shanxi Normal University Linfen 041000 China Key Laboratory of Biogeology and Environmental geology of ministry of Education China University of Geosciences Wuhan 430074 China Institute of geomechanics Chinese Academy of Geological Sciences Beijing 100081 China

Loess deposits with varying thickness are widely distributed on the intermontane valleys and piedmont zones on the northern side of the central Shandong mountainous regions. However, the basal ages and material resources of the loess deposits are not clear. The paper studied the Qingzhou loess profile in Shandong with magnetostratigraphic and optical stimulated luminescence （OSL） methods and further investigated its main provenances with the mineralogical methods. The magnetostratigraphic results showed that the Brunhes/matuyama （B/m） reversal boundary was not recognized, suggesting a basal age younger than 0.78 ma. Extrapolations by sedimentation rates, based on the upper part depositional rate from the OSL age, the basal age of the Qingzhou loess is about 0.5 ma. Until now, older loess deposits have not been reported on the northern side of the central Shandong mountainous regions. The results of the paper indicate that the loess deposits in this area might have strated from the middle Pleistocene. The basal age of Qingzhou loess is approximately synchronous with the Xiashu loess in the middle-lower reaches of Yangtze River. major components of clay minerals in the Qingzhou profile are dominated by illite. Other clay mineral compositions are mainly smectite, chlorite and kaolinite, which are similar with the Xifeng loess in the Loess Plateau. However, the contents of smectite and the ratios of illite and kaolinte in the Qingzhou loess samples are higher than those in the Xifeng loess samples of the Loess Plateau, indicating that the loess in the northern side of the central Shandong mountainous regions has different sources from that of the loess deposits in the Loess Plateau. The clay mineral analysis further reinforces the earlier conclu- sion that the marine strata exposed in the Laizhou Bay and the fluvial plain of the lower reaches of Yellow River during the glacier periods are the main material sources for the Qingzhou loess deposits, which is an indicator t

关键词： Loess magnetostratigraphy sedimentology material provenance Qingzhou

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一种新的连续动作集学习自动机

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数据采集与处理 2015年第6期30卷 1310-1317页

作者：刘晓毛宁中航工业西安航空计算技术研究所西安710065

学习自动机(Learning automation,LA)是一种自适应决策器。其通过与一个随机环境不断交互学习从一个允许的动作集里选择最优的动作。在大多数传统的LA模型中,动作集总是被取作有限的。因此,对于连续参数学习问题,需要将动作空间离散化,... 详细信息

学习自动机(Learning automation,LA)是一种自适应决策器。其通过与一个随机环境不断交互学习从一个允许的动作集里选择最优的动作。在大多数传统的LA模型中,动作集总是被取作有限的。因此,对于连续参数学习问题,需要将动作空间离散化,并且学习的精度取决于离散化的粒度。本文提出一种新的连续动作集学习自动机(Continuous action-set learning automaton,CALA),其动作集为一个可变区间,同时按照均匀分布方式选择输出动作。学习算法利用来自环境的二值反馈信号对动作区间的端点进行自适应更新。通过一个多模态学习问题的仿真实验,演示了新算法相对于3种现有CALA算法的优越性。

关键词：机器学习强化学习在线学习学习自动机连续动作集学习自动机

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Possibilities and challenges of expanding dimensions of waterway downstream of Three gorges Dam

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Water Science and Engineering 2019年第2期12卷 136-144页

作者： Tao Yan Yun-ping Yang Yi-bing Li Yuan-fang Chai xiao-bing Cheng Key Laboratory of Yellow River Sediment Research Ministry of Water ResourcesZhengzhou 450003China Key Laboratory of Engineering Sediment Tianjin Research Institute for Water Transport EngineeringMinistry of TransportTianjin 300456China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China

The waterway in the middle and lower reaches of the Yangtze River has long been known as the golden Waterway and has served as an important link in the construction of the Yangtze River Economic ***,expanding its dimensions is a significant goal,particularly given the long-range cumulative erosion occurring downstream of the Three gorges Dam (TgD),which has been concentrated in the dry river *** the regulation of the volume from upstream reservoirs and the TgD,the minimum discharge and water level of the river downstream are increasing,and creating favorable conditions for the increase of the depth of the *** discharge compensation effect during the dry season offsets the decline in the water level of the river channel caused by the down-cutting of part of the riverbed,but the minimum navigable water level of the segment near the dam still shows a declining *** recent years,several waterway remediation projects have been implemented in the downstream reaches of the TgD and although the waterway depth and width have been increased,the channel dimensions are still insufficient in the Yichang-Anqing reach (with a total length of 1026 km),as compared to the upstream reservoir area and the deep water channel in the downstream tidal reaches.A comprehensive analysis of the water depth and the number and length of shoals in the waterway indicates that its dimensions can be increased to 4.5 m ×200 m and 6.0 m×200 m in the Yichang-Wuhan and Wuhan-Anqing reaches,*** is also feasible given the remediation technologies currently available,but remediation projects need to be coordinated with those for flood prevention and ecological protection.

关键词： Waterway dimension Condition analysis Three gorges Project Yichang-Anqing reach Yangtze River

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