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Fluorescence Properties of Eu^(3+) Doped in Na_5Lu_9F_(32) Single Crystals

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Journal of Wuhan University of Technology(Materials Science) 2019年第2期34卷 317-323页

作者：王珲夏海平 shi xudong CHENG Guanghai ZHANG Jianli Key Laboratory of Photoelectronic Materials Ningbo University

Eu^(3+) ion doped cubic Na_5Lu_9F_(32) single crystals with high quality were synthesized by a modified Bridgman method by using a high 70-90 ℃/cm temperature gradient for cross solid-liquid interface. The optical spectroscopic investigations of the obtained single crystal were reported for the absorption, excitation and emission. The experimental results show that a strong red emission at 609 nm attributing to the ~5D_0→~7F_2 transition of Eu^(3+) doped Na_5Lu_9F_(32) single crystals can be obtained under the excitation of 394 nm light and reach the maximum when the Eu^(3+) doping concentration is 4 mol% in present research. The local covalent is enhanced and symmetry is reduced with the increase of Eu^(3+) concentrations inferring from the strength parameters Ω_2 and Ω_4 calculated by their measured emission spectra. The CIE chromaticity coordinates of the 4 mol% Eu^(3+) doped Na_5Lu_9F_(32) single crystals are calculated as(x=0.626, y=0.3736), which are close to the NTSC standard values for red(x=0.67, y=0.33). The experimental results reveal that the single crystal can be used as potential red phosphors under near ultraviolet(NUV) light excitation.

关键词： optical materials crystal growth red phosphors rare earth

An analysis of the Circumferential Grooves Casing Treatment for transonic compressor flow

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Science China(Physics,Mechanics & Astronomy) 2010年第2期53卷 353-359页

作者： HUANG xudong,CHEN HaiXin,shi Ke & FU Song School of Aerospace,Tsinghua University,Beijing 100084,China 1. School of Aerospace Tsinghua University Beijing 100084 China

The stall mechanism of the NASA Rotor 37 is investigated through the analysis of the critical flow structures near the stall under the transonic condition. The performance of the rotor with Circumferential Grooves Casing Treatment (CGCT) is also studied based on the Reynolds-Averaging Navier-Stokes approach. The study finds that stall margin improvement can be achieved without significant penalty on the efficiency for the two CGCT configurations applied. The effects of circumferential grooves on the critical flow structures are studied through the analysis of the tip leakage mass and momentum transport that further re-veal the CGCT mechanism.

关键词： transonic compressor Circumferential Grooves Casing Treatment stall margin leakage mass and momentum trans-portation analysis

Failure characteristics and the damage evolution of a composite bearing structure in pillar-side cemented paste backfilling

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International Journal of Minerals,Metallurgy and Materials 2023年第8期30卷 1524-1537页

作者： Boqiang Cui Guorui Feng Jinwen Bai Gaili Xue Kai Wang xudong shi Shanyong Wang Zehua Wang Jun Guo College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China Key Laboratory of Shanxi Province for Mine Rock Strata Control and Disaster Prevention Taiyuan 030024China Shanxi Coking Coal Group Co. Ltd.Taiyuan 030024China Priority Research Centre for Geotechnical Science and Engineering School of EngineeringThe University of NewcastleCallaghanNSW 2308Australia

A backfilling body-coal pillar-backfilling body(BPB)structure formed by pillar-side cemented paste backfilling can bear overburden stress and ensure safe ***,the failure response of BPB composite samples must be *** paper examines the deformation characteristics and damage evolution of six types of BPB composite samples using a digital speckle correlation method under uniaxial compression conditions.A new damage evolution equation was established on the basis of the input strain energy and dissipated strain energy at the peak *** prevention and control mechanisms of the backfilling body on the coal pillar instability were *** results show that the deformation localization and macroscopic cracks of the BPB composite samples first appeared at the coal-backfilling interface,and then expanded to the backfilling elements,ultimately appearing in the coal *** elastic strain energy in the BPB composite samples reached a maximum at the peak stress,whereas the dissipated energy continued to accumulate and *** damage evolution curve and equation agree well with the test results,providing further understanding of instability prevention and the control mechanisms of the BPB composite *** restraining effect on the coal pillar was gradually reduced with decreasing backfilling body element's volume ratio,and the BPB composite structure became more vulnerable to *** research is expected to guide the design,stability monitoring,instability prevention,and control of BPB structures in pillar-side cemented paste backfilling mining.

关键词： backfilling body-coal pillar-backfilling body composite structure digital speckle correlation method uniaxial compression deformation characteristics damage evolution

HPTLC-fluorescent densitometry for screening aflatoxin B1 in millet and buckwheat

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Food Science and Human Wellness 2024年

作者： xudong shi Xingjun Xi Yuetao Jia Zhijian Wang Jiawei Guo shiyao Wang Xiaoqian Tang Yisheng Chen College of Food Science and Engineering， Shanxi Agricultural University China National Institute of Standardization Key Laboratory of Detection for Mycotoxins， Ministry of Agriculture and Rural Affairs Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences

Given severe health-hazardous effects of aflatoxin B1 (AFB1) widely occurring in cereal grains and animal feeds， it is highly urgent to develop analytical methods for its rapid screening. In this work， we proposed a simple and high-throughput method for the determination of AFB1 in millet and buckwheat samples using high performance thin layer chromatography (HPTLC) linked to fluorescence densitometry. The first step was to optimize the solid-liquid extraction for the crude clean-up of the samples. The QuEChERS (Quick， Easy， Cheap， Effective， Robust and Safe) extraction strategy was used and different solvent systems for their extraction efficiency of AFB1 from the samples were evaluated. Then， trichloromethane/ethyl acetate (7/3， v/v) was used as the mobile phase to realize the separation of the targeted compound from background noises on silica gel plates. Quantification was readily performed with densitometry in fluorescence mode. In order to fix the optimal excitation wavelength， spectra scanning from 250-400 nm was carried out， revealing that 364 nm light gave the highest signal. With the optimized optical system， high sensitivity to AFB1 was achieved， with a limit of detection (LOD) at 3 μg/kg. Apart from that， good linearity (0.999) was obtained within the range of 1-80 ng/band of AFB1. To assess the analysis accuracy， two levels of AFB1 (50 and 100 μg/kg) were spiked into real grain samples. The obtained results showed that the recovery rates were within the range of (81.6–114.0)%. The proof-of-concept results of this work evidenced that HPTLC is a promising analytical tool for the screening of mycotoxin in difficult samples.

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Combined tests with Xpert MTB/RIF assay with bronchoalveolar lavage fluid increasing the diagnostic performance of smear-negative pulmonary tuberculosis in Eastern China

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Combined tests with Xpert MTB/RIF assay with bronchoalveolar...

Low-intensity focused ultrasound stimulation promotes stroke recovery via astrocytic HMGB1 and CAMK2N1 in mice

中国防痨协会2023年第34届全国学术大会暨结核病诊防治新技术推广应用论坛

作者： Qiao Liu xudong shi Yi Zeng Department of Chronic Communicable Disease Center for Disease Control and Prevention of Jiangsu Province Nanjing Second Hospital Nanjing Hospital Affiliated to Nanjing University of Traditional Chinese Medicine

Tuberculosis(TB) remains a global public health *** and delayed therapy of sputum smear-negative TB can affect the treatment outcomes and promote pathogen *** application of Xpert MTB/RIF assay in bronchoalveolar lavage fluid(BALF) has been recommended but needs clinical *** carried out a prospective study in the Nanjing Public Health Medical Center from September 2018 to August *** tuberculosis(PTB) patients were enrolled in the study if they had negative results of sputum *** compared the performance of Xpert MTB/RIF assay in sputum and BALF using sputum culture as the *** addition to this,we applied parallel tests using sputum culture,sputum-based Xpert MTB/RIF assay and BALF-based Xpert MTB/RIF assay to jointly detect smear-negative PTB using clinical diagnosis as the *** mycobacterial culture as the reference standard,Xpert MTB/RIF of BALF showed a higher sensitivity(14/16,87.5%),but a relatively lower specificity(57/92,62.0%).Xpert MTB/RIF of sputum showed relatively lower sensitivity(6/10,60.0%) and higher specificity(63/88,71.6%).Compared with sputum culture,Xpert MTB/RIF assay reduced the median detection time of MTB from 30 to 0 days,which significantly shortened the diagnosis time of the smear-negative TB *** the combined detections,the positive detection proportion was improved with significant differences comparing with sputum culture only,from 11.1%(10/90) to 46.7%(42/90)(P < 0.05).Our study showed Xpert MTB/RIF in BALF had a better performance in detecting MTB of smear-negative patients.

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Stroke & Vascular Neurology 2024年第5期9卷 505-518页

作者： Lin Qi Cheng Wang Lidong Deng Jia-Ji Pan Qian Suo Shengju Wu Lin Cai xudong shi Junfeng Sun Yongting Wang Yaohui Tang Weibao Qiu Guo-Yuan Yang Jixian Wang Zhijun Zhang Shanghai Jiao Tong Affiliated Sixth People's Hospital School of Biomedical EngineeringShanghai Jiao Tong UniversityShanghaiShanghaiChina Department of Neurosurgery Huashan HospitalShanghai Medical CollageFudan UniversityShanghaiChina Department of Neurosurgery Shanghai Sixth People’s Hospital Affiliated to Shanghai Jiao Tong UniversityShanghaiChina Paul C.Lauterbur Research Center for Biomedical Imaging Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesBeijingChina Neuroscience and Neuroengineering Center Shanghai Jiao Tong University School of Biomedical EngineeringShanghaiChina Shanghai Jiao Tong University Medical School Affiliated Ruijin Hospital ShanghaiChina

Background Low-intensity focused ultrasound stimulation(LIFUS)has been developed to enhance neurological repair and remodelling during the late acute stage of ischaemic stroke in ***,the cellular and molecular mechanisms of neurological repair and remodelling after LIFUS in ischaemic stroke are *** Ultrasound stimulation was treated in adult male mice 7 days after transient middle cerebral artery *** was measured by laser speckle imaging and histological *** and fibre photometry records were used for *** atrophy volume and neurobehaviour were assessed 0–14 days after *** proteomic analysis was performed to explore the differentially expressed ***-seq was used for subcluster analysis of *** in situ hybridisation and Western blot detected the expression of HMGB1 and *** Optimal ultrasound stimulation increased cerebral blood flow,and improved neurobehavioural outcomes in ischaemic mice(p<0.05).iTRAQ proteomic analysis revealed that the expression of HMGB1 increased and CAMK2N1 decreased in the ipsilateral hemisphere of the brain at 14 days after focal cerebral ischaemia with ultrasound treatment(p<0.05).scRNA-seq revealed that this expression pattern belonged to a subcluster of astrocytes after LIFUS in the ischaemic *** upregulated HMGB1 expression,accompanied by VEGFA elevation compared with the control group(p<0.05).Inhibition of HMGB1 expression in astrocytes decreased microvessels counts and cerebral blood flow(p<0.05).LIFUS reduced CAMK2N1 expression level,accompanied by increased extracellular calcium ions and glutamatergic synapses(p<0.05).CAMK2N1 overexpression in astrocytes decreased dendritic spines,and aggravated neurobehavioural outcomes(p<0.05).Conclusion Our results demonstrated that LIFUS promoted angiogenesis and synaptogenesis after focal cerebral ischaemia by upregulating HMGB1 and downregulating CAMK2N1 in

关键词： stimulation behaviour intensity

不同溶剂制备的聚乳酸多孔微球的形成机理(英文)

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高分子学报 2011年第8期21卷 866-873页

作者：石旭东孙磊甘志华中国科学院化学研究所工程塑料院重点实验室北京100190 北京积水潭医院北京市创伤骨科研究所北京100035

利用改进的双乳液溶剂挥发法制备了多孔聚乳酸(PLA)微球.通过采用具有不同沸点和水溶性的有机溶剂制备得到不同多孔结构的PLA微球.结果发现以二氯甲烷、氯仿和甲苯为溶剂制备的微球具有相似的均匀多孔结构,而以乙酸乙酯制备的微球却具... 详细信息

利用改进的双乳液溶剂挥发法制备了多孔聚乳酸(PLA)微球.通过采用具有不同沸点和水溶性的有机溶剂制备得到不同多孔结构的PLA微球.结果发现以二氯甲烷、氯仿和甲苯为溶剂制备的微球具有相似的均匀多孔结构,而以乙酸乙酯制备的微球却具有中空结构和多孔的壳层.通过进一步的实验研究了溶剂种类对于微球多孔结构的影响.结果表明溶剂的移出速率对于微球的多孔结构起到决定作用.最后在以上实验基础上探讨了以不同溶剂制备多孔微球的形成机理.

关键词：聚乳酸多孔微球溶剂移出速率

Study on the Manufacturability Evaluation Based on Double-layer Model of Manufacturing Resources

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High Technology Letters 2001年第2期7卷 61-65页

作者：石旭东 FU Yili Dai Yong Ma Yulin Advanced Manufacturing Technology Center Harbin Institute of Technology

Virtual organization is a new production patter and a principal part in advanced manufacturing systems such as agile manufacturing. Manufacturability evaluation is the necessary condition to form the virtual organization. A new manufacturability evaluation approach is described in this paper, which is carried out based on every process feature under the double-layer model of manufacturing resources proposed by authors. The manufacturing resources that build up the virtual organization are selected according to the results of manufacturability evaluation.

关键词： Manufacturability evaluation Double-layer model of manufacturing resources Virtual organization

端三吡啶基聚异丙基丙烯酰胺的合成及其金属配合物

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高分子学报 2010年第4期20卷 383-389页

作者：孙培健石旭东甘志华中国科学院化学研究所工程塑料实验室北京100190 中国科学院研究生院北京100039

合成出三吡啶官能化的二硫代酯并以其作为链转移剂进行了异丙基丙烯酰胺(NIPAAm)的可逆加成断裂链转移(RAFT)聚合,得到分子量可控和窄分子量分布的端三吡啶基聚异丙基丙烯酰胺(tpy-PNIPAAm),聚合反应为对单体浓度的一级动力学关系.Tpy-P... 详细信息

合成出三吡啶官能化的二硫代酯并以其作为链转移剂进行了异丙基丙烯酰胺(NIPAAm)的可逆加成断裂链转移(RAFT)聚合,得到分子量可控和窄分子量分布的端三吡啶基聚异丙基丙烯酰胺(tpy-PNIPAAm),聚合反应为对单体浓度的一级动力学关系.Tpy-PNIPAAm在水中既保持了与聚异丙基丙烯酰胺类似的相转变行为,又拥有三吡啶(tpy)的强络合能力.将tpy-PNIPAAm与金属核素模型进行络合得到金属配合物,所得金属配合物在水中拥有与PNIPAAm类似的相转变行为,同时tpy-PNIPAAm的金属配合物由于其两亲性,在水中可以形成纳米粒子,由于纳米粒子间的静电排斥作用,这种纳米粒子即使在高于相转变温度时,仍能稳定于水中.

关键词： RAFT聚合三吡啶聚异丙基丙烯酰胺温度敏感性核素