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Effect of Ti content on microstructures and mechanical properties of cast Al-2Li-2Cu-0.5Mg alloy

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China Foundry 2023年第3期20卷 179-188页

作者： You-jie Guo Dong-chen Yang Liang Zhang Guo-hua Wu Yi-xiao Wang Pei-sen Li Guang-xiao ren Liang-bin Li Xun-man Xiong National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanxi Jianghuai Heavy Industry Co. Ltd.Jincheng 048000ShanxiChina Jiangxi Ganfeng Lithium Co. LtdXinyu 338004JiangxiChina

Ti is regarded as one of the promising grain refiners in cast Al-Li-Cu alloys,but few research works have been done on its independent *** this study,the effect of Ti on the microstructure evolution and mechanical properties of cast Al-2Li-2Cu-0.5Mg base alloy was *** results revealed that the grains can be prominently refined with the increase of Ti *** adding Ti,high density TiB_(2)-Al_(3)Ti composite particles with a low lattice misfit form as heterogeneous nucleation sites for the α-Al matrix.δ’(Al3Li) and T_(1)(Al_(2)CuLi) precipitates that provide enhanced strength are dominated in the alloys after T6 aging *** average size of both δ’ and half-width of δ’-precipitation free zone(PFZ) decreases gradually with the increase of Ti *** is because the higher binding energy between Ti atoms and vacancies limits the diffusion efficiency of Li atoms,and thus results in a higher ***,no nano-sized Al_(3)Ti or core-shell structure of Al_(3)(Li,Ti) particles are *** tensile property test results indicate that the Al-2Li-2Cu-0.5Mg alloy achieves optimal properties after aging at 175 °C for 32 h when 0.15wt.% Ti is *** exhibits a yield strength of 352±5 MPa,an ultimate tensile strength of 423±6 MPa,and an elongation of(3±0.4)%.These findings are expected to offer a reliable theoretical guidance for the industrial composition design of the Al-Li-Cu series cast alloys.

关键词： cast Al-Li-Cu alloy Ti content grain refiner mechanical property microstructure

Biliary cystadenocarcinoma diagnosed with real-time contrast-enhanced ultrasonography:Report of a case with diagnostic features

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World Journal of Gastroenterology 2010年第1期16卷 131-135页

作者： ren, xiao-Long Yan, Rui-Ling Yu, xiao-Hui Zheng, Ying Liu, Jun-E Hou, xiao-Bin Zuo, Si-Yang Fu, xiao-Yan Chang, Hong Lu, Jian-Hong Gen Hosp Lanzhou Mil Area Command Dept Ultrasonog Lanzhou 730050 Gansu Peoples R China

Biliary cystadenocarcinoma is a very rare malignant cystic tumor of the liver,which is often misdiagnosed due to a poor recognition of *** report a case of a 60-year-old man with biliary cystadenocarcinoma with his real time contrast enhanced ultrasound(CEUS)characteristics compared to those of computed tomography(CT)and magnetic resonance imaging(MRI),which were correlated with the surgical and pathologic *** wall enhancement,internal septations and intra-cystic solid portions in the arterial phase were observed on CEUS after contrast agent *** enhancement was washed out progressively and depicted as hypo-enhancement in the portal and late *** revealed a large irregular cystic lesion in the left liver lobe with no clear septations and solid *** showed an irregular cystic occupying lesion with septations.

关键词： Biliary cystadenocarcinoma Cystic neoplasm Hepatic disease Contrast medium Ultrasonography

Recent progress in single crystal perovskite X-ray detectors

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Science China(Information Sciences) 2024年第3期67卷 5-19页

作者： xiao LIU Jun ren Yu-Ang CHEN Xiangshun GENG Dan XIE Tian-Ling ren School of Integrated Circuits Tsinghua University Beijing National Research Center for Information Science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

Online estimation and characteristic analysis of double nugget diameters during aluminum/steel resistance spot welding process

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Journal of Iron and Steel Research International 2024年第8期31卷 2053-2067页

作者： Kang Zhou Wen-xiao Yu Bao-kai ren Gang Wang School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

Online estimation of the double nugget diameters was performed by means of a back propagation neural *** double nugget diameters were obtained using actual welding experiment and numerical simulation,according to different characteristics of aluminum nugget and steel *** input of the neural network was some key characteristic parameters extracted from dynamic power signal,which were peak point,knee point and their variation rate over time,as well as heat energy delivered into the welding *** architecture of the neural network was confirmed by confirming the number of neurons in hidden layer through a series of *** key parameters of the neural network were obtained by means of training 81 arrays of data ***,the neural network was used to test the remaining 20 arrays of verifying data set,and the results showed that both of the mean errors for the two nugget diameters were below 3%.In addition,corresponding analyses showed that the accuracy of two nugget diameters was higher than that of tensile-shear strength.

关键词： Resistance spot welding Aluminum Steel Double nugget Dynamic power signal.Neural network

Evaluation of high-resolution satellite precipitation products with surface rain gauge observations from Laohahe Basin in northern China

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Water Science and Engineering 2010年第4期3卷 405-417页

作者： Shan-hu JIANG Li-liang ren Bin YONG xiao-li YANG Lin SHI State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 P. R. China

Three high-resolution satellite precipitation products, the Tropical Rainfall Measuring Mission （TRMM） standard precipitation products 3B42V6 and 3B42RT and the Climate Precipitation Center＇s （CPC） morphing technique precipitation product （CMORPH）, were evaluated against surface rain gauge observations from the Laohahe Basin in northern China. Widely used statistical validation indices and categorical statistics were adopted. The evaluations were performed at multiple time scales, ranging from daily to yearly, for the years from 2003 to 2008. The results show that all three satellite precipitation products perform very well in detecting the occurrence of precipitation events, but there are some different biases in the amount of precipitation. 3B42V6, which has a bias of 21%, fits best with the surface rain gauge observations at both daily and monthly scales, while the biases of 3B42RT and CMORPH, with values of 81% and 67%, respectively, are much higher than a normal receivable threshold. The quality of the satellite precipitation products also shows monthly and yearly variation： 3B42RT has a large positive bias in the cold season from September to April, while CMORPH has a large positive bias in the warm season from May to August, and they all attained their best values in 2006 （with 10%, 50%, and -5% biases for 3B42V6, 3B42RT, and CMORPH, respectively）. Our evaluation shows that, for the Laohahe Basin, 3B42V6 has the best correspondence with the surface observations, and CMORPH performs much better than 3B42RT. The large errors of 3B42RT and CMORPH remind us of the need for new improvements to satellite precipitation retrieval algorithms or feasible bias adjusting methods.

关键词： satellite precipitation product TRMM 3B42RT TRMM 3B42V6 CMORPH surface rain gauge observation Laohahe Basin

Risk factors for depression in patients with chronic obstructive pulmonary disease

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World Journal of Psychiatry 2020年第4期10卷 59-70页

作者： Hui-Ming Yao ren-Sen xiao Ping-Liang Cao xiao-Lei Wang Wei Zuo Wei Zhang Department of Respiratory and Critical Care Medicine The First Affiliated Hospital of Nanchang UniversityNanchang 330006Jiangxi ProvinceChina Second Department of Cardiovascular Medicine Jiangxi Provincial People's Hospital Affiliated to Nanchang UniversityNanchang 330006Jiangxi ProvinceChina

BACKGROUND The prevalence of depression in patients with chronic obstructive pulmonary disease(COPD)ranges from 10%to 42%,but the diagnosis of depression in patients with COPD is often unrecognized and *** depression has major implications for compliance with medical treatment,prolonged lengths of stay,increased frequency of hospital admissions,and increased consultations with primary care *** studies have attempted to identify risk factors for progression,prognosis and response to therapy in patients with ***,few studies have examined the risk factors for depression in patients with COPD,and some results remain *** To identify the potential risk factors to define patients with COPD who are at“high risk”of *** The clinical data of 293 patients with COPD were reviewed from January 2017 to December *** correlations between demographics,clinical characteristics and depression were *** risk factors for depression in patients with COPD were identified by multivariate logistic regression *** cutoff value,sensitivity and specificity of the independent correlation factors were calculated with a receiver operating characteristic *** Of the 293 patients included,65(22.18%)individuals were identified to have *** differences were detected between patients with and without depression in terms of body mass index(BMI),forced expiratory volume in 1 s(FEV1),and COPD assessment test(CAT)score(all P<0.05).Low BMI,low FEV1,and high CAT were independent risk factors for depression in patients with COPD and the cutoff values of BMI,FEV1,and CAT scores were 21.373 kg/m2,0.855 L and 12.5,*** Low BMI,low FEV1,and high CAT score were identified as independent risk factors for depression in patients with COPD.

关键词： Depression Chronic obstructive pulmonary disease Body mass index Forced expiratory volume in 1 second Chronic obstructive pulmonary disease assessment test scores Risk factors

Growth of Self-Catalyzed InP Nanowires by Metalorganic Chemical Vapour Deposition

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Chinese Physics Letters 2012年第12期29卷 145-147页

作者： LV xiao-Long ZHANG Xia YAN Xin LIU xiao-Long CUI Jian-Gong LI Jun-Shuai HUANG Yong-Qing ren xiao-Min State Key Laboratory of Information Photonics&Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876

The fabrication of self-catalyzed InP nanowires(NWs)is investigated under different growth *** droplets induced by surface reconstruction act as nucleation sites for NW *** standing NWs with uniform cross sections are obtained under optimized *** is confirmed that the growth rate of NWs is strongly affected by the surface diffusion adatoms while contributions from the direct impingement of vapor species onto the In droplets can be *** results indicate that the droplet acts as an adatom collector rather than a ***,the diffusion flow rate of adatoms increases with time at the beginning of growth and stabilizes as the growth proceeds.

关键词： nanowires diffusion negligible

Effects of Hot Bending Parameters on Microstructure and Mechanical Properties of Weld Metal for X80 Hot Bends

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Journal of Iron and Steel Research International 2014年第12期21卷 1129-1135页

作者： Xu WANG Bo LIAO Da-yong WU Xiu-lin HAN Yuan-sheng ZHANG Fu-ren xiao Key Laboratory of Metastable Materials Science and Technology College of Materials Science and EngineeringYanshan University CNPC Bohai Petroleum Equipment Manufacture Co. Ltd. China Petroleum Technology and Development Corporation

Mechanical properties of weld metal are the key factors affecting the quality of heavy-wall X80 hot induction bends. The effects of bending parameters on the mechanical properties of weld metal for hot bends were investigated by simulation conducted on a Gleeble 3500 thermal simulator. Continuous cooling transformation （CCT） dia- grams of the weld metal were also constructed. The influences of hot bending parameters （such as reheating temperature, cooling rate, and tempering temperature） on the microstructure and mechanical properties of weld metal were also analyzed. Results show that the strength of all weld metal specimens is higher than the value indicated in the technical specification and increases with the increase of reheating temperature, cooling rate, and tempering tempera ture. The impact toughness is apparently related to the variation of reheating temperature, cooling rate, and tempering temperature.

关键词： hot induction bend X80 steel weld metal heat treatment microstructure

Lactic Acid Reduces LPS-Induced TNF-a and IL-6 mRNA Levels Through Decreasing I?Ba Phosphorylation

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Journal of Integrative Agriculture 2013年第6期12卷 1073-1078页

作者： XU Guang-yong JIANG Jin-qi WANG Ming LI Jie SU Jing-liang ren xiao-ming Animal Science and Technology College Beijing University of Agriculture Beijing Key Laboratory of Traditional Chinese Veterinary Medicine Beijing University of Agriculture College of Veterinary Medicine China Agricultural University

This study explored the effects over time of lactic acid （LA） on IκBα phosphorylation and nuclear factor-kappa B （NF-κB） p65 protein expression, and on tumor necrosis factor a （TNF-α） and interleukin-6 （IL-6） mRNA levels in rat intestinal mucosa microvascular endothelial cells （RIMMVECs） stimulated by lipopolysaccharide （LPS）. I？Ba, phosphorylated IκBa （p-IκBa） and p65 protein levels were monitored by Western blot analysis, and TNF-a and IL-6 mRNA levels were analyzed using real-time PCR. LA treatment reduced TNF-a and IL-6 mRNA levels in LPS-stimulated RIMMVECs, with the greatest effect being after 3 h. The highest inhibitory effect of LA on IκBa phosphorylation to prevent activation of NF-κB was after 6 h. These results suggest that LA reduces TNF-a and IL-6 mRNA levels through decreasing IκBa phosphorylation and blocking the dissociation of IKK complex, which prevents activation of NF-κB.

关键词： lactic acid TNF-a IL-6 IκBa NF-κB