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Hot deformation behavior and microstructure evolution of GH3536-TiBcomposites fabricated by powder metallurgy

Science China Technological Sciences 2024年

作者： ZHOU ShiPeng WANG Shuai HUANG LuJun ZHANG Rui chen xin MENG FanChao chen Run SUN FengBo WANG CunYu GENG Lin School of Materials Science and Engineering Harbin Institute of Technology State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Waikato Centre for Advanced Materials and Manufacturing School of Engineering University of Waikato

The hot deformation behavior and microstructure evolution of GH3536-TiB2composites fabricated by powder metallurgy(PM)were examined in the temperature range of 950–1150°C and strain rate range of 0.001–1s-1. The hot compression stress-strain curves and the constitutive equation were obtained. In addition, the hot processing map was drawn, which indicated that the appropriate hot working window was 950–1050°C/0.001–0.1 s-1and 1050–1100°C/0.001–0.01 s-1. The microstructure analysis showed that the splitting and spheroidization of M3B2led to a decrease in size and volume fraction at 950–1100°C. At 1150°C,the eutectic microstructure of M3B2+ γ was formed due to the dissolution of M3B2, which caused macroscopic cracking of the deformed sample. Additionally, the deformation temperature and the strain rate had little effect on the size and volume fraction of M3B2. Besides, discontinuous dynamic recrystallization(DDRX) and continuous dynamic recrystallization(CDRX) were found in the deformed microstructure, while the former was dominant. Within the test range of this work, the dynamic recrystallization(DRX) fraction of the deformed composites was high due to the bulging nucleation of numerous interfaces. The DRX grain size increased with increasing deformation temperature or decreasing strain rate. Texture analysis showed that the deformation texture of //compression direction RD existed in the matrix when the deformation temperature was below 1100°C, and the texture type became //RD at 1100°C. Additionally, it was also found that the //RD texture was formed in M3B2under the strain rates of 0.1 and 0.01 s-1.

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Homojunction and ohmic contact coexisting carbon nitride for efficient photocatalytic hydrogen evolution

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Nano Research 2023年第7期16卷 8782-8792页

作者： Xiao Fang Lu chen Hongrui cheng Xiaoqiong Bian Wenhao Sun Kaining Ding xinghe Xia xin chen Jiefang Zhu Yuanhui Zheng College of Chemistry Fujian Provincial Key Laboratory of Advanced Inorganic Oxygenated MaterialsFuzhou UniversityFuzhou 350116China Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350116China College of Physics and Information Engineering Fuzhou UniversityFuzhou 350116China Department of Chemistry−Ångström Laboratory Uppsala UniversityUppsala SE-75121Sweden The Key Laboratory for Ultrafine Materials of The Ministry of Education East China University of Science and TechnologyShanghai 200237China

Carbon nitride(CN)has attracted intensive attention as a visible light photocatalyst,but the rapid recombination of photogenerated charge carriers limits its photocatalytic activity.Herein,we develop a new strategy to construct both homojunction and ohmic junction into CN via selectively introducing metallized CN(MCN),which leads to rapid separation and transfer of photogenerated charge carriers.The polymerization of urea in the presence of KOH creates CN homojunction with amino and cyano groups.The subsequent molten salt treatment induces a new type of cyano-terminated CN that can be converted to MCN through photodoping,forming homojunction and ohmic contact coexisting CN(HOCN).The formed HOCN photocatalyst exhibits a high photocatalytic H_(2)evolution rate of 18.5 mmol·g^(-1)·h^(-1)under visible light irradiation,45-fold higher than that of bulk CN.This strategy provides a new idea for designing ohmic contact between semiconductor and metal,and realizing efficient photocatalysis by improving charge separation and transfer.

关键词： carbon nitride photocatalysis homojunction ohmic contact hydrogen evolution

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Optimizing geometric configuration of single Zn-N_(4) sites for boosting reciprocal transformation between aromatic alcohols and aldehydes

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Nano Research 2023年第7期16卷 9132-9141页

作者： Shengjie Wei Yucheng Jin Chunlin Lv Chao Lian Zheng chen Xiao Liang Qinghua Zhang xin chen Dongdong Qi Zhi Li School of Materials Science and Engineering Nankai UniversityTianjin 300350China Department of Chemistry Tsinghua UniversityBeijing 100084China Beijing Key Laboratory for Science and Application of Functional Molecular and Crystalline Materials Department of ChemistryUniversity of Science and Technology BeijingBeijing 100083China School of Pharmacy and Center on Translational Neuroscience Minzu University of ChinaBeijing 100081China Department of Chemistry School of ScienceBeijing Jiaotong UniversityBeijing 100091China School of Chemistry and Materials Science Anhui Normal UniversityWuhu 241002China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Beijing Advanced Innovation Center for Materials Genome Engineering Institute of Solid State ChemistryUniversity of Science and Technology BeijingBeijing 100083China College of Chemistry Beijing Normal UniversityBeijing 100875China

It is significant to optimize geometric configuration of metal catalytic sites and boost their catalytic activity.Herein,we synthesized isolated single Zn-N_(4)sites on N-doped carbon(Zn-CN)by pyrolyzing zeolite imidazole framework-8(ZIF-8)at different temperatures.For the reciprocal transformation between benzyl alcohol and benzaldehyde,the catalytic activities of Zn-CN catalysts exhibited a volcano-like trend as the pyrolysis temperatures increased.The optimal catalyst was Zn-CN-900,with outstanding catalytic activity exceeding commercial 20 wt.%Pd/C and 20 wt.%Pt/C,promising to substitute the noble metalbased catalysts.X-ray absorption near-edge structure(XANES)measurements and density functional theory(DFT)calculation revealed the gradual transformation from tetrahedral ZnN_(4)sites of ZIF-8 into planar ZnN_(4)sites above 700℃,with the maximum planar ZnN_(4)sites in Zn-CN-900.The stronger adsorption between reactants and planar ZnN_(4)sites facilitated the activation of reactants compared with tetrahedral ZnN_(4)sites.This work will provide valuable insight into rational design of efficient catalysts by optimizing geometric configuration of catalytic sites.

关键词： geometric configuration single Zn-N_(4)sites benzyl alcohol oxidation hydrogen transfer reaction

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Activation of natural killer T cells contributes to Th1 bias in the murine liver after 14 d of ethinylestradiol exposure

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World Journal of Gastroenterology 2022年第26期28卷 3150-3163页

作者： Meng-Zhi Zou Wei-Chao Kong Heng Cai Meng-Tao xing Zi-Xun Yu xin chen Lu-Yong Zhang xin-Zhi Wang New Drug Screening Center China Pharmaceutical UniversityNanjing 210009Jiangsu ProvinceChina Department of Pharmacology China Pharmaceutical UniversityNanjing 210009Jiangsu ProvinceChina Center for Drug Research and Development Guangdong Pharmaceutical UniversityGuangzhou 510006Guangdong ProvinceChina

BACKGROUND As the main component of oral contraceptives(OCs),ethinylestradiol(EE)has been widely applied as a model drug to induce murine intrahepatic cholestasis.The clinical counterpart of EE-induced cholestasis includes women who are taking OCs,sex hormone replacement therapy,and susceptible pregnant women.Taking intrahepatic cholestasis of pregnancy(ICP)as an example,ICP consumes the medical system due to its high-risk fetal burden and the impotency of ursodeoxycholic acid in reducing adverse perinatal outcomes.AIM To explore the mechanisms and therapeutic strategies of EE-induced cholestasis based on the liver immune microenvironment.METHODS Male C57BL/6J mice or invariant natural killer T(iNKT)cell deficiency(Jα18-/-mice)were administered with EE(10 mg/kg,subcutaneous)for 14 d.RESULTS Both Th1 and Th2 cytokines produced by NKT cells increased in the liver skewing toward a Th1 bias.The expression of the chemokine/chemokine receptor Cxcr6/Cxcl16,toll-like receptors,Ras/Rad,and PI3K/Bad signaling was upregulated after EE administration.EE also influenced bile acid synthase Cyp7a1,Cyp8b1,and tight junctions ZO-1 and Occludin,which might be associated with EEinduced cholestasis.iNKT cell deficiency(Jα18-/-mice)robustly alleviated cholestatic liver damage and lowered the expression of the abovementioned signaling pathways.CONCLUSION Hepatic NKT cells play a pathogenic role in EE-induced intrahepatic cholestasis.Our research improves the understanding of intrahepatic cholestasis by revealing the hepatic immune microenvironment and also provides a potential clinical treatment by regulating iNKT cells.

关键词： Natural killer T cell Th1/Th2 IFN-γ Estrogen Cholestasis

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Prognostic significance of hemoglobin,albumin,lymphocyte,platelet in gastrointestinal stromal tumors:A propensity matched retrospective cohort study

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World Journal of Gastroenterology 2022年第27期28卷 3476-3487页

作者： Zhou Zhao Xiao-Nan Yin Jian Wang xin chen Zhao-Lun Cai Bo Zhang Department of Gastrointestinal Surgery Sichuan University West China HospitalChengdu 610041Sichuan ProvinceChina

BACKGROUND The combined index of hemoglobin,albumin,lymphocyte,and platelet(HALP)can reflect systemic inflammation and nutritional status simultaneously,with some evidence revealing its prognostic value for some tumors.However,the effect of HALP on recurrence-free survival(RFS)in patients with gastrointestinal stromal tumors(GISTs)has not been reported.AIM To investigate the prognostic value of HALP in GIST patients.METHODS Data from 591 untreated patients who underwent R0 resection for primary and localized GISTs at West China Hospital between December 2008 and December 2016 were included.Clinicopathological data,preoperative albumin,blood routine information,postoperative treatment,and recurrence status were recorded.To eliminate baseline inequivalence,the propensity scores matching(PSM)method was introduced.Ultimately,the relationship between RFS and preoperative HALP was investigated.RESULTS The optimal cutoff value for HALP was determined to be 31.5 by X-tile analysis.HALP was significantly associated with tumor site,tumor size,mitosis,Ki67,National Institutes of Health(NIH)risk category,and adjuvant therapy(all P<0.001).Before PSM,GIST patients with an increased HALP had a significantly poor RFS(P<0.001),and low HALP was an independent risk factor for poor RFS[hazard ratio(HR):0.506,95%confidence interval(95%CI):0.291-0.879,P=0.016].In NIH high-risk GIST patients,GIST patients with low HALP had a worse RFS than patients with high HALP(P<0.05).After PSM,458 GIST patients were identified;those with an increased HALP still had significantly poor RFS after PSM(P<0.001)and low HALP was still an independent risk factor for poor RFS(HR:0.558,95%CI:0.319-0.976,P=0.041).CONCLUSION HALP was significantly correlated with postoperative pathology and postoperative treatment.Furthermore,HALP showed a strong ability to predict RFS in GIST patients who underwent radical resection.

关键词： Gastrointestinal stromal tumors Nutrition assessment Immuno-inflammatory-based prognostic scores Prognosis Propensity score

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Heating properties of bridge decks using hydronic heating systems with internal or external circulation tubes

Energy and Built Environment

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Energy and Built Environment 2023年第4期4卷 467-476页

作者： xin chen Gang qiang Kong Han long Liu Qiang Jiang College of Civil Engineering Jiangsu Open UniversityNanjingPR China Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNo.1 Xi kang RoadNanjingJiangsu 210024PR China College of Civil Engineering Chongqing UniversityChongqingPR China Jiang yin Management Center of Urban Major Construction Projects PR China

A comparison analysis of the heating properties of the hydronic heating system of bridge decks with external(exchange tubes installed at the bottom of the existing bridge deck with voids inside)or internal(exchange tubes embedded in pavement of the newly built bridge deck)tubes was carried out through field tests.Two heating methods(constant heating power and constant inlet fluid temperature)were used to analyze the heat exchange flux and the temperature increments as well as thermally induced stress of the slab.Numerical simulation was conducted to model the bridge deck heating process to analyze the temperature distribution of the bridge surface.The results shows that the heat exchange flux are the same under the same constant heating powers for the two embedded tube position heating systems;the maximum temperature increment of the bridge deck surface obtained by the external heating system is 0.46 times that obtained by the internal heating system;the maximum thermally induced stress caused by the external heating is 20.4%of the concrete strength(19.1 MPa),which is much higher than that caused by the internal heating under the same heating powers.The thermal efficiencies of the external and internal heating systems are approximately 24.4%and 47.9%,respectively.Under the same constant inlet temperatures,the temperature increment of the bridge deck caused by the external heating is 20.4%of that of the internal heating.

关键词： Bridge deck Hydronic heating system Thermal efficiency Field test

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Oscillatory velocity in boundary layer over mobile sediment bed under asymmetric wave and current conditions

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Journal of Hydrodynamics 2021年第6期33卷 1242-1254页

作者： xin chen Beijing Engineering Research Center of Safety and Energy Saving Technology for Water Supply Network System China Agricultural UniversityBeijing 100083China Key Laboratory of Water-Sediment Sciences and Water Disaster Prevention of Hunan Province Changsha University of Science and TechnologyChangsha 410114China

The oscillatory flow provides the major dynamic force for the mass and energy transport in estuary and coastal areas.An analytical approximate velocity formula is proposed to evaluate the oscillation in the boundary layer over the mobile sediment bed of the sheet flow induced by the asymmetric wave and current.The velocity formula consists of an oscillatory force part and a constant force part corresponding to the Navier-Stokes equation of the asymmetric oscillatory sheet flow over the mobile sediment bed.The mobile sediment bed is defined by an erosion depth formula with consideration of the phase lag,the acceleration and the flow asymmetry.The wave part includes the phase lead parameters from all components of the free stream velocity.The development of the wave part is affected by the current part through the erosion depth and the boundary layer thickness.The erosion depth,the roughness height and the boundary layer thickness of the mobile sediment bed are introduced into the current part without a transition area for the wave-current eddy viscosity.The current part is induced by the wave eddy viscosity within the boundary layer and influenced by the wave-current apparent roughness outside the boundary layer.The velocity profile and duration are evaluated by an approximate velocity formula through experiments for both asymmetric wave and wave-current cases.The oscillation feature in the boundary layer is illustrated by the approximate velocity formula through the asymmetric wave cases over the mobile sediment bed.

关键词： Analytical approximation asymmetric wave and current eddy viscosity mobile sediment bed oscillatory sheet flow

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量子自注意力神经网络的时间序列预测

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电子科技大学学报 2024年第1期53卷 110-118页

作者：陈欣李闯金凡中金金融认证中心有限公司北京100176

在“量子-经典”混合模式下,设计了多头量子自注意力神经网络预测模型(MQSAPN)用以进行时间序列预测,模型包括多头量子自注意力模块以及变分量子线路预测模块两部分。通过对输入数据按时间步长分别进行量子态编码以及K、Q、V的计算,借... 详细信息

在“量子-经典”混合模式下,设计了多头量子自注意力神经网络预测模型(MQSAPN)用以进行时间序列预测,模型包括多头量子自注意力模块以及变分量子线路预测模块两部分。通过对输入数据按时间步长分别进行量子态编码以及K、Q、V的计算,借鉴已有研究使用高斯函数进行自注意力系数的估计方式,将量子自注意力特征提取后的数据再次编码到变分预测线路中,经过线路演化及测量,最终获取预测结果。完整流程与模型搭建均采用VQNet框架实现。在天气学变量的时间序列预测任务中,该模型表现出与经典多头自注意力模型预测模型以及长短期记忆单元网络模型相当的预测精度。此外,相对于同样是量子机器学习的data-reuploading变分线路而言,在近乎同等规模线路深度与参数量的前提下,表现出更高的预测精度,这也进一步验证了引入量子自注意力机制的有效性。值得指出的是,作为预测部分的变分线路会随着输入数据量的增多(如时间窗加长、特征变量规模增加等),其参数量与线路深度也会显著增加,尽管多层QSA能够较好地进行特征表达,但依然有可能因遇到“贫瘠高原”困难而成为整个网络的瓶颈。

关键词：量子计算量子机器学习自注意力机制时间序列预测

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阴道微生态与高危型人乳头瘤病毒感染患者人乳头瘤病毒清除率的相关性

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中国微生态学杂志 2024年第5期36卷 594-597页

作者：陈鑫安吉县妇幼保健院妇科浙江湖州313300

目的探讨女性阴道微生态与高危型人乳头瘤病毒(HR-HPV)感染患者HPV清除率之间的关系,为临床防治宫颈癌提供新思路。方法选取2020年5月至2022年6月于我院就诊的女性生殖道感染患者作为研究对象,收集患者的病例信息、阴道分泌物及HPV核酸... 详细信息

目的探讨女性阴道微生态与高危型人乳头瘤病毒(HR-HPV)感染患者HPV清除率之间的关系,为临床防治宫颈癌提供新思路。方法选取2020年5月至2022年6月于我院就诊的女性生殖道感染患者作为研究对象,收集患者的病例信息、阴道分泌物及HPV核酸检测标本并进行阴道微生态检查。对所有HR-HPV患者连续随访1.5年并每间隔6个月进行1次生殖道HPV分型检测,间隔3个月复查1次白带常规。使用二元Logistic回归分析HR-HPV清除率与阴道微生态的关系。结果HPV分型显示HPV 16、52、58型感染人数最多,分别为39例(27.46%)、28例(19.72%)、32例(22.54%)。阴道微生态检查结果显示,23例(7.37%)患者诊断为滴虫性阴道炎(TV),132例(42.31%)患者诊断为外阴阴道假丝酵母病(VVC),157例(50.32%)患者诊断为细菌性阴道病(BV)。单因素分析结果显示,TV、VVC不是HR-HPV感染的危险因素(χ^(2)=1.988,P=0.159;χ^(2)=1.765,P=0.184),BV是HR-HPV感染的危险因素(χ^(2)=4.200,P=0.040)。110例HR-HPV阳性患者中,有67例患者阴道微生态改善,其中有41例(61.19%)患者HPV核酸检测结果为阴性;43例患者阴道微生态未改善,但有15例(34.88%)患者HPV核酸检测结果转阴,提示阴道微生态可能是HR-HPV清除率的影响因素(χ^(2)=7.254,P=0.007)。二元Logistic回归分析结果显示阴道微生态改善是HR-HPV清除(转阴)的保护因素(OR=0.340,95%CI:0.153~0.754,P=0.008)。结论阴道微生态改善可以显著提高HR-HPV清除率,是HR-HPV清除的保护因素。

关键词：阴道微生态高危型人乳头瘤病毒清除率宫颈癌

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Electroacupuncture alleviates water avoidance stress-induced irritable bowel syndrome in mice by improving intestinal barrier functions and suppressing the expression of inflammatory cytokines

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Journal of Traditional Chinese Medicine 2023年第3期43卷 494-500页

作者： SUN Mengzhu ZHANG Yujie SONG Yafang GUO Jing WANG Yuhang xin chen GU Dongmei SUN Jianhua PEI Lixia Department of acupuncture Affiliated Hospital of Nanjing University of Chinese MeidicneNanjing 210023China Department of acupuncture Jiangsu Province Hospital of Chinese MedicineNanjing 210029China

OBJECTIVE:To evaluate the effects and related mechanisms of electroacupuncture(EA)on irritable bowel syndrome(IBS).METHODS:Male C57BL/6 mice were randomly allocated into normal,model,and EA groups.Experimental IBS mice models were established by exposure to water avoidance stress(WAS).Mice in the EA group were treated with EA at bilateral Tianshu(ST 25)and Zusanli(ST 36)for 7 consecutive days,15 min each day.Abdominal withdrawal reflex(AWR)tests and intestinal motility tests were performed to evaluate visceral sensitivity and intestinal motility of mice.Expression levels of tight junction proteins(TJPs)and inflammatory cytokines in colon tissues were determined through immunofluorescence,real-time polymerase chain reactions(PCR)and Western blot assays.RESULTS:EA alleviated visceral hypersensitivity and intestinal hypermotility in WAS-induced IBS mice.Moreover,EA promoted the expression of zonula occludens(ZO)-1,claudin-1,and occludin while suppressing the expression of interleukin(IL)-8,interferon(IFN)-γ,and tumor necrosis factor(TNF)-αin water avoidance stress(WAS)-induced irritable bowel syndrome(IBS)mice.CONCLUSION:EA alleviated WAS-induced IBS in mice by promoting intestinal barrier functions and suppressing the expression of inflammatory cytokines.

关键词： electroacupuncture irritable bowel syndrome intestinal barrier function tight junction proteins inflammatory cytokines

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