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High-current pulsed electron beam modification on microstructure and performance of Cu/CuW diffusion bonding joints

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Rare Metals 2024年第6期43卷 2819-2831页

作者： Na-Na Tian Cong-Lin Zhang Peng Lyu Jin-Tong Guan Jie Cai Qing-Feng Guan shun guo School of Materials Science and Engineering Jiangsu University School of Material Science and Engineering Yancheng Institute of Technology Engineering Institute of Advanced Manufacturing and Modern Equipment Technology Jiangsu University

This study investigates the influence of high-current pulsed electron beam（HCPEB） modification on the microstructure and shear strength of Cu/CuW joints.Reliable solid-state diffusion bonding of modified-Cu（MCu） and modified-CuW（M-CuW） was achieved by HCPEB modification pretreatment at a temperature of 800-900 ℃ and a pressure of 5 MPa for 10-50 min.Experiments demonstrate that HCPEB modification facilitates the dissolution of W and Cu,resulting in the formation of a Cu0.4W0.6solid solution and thus enhancing the uniform distribution of microstructures.Additionally,HCPEB-induced defects play a beneficial role in promoting the diffusion process by providing fast diffusion paths for elements.The optimal joints with the maximum shear strength of 213.7 MPa were obtained through bonding M-Cu and M-CuW at 900℃ and 5 MPa for 30 min,which attributes to the combined effects of fine-grained strengthening and solid solution strengthening.Overall,the application of HCPEB modification showcases its effectiveness in promoting element diffusion and enhancing the mechanical performance of the joints.

关键词： HCPEB Element diffusion Shear strength Crystal defects Surface modification

Understanding the Thermal Impedance of Silicone Rubber/Hexagonal Boron Nitride Composites as Thermal Interface Materials

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Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： Yuan Ji Shi-Da Han Hong Wu Shao-Yun guo Feng-shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials Hexagonal boron nitride Thermal impedance Surfaces

Tbx 4 and Tbx 5 gene expression associated with appendage development and its relationship with the absence of the pelvic fin in Pampus argenteus

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Journal of Oceanology and Limnology 2024年第2期42卷 580-593页

作者： shun ZHANG Xiaojing ZHU Lingzhu HU Kai LIAO Shanliang XU Danli WANG Chunyang guo School of Marine Science Ningbo UniversityNingbo 315211China Key Laboratory of Applied Marine Biotechnology Ningbo UniversityChinese Ministry of EducationNingbo 315211China

The Tbx family is first known through the study of their functions in the body and limbs,and its members Tbx4 and Tbx5 genes are important factors in determining the characteristics of the appendages.Pampus argenteus is one of the important economical marine fishes widely distributed in offshore areas.Therefore,it is necessary to study the role of Tbx family genes in the deletion of pelvic fin in P.argenteus.In this study,we cloned Tbx4 and Tbx5 cDNA sequence of P.argenteus(GenBank:MH709128 and MH712458).The Western blot and real time PCR were used to detect the expressions of Tbx4 and Tbx5 in different developmental stages and tissues of P.argenteus.In addition,whole-mount in-situ hybridization was used to study the localization of Tbx4 and Tbx5 genes in different developmental stages of P.argenteus.Results show that the translation of Tbx4 mRNA was inhibited during the critical period of pelvic fin development.Among different tissues,Tbx4 protein levels were the lowest in the abdominal epithelium,and even lower than that in the pectoral fin,suggesting that the protein expression was also inhibited in the abdominal epithelium of adult P.argenteus.Therefore,the results indicated that upstream genes regulation led to the key stage-specific and low expression of Tbx4 during pelvic fin development and in the abdominal epithelium.

关键词： Stromateidae pelvic fin protein translation T-box aquaculture broodstock

Comparative transcriptomic evidence of physiological changes and potential relationships in vertebrates under different dormancy states

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Zoological Research 2024年第2期45卷 341-354页

作者： Yu-Han Niu Li-Hong Guan Cheng Wang Hai-Feng Jiang guo-Gang Li Lian-Dong Yang shun-Ping He State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhanHubei 430072China College of Life Sciences Qinghai Normal UniversityXiningQinghai 810008China Academy of Plateau Science and Sustainability Qinghai Normal UniversityXiningQinghai 810016China Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization of the Qinghai-Tibet Plateau in Qinghai Province Qinghai Normal UniversityXiningQinghai 810008China College of Life Sciences and Technology Xinxiang Medical UniversityXinxiangHenan 453003China College of Animal Science and Technology Northwest A&F UniversityYanglingShaanxi 712100China

Dormancy represents a fascinating adaptive strategy for organisms to survive in unforgiving environments.After a period of dormancy,organisms often exhibit exceptional resilience.This period is typically divided into hibernation and aestivation based on seasonal patterns.However,the mechanisms by which organisms adapt to their environments during dormancy,as well as the potential relationships between different states of dormancy,deserve further exploration.Here,we selected Perccottus glenii and Protopterus annectens as the primary subjects to study hibernation and aestivation,respectively.Based on histological and transcriptomic analysis of multiple organs,we discovered that dormancy involved a coordinated functional response across organs.Enrichment analyses revealed noteworthy disparities between the two dormant species in their responses to extreme temperatures.Notably,similarities in gene expression patterns pertaining to energy metabolism,neural activity,and biosynthesis were noted during hibernation,suggesting a potential correlation between hibernation and aestivation.To further explore the relationship between these two phenomena,we analyzed other dormancy-capable species using data from publicly available databases.This comparative analysis revealed that most orthologous genes involved in metabolism,cell proliferation,and neural function exhibited consistent expression patterns during dormancy,indicating that the observed similarity between hibernation and aestivation may be attributable to convergent evolution.In conclusion,this study enhances our comprehension of the dormancy phenomenon and offers new insights into the molecular mechanisms underpinning vertebrate dormancy.

关键词： Hibernation Aestivation Multi-organs Convergent evolution

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Sensitizing photoactive metal-organic frameworks via chromophore for significantly boosting photosynthesis

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Chinese Chemical Letters 2024年第5期35卷 519-522页

作者： Lihua Ma Song guo Zhi-Ming Zhang Jin-Zhong Wang Tong-Bu Lu Xian-shun Zeng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute for New Energy Materials and Low Carbon Technologies School of Material Science&EngineeringTianjin University of TechnologyTianjin 300384China

Photosensitization related to energy/electron transfer process is of great importance to natural photosynthesis.Herein,we proposed a promising strategy to improve the sensitizing ability of the typical photoactive MOFs(UiO-Ir)by engineering its metal coordination center with NBI(1,8-naphthalenebenzimidizole)chromophore.The resulting MOFs(UiO-Ir-NBI)exhibited a strong sensitizing ability for significantly boosting photosynthesis.Impressively,the catalytic yield of 2-chloroethyl ethyl sulfoxide with UiO-Ir-NBI can reach 99%,over 6 times higher than that with UiO-Ir(16.4%).Moreover,UiO-Ir-NBI exhibited an excellent catalytic stability and a broad substrate tolerance,highlighting its great application prospect.Systematic investigations revealed that the strong visible light absorption,long excited state lifetime and efficient electron-hole separation of UiO-Ir-NBI greatly contributed to harvesting visible light and facilitating interface electron/energy transfer for efficient solar energy utilization.This work provides a new horizon to boost photosythesis of MOFs by engineering their metal sensitizing centers at a molecular level.

关键词： Metal-organic framework Photocatalysis Excited state Strong visible absorption Iridium complex

Variable Selection for Interval-censored Failure Time Data under the Partly Linear Additive Generalized Odds Rate Model

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Acta Mathematica Sinica,English Series 2024年

作者： Yang XU Shi shun ZHAO Tao HU Jian guo SUN School of Mathematical Sciences Shanxi University Center for Applied Statistical Research and College of Mathematics Jilin University School of Mathematical Sciences Capital Normal University Department of Statistics University of MissouriColumbia

Abstract This paper discusses variable selection for interval-censored failure time data, a general type of failure time data that commonly arise in many areas such as clinical trials and follow-up studies. Although some methods have been developed in the literature for the problem, most of the existing procedures apply only to specific models. In this paper, we consider the data arising from a general class of partly linear additive generalized odds rate models and propose a penalized variable selection approach through maximizing a derived penalized likelihood function. In the method, the Bernsetin polynomials are employed to approximate both the unknown baseline hazard functions and the nonlinear covariate effects functions, and for the implementation of the method, a coordinate descent algorithm is developed. Also the asymptotic properties of the proposed estimators, including the oracle property, are established. An extensive simulation study is conducted to assess the finite-sample performance of the proposed estimators and indicatesthat it works well in practice. Finally, the proposed method is applied to a set of real data on Alzheimer’s disease.

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Analysis of risk factors leading to anxiety and depression in patients with prostate cancer after castration and the construction of a risk prediction model

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World Journal of Psychiatry 2024年第2期14卷 255-265页

作者： Rui-Xiao Li Xue-Lian Li guo-Jun Wu Yong-Hua Lei Xiao-shun Li Bo Li Jian-Xin Ni Urology Hospital Xi'an People's Hospital(Xi'an Fourth Hospital)Xi'an 710199Shaanxi ProvinceChina Department of Surgery Xi'an Hospital of Traditional Chinese MedicineXi'an 710199Shaanxi ProvinceChina

BACKGROUND Cancer patients often suffer from severe stress reactions psychologically,such as anxiety and depression.Prostate cancer(PC)is one of the common cancer types,with most patients diagnosed at advanced stages that cannot be treated by radical surgery and which are accompanied by complications such as bodily pain and bone metastasis.Therefore,attention should be given to the mental health status of PC patients as well as physical adverse events in the course of clinical treatment.AIM To analyze the risk factors leading to anxiety and depression in PC patients after castration and build a risk prediction model.METHODS A retrospective analysis was performed on the data of 120 PC cases treated in Xi'an People's Hospital between January 2019 and January 2022.The patient cohort was divided into a training group(n=84)and a validation group(n=36)at a ratio of 7:3.The patients’anxiety symptoms and depression levels were assessed 2 wk after surgery with the Self-Rating Anxiety Scale(SAS)and the Selfrating Depression Scale(SDS),respectively.Logistic regression was used to analyze the risk factors affecting negative mood,and a risk prediction model was constructed.RESULTS In the training group,35 patients and 37 patients had an SAS score and an SDS score greater than or equal to 50,respectively.Based on the scores,we further subclassified patients into two groups:a bad mood group(n=35)and an emotional stability group(n=49).Multivariate logistic regression analysis showed that marital status,castration scheme,and postoperative Visual Analogue Scale(VAS)score were independent risk factors affecting a patient's bad mood(P<0.05).In the training and validation groups,patients with adverse emotions exhibited significantly higher risk scores than emotionally stable patients(P<0.0001).The area under the curve(AUC)of the risk prediction model for predicting bad mood in the training group was 0.743,the specificity was 70.96%,and the sensitivity was 66.03%,while in the validation group,the AUC,specificity,and sensitivity were 0

关键词： Prostate cancer Castration Anxiety and depression Risk factors Risk prediction model

Heterointerface engineering of assembled CoP_(2) on N-modified carbon as efficient trifunctional electrocatalysts for Zn-Air batteries and overall water splitting

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Nano Research 2024年第5期17卷 3801-3809页

作者： Yan Chen Zhenrui Yang Juan Wang Yun Yang Xuedong He Yang Wang Jiadong Chen Yaqing guo Xin Wang shun Wang Huile Jin Wenzhou Key Lab of Advanced Energy Storage and Conversion Zhejiang Province Key Lab of Leather EngineeringCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035China Zhejiang Engineering Research Center for Electrochemical Energy Materials and Devices Institute of New Materials and Industrial TechnologiesWenzhou UniversityWenzhou 325035China School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingapore 637459Singapore

Enhancing catalytic activity through modulating the interaction between N-doped carbon and metal phosphides clusters is an effective approach.Herein,the electronic structure modulation of CoP_(2) supported N-modified carbon(CoP_(2)/NC)has been designed and prepared as efficient electrocatalysts for oxygen reduction reaction(ORR),oxygen evolution reaction(OER),and hydrogen evolution reaction(HER).Notably,CoP_(2)/NC-1 catalyst exhibits impressive performance in alkaline media,with an ORR half-wave potential of 0.84 V,as well as OER and HER overpotentials of 290 and 129 mV(at 10 mA·cm^(−2)),respectively.In addition,CoP_(2)/NC-1 produces a power density as high as 172.9 mW·cm^(−2),and excellent reversibility of 100 h at 20 mA·cm^(−2) in home-made Zn-air batteries.The experimental results demonstrate that the synergistic interactions between N modified carbon substrate and CoP_(2) material significantly enhance the kinetics of ORR,OER,and HER.Density functional theory(DFT)calculations reveal the strong electrons redistribution of CoP_(2) induced by high-density N atoms at the interface,thus optimizing the key intermediates and significantly lower the energy barrier of reactions.These electronic adjustments of CoP_(2) greatly enhance its kinetics of ORR/OER/HER,leading to faster reactions.This study provides profound insights into the specific modification of CoP_(2) by N-doped carbon,enabling the construction of efficient catalysts.

关键词： two-dimensional(2D)carbon metal-organic framework cobalt phosphide zinc air battery water splitting

Mechanism and threshold fluence of nanosecond pulsed laser paint removal

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Rare Metals 2022年第3期41卷 1022-1031页

作者： Qi Sun Jian-Zhong Zhou Xian-Kai Meng Jia-Nian Yang Zhao-Heng guo Ming Zhu shun guo School of Mechanical Engineering Jiangsu UniversityZhenjiang 212013China School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013China

In this paper, the nanosecond pulse laser surface treatment of the waterborne anti-rust paint on HT250 gray cast iron was carried out. The area and depth of the per-pulse laser ablation paint layer were measured. The threshold of laser energy density was determined through the relations with ablation area and depth. The paint removal mechanism was discussed by analyzing the ablation features of the paint layer on laser cleaning. The features of the paint removal under various laser energy densities were characterized, and the process parameters in the experiments were investigated.The results showed that there were four thresholds and three kinds of mechanisms in the paint removal process with nanosecond pulsed laser. The ablation threshold of substrate was deepened on the laser parameters. The ablation processes were included thermal ablation, thermal vibration and paint ionization concurrently, respectively. The surface cracks and paint debris were observed at the edge of the cleaning path, which were ascribed to the vibration effect by laser. In addition, the vibration effect could significantly increase the width of paint removal. Paint ionization has also a significant influence on the substrate morphology. Paint ionization would have an obvious impact on the formation of the substrate morphology. It is desirable to fabricate approach to remove the paint layer without damaging the substrate under optimized laser parameters by nanosecond pulse laser.

关键词： Laser paint removal Threshold of energy density Paint removal mechanism Surface morphology