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Effect of slow shot speed on externally solidified crystal,porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy

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China Foundry 2024年第1期21卷 11-19页

作者： wen-ning Liu Wei Zhang Peng-yue Wang Yi-xian Liu Xiang-yi Jiao Ao-xiang Wan Cheng-gang Wang Guo-dong Tong Shou-mei Xiong School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Tsinghua UniversityBeijing 100084Beijing China FAW Group Co. Ltd.Changchun 130013China China FAW Foundry Co. Ltd.Changchun 130013China

The effect of slow shot speed on externally solidified crystal(ESC),porosity and tensile property in a newly developed high-pressure die-cast Al-Si alloy was investigated by optical microscopy(OM),scanning electron microscopy(SEM)and laboratory computed tomography(CT).Results showed that the newly developed AlSi9MnMoV alloy exhibited improved mechanical properties when compared to the AlSi10MnMg alloy.The AlSi9MnMoV alloy,which was designed with trace multicomponent additions,displays a notable grain refining effect in comparison to the AlSi10MnMg alloy.Refining elements Ti,Zr,V,Nb,B promote heterogeneous nucleation and reduce the grain size of primaryα-Al.At a lower slow shot speed,the large ESCs are easier to form and gather,developing into the dendrite net and net-shrinkage.With an increase in slow shot speed,the size and number of ESCs and porosities significantly reduce.In addition,the distribution of ESCs is more dispersed and the net-shrinkage disappears.The tensile property is greatly improved by adopting a higher slow shot speed.The ultimate tensile strength is enhanced from 260.31 MPa to 290.31 MPa(increased by 11.52%),and the elongation is enhanced from 3.72%to 6.34%(increased by 70.52%).

关键词： hypoeutectic Al-Si alloy high pressure die casting porosity externally solidified crystal tensile property

In maize,co-expression of GAT and GR79-EPSPS provides high glyphosate resistance,along with low glyphosate residues

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aBIOTECH 2023年第4期4卷 277-290页

作者： Shengyan Li Pengcheng Li Xiangyin Li ning wen Yinxiao Wang Wei Lu Min Lin Zhihong Lang Biotechnology Research Institute Chinese Academy of Agricultural SciencesBeijingChina National Nanfan Research Institute(Sanya) Chinese Academy of Agricultural SciencesSanyaHainanChina

Herbicide tolerance has been the dominant trait introduced during the global commercialization of genetically modified(GM)crops.Herbicide-tolerant crops,especially glyphosate-resistant crops,offer great advantages for weed management;however,despite these benefits,glyphosate-resistant maize(Zea mays L.)has not yet been commercially deployed in China.To develop a new bio-breeding resource for glyphosate-resistant maize,we introduced a codon-optimized glyphosate N-acetyltransferase gene,gat,and the enolpyruvyl-shikimate-3-phosphate synthase gene,gr79-epsps,into the maize variety B104.We selected a genetically stable high glyphosate resistance(GR)transgenic event,designated GG2,from the transgenic maize population through screening with high doses of glyphosate.A molecular analysis demonstrated that single copy of gat and gr79-epsps were integrated into the maize genome,and these two genes were stably transcribed and translated.Field trials showed that the transgenic event GG2 could tolerate 9000 g acid equivalent(a.e.)glyphosate per ha with no effect on phenotype or yield.A gas chromatography-mass spectrometry(GC–MS)analysis revealed that,shortly after glyphosate application,the glyphosate(PMG)and aminomethylphosphonic acid(AMPA)residues in GG2 leaves decreased by more than 90%compared to their levels in HGK60 transgenic plants,which only harbored the epsps gene.Additionally,PMG and its metabolic residues(AMPA and N-acetyl-PMG)were not detected in the silage or seeds of GG2,even when far more than the recommended agricultural dose of glyphosate was applied.The co-expression of gat and gr79-epsps,therefore,confers GG2 with high GR and a low risk of herbicide residue accumulation,making this germplasm a valuable GR event in herbicide-tolerant maize breeding.

关键词： Transgenic maize Glyphosate resistance Gr79-epsps gene Gat gene Low residues

3D-printed strontium-incorporatedβ-TCP bioceramic triply periodic minimal surface scaffolds with simultaneous high porosity,enhanced strength,and excellent bioactivity

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Journal of Advanced Ceramics 2023年第9期12卷 1671-1684页

作者： Yanbo Shan Yang Bai Shuo Yang Qing Zhou Gang Wang Biao Zhu Yiwen Zhou wencan Fang ning wen Rujie He Lisheng Zhao Chinese PLA Medical School Beijing 100853China Institute of Stomatology&Oral Maxilla Facial Key Laboratory First Medical Center of Chinese PLA General HospitalBeijing 100853China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China

In bone tissue engineering,scaffolds with excellent mechanical and bioactive properties play prominent roles in space maintaining and bone regeneration,attracting increasingly interests in clinical practice.In this study,strontium-incorporatedβ-tricalcium phosphate(β-TCP),named Sr-TCP,bioceramic triply periodic minimal surface(TPMS)structured scaffolds were successfully fabricated by digital light processing(DLP)-based 3D printing technique,achieving high porosity,enhanced strength,and excellent bioactivity.The Sr-TCP scaffolds were first characterized by element distribution,macrostructure and microstructure,and mechanical properties.Notably,the compressive strength of the scaffolds reached 1.44 MPa with porosity of 80%,bringing a great mechanical breakthrough to porous scaffolds.Furthermore,the Sr-TCP scaffolds also facilitated osteogenic differentiation of mouse osteoblastic cell line(MC3T3-E1)cells in both gene and protein aspects,verified by alkaline phosphatase(ALP)activity and polymerase chain reaction(PCR)assays.Overall,the 3D-printed Sr-TCP bioceramic TPMS structured scaffolds obtained high porosity,boosted strength,and superior bioactivity at the same time,serving as a promising approach for bone regeneration.

关键词： strontium β-tricalcium phosphate(β-TCP) digital light processing(DLP) 3D printing triply periodic minimal surface(TPMS) bone scaffold

Microstructure,Mechanical Properties and In Vitro Degradation Behavior of a Novel Biodegradable Mg-1.5Zn-0.6Zr-0.2Sc Alloy

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Journal of Materials Science & Technology 2015年第7期31卷 744-750页

作者： Tao Li Hailong Zhang Yong He ning wen Xitao Wang State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Institute of Stomatology General Hospital of Chinese People's Liberation Army

A novel Mg-1.5Zn-0.6Zr-0.2Sc （denoted as ZK21-0.2Sc） alloy was developed as potential biodegrad- able implant materials. The microstructure, mechanical properties, and in vitro degradation behavior of the as-cast ZK21-0.2Sc alloy were investigated and compared with ZK21 alloy and pure Mg. The ZK21 -0.2Sc alloy showed a single-phase structure with fine equiaxed grains. The alloy exhibited a good balance between strength and ductility. Both immersion tests and electrochemical tests showed that the ZK21-0.2Sc alloy had the lowest degradation rate in Hank＇s solution. The excellent degradation behavior of ZK21-0.2Sc alloy could be explained by the single-phase and fine grain structure, the more effective protection corrosion film, and the beneficial alloying effects of Zn, Zr and Sc.

关键词： Magnesium alloysScandiumBiomaterialsBiodegradableCorrosion

乡村振兴战略下农村居民生活垃圾的合作治理研究

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黑龙江环境通报 2024年第5期37卷 117-119页

作者：温宁洛阳理工学院经济与管理学院河南洛阳471000

随着经济发展和社会进步,农村居民生活质量已明显提高,城乡共同发展被逐渐重视。农村居民环境治理问题成为社会重点关注内容。随着乡村振兴战略文件的颁发,各级相关部门逐步开展农村居民生活垃圾有效治理,以提升农村居民生活质量为目标... 详细信息

随着经济发展和社会进步,农村居民生活质量已明显提高,城乡共同发展被逐渐重视。农村居民环境治理问题成为社会重点关注内容。随着乡村振兴战略文件的颁发,各级相关部门逐步开展农村居民生活垃圾有效治理,以提升农村居民生活质量为目标,实现农村绿色发展。但对当前阶段,农村居民生活垃圾治理工作中存在治理力度不足、垃圾处理基础设施落后等问题,需要提出创新性治理策略,推进高效改革。基于此,本文首先阐述农村居民生活垃圾治理的意义,提出当前阶段生活垃圾治理中存在的问题,并提出相应合作治理策略,为贯彻落实乡村振兴战略、推动垃圾治理工作顺利开展提供参考。

关键词：乡村振兴战略农村居民生活垃圾合作治理

Cases of Residual Paralysis in an Acute Flaccid Paralysis Surveillance System--China,2001−2010

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China CDC weekly 2020年第50期2卷 962-967页

作者： ning wen Qiru Su Chunxiang Fan Haibo Wang Yong Zhang Lei Cao Wei Xia Zhijie An Huiming Luo Chinese Center for Disease Control and Prevention BeijingChina Shenzhen Children’s hospital ShenzhenGuangdongChina Clinical Research Institute Peking UniversityBeijingChina National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and PreventionBeijingChina

Background:China has been polio-free since 2000 and maintains an acute flaccid paralysis(AFP)surveillance system.Residual paralysis(RP)in children with acute flaccid paralysis can be caused by Sabinstrain poliovirus(PV)and non-polio enteroviruses(NPEV).Methods:The national AFP surveillance data was analyzed to describe AFP cases with RP in the mainland of China during 2001 to 2010.Epidemiological patterns and virus detection of AFP cases with RP were described.Results:Annual incidence of AFP with RP among children aged<15 years old ranged between 0.22-0.35 cases per 100,000.The peak age for AFP with RP and PV was 2 to 4 months.Among cases with viral Sabinstrain viral isolates,types Ⅱ and Ⅲ were the most common.A summer season peak in RP cases was similar to cases with NPEV isolated.Conclusions and Implications for Public Health Practice:The first ten years after polio eradication of AFP surveillance data for the occurrence of RP can serve as a baseline rate for poliovirus vaccine changes in the routine immunization system to help detect vaccine safety signals in a timely manner and to support the routine polio immunization program switch in China.

关键词： routine vaccine acute

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三特异性抗体在肿瘤免疫治疗中的研究进展

生命科学 2024年第4期36卷 433-447页

作者：许林宁文静刘雪罗文新厦门大学公共卫生学院国家传染病诊断试剂与疫苗工程技术研究中心厦门361102

三特异性抗体(trispecific antibodies, TsAbs)是一种可以同时靶向肿瘤细胞或免疫效应细胞三种不同抗原结合位点的创新疗法。与单克隆抗体和双特异性抗体相比,三特异性抗体可增加结合特异性,降低脱靶毒性,在肿瘤免疫治疗领域具有广阔的... 详细信息

三特异性抗体(trispecific antibodies, TsAbs)是一种可以同时靶向肿瘤细胞或免疫效应细胞三种不同抗原结合位点的创新疗法。与单克隆抗体和双特异性抗体相比,三特异性抗体可增加结合特异性,降低脱靶毒性,在肿瘤免疫治疗领域具有广阔的应用前景。本文主要介绍了三特异性抗体的发展进程、主要构建形式及其作用机制,总结了不同靶点组合的代表性药物的最新研究进展,并讨论了其存在的挑战和未来发展方向,旨在为三特异性抗体药物的发展提供新思路。

关键词：三特异性抗体肿瘤免疫疗法 CD3 T细胞接合器免疫检查点

ESG表现对于企业投资效率研究——基于A股上市公司的经验证据

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生产力研究 2024年第6期 154-160页

作者：许文宁江苏大学财经学院江苏镇江212013

文章选用面板效应模型,基于沪深A股上市公司2013—2022年数据研究ESG对企业投资效率的促进效应。经研究发现ESG对企业投资效率起到正相关关系,且通过降低代理成本,相对减少选用四大作为审计单位共同促进投资效率,此外内部控制与媒体关... 详细信息

文章选用面板效应模型,基于沪深A股上市公司2013—2022年数据研究ESG对企业投资效率的促进效应。经研究发现ESG对企业投资效率起到正相关关系,且通过降低代理成本,相对减少选用四大作为审计单位共同促进投资效率,此外内部控制与媒体关注起到正向调节作用,经过以下检验均成立。依次选用前5大股东持股比例,机构投资者持股比例,投资水平作为门限变量,构建门槛检验。通过工具变量法选用地级市到杭州的球面距离和每百万人邮局数量作为工具变量,与1:1近邻匹配方法的倾向得分作为内生性检验证明原假设成立。且通过替换被解释变量、滞后一期检验均证明结论成立且稳健。通过异质性分组检验,国企、非重污染、衰退期企业,回归效果更为明显。

关键词： ESG表现投资效率代理成本审计质量

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免疫粒子群算法的测试数据生成

计算机工程与设计 2024年第5期45卷 1435-1442页

作者：焦重阳周清雷张文宁中国人民解放军战略支援部队信息工程大学河南郑州450001 数学工程与先进计算国家重点实验室河南郑州450001 郑州工业安全职业学院河南信息工程学校河南郑州450011 郑州大学计算机与人工智能学院河南郑州450001 中原工学院软件学院河南郑州450007

为有效改善粒子群算法进化后期收敛速度慢,克服易陷入局部极值的缺陷,提出一种自适应免疫粒子群算法并在面向路径的测试数据生成中得到应用。本文提出自适应的惯性权重的调整方法和学习因子的调节策略,加快算法的搜索速率;引入免疫算法... 详细信息

为有效改善粒子群算法进化后期收敛速度慢,克服易陷入局部极值的缺陷,提出一种自适应免疫粒子群算法并在面向路径的测试数据生成中得到应用。本文提出自适应的惯性权重的调整方法和学习因子的调节策略,加快算法的搜索速率;引入免疫算法中的免疫算子,提出抗体的浓度调节机制,使得粒子群的多样性更加丰富,提升算法的寻优能力;通过免疫选择操作,避免算法的早熟收敛;以分支函数叠加法构造适应度函数。实验结果表明,该算法避免了粒子群算法早熟收敛现象的发生,有效地提高了测试数据自动生成的效率。

关键词：粒子群算法测试数据生成惯性权重学习因子免疫算子种群多样性免疫选择