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Evolution of Microstructure,Mechanical Properties and Corrosion Resistance of Ultrasonic Assisted Welded-Brazed Mg/Ti Joint

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Journal of Materials Science & Technology 2016年第12期32卷 1253-1259页

作者： Chuan Xu Guangmin Sheng xuezhen cao Xinjian Yuan College of Materials Science and Engineering Chongqing University

Ultrasonic vibration with different powers from 0 k W to 1.6 k W was applied during the tungsten inert gas welding-brazing of Mg/*** microstructures,mechanical properties and corrosion resistance of the ultrasonic assisted tungsten inert gas（U-TIG） welded-brazed Mg/Ti joint were *** results showed that,without being subjected to ultrasonic vibration,coarse columnar α-Mg grains occurred in the fusion zone of Mg/Ti ***,with ultrasonic power of 1.2 k W,the average grain size of columnar α-Mg grains was refined from 200 μm to about 50 μm and the tensile strength of joints increased^18% up to 228 ***,high fraction of grain boundaries was introduced by grain refinement,contributing to improve the corrosion resistance in two ways：（i） accelerating the formation of Mg（OH）2protective layer and（ii） reducing the mismatch and disorder between Mg（OH）2 protective layer and Mg alloy surface.

关键词： Magnesium alloy Titanium alloy Microstructure Mechanical properties Corrosion resistance Ultrasonic vibration

Hcy、维生素B12及叶酸在妊娠期亚临床甲状腺功能减退中的水平变化及临床意义

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分子诊断与治疗杂志 2024年第6期16卷 1032-1035,1039页

作者：黄敏曹雪珍周芳烨成都市第五人民医院检验科四川成都611130

目的探究同型半胱氨酸(Hcy)、维生素B12及叶酸在妊娠期亚临床甲状腺功能减退(SCH)中的水平变化和临床意义。方法选取2021年7月至2023年2月成都市第五人民医院收治的58例SCH患者为观察组,另选取同期53名甲状腺功能正常的妊娠期女性为... 详细信息

目的探究同型半胱氨酸(Hcy)、维生素B12及叶酸在妊娠期亚临床甲状腺功能减退(SCH)中的水平变化和临床意义。方法选取2021年7月至2023年2月成都市第五人民医院收治的58例SCH患者为观察组,另选取同期53名甲状腺功能正常的妊娠期女性为对照组。比较两组Hcy、维生素B12、叶酸水平和甲状腺功能[促甲状腺激素(TSH)、血清游离三碘甲状原氨酸(FT3)、血清游离甲状腺素(FT4)水平],使用Spearma相关性分析Hcy、维生素B12、叶酸与甲状腺功能减退之间的关系,使用ROC曲线分析Hcy、维生素B12、叶酸单独及联合检测SCH的诊断效能。结果观察组Hcy、TSH水平比对照组高,维生素B12、叶酸水平比对照组低,差异具有统计学意义(P0.05);经Spearman相关性分析显示:Hcy与TSH水平呈正相关(r=0.536,P0.05);维生素B12与FT3、FT4水平呈正相关(r=0.624、0.528,P值均0.05);ROC曲线显示,Hcy、维生素B12、叶酸检测诊断SCH的AUC值分别为0.766、0.631、0.723,三者联合诊断AUC值为0.901、灵敏度为0.879、特异度为0.902、95%CI为0.833~0.967,联合检测诊断效能高于三指标单独检测(P<0.05)。结论妊娠期亚临床甲状腺功能减退患者Hcy、维生素B12、叶酸水平存在异常,检测上述指标水平可为临床评估、诊断病情提供依据。

关键词： Hcy 维生素B12 叶酸妊娠期亚临床甲状腺功能减退

Effect of Twin Boundary–Dislocation–Solute Interaction on Detwinning in a Mg–3Al–1Zn Alloy

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Journal of Materials Science & Technology 2016年第12期32卷 1239-1244页

作者： Jing Xu Bo Guan Huihui Yu xuezhen cao Yunchang Xin Qing Liu School of Materials Science and Engineering Chongqing University

In the present study,the influence of solute atoms together with dislocations at {101^-2} twin boundary（TB） on mechanical behavior of a detwinning predominant deformation in a Mg alloy AZ31 plate was systematically *** results show that a large number of {101^-2} twins disappear during recompression along the normal *** the TB-dislocation interaction and TB-solute-dislocation interaction can greatly enhance the yield stress of the recompression along the normal direction（ND）.However,the solute segregation at {1012} TBs with an intensive interaction with 〈a〉 dislocations cannot further enhance the yield stress of ND *** samples with TB-dislocation interaction show a similar working hardening performance with that subjected to a TB-solute-dislocation *** the TB-dislocation interaction and TB-solute-dislocation interaction greatly reduce the value of work hardening peaks during a detwinning predominant deformation.

关键词： Magnesium alloy Mechanical behavior Twinning Dislocation

传染性法氏囊病毒新型变异株荧光定量RT-PCR检测方法的建立

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广东畜牧兽医科技 2024年第3期49卷 54-59,82页

作者：曹雪珍周庆丰王连想严专强林丽苗李薇李群辉仲恺农业工程学院动物科技学院广东广州510640 温氏食品集团股份有限公司/广东省畜禽健康养殖与环境控制企业重点实验室广东云浮527400

传染性法氏囊病病毒新型变异株(Novel variant Infectious bursal disease virus,nVarIBDV)给我国养禽业防控法氏囊带来更大的挑战。目前缺乏快速、灵敏的针对nVarIBDV的检测方法。为解决这一问题,该试验根据已发表的nVarIBD的VP2基因序... 详细信息

传染性法氏囊病病毒新型变异株(Novel variant Infectious bursal disease virus,nVarIBDV)给我国养禽业防控法氏囊带来更大的挑战。目前缺乏快速、灵敏的针对nVarIBDV的检测方法。为解决这一问题,该试验根据已发表的nVarIBD的VP2基因序列,设计了一对引物和一条特异性Taq Man探针,建立了一种nVarIBD的Taq Man荧光定量RT-PCR检测方法,该方法可通过特异性扩增nVarIBD VP2基因来确定样品是否为IBDV新型变异株。通过构建重组质粒pMD18-T-VP2对引物和探针进行灵敏性和重复性试验,以及特异性检测,最后使用该检测方法对临床样品进行验证。荧光定量RT-PCR结果显示灵敏性可达1.32×10^(1)copies/μL,高于常规RT-PCR的100倍。批内和批间重复试验变异系数(CV)均小于0.5%,结果表明该检测方法有良好的重复性与稳定性。该方法与常见禽病毒核酸无交叉反应,说明检测方法具有较好的特异性。综合本研究结果表明,该研究建立的nVarIBD荧光定量RT-PCR检测方法特异性强、灵敏性高、重复性好,可用于临床样品中IBDV新型变异株的监测。

关键词：传染性法氏囊病病毒新型变异株荧光定量RT-PCR Taq Man探针

猴耳环提取物对黄羽肉鸡生长性能、屠宰性能、抗氧化能力及肉品质的影响

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中国家禽 2024年第8期46卷 52-60页

作者：梁宇陈宋昕王海悦杨晓珊刘文晓曹雪珍杨明炜曹楠李冰心李婉雁许丹宁田允波黄运茂付新亮仲恺农业工程学院动物科技学院广东广州510225 广东省水禽健康养殖工程技术研究中心广东广州510225 广东态合堂实业有限公司广东惠州516000

为探究猴耳环提取物对黄羽肉鸡生长性能、屠宰性能、抗氧化能力和肉品质等的影响,试验将240只1日龄黄羽雏公鸡随机分为4组,每组6个重复,每个重复10只雏鸡。对照组饲喂基础日粮,试验组分别在基础日粮中添加0.5、1.0和2.0 g/kg猴耳环提取... 详细信息

为探究猴耳环提取物对黄羽肉鸡生长性能、屠宰性能、抗氧化能力和肉品质等的影响,试验将240只1日龄黄羽雏公鸡随机分为4组,每组6个重复,每个重复10只雏鸡。对照组饲喂基础日粮,试验组分别在基础日粮中添加0.5、1.0和2.0 g/kg猴耳环提取物,试验期为70 d。分别于20、40和70日龄采集各组血清、肝脏等组织,测定抗氧化等指标,并于70日龄测定各组生产性能、屠宰性能和肌肉品质。结果显示:(1)饲粮添加猴耳环提取物对黄羽肉鸡的生产性能和屠宰性能无显著影响(P>0.05),但2.0 g/kg猴耳环提取物组黄羽肉鸡皮肤b*45 min黄度值显著高于对照组(P<0.05);(2)70日龄各试验组胸肌亚油酸含量以及腿肌肌苷酸含量与对照组相比显著升高(P<0.05),与饲粮中猴耳环提取物添加水平呈线性相关(P<0.05)和二次曲线相关(P<0.05),并且2.0 g/kg猴耳环提取物组胸肌中粗脂肪含量也显著高于对照组(P<0.05);(3)与对照组相比,0.5 g/kg、1.0 g/kg和2.0 g/kg猴耳环提取物组70日龄黄羽肉鸡的总抗氧化能力(T-AOC)显著升高(P<0.05),呈线性相关(P<0.05)和二次曲线相关(P<0.05),且0.5 g/kg和1.0 g/kg猴耳环提取物组肝脏中与抗应激相关的热休克蛋白70(HSP70)和热休克蛋白90(HSP90)的基因表达水平也显著升高(P<0.05)。综上所述,饲粮添加0.5~2.0 g/kg猴耳环提取物可显著提高黄羽肉鸡的总抗氧化能力,并显著提高腿肌肌苷酸和胸肌亚油酸等不饱和脂肪酸含量,提升肉品质;综合抗氧化能力、腿肌肌苷酸和胸肌亚油酸含量,本试验条件下黄羽肉鸡饲粮中猴耳环提取物的适宜添加水平为1.3~1.6 g/kg。

关键词：猴耳环生长性能屠宰性能肌肉品质抗氧化能力黄羽肉鸡

Zeros of Complete Symmetric Polynomials over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1772-1788页

作者： cao Wei School of Mathematics and Statistics Minnan Normal UniversityZhangzhou 363000China

Wan and Zhang(2021) obtained a nontrivial lower bound for the number of zeros of complete symmetric polynomials over finite fields,and proposed a problem whether their bound can be *** this paper,the author improves Wan-Zhang's bound from three *** proposed results are based on the estimates related to the number of certain permutations and the value sets of non-permutation polynomials associated to the complete symmetric *** the author believes that there are still possibilities to improve the bounds and hence Wan-Zhang's bound.

关键词： Complete symmetric polynomial finite field permutation polynomial value set

Pt nanodendrites with a PtIr alloy surface structure exhibit excellent stability toward acidic hydrogen evolution reaction

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Nano Research 2024年第6期17卷 4844-4849页

作者： Chang Liu Zongnan Wei Minna cao Rong cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

The development of effective and stable electrocatalysts for the hydrogen evolution reaction(HER)in acidic electrolytes is a significant *** this work,homogeneous Pt nanodendrites(Pt NDs)with a PtIr shell were successfully synthesized by a two-step wet chemical *** open three-dimensional(3D)dendritic structure exhibited exceptional electrocatalytic characteristics,exposing as many active sites as ***,by alloying Ir with Pt on the surface,catalytic activity was greatly enhanced while ensuring extremely high *** surface-enriched platinum nanodendritic catalysts(Pt@PtIr NDs)outperformed the control samples and the commercial *** acidic HER test,Pt@PtIr NDs had a lower overpotential(22 mV)than Pt NDs(26 mV)and commercial Pt/C(31 mV)at 10 mA/cm^(2),and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h,which was much superior to the performance of commercial Pt/C(10 h)under identical test *** study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER.

关键词： Pt nanodendrites iridium high stability hydrogen evolution reaction alloy

Quantitative phase imaging based on holography:trends and new perspectives

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Light(Science & Applications) 2024年第7期13卷 1235-1277页

作者： Zhengzhong Huang Liangcai cao Department of Precision Instrument Tsinghua UniversityBeijing 100084China

In 1948,Dennis Gabor proposed the concept of holography,providing a pioneering solution to a quantitative description of the optical *** 75 years of development,holographic imaging has become a powerful tool for optical wavefront measurement and quantitative phase *** emergence of this technology has given fresh energy to physics,biology,and materials *** holography(DH)possesses the quantitative advantages of wide-field,non-contact,precise,and dynamic measurement capability for *** has unique capabilities for the propagation of optical fields by measuring light scattering with phase *** offers quantitative visualization of the refractive index and thickness distribution of weak absorption samples,which plays a vital role in the pathophysiology of various diseases and the characterization of various *** provides a possibility to bridge the gap between the imaging and scattering *** propagation of wavefront is described by the complex *** complex-value in the complex-domain is reconstructed from the intensityvalue measurement by camera in the ***,we regard the process of holographic recording and reconstruction as a transformation between complex-domain and real-domain,and discuss the mathematics and physical principles of *** review the DH in underlying principles,technical approaches,and the breadth of *** conclude with emerging challenges and opportunities based on combining holographic imaging with other methodologies that expand the scope and utility of holographic imaging even *** multidisciplinary nature brings technology and application experts together in label-free cell biology,analytical chemistry,clinical sciences,wavefront sensing,and semiconductor production.

关键词： holographic phase precise

Dynamic Setting Method of Assessment Indicators for Power Curves of Renewable Energy Sources Considering Scarcity of Reserve Resources

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 101-114页

作者： Minghao cao Jilai Yu the Department of Electrical Engineering Harbin Institute of TechnologyHarbinChina

With the increasing proportion of renewable energy sources(RESs)in power grid,the reserve resource(RR)scarcity for correcting power deviation of RESs has become a potential ***,the power curve of RES needs to be more rigorously *** RR scarcity varies during different time periods,so the values of assessment indicators should be dynamically *** assessment indicators in this paper include two aspects,i.e.,deviation exemption ratio and penalty ***,this paper proposes a method for dynamically calculating the supply capacity and RR cost,primarily taking into account the operating status of thermal units,forecast information of RES,and load ***,after clarifying the logical relationship between the degree of RR scarcity and the values of assessment indicators,this paper establishes a mapping function between *** on this mapping function,a dynamic setting method for assessment indicators is *** the future,RES will generally be equipped with battery energy storage systems(BESSs).Reasonably utilizing BESSs to reduce the power deviation of RESs can increase the expected income of ***,this paper proposes a power curve optimization strategy for RESs considering self-owned *** case study demonstrates that the dynamic setting method of assessment indicators can increase the revenue of RESs while ensuring that the penalty fees paid by RESs to the grid are sufficient to cover the RR ***,the power curve optimization strategy can help RESs further increase income and fully utilize BESSs to reduce power deviation.

关键词： Renewable energy battery energy storage system(BESS) power curve assessment reserve service parameter setting