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Bioinspired PcBN/hBN fibrous monolithic ceramic:High-temperature crack resistance responses and self-lubricating performances

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Journal of Advanced Ceramics 2022年第9期11卷 1391-1403页

作者： Shu-na chen Hengzhong FAN Yunfeng SU jicheng LI Junjie SONG Litian HU Yongsheng ZHANG State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

The high strength and toughness of natural materials are mainly determined by a combination of mechanisms operating at different length scales,which can be used as a strategy to reduce the intrinsic brittleness of *** by the architectures of bamboo,the polycrystalline cubic boron nitride/hexagonal boron nitride(PcBN/hBN)fibrous monolithic ceramics with a long fiber arrangement structure was constructed with PcBN fiber cells and hBN cell boundaries,and its crack resistance responses and tribological performances were *** composite ceramic failed in a non-brittle manner with the rising resistance curve(R-curve)behavior,which was attributed to multiscale crack effects in the hierarchical *** maximum crack growth toughness was extremely high(approximately 21 MPa×m^(1/2)),corresponding to a 270%increase over the crack initiation *** fracture resistance could be retained even above 1000℃.Moreover,the composite ceramic exhibited low and stable friction coefficients(approximately 0.33)when paired with a Si_(3)N_(4)pin at high temperature(1000℃),owing to the lubrication function of hBN cell boundaries with weak van der Waals forces and a small amount of liquid B_(2)O_(3)*** a result,a synergistic improvement of mechanical and tribological properties at high temperature(1000℃)was realized by combining bionic structure and tribological *** provides important theoretical and technical support for expanding the application of self-lubricating composite ceramics in harsh environments.

关键词： self-lubricating composite ceramic bioinspired structure resistance curve(R-curve) high-temperature property friction and wear

保乳联合前哨淋巴结活检术在23例早期乳腺癌治疗中的临床应用价值

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当代医学 2018年第35期24卷 120-122页

作者：杨炳林肖坚陈文新王合兵张茂泉陈基铖福建医科大学附属三明第一医院乳腺科福建三明365000

目的探讨保乳联合前哨淋巴结活检术在23例早期乳腺癌治疗中的临床应用价值。方法选取2016年7月至2017年7月本院收治的46例早期乳腺癌的患者作为研究对象,随机分为对照组(n=23)和观察组(n=23)。对照组给予乳腺癌改良根治术治疗,观察组给... 详细信息

目的探讨保乳联合前哨淋巴结活检术在23例早期乳腺癌治疗中的临床应用价值。方法选取2016年7月至2017年7月本院收治的46例早期乳腺癌的患者作为研究对象,随机分为对照组(n=23)和观察组(n=23)。对照组给予乳腺癌改良根治术治疗,观察组给予保乳联合前哨淋巴结活检术。比较两组的治疗效果。结果观察组手术时间(65.3±8.2)min、术中出血量(60.5±10.1)ml明显少于对照组的(89.1±8.0)min、(140.1±12.9)ml;观察组并发症发生率4.35%(1/23)明显低于对照组的26.09%(6/23);观察组生活质量评分显著优于对照组(P<0.05)。结论保乳联合前哨淋巴结活检术用于早期乳腺癌的治疗中,手术时间短,术中出血量少,并发症发生率低,且可以改善患者的生活质量,值得在临床上进一步探讨和推广。

关键词：保乳前哨淋巴结活检术早期乳腺癌

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一种简易钻杆更换装置的研制与应用

机械工程师 2020年第4期 126-128页

作者：王志伟陈基成刘欣荣武生财刘瑞军张家口阿斯嘉特机械制造有限公司河北张家口075100

针对目前潜孔钻机接换钻杆过程中所产生的问题,研制了一种简易钻杆更换装置,减轻了施工者的劳动强度,降低了钻机因使用自动换杆装置而造成的高昂成本,保证了工作人员不用扛钻杆便可以完成钻杆更换的工作,避免了因自动换杆装置所产生的故... 详细信息

针对目前潜孔钻机接换钻杆过程中所产生的问题,研制了一种简易钻杆更换装置,减轻了施工者的劳动强度,降低了钻机因使用自动换杆装置而造成的高昂成本,保证了工作人员不用扛钻杆便可以完成钻杆更换的工作,避免了因自动换杆装置所产生的故障,又创造了经济效益。

关键词：钻机钻杆更换装置工作效率

VabHLH137 promotes proanthocyanidin and anthocyanin biosynthesis and enhances resistance to Colletotrichum gloeosporioides in grapevine

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Horticulture Research 2023年第2期10卷 106-117页

作者： Dan Yu Wei Wei Zhongqi Fan Jianye chen Yilin You Weidong Huang jicheng Zhan Beijing Key Laboratory of Viticulture and Enology College of Food Science and Nutritional EngineeringChina Agricultural UniversityBeijing 100085China State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources/Guangdong Provincial Key Laboratory of Postharvest Science of Fruits and Vegetables College of HorticultureSouth China Agricultural UniversityGuangzhou510642China

Proanthocyanidins(PAs)and anthocyanins are involved in the response of plants to various environmental ***,the mechanism behind defense-induced PA biosynthetic regulation is still not completely elucidated,also in *** study performed a transcriptome sequencing analysis of grape berries infected with Colletotrichum gloeosporioides to highlight the induction of the VabHLH137 factor from the basic helix-loop-helix(bHLH)XII subfamily by the fungus,which appeared to be significantly co-expressedwith PA-related *** functional analysis of VabHLH137 overexpression and knockdownin transgenic grape calli showed that it positively regulated PA and anthocyanin ***,VabHLH137 overexpression in the grape calli significantly increased resistance to ***.A yeast one-hybrid and electrophoretic mobility shift assay revealed that VabHLH137 directly bound to the VaLAR2 promoter,enhancing its activity and interacting with VaMYBPAR,a transcriptional activator of PA ***,transient experiments showed that although the VabHLH137+VaMYBPAR complex activated VaLAR2 expression,it failed to further enhance VaLAR2 expression compared to VaMYBPAR *** findings indicated that VabHLH137 enhanced PA biosynthesis by activating of VaLAR2 expression,providing new insight into the transcriptional regulation of defense-induced PA biosynthesis in grapevine.

关键词： resistance alone biosynthesis

Visualizing experimental investigation on gas-liquid replacements in a microcleat model using the reconstruction method

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Deep Underground Science and Engineering 2023年第3期2卷 295-303页

作者： Shaojie chen jicheng Zhang Dawei Yin Faxin Li Jialin Lu Peiyang Zhu College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdaoChina State Key Laboratory of Strata Intelligent Control and Green Mining Shandong University of Science and TechnologyQingdaoChina

Cleats are the main channels for fluid transport in coal ***,the microscale flow characteristics of both gas and water phases in primary cleats have not been fully studied as ***,the local morphological features of the cleat were determined using image processing technology and a transparent cleat structure model was constructed by microfluidic lithography using the multiphase fluid visualization test ***,the effect of microchannel tortuosity characteristics on two‐phase flow was analyzed in this *** results are as follows:(1)The local width of the original cleat structure of coal was strongly *** cleats showed contraction and expansion in the horizontal direction and undulating characteristics in the vertical direction.(2)The transient flow velocity fluctuated due to the structural characteristics of the primary *** water‐driven gas interface showed concave and convex instability during flow,whereas the gas‐driven water interface presented a relatively stable concave surface.(3)The meniscus advanced in a symmetrical pattern in the flat channel,and the flow stagnated due to the influence of undulation points in a partially curved *** flow would continue only when the meniscus surface bypassed the stagnation point and reached a new equilibrium position.(4)Enhanced shearing at the gas-liquid interface increased the gas‐injection pressure,which in turn increased residual liquids in wall grooves and liquid films on the wall surface.

关键词： dynamic contact angle flow visualization instantaneous velocity microcleat residual liquid

Ti6Al4V薄板脉冲激光拼焊的焊缝成形及力学性能

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机械制造文摘（焊接分册） 2022年第5期 1-7页

作者：孔斌杜心伟海沁雨陈纪城刘仁培魏艳红南京航空航天大学南京211100

为了改善钛合金薄板激光焊接过程中因工装误差或存在毛刺造成的焊穿、焊漏等缺陷,采用光纤激光器对1.2 mm厚的Ti6Al4V薄板进行脉冲激光焊接试验。分析脉冲频率、对接间隙及激光峰值功率3个工艺条件对焊缝成形的影响,针对外观成形较好的... 详细信息

为了改善钛合金薄板激光焊接过程中因工装误差或存在毛刺造成的焊穿、焊漏等缺陷,采用光纤激光器对1.2 mm厚的Ti6Al4V薄板进行脉冲激光焊接试验。分析脉冲频率、对接间隙及激光峰值功率3个工艺条件对焊缝成形的影响,针对外观成形较好的焊缝进行显微组织与力学性能测试,确定了适合Ti6Al4V薄板拼焊的最佳焊接工艺参数。结果表明,采用脉冲频率40 Hz,占空比60%,激光峰值功率2.0 kW,光斑直径0.7 mm,焊接速度1.8 m/min的脉冲激光焊接工艺可以获得质量优异的焊缝;焊缝由粗大的柱状β晶粒和针状α′相组成,热影响区形成了短针状α′相;随着峰值功率的增大,焊缝的显微硬度明显增大,抗拉强度逐渐减小。最优焊接工艺参数下的焊缝强度可以达到母材的98%,拉伸断口表面平整、规则,断面与拉伸轴线方向呈45°,断口含有大量韧窝。

关键词： Ti6Al4V合金脉冲激光焊焊接工艺参数优化力学性能

产教融合背景下职业本科培养畜牧兽医专业牛羊产业高层次人才模式初探

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现代畜牧科技 2024年第8期 167-169页

作者：潘艳陈集成莫峰苏亚权陆有飞周明旭广西农业职业技术大学广西南宁530007

在产教融合、校企合作的背景下,以广西农业职业技术大学为例,分析畜牧兽医专业牛羊产业高层次人才培养存在的问题,对人才培养模式进行探讨,创新育人模式,提高教学质量。

关键词：产教融合牛羊产业人才模式

Synthesis and electrochemical properties of a series of novel tetra(4-benzoyl)phenoxyphthalocyanine derivatives

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Science China Chemistry 2012年第9期55卷 1872-1880页

作者： WANG Kun FU Qiang MA jicheng LI WeiLi LlWenJu HOU Yang chen LiLi ZHAO BaoZhong Faculty of Chemistry Northeast Normal UniversityChangchun 130024China

A novel phthalocyanine, 2,9（10）,16（17）,23（24）-tetra（4-benzoyl）phenoxyphthalocyanine, and its complexes with Zn（Ⅱ）, Cu（Ⅱ）, Co（Ⅱ）, and Ni（Ⅱ） have been synthesized and characterized by a combination of elemental analysis, IR, IH NMR, UV-vis spectroscopy and mass spectrometry. All of the materials are very soluble in common organic solvents such as dichloro- methane, chloroform, tetrahydrofuran, N,N-dimethylformamide and dimethyl sulfoxide. The Q band wavelengths of the com- plexes decrease in the order： Zn 〉 Cu 〉 Ni 〉 Co. Redox processes were observed at -1.06, -0.74, 0.51 and 0.98 V for the free phthalocyanine, at -0.72 and 1.04 V for the Co（Ⅱ） complex, at -1.24, -0.77, -0.24, 0.61 and 0,91 V for the Cu（Ⅱ） complex, and at -0.74 and 1.20 V for the Ni（Ⅱ） complex. The cyclic voltammograms of the phthalocyanine ring of the four species are similar, with reduction and oxidation couples each involving a one-electron transfer process.

关键词： synthesis electrochemical (4-benzoyl)phenoxy phthalocyanine

Influence of binder systems on sintering characteristics, microstructures, and mechanical properties of PcBN composites fabricated by SPS

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Journal of Advanced Ceramics 2022年第2期11卷 321-330页

作者： Shuna chen Hengzhong FAN Yunfeng SU Wensheng LI jicheng LI Bing YAN Junjie SONG Litian HU Yongsheng ZHANG State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China

Cubic boron nitride(cBN)with high hardness,thermal conductivity,wear resistance,and chemical inertness has become the most promising abrasive and machining *** to the difficulty of fabricating pure cBN body,generally,some binders are incorporated among cBN particles to prepare polycrystalline cubic boron nitride(PcBN).Hence,the binders play a critical factor to the performances of PcBN *** this study,the PcBN composites with three binder systems containing ceramic and metal phases were fabricated by spark plasma sintering(SPS)from 1400 to 1700℃.The sintering behaviors and mechanical properties of the composites were *** show that the effect of binder formulas on mechanical properties mainly related to the compactness,mechanical performances,and thermal expansion coefficient of binder phases,which affect the carrying capacity of the composites and the bonding strength between binder phases and cBN *** PcBN composite with SiAlON phase as binder presented optimal flexural strength(465±29 MPa)and fracture toughness(5.62±0.37 MPa·m^(1/2)),attributing to the synergistic effect similar to transgranular and intergranular ***,the excellent mechanical properties can be maintained a comparable level when the temperature even rises to 800℃.Due to the weak bonding strength and high porosity,the PcBN composites with Al_(2)O_(3)–ZrO_(2)(3Y)and Al–Ti binder systems exhibited inferior mechanical *** possible mechanisms to explain these results were also analyzed.

关键词： polycrystalline cubic boron nitride(PcBN) binder system sintering characteristic high temperature mechanical property fracture mechanism