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油底壳螺栓组紧固顺序的研究

内燃机与配件 2024年第7期 1-4页

作者：张雅萍陈冬民许林江铃汽车股份有限公司JMC 江西南昌330000

为了能够挑选出最优的油底壳螺栓紧固顺序。本文以某柴油机为研究对象,设定4种油底壳螺栓紧固顺序方案,运用Abaqus进行螺栓紧固次序分析,得到各紧固螺栓的残余预紧力、油底壳安装面变形、油底壳自身应力、油底壳密封垫变形。综合计算结... 详细信息

为了能够挑选出最优的油底壳螺栓紧固顺序。本文以某柴油机为研究对象,设定4种油底壳螺栓紧固顺序方案,运用Abaqus进行螺栓紧固次序分析,得到各紧固螺栓的残余预紧力、油底壳安装面变形、油底壳自身应力、油底壳密封垫变形。综合计算结果,发现先拧紧四角,再拧紧中间,然后按照顺时针顺序紧固的方案最佳。计算分析过程可以为油底壳装配后密封稳定性提供设计依据。

关键词：油底壳螺栓密封性拧紧次序

Relationship between HBV viremia level of pregnant women and intrauterine infection:neated PCR for detection of HBV DNA

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World Journal of Gastroenterology 1998年第1期4卷 66-68页

作者： ZHANG Shu-Lin HAN Xiao-Bing YUE ya-Fei 不详

IM To determine the incidence of hepatitis B virus (HBV) intrauterine infection and to explore the relationship between HBV viremia level of pregnant women and HBV intrauterine infection.METHoDS Sixtynine pregnant women were divided into three groups. Group A, 41 HBsAg positive patients, 14 of them were HBeAg positive (group A1), and 27 HBeAg negative (group A2); Group B, 12 HBsAg negative patients, but positive for antiHBs and/or antiHBe and/or antiHBc; and Group C, 16 patients negative for all HBV markers. Blood samples of mothers were taken at delivery, samples of their infants were collected within 24 hours after birth (before injection of HBIG and HBV vaccine). All the serum samples were stored at -20℃. HBV serum markers were tested by radioimmunoassay and HBV NDA were detected by nested polymerase chain reaction.RESULTS In group C, all of 16 newborns were negative for HBsAg and HBV DNA. In group A, 7 infants were HBsAg positive (171%), and 17 (415%) were HBV DNA positive (Pof intrauterine HBV infection was much higher in group A1 than that in group A2 (HBsAg 429% vs 37%, HBV DNA 929% vs 148%, Pof HBV intrauterine infection was significantly different between high and low HBV viremia of mothers (933% vs 429%, PoNCLUSIoN The incidence of HBV intrauterine infection is high when HBV DNA in newborns detected with nested PCR is used as a marker of HBV infection. It is related to HBV viremia level of mothers.

关键词： hepatitis B DNA,viral/analysis radioimmunoassay polymerase chain reaction intrauterine infection

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瓶装材料对核桃油品质及预测货架期的影响

粮油食品科技 2024年第4期32卷 169-177页

作者：胡伯凯税会霞耿阳阳李学琴曾亚军杨光贵州省林业科学研究院贵州省核桃研究所贵州省核桃工程技术研究中心贵州贵阳550005 贵阳信息科技学院贵州贵阳550025 贵州阳光食品有限公司贵州毕节551600

为探究不同瓶装材料对核桃油品质变化的影响,分别用敞口玻璃烧杯、马口铁罐、玻璃油瓶盛装核桃油,采用Schaal烘箱法加速油脂氧化,以过氧化值、酸值、脂肪酸组成、驰豫特性为评价指标,研究不同瓶装材料对核桃油氧化稳定性及预测货架期的... 详细信息

为探究不同瓶装材料对核桃油品质变化的影响,分别用敞口玻璃烧杯、马口铁罐、玻璃油瓶盛装核桃油,采用Schaal烘箱法加速油脂氧化,以过氧化值、酸值、脂肪酸组成、驰豫特性为评价指标,研究不同瓶装材料对核桃油氧化稳定性及预测货架期的影响。结果表明,以过氧化值≤0.25 g/100 g为限量值时(植物油国家标准规定),添加特丁基对苯二酚(TBHQ)的烧杯、马口铁罐、玻璃油瓶盛装核桃油和空白对照的预测货架期分别为160、112、336和64 d,在预测货架期内,核桃油酸价均在二级核桃油要求范围内。3种包装材料对添加TBHQ的核桃油氧化稳定性强弱顺序为:玻璃油瓶>烧杯>马口铁罐;核桃油长期贮藏建议以玻璃油瓶盛装为佳。

关键词：核桃油瓶装材料预测货架期氧化稳定性

Progress in mechanochromic luminescence of gold(Ⅰ) complexes

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Chinese Chemical Letters 2021年第12期32卷 3718-3732页

作者： Shiqi Cheng Zhao Chen ya Yin Yue Sun Shenghua Liu Hubei Key Laboratory of Catalysis and Materials Science College of Chemistry and Material SciencesSouth-Central University for NationalitiesWuhan 430074China Jiangxi Key Laboratory of organic Chemistry Jiangxi Science and Technology Normal UniversityNanchang 330013China Key Laboratory of Pesticide and Chemical Biology Ministry of EducationCollege of ChemistryCentral China Normal UniversityWuhan 430079China

Photophysical properties of organic and organometallic luminophors are closely related with their molecular packings, enabling the exploitation of stimuli-responsive functional luminescent *** molecules, which can change their luminescence characteristics after mechanical stimulus, have received an increasing interest due to their promising applications in multifunctional sensors and molecular switches. During the past two decades, the development of gold(Ⅰ) chemistry has been attracting the attention of plenty of researchers. Indeed, a variety of gold(I) complexes with fascinating photophysical behaviors have been discovered. This review focuses on the research progress in the different types of mechanoluminochromic gold(Ⅰ) complexes, including mono-, bi-and multi-nuclear gold(Ⅰ)systems. Their interesting luminescence behaviors of these gold(Ⅰ)-containing luminogens upon mechanical stimulus and the proposed mechanisms of their observed mechanochromic luminescence are summarized systematacially. Moreover, this review will put forward an outlook about the possible opportunities and challenges in this significative scientific field.

关键词： Gold(Ⅰ)complexes Mechanochromic luminescence Mechanisms Molecular packings Aurophilic interactions

Synthesis, self-assembly and photo-responsive behavior of AB_2 shaped amphiphilic azo block copolymer

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Chinese Chemical Letters 2015年第7期26卷 857-861页

作者： Ren-Bo Wei Xiao-Gong Wang ya-Ning He Department of Chemical Engineering Key Laboratory of Advanced Materials (MOE) Tsinghua University

In this work, we report the synthesis of AB2 shaped amphiphilic azo block copolymer by macromolecular azo coupling reaction. The product and intermediates were characterized by various methods. The self- assembly in selected solvents and photo-responsive behavior of the copolymer were studied by means of UV-vis spectrophotometry and TEM. Spherical aggregates can be obtained by gradually adding water into the solution of this amphiphilic azo block copolymer. Upon irradiation with polarized UV （365 nm） light, the aggregates can be elongated in the polarized direction.

关键词： Azo block copolymerSelf-assemblySpherical aggregatesPhotoinduced deformationMacromolecular azo-coupling reaction

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低等级干线公路安全设施精细化提升设计研究

现代工程科技 2024年第17期3卷 57-60页

作者：张亚魏梦姚伟王如航贵州省铜仁公路管理局贵州铜仁554399 北京中交华安科技有限公司北京100071

随着交通行业的持续发展,交通事故数量亦在逐年攀升。一些干线公路因地形、环境等多重因素的制约,技术等级有所降低,然而其承担的交通量依然较大。深入探讨了低等级干线公路交通安全设施的精细化提升策略,旨在为公路交通安全设施设计提... 详细信息

随着交通行业的持续发展,交通事故数量亦在逐年攀升。一些干线公路因地形、环境等多重因素的制约,技术等级有所降低,然而其承担的交通量依然较大。深入探讨了低等级干线公路交通安全设施的精细化提升策略,旨在为公路交通安全设施设计提供理论依据和技术支撑,以期提高行车安全性。研究结果指出,因低等级干线公路功能的特殊性,其交通安全设施的提升应更注重安全性与完整性。

关键词：交通安全低等级干线公路设施设计精细化提升

中国制造业产业链、创新链、资金链、人才链耦合协调发展:统计测度与演进态势

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当代金融研究 2024年第5期 12-34页

作者：王亚飞石铭黄欢欢重庆师范大学经济与管理学院重庆401331

推动产业链、创新链、资金链、人才链融合发展是贯彻新发展理念、构建新发展格局的重要战略举措。基于2012-2021年中国30个省(区、市)的数据,利用耦合协调度模型测算分析中国制造业产业链、创新链、资金链和人才链(以下简称“四链”)的... 详细信息

推动产业链、创新链、资金链、人才链融合发展是贯彻新发展理念、构建新发展格局的重要战略举措。基于2012-2021年中国30个省(区、市)的数据,利用耦合协调度模型测算分析中国制造业产业链、创新链、资金链和人才链(以下简称“四链”)的耦合协调度,运用核密度估计法和Dagum基尼系数考察其时间演进态势和空间差异来源,利用障碍度模型探究影响中国制造业“四链”耦合协调度的主要因素。研究结果表明:制造业“四链”耦合协调发展态势维稳向好,整体处于中度耦合协调阶段;创新链子系统发展持续滞后于产业链、资金链、人才链子系统;除“产业链-资金链”外,其他子系统“两两”间的耦合协调度均呈增长趋势;制造业“四链”耦合协调发展的区域差异大致呈现先上升后下降的倒“U”型趋势,主要来自区域间差异;目前要素层面临的主要障碍因子分别为产业链宽度、创新环境、资金周转能力和人才结构。最后,从鼓励区域间合作、优化创新激励机制、完善金融支持体系和引领人才回归实体经济部门等方面提出建议。

关键词： “四链” 耦合协调度时空特征演化障碍

Spectral Characteristics of White organic Light-emitting Diodes Based on Novel Phosphorescent Sensitizer

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Chinese Journal of Chemical Physics 2008年第6期21卷 510-514页

作者： Xiao-qing Tang Jun-sheng Yu Lu Li Wen Wen ya-dong Jiang State Key Laboratory of Electronic Thin Films and Integrated Devices School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China

White organic light-emitting diodes were fabricated by using a novel phosphorescence bis（1,2-diphenyl-1H-benzoimidazole）iridium（acetylacetonate）[（pbi）2Ir（acac）] as sensitizer and a fluorescent dye of 4- （dicyanomethylene）-2-t-butyl-6-（1,1,7,7-tetramethyljulolidyl-9-enyl）-4H-pyran （DCJTB） codoped into a carbazole polymer of poly（N-vinylcarbazole）（PVK）. Through characterizing the UV-Vis absorption spectra, the photoluminescence spectra of （pbi）2Ir（acac） and DCJTB, and the electroluminescence spectral properties of the WoLEDs, the energy transfer mechanisms of the codoped polymer system were deduced. The results demonstrate that the luminescent spectra with different intensity of （pbi）2Ir（acac） and DCJTB were co-existent in the EL spectra of the blended system, which is ascribed to an incomplete energy transfer process in the EL process. The efficient Forster and Dexter energy transfer between the host and the guests enabled a strong yellow emission from （pbi）2Ir（acac） and DCJTB, where （pbi）2Ir（acac） plays an important role as a phosphorescent sensitizer for DCJTB. With the blue emitting-layer of N,N＇-diphenyl-N,N＇-bis（1- naphthyl）（1,1＇-biphenyl）-4,4＇-diamine, the codoped system device achieved white emission. The codoped system showed that its Commissions Internationale de 1＇Eclairage coordinates were more independent of the variation of bias voltage than those of phosphorescent doped PVK systems.

关键词： White organic light-emitting diode Phosphorescent sensitizer Spectrum analysis

Computational identification and evolutional analysis of Piwi subfamily in 11 Drosophila species

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Insect Science 2008年第6期15卷 537-544页

作者： Xue Zhou ya-Long Xu Luo-Gen Cheng Fei Li College of Life Science Nanjing Normal University Department of Entomology Nanjing Agricultural University Nanjing China

The complete genome sequences of 11 Drosophila species provide an opportunity to investigate the gene family evolution in closely related species. Drosophila Piwi subfamily, including three members, piwi, Aub and Ago3, has attracted increasing attention as it participates in the biogenesis of piRNA. Here, we identified 33 Piwi homologs from the genome of 11 Drosophila species. The full-length cDNA sequences ofpiwi and Aub genes were obtained by using New GENSCAN Web Server. The Ago3 homologs were difficult regarding full-length information because they had long introns. The genomic structure of Piwi subfamily genes are highly conserved among diverse Drosophila species. Insect piwi and Aub genes have long first introns. The average length of the first intron is 1 284 bp for piwi and 840 bp for Aub, which is much larger than those of other introns （93 bp for Piwi and 54 bp for Aub）. However, this phenomenon is not observed in mammalian piwi genes. We also found that there were abundant repeat sequences in both exons and introns of insect Ago3 genes. Due to recent insertions of long terminal repeat elements in four Drosophila species, part of the third introns exhibit higher conservation than adjacent exons and other introns. An evolutional tree created by Minimum Evolution method indicates that mammalian piwi genes are more closely related to the insect Ago3 Piwi subfamily.

关键词： evolution Drosophila genome intron Piwi subfamily