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Effect of temperature on antioxidant defense and innate immunity in Brandt’s voles

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Zoological Research 2019年第4期40卷 305-316页

作者： de-li Xu Meng-Meng Xu de-Hua Wang College of life Sciences Qufu Normal UniversityQufu Shandong 273165China State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China

Ambient temperature is an importa nt factor in flue ncing many physiological processes, in eluding antioxidant defense and immunity. In the present study, we tested the hypothesis that antioxidant defense and immunity are suppressed by high and low temperature treatme nt in Bran dt's voles (Lasiopodomys brandtii). Thirty male voles were randomly assigned into different temperature groups (4, 23, and 32℃, n=10 for each group), with the treatment course lasting for 27 d. Results showed that low temperature in creased gross en ergy in take (GEI) and liver, heart, and kidney mass, but decreased body fat mass and dry carcass mass. With the decline in temperature, hydrogen peroxide (H2O2) concentration, which is indicative of reactive oxyge n species (ROS) levels, in creased in the liver, decreased in the heart, and was unchanged in the kidney, testis, and small intestine. lipid peroxidation indicated by malonaldehyde (MDA) content in the liver, heart, kidney, testis, and small intestine did not differ among groups, implying that high and low temperature did not cause oxidative damage. Similarly, superoxide dismutase (SOD) and catalase (CAT) activities and total antioxidant capacity (TAOC) in the five tissues did not respond to low or high temperature, except for elevation of CAT activity in the testis upon cold exposure. Bacteria killing capacity, which is indicative of innate immunity, was nearly suppressed in the 4℃ group in contrast to the 23℃ group, whereas spleen mass and white blood cells were un affected by temperature treatment. The levels of testosterone, but not corticostero ne, were in flue need by temperature treatment, though neither were correlated with innate immunity, H2O2 and MDA levels, or SOD, CAT, and TAOC activity in any detected tissues. Overall, these results showed that temperature had different in flue nces on oxidative stress, an tioxida nt en zymes, and immunity, which depended on the tissues and parameters tested. Up-regulation or maintenance

关键词： Antioxidant defense Brandt's voles(Lasiopodomys brandtii) Immunity Temperature

高导热镁合金滤波器壳体压铸工艺、组织与性能研究

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铸造 2024年第2期73卷 194-201页

作者：周丽萍李子昕张玮宸林占宏金晨赵寿曾小勤李德江上海交通大学材料科学与工程学院轻合金精密成型国家工程研究中心上海200240 青海盐湖特立镁有限公司青海西宁811600

以Mg-4La-2Al-0.3Mn(LA42)合金为研究对象,利用OM、XCT、数值模拟等方法,对比AZ91D常规压铸工艺,优化出适用于LA42合金滤波器壳体的压铸工艺。研究表明,滤波器壳体的最优压铸工艺是浇注温度720℃、模具温度250℃、增压压力90 MPa。该工... 详细信息

以Mg-4La-2Al-0.3Mn(LA42)合金为研究对象,利用OM、XCT、数值模拟等方法,对比AZ91D常规压铸工艺,优化出适用于LA42合金滤波器壳体的压铸工艺。研究表明,滤波器壳体的最优压铸工艺是浇注温度720℃、模具温度250℃、增压压力90 MPa。该工艺下成形的滤波器壳体,其背部与散热齿的显微组织与性能相差较大。壳体背部冷却速率慢,晶粒尺寸大,伴随大量预结晶组织,而散热齿冷却速率快,晶粒尺寸细小,伴随冷隔和孔洞缺陷。散热齿热导率[107.7W/(m·K)]低于壳体背部热导率[112.3W/(m·K)]。散热齿屈服强度(170.1 MPa),远高于壳体背部屈服强度(138.4 MPa)。但散热齿区域因为含有明显冷隔和孔洞缺陷,显著影响伸长率。

关键词：镁合金热导率力学性能压铸

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光纤光栅索力传感器的酸碱耐久性

科学技术与工程 2024年第20期24卷 8606-8614页

作者：覃荷瑛祝健强李纯德罗伯光桂林理工大学广西壮族自治区智慧结构材料工程研究中心桂林541004 桂林理工大学广西岩土力学与工程重点实验室桂林541004

拉索作为斜拉桥的主要受力构件常处于复杂、恶劣的工作环境,传统的索力监测手段存在一定的局限性。将光纤光栅传感器内嵌封装进金属承压块上的凹槽,研制一种光纤光栅索力传感器,并对两种环氧树脂胶黏剂封装的光纤光栅索力传感器在酸碱... 详细信息

拉索作为斜拉桥的主要受力构件常处于复杂、恶劣的工作环境,传统的索力监测手段存在一定的局限性。将光纤光栅传感器内嵌封装进金属承压块上的凹槽,研制一种光纤光栅索力传感器,并对两种环氧树脂胶黏剂封装的光纤光栅索力传感器在酸碱腐蚀环境下的耐久性能进行研究,然后依托逆幂律模型与老化动力学理论,推导出传感器寿命预测方程。试验结果表明:该传感器的线性度和稳定性良好,传感器在腐蚀溶液中失效的主要原因是封装部位界相区胶黏剂受腐蚀剥落。A类传感器的耐酸碱性强于B类传感器,A类传感器在弱酸弱碱环境中的使用寿命均超过35年,大于斜拉桥拉索平均20年的换索年限,可以实现拉索全生命周期的监测。

关键词：索力监测光纤光栅传感器酸碱腐蚀寿命预测

description of a new species and new distributional data for two species of Aphytis (Hymenoptera: Aphelinidae) from China

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Journal of Forestry Research 2017年第6期28卷 1259-1263页

作者： Yan Gao Cheng-de li School of Forestry Northeast Forestry University HarbinHeilongjiang 150040 People’s Republic of China

Aphytis tridentatus Gao and li sp. nov. is described and illustrated from southwest China, and A. bangalorensis Rosen and deBach is newly recorded from China. New distributional data for A. chionaspis Ren are also pro... 详细信息

关键词： Aphytis tridentatus Chalcidoidea China Distribution New species

Roles of Pectin Methylesterases in Pollen-Tube Growth

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Journal of Integrative Plant Biology 2007年第1期49卷 94-98页

作者： li-Qun Chen de Ye State Key Laboratory of Plant Physiology and Biochemistry College of Biological Sciences China Agricultural University Beijing 100094 China

Elongation of the pollen tube in pistil is essential for delivering sperms into the female gametophyte in sexual plant reproduction. Recently, a group of cell wall enzymes, pectin methylesterases （PMEs）, have been identified as playing an important role in this process. This article reviews the new understanding of the roles of PMEs in regulating pollen tube growth.

关键词： PME pollen tube male gametophyte sexual plant reproduction Arabidopsis

Theoretical and Experimental Study of A Coaxial Double-Buoy Wave Energy Converter

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China Ocean Engineering 2021年第3期35卷 454-464页

作者： li de-min DONG Xiao-chen SHI Hong-da li Yan-ni department of Ocean Engineering College of EngineeringOcean University of ChinaQingdao 266100China Shandong Provincial Key Laboratory of Ocean Engineering Ocean University of ChinaQingdao 266100China Qingdao Municipal Key Laboratory of Ocean Renewable Energy Ocean University of ChinaQingdao 266100China Pilot National Laboratory for Marine Science and Technology(QingDao) Qingdao 266200China

The double-body heave wave energy converter(WEC)is one of the most conducive devices to absorb the wave energy from relative motion while the law of which is not well *** paper makes an in-depth study on this wave energy converter,by means of the combination of theoretical analysis and physical model *** hydrodynamic characteristics and energy capture of the double-buoy under constant and linear Power Take-Off(PTO)damping are *** of absolute mass and mass ratio are discussed in the theoretical *** displacement amplitude and average power output are tested in the experiment to analyze the effect of the wave period and outer buoy’s mass,while the capture width ratio(CWR)is also *** show that the wave period and mass of the buoys have a significant effect on the *** forms of PTO damping have no influence on the optimal wave period and mass ratio of this *** is recommended to select the double-buoy converter with a mass ratio of 0.80 and to place it in an area with the frequent wave period close to the natural period of the outer buoy to achieve the optimal energy capture.

关键词： coaxial double-buoy wave energy converter hydrodynamic characteristics model test power take-off

Colorectal cancer,one entity or three

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2009年第3期10卷 219-229页

作者： Feng-ying li Mao-de LAI department of Pathology School of Medicine Zhejiang University Hangzhou 310058 China

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability （MSI）. However, distal colon cancer is usually associated with specific chromosomal instability （CIN）. The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. ＂Proximal shift＂ of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of coloreetal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of coloreetal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data coneerning the site-specific mechanism of eolorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception.

关键词： Colorectal cancer Proximal colon Distal colon Rectum Carcinogenesis Epidemiology and prognosis

A review of down-hole tubular string buckling in well engineering

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Petroleum Science 2015年第3期12卷 443-457页

作者： de-li Gao Wen-Jun Huang MOE Key Laboratory of Petroleum Engineering China University of Petroleum

Down-hole tubular string buckling is the most classic and complex part of tubular string mechanics in well engineering. Studies of down-hole tubular string buckling not only have theoretical significance in revealing the buckling mechanism but also have prominent practical value in design and control of tubular strings. In this review, the basic principles and applicable scope of three classic research methods （the beam-column model, buck- ling differential equation, and energy method） are intro- duced. The critical buckling loads and the post-buckling behavior under different buckling modes in vertical, inclined, horizontal, and curved wellbores from different researchers are presented and compared. The current understanding of the effects of torque, boundary condi- tions, friction force, and connectors on down-hole tubular string buckling is illustrated. Meanwhile, some unsolved problems and controversial conclusions are discussed. Future research should be focused on sophisticated description of buckling behavior and the coupling effect of multiple factors. In addition, active control of down-hole tubular string buckling behavior needs some attention urgently.

关键词： Down-hole tubular mechanics Tubular stringbuckling Wellbore configuration Boundary condition Friction force

近净成形快堆支承环用316H不锈钢锻件的晶粒度与力学性能

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材料热处理学报 2024年第4期45卷 122-129页

作者：任利国傅万堂张皓周岩温瑞洁赵德利王宝忠亚稳材料制备技术与科学国家重点实验室燕山大学材料科学与工程学院河北秦皇岛066004 天津重型装备工程研究有限公司天津300457 中国第一重型机械股份公司黑龙江齐齐哈尔161042

采用电渣重熔钢锭,经开坯锻造后,通过热挤压制备高品质坯料,随后在专用模具内进行胎模锻造成形,研制出国内首支外径15.5米、重量15吨的快堆支撑环1/6弧段316H不锈钢锻件,突破了超大规格快堆支撑环锻件制造技术瓶颈。结果表明:锻件各部... 详细信息

采用电渣重熔钢锭,经开坯锻造后,通过热挤压制备高品质坯料,随后在专用模具内进行胎模锻造成形,研制出国内首支外径15.5米、重量15吨的快堆支撑环1/6弧段316H不锈钢锻件,突破了超大规格快堆支撑环锻件制造技术瓶颈。结果表明:锻件各部位晶粒度、拉伸性能均匀一致且无各向异性,疲劳性能完全满足ASME设计曲线标准要求。所采用的近净成形制造工艺大大缩短了产品制造周期,提高了经济效益,实现了同类产品的国产化制造。

关键词： 316H不锈钢锻件晶粒度拉伸性能疲劳性能