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Phase composition of SiC-ZrO2 composite materials synthesized from zircon doped la2O3

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Journal of Rare Earths 2009年第5期27卷 806-810页

作者： ma Beiyue YU Jingkun School of materials and Metallurgy Northeastern University Shenyang 110004 China School of Materials and Metallurgy Northeastern University Shenyang 110004 China

A study was carried out to determine the optimum parameters for synthesis of SiC-ZrO2 composite materials by carbothermal re-duction of zircon. Test samples were prepared by mixing average mesh size of less than 30 μm of carbon black and 40 μm of zircon with C/ZrSiO4 mass ratio of 0.2 and the extra addition amount of la2O3 was 0, 1 wt.% and 2 wt.%. Prepared samples were subjected to the car-bothermal reduction process at temperatures of 1723, 1753, 1773 and 1803 K for 4 h, respectively. The carbothermal reduction process was conducted in an atmosphere controlled tube furnace at an argon flow of 1.5 L/min. All products were examined by X-ray diffraction (XRD) to determine the transformation. The results showed that the best transformation of SiC-ZrO2 composite materials occurred at 1803 K for 4 h with the amount of 2 wt.%la2O3.

关键词： composite materials carbothermal reduction zircon lanthanum oxide rare earths

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桑桑牦牛乳品质特性分析

中国草食动物科学 2024年第1期44卷 52-56页

作者：张梦帆洛桑顿珠喇永福任稳稳马晓明张强卓玛次仁尼玛加措平措占堆梁春年中国农业科学院兰州畜牧与兽药研究所甘肃省牦牛繁育工程重点实验室兰州730050 农业农村部青藏高原畜禽遗传育种重点实验室兰州730050 西藏自治区农牧科学院畜牧兽医研究所拉萨850004 日喀则市昂仁县农业农村局日喀则857001

桑桑牦牛是西藏自治区日喀则市昂仁县的特色牛种,已被列为全国农产品地理标志。为深入开发利用桑桑牦牛乳产品,2023年8月份采集了10头桑桑牦牛的乳样,依据国家标准对其营养成分、氨基酸及脂肪酸含量进行了检测,同时与奶牛乳及不同品种... 详细信息

桑桑牦牛是西藏自治区日喀则市昂仁县的特色牛种,已被列为全国农产品地理标志。为深入开发利用桑桑牦牛乳产品,2023年8月份采集了10头桑桑牦牛的乳样,依据国家标准对其营养成分、氨基酸及脂肪酸含量进行了检测,同时与奶牛乳及不同品种的牦牛乳进行了营养成分对比。结果表明,桑桑牦牛乳的蛋白质含量为4.78%,脂肪含量为5.20%,非乳脂固体含量为11.71%,乳糖含量为5.17%,其营养成分含量远高于奶牛乳。与其他牦牛品种相比,桑桑牦牛乳的蛋白质及乳糖含量也比较高。桑桑牦牛乳的氨基酸总量(TAA)为4.88 g/100 g,谷氨酸的含量最高,为1.21 g/100 g,半胱氨酸的含量最少,为0.05 g/100 g。其中必需氨基酸(EAA)为1.90 g/100 g,非必需氨基酸(NEAA)为2.98 g/100 g,EAA/TAA为38.93%,EAA/NEAA为63.76%。与奶牛及其他品种牦牛相比,桑桑牦牛乳是氨基酸含量最高的牛乳。桑桑牦牛乳中共检出14种脂肪酸,主要以不饱和脂肪酸为主,占89.63%;多不饱和脂肪酸有反亚油酸和γ-亚油酸,分别为0.84%和1.03%。综上说明,桑桑牦牛乳含有丰富的营养物质,有着极高的开发利用潜力以及研究价值。

关键词：桑桑牦牛乳乳品质氨基酸脂肪酸

Impact of oceans on climate change in drylands

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Science China Earth Sciences 2019年第6期62卷 891-908页

作者： Xiaodan GUAN Jieru ma Jianping HUANG Ruixin HUANG Lei ZHANG Zhuguo ma Key laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric Sciences Lanzhou University Woods Hole Oceanographic Institution State Key laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Key laboratory of Regional Climate-Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences

Drylands account for approximately 41% of the global total land area. Significant warming and rare precipitation in drylands result in a fragile ecology and deterioration of the living environment, making it more sensitive to global climate change. As an important regulator of the Earth's climate system, the oceans play a vital role in the process of climate change in drylands. In modern climate change in particular, the impact of marine activities on climate change in drylands cannot be neglected. This paper reviews the characteristics of climate change in drylands over the past 100 years, and summarizes the researches conducted on the impact of marine activities on these changes. The review focuses on the impact of the Pacific Decadal Oscillation(PDO), Atlantic Multidecadal Oscillation(AMO), El Ni?o and la Ni?a on climate change in drylands, and introduces the mechanisms by which different oceanic oscillation factors synergistically affect climate change in *** have shown that global drylands have experienced a significant intensification in warming in the past 100 years, which shows obvious characteristics of interdecadal dry/wet variations. The characteristics of these changes are closely related to the oscillatory factors of the oceanic interdecadal scale. Different phase combinations of oceanic oscillation factors significantly change the land-sea thermal contrast, which in turn affects the westerly jet, planetary wave and blocking frequency, resulting in changes in the temperature and dry/wet characteristics of drylands. With the intensification of climate change in drylands, the impact of marine activities on these regions will reveal new characteristics in the future, which will increase the uncertainty of future climate change in drylands and intensify the impact of these drylands on global climate.

关键词： Impact of oceans on climate change in drylands AMO

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美日韩强化三边安全合作的趋势及影响

东北亚学刊 2024年第3期 47-61,145页

作者：马晶王晓波大连理工大学马克思主义学院大连116081 延边大学人文社会科学学院延吉133002

日本和韩国是美国在东北亚地区最重要的盟友。长期以来,与日韩建立紧密三边合作关系是美国外交政策的重要战略目标。拜登政府重视同盟关系重塑,致力于修复日韩关系并强化美日韩三边协调,以求在地缘战略竞争中充分发挥盟友作用。日韩政... 详细信息

日本和韩国是美国在东北亚地区最重要的盟友。长期以来,与日韩建立紧密三边合作关系是美国外交政策的重要战略目标。拜登政府重视同盟关系重塑,致力于修复日韩关系并强化美日韩三边协调,以求在地缘战略竞争中充分发挥盟友作用。日韩政府也试图改善两国关系,以所谓“民主价值观”为基础积极参与美国主导的联合,但影响两国矛盾的因素依然存在。日韩历史矛盾及三国利益冲撞作为美日韩合作障碍的现实不会改变。未来一段时间,美日韩三边合作仍会继续局限于某些特定领域。

关键词：美日韩三边安全合作拜登政府美日同盟美韩同盟朝核问题牵制中国

维普期刊数据库博看期刊

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爱别离

山花 2010年第9期 85-97页

作者：马拉华中科技大学新闻学院

小艾手里握着一枚硬币,她一直那么握着,没松开手,像是握着她的命。硬币有些湿润了,她还是没有松开手。她想着要不要扔一下。这个念头折磨了小艾一个下午,扔还是不扔,这是个大问题。硬币

关键词：王树和

Deformation Mechanism of Bimodal Structured 2205 Duplex Stainless Steel in Two Yield Stages

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Journal of Wuhan University of Technology(materials Science) 2023年第1期38卷 184-191页

作者：盛捷 DU Mingchen LI Yufeng ma Guocai CHEN Weiqian ZHENG Yuehong ZHAN Faqi REN Junqiang G I Raab 喇培清 State Key laboratory of Gansu Advanced Non-Ferrous Metal materials Lanzhou University of TechnologyLanzhou 730050China Jiuquan Iron and Steel(Group)Co. Ltd.Jiayuguan 735100China Key laboratory of Solar Power System Engineering Jiuquan Vocational and Technical CollegeJiuquan 735000China Institute of Physics of Advanced materials Ufa State Aviation Technical University12 K.Marx StreetUfa 450008Russia

A kind of micro/nanostructured 2205 duplex stainless steel(DSS)with uniform distribution of nanocrystals was prepared via aluminothermic reaction *** analysis of stress-strain curve showed that the fracture strength and elongation of the specimen were 946 MPa and 24.7%,*** present,the research on microstructure of bimodal 2205 DSS at room temperature(RT)mainly depended on scanning electron microscope(SEM)observation after loading *** test result indicates that there are two different yield stages in stress-strain curve of specimen during tensile *** microstructure of duplex bimodal structured stainless steel consists of two pairs of soft hard regions and *** studying deformation mechanism of bimodal structured stainless steel,the interaction between soft phase and hard phase are *** principle of composition design and microstructure control of typical duplex stainless steel is obtained,which provides an important research basis for designing of advanced duplex stainless steel.

关键词： 2205 duplex stainless steel bimodal structure in-situ tensile test deformation mechanism two different yield stages

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未完成的肖像

山花 2005年第5期 83-88页

作者：马拉

过了七十岁之后,每天早上起床对汤大为来说就成了一个事件。他睡不着,日益老去的身体里面像是藏着一只闹钟,每天早上五点,他就醒了。汤大为仿佛能听见身体里面的'滴答滴答'的秒钟走动的声音,他感觉他的身体现在已经成了一部老化的机器,... 详细信息

过了七十岁之后,每天早上起床对汤大为来说就成了一个事件。他睡不着,日益老去的身体里面像是藏着一只闹钟,每天早上五点,他就醒了。汤大为仿佛能听见身体里面的'滴答滴答'的秒钟走动的声音,他感觉他的身体现在已经成了一部老化的机器,点再多的润滑油也无济于事,骨头里面

关键词：未完成配音演员

Speckle reduction using phase plate array and lens array

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Opto-Electronic Advances 2020年第1期3卷 16-21页

作者： Xiaohui ma Anting Wang Fenghua ma Shuimei Wu Hai Ming Department of Optical Engineering School of Electronic Science and Applied PhysicsHefei University of TechnologyHefei 230601China Department of Optics and Optical Engineering University of Science and Technology of ChinaHefei 230026China

In this paper,a solution for speckle reduction using phase plate array(PPA)and lens array(la)in a motionless way is *** specially designed PPA is composed of sub-phase plates,which are constituted by phase patterns formed by Hadamard *** component of the proposed optical system should satisfy the stated *** incident laser beam will be incoherent after passing through PPA,and superpose on the screen under the action of la and main *** reduction can be achieved by the averaging of the incoherent speckle *** of abandoning the mechanical movement,it will be suitable for laser displays and images.

关键词： laser display speckle reduction lens array Hadamard

一种基于局部分类精度的概念漂移数据流分类算法

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广西科学 2024年第1期31卷 100-109页

作者：张玲马士伦黎利辉文益民桂林电子科技大学广西图像与图形智能处理重点实验室广西桂林541004

概念漂移数据流分类是一个极具挑战性的问题。当新概念出现时,该概念下的学习样本过少,无法对分类器进行及时调整,进而导致分类精度不高。为了解决该问题,本文提出一种基于局部分类精度的概念漂移数据流分类算法——la-MS-CDC。第一,la-... 详细信息

概念漂移数据流分类是一个极具挑战性的问题。当新概念出现时,该概念下的学习样本过少,无法对分类器进行及时调整,进而导致分类精度不高。为了解决该问题,本文提出一种基于局部分类精度的概念漂移数据流分类算法——la-MS-CDC。第一,la-MS-CDC将k-means聚类和局部分类精度算法结合,从分类器池中挑选出最优源领域分类器;第二,将最优源领域分类器与目标领域分类器加权集成,进而对样本分类;第三,根据分类样本的真实标签分别计算各分类器的损失,并对目标领域和源领域的分类器权重进行更新;第四,再利用该分类样本对目标领域分类器、最优源领域分类器进行更新;最后,完成分类器池的更新。在公开数据集上的实验结果表明,la-MS-CDC能够有效地将源领域知识迁移到目标领域,与现有方法相比,其分类效果具有显著性提升。算法代码可在https://***/ymw12345/laMSCDC上获取。

关键词：概念漂移多源在线迁移学习局部分类精度集成学习多样性