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magnetocaloric effect and phase transition critical behavior of la0.75Sr0.25Mn0.9Co0.1O3 compound synthesized under the high pressure

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Tungsten 2024年第3期6卷 621-632页

作者： Jing Zhao Lei Gao Jian-Jun Zhao Wei Wei Hui-Qin Yun Ru Xing Huai-Jin ma Xiang Jin Luo-Meng Chao School of Physical Science and Technology Key Laboratory of Magnetism and Magnetic Materials for Higher Education in Inner Mongolia Autonomous Region Baotou Teachers' College National Key laboratory of Baiyunobo Rare Earth Resource Research and Comprehensive Utilization Baotou Research Institute of Rare Earths School of Physics and Electronic Information Inner Mongolia Normal University College of Science Inner Mongolia University of Science and Technology

In this study,a novel method is proposed for producing perovskite rare-earth manganese oxide magnetic refrigeration materials that exhibit superior properties compared to similar *** maximum magnetic entropy change values for this sample are 1.44 and 3.75 J·kg-1·K-1for magnetic fields of 2 and 7 T,***,its relative cooling power has been calculated to be 101.96 and 404.78 J·kg-1,indicating good *** results were obtained using the sample synthesized under a pressure of 4 GPa,and the sample has undergone a second phase *** critical behavior of the sample fits well with the mean field *** different magnetic fields,there is a significant overlap between the values of the maximum magnetic entropy change and the temperature-averaged entropy change,indicating that the refrigeration performance of the sample after high pressure can approach its maximum capability.

关键词： High-pressure synthesis magnetocaloric effect Relative cooling power magnetic phase transition

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雪宝顶白钨矿的谱学特征及主微量元素分析

光谱学与光谱分析 2024年第6期44卷 1689-1696页

作者：曹沁元史淼马世玉河北地质大学地球科学学院河北石家庄050031 河北地质大学宝石与材料学院河北石家庄050031 河北省岩石矿物材料绿色开发重点实验室河北石家庄050031 硅酸盐固废资源化利用河北省工程研究中心河北石家庄050031

白钨矿是一种稀有宝石,具粒状、块状构造,颜色为白-浅黄色,油脂光泽,荧光性明显。四川平武雪宝顶白钨矿矿床为围岩蚀变较弱的脉状热液巨晶宝石级矿床,产出白钨矿颜色饱和度较高,具完美晶型且色泽纯正,与绿柱石、锡石和白云母共生。该研... 详细信息

白钨矿是一种稀有宝石,具粒状、块状构造,颜色为白-浅黄色,油脂光泽,荧光性明显。四川平武雪宝顶白钨矿矿床为围岩蚀变较弱的脉状热液巨晶宝石级矿床,产出白钨矿颜色饱和度较高,具完美晶型且色泽纯正,与绿柱石、锡石和白云母共生。该研究选取雪宝顶近无色-橘黄色调白钨矿为研究对象,使用X射线粉晶衍射(XRD)、傅里叶变换红外光谱分析仪、紫外-可见分光光度计、激光拉曼光谱仪、电子探针、激光剥蚀电感耦合等离子体质谱仪(la-ICP-MS)的综合分析,结合矿物学、谱学与主微量元素特征,确定近无色-橘黄色调白钨矿的矿物成分、晶体结构、特征鉴别谱带、致色离子以及主微量、稀土等化学组分含量,探讨白钨矿稀土元素含量与颜色成因关系,为雪宝顶近无色-橘黄色调白钨矿提供诊断性鉴别依据。研究结果表明,白钨矿结晶程度较好,化学成分均匀,无明显间断,矿物成分含量相对集中,共生矿物多为白云母和伊利石。样品具典型的白钨矿红外特征峰440、809和870 cm^(-1)及与Ca_(2+)有关的448 cm^(-1)特征峰,谱峰显示色调越深者吸收度越高;拉曼特征峰909 cm^(-1)和Ca—O晶格振动峰207 cm^(-1),随色调加深强度加深;紫外吸收峰表现为橙黄区强吸收,尖峰在383、570、584和804 nm附近,近无色调者仅具383 nm尖峰,黄色调较浅者近紫外区Fe^(3+)吸收度较低,黄色调较深者蓝紫区Fe^(3+)强吸收且其橘黄色调由Nd^(3+)所致;白钨矿化学组分WO_(3)和CaO质量比接近甚至超过理想值,近无色者含量相对集中;微量元素中Fe元素与色调呈正相关,黄色调越深者,含量越高;稀土总量变化范围大,轻稀土更为富集,具明显的Eu负异常,Ce异常不明显。浅黄色调受微量元素Si、Fe元素及Fe^(3+)的d—d电子跃迁影响,黄色调受微量元素Mn、Fe元素及Fe^(3+)的电子跃迁所致,橘黄色调受稀土Nd和Sm元素影响较大。

关键词：雪宝顶白钨矿近无色-橘黄色调谱学特征原位微区主微量元素特征

Two-dimensional atomically thin Pt layers on MXenes: The role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe Li Tobias K.Misicko Fan Yang Xiaopeng Liu Zhenwei Wu Xiaoyang Gao Tao ma Jeffrey T.Miller Daniela S.mainardi Collin D.Wick Zhenhua Zeng Yang Xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and Science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2TiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(TOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

苜蓿皂苷提取物对断奶湖羊免疫、抗氧化能力和瘤胃微生物区系的影响

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中国畜牧兽医 2024年第7期51卷 2799-2809页

作者：张艳马森栗守仁皇甫卫康腊邵凯马季祥王志昌史莹华河南农业大学动物科技学院郑州450002 河南省草地资源创新与利用重点实验室郑州450002 河南省牧草工程技术研究中心郑州450002

【目的】苜蓿皂苷作为一类天然生物活性物质,具有提高畜禽机体免疫力、促生长及调节胃肠道功能等多方面效用。试验旨在探究苜蓿皂苷提取物对断奶湖羊生长性能、免疫功能、抗氧化能力和瘤胃微生物区系的影响。【方法】选取45日龄、体重相... 详细信息

【目的】苜蓿皂苷作为一类天然生物活性物质,具有提高畜禽机体免疫力、促生长及调节胃肠道功能等多方面效用。试验旨在探究苜蓿皂苷提取物对断奶湖羊生长性能、免疫功能、抗氧化能力和瘤胃微生物区系的影响。【方法】选取45日龄、体重相近(15.67 kg±1.18 kg)的断奶湖羊32只,随机分为2组,每组4个重复,每个重复4只羊。对照组(CON)湖羊饲喂基础饲粮,皂苷组(AS)湖羊在基础饲粮中添加2 g/kg(饲粮干物质基础)苜蓿皂苷提取物,预试期7 d,正试期60 d。试验结束后收集断奶湖羊瘤胃液测定微生物组成,采集颈静脉血用于测定血清免疫和抗氧化性能相关指标。【结果】(1)两组湖羊平均日增重(ADG)和料重比(F/G)均无显著差异(P>0.05)。(2)与对照组相比,皂苷组湖羊血清中免疫球蛋白(IgA、IgM)、抗炎因子白介素-10(IL-10)、CD4^(+)T细胞和CD4/CD8水平极显著或显著升高(P0.05)。(5)两组间湖羊Shannon指数、Simpson指数和主坐标分析(PCoA)均无明显差异;在属水平上,皂苷组湖羊瘤胃液中硫酸盐还原菌脱硫弧菌属(Desulfovibrio)和有益菌罗氏菌属(Roseburia)、凸腹真杆菌群(Eubacterium_ventriosum_group)等的相对丰度均显著高于对照组(P<0.05)。【结论】饲粮中添加苜蓿皂苷提取物可以影响断奶湖羊瘤胃微生物的组成,提高机体免疫和抗氧化能力,且一定程度上有利于机体健康。

关键词：断奶湖羊苜蓿皂苷提取物免疫功能抗氧化能力瘤胃微生物

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Highly efficient and aberration-free off-plane grating spectrometer and monochromator for EUV—soft X-ray applications

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Light(Science & Applications) 2024年第1期13卷 68-79页

作者： Jie Li Kui Li Xiaoshi Zhang Dimitar Popmintchev Hao Xu Yutong Wang Ruixuan Li Guangyin Zhang Jiyue Tang Jin Niu Yongjun ma Runyu Meng Changjun Ke Jisi Qiu Yunfeng ma Tenio Popmintchev Zhongwei Fan Aerospace Information Research Institute Chinese Academy of SciencesBeijing100094China School of Optoelectronics University of the Chinese Academy of SciencesBeijing100049China Yunnan University KunmingYunnan650500China Photonics Institute TU WienViennaA-1040Austria Yunnan Observatories Chinese Academy of SciencesKunmingYunnan650011China University of California Physics DepartmentSan DiegoLa JollaCA92093USA

We demonstrate a novel flat-field,dual-optic imaging EUV—soft X-ray spectrometer and monochromator that attains an unprecedented throughput efficiency exceeding 60%by design,along with a superb spectral resolution ofλ/Δλ>200 accomplished without employing variable line spacing *** the benefits of the conical diffraction geometry,the optical system is globally optimized in multidimensional parameter space to guarantee optimal imaging performance over a broad spectral range while maintaining circular and elliptical polarization states at the first,second,and third diffraction ***,our analysis indicates minimal temporal dispersion,with pulse broadening confined within 80 fs tail-to-tail and an FWHM value of 29 fs,which enables ultrafast spectroscopic and pump-probe studies with femtosecond ***,the spectrometer can be effortlessly transformed into a monochromator spanning the EUV—soft X-ray spectral region using a single grating with an aberration-free spatial *** capability allows coherent diffractive imaging applications to be conducted with highly monochromatic light in a broad spectral range and extended to the soft X-ray region with minimal photon loss,thus facilitating state-of-the-art imaging of intricate nano-and bio-systems,with a significantly enhanced spatiotemporal resolution,down to the nanometer–femtosecond level.

关键词： chromato Highly exceeding

北赤道逆流影响的热带西太平洋秋冬转换期海表叶绿素浓度与ENSO循环

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海洋学报 2024年第3期46卷 12-21页

作者：高微马本俊青岛黄海学院山东青岛266427 哈尔滨工程大学青岛创新发展基地山东青岛266427

在厄尔尼诺-南方涛动(El Nino-Southern Oscillation, ENSO)的发生、发展中,北赤道逆流也有明显的年际变化,但北赤道逆流的变化如何影响海洋水文生态条件的变化过程尚不清楚。本文以位于热带西太平洋的北赤道逆流影响区为研究海区,分析... 详细信息

在厄尔尼诺-南方涛动(El Nino-Southern Oscillation, ENSO)的发生、发展中,北赤道逆流也有明显的年际变化,但北赤道逆流的变化如何影响海洋水文生态条件的变化过程尚不清楚。本文以位于热带西太平洋的北赤道逆流影响区为研究海区,分析了2006-2022年ENSO循环期间研究区不同阶段秋冬转换期水文生态气候条件的变化特征。结果表明,北赤道逆流源区及其路径上存在海表叶绿素浓度高值条带,这是由北赤道逆流从其源区携带的和新几内亚海岸潜流携带的营养物质共同影响下形成的,棉兰老冷穹上升流也会对其营养盐供给产生较大影响。厄尔尼诺事件发生时,热带西太平洋西风事件增多,北赤道逆流增强,大量表层水东移,研究区海平面降低,深水向浅层补给增加,深层冷水上抬,共同增强的北赤道逆流、新几内亚海岸流、新几内亚海岸潜流和棉兰老冷穹上升流将更多的养分从水平和垂直层面输送到海面,导致海面叶绿素浓度和原位有机碳总量显著增加。拉尼娜事件发生时,北赤道逆流影响区生态水文气候条件变化与厄尔尼诺事件发生时的变化特征几乎相反,但其变化程度弱于厄尔尼诺时期,共同减弱的北赤道逆流、新几内亚海岸潜流和棉兰老冷穹上升流使从水平和垂直层面输送到海面的养分显著减少,导致海面叶绿素浓度和原位有机碳总量显著降低。本文提出了北赤道逆流影响区水文生态气候条件演化对厄尔尼诺事件和拉尼娜事件的响应机制模型,这有利于进一步分析ENSO循环在局地生态效应和水文气候演化中的作用,对认识全球气候变化对物质循环的影响具有重要意义。

关键词：北赤道逆流厄尔尼诺-南方涛动(ENSO) 海洋环境要素热带西太平洋

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新疆紫草野生品与栽培品的质量比较研究

药物分析杂志 2024年第5期44卷 783-795页

作者：黄瑞戴胜云吴东雪马晓军刘杰过立农道尔加拉敬松马双成郑健中国食品药品检定研究院北京102629 中国药科大学南京211198 伊犁哈萨克自治州检验检测认证研究院伊犁835000 新疆德立凯农牧科技发展有限公司乌鲁木齐830000 新疆欣嘉农业科技开发有限公司伊犁835400

目的:对新疆紫草野生品与栽培品的质量进行比较研究,包括性状对比和结合化学计量学分析新疆紫草野生品与3个不同地区栽培品的差异性成分。方法:分别采集新疆紫草野生品与栽培品,对其性状进行对比;采用Waters ACQUITY UPLC BEH C_(18)(10... 详细信息

目的:对新疆紫草野生品与栽培品的质量进行比较研究,包括性状对比和结合化学计量学分析新疆紫草野生品与3个不同地区栽培品的差异性成分。方法:分别采集新疆紫草野生品与栽培品,对其性状进行对比;采用Waters ACQUITY UPLC BEH C_(18)(100 mm×2.1 mm,1.7μm)色谱柱,以乙腈-0.05%甲酸水为流动相,检测波长275 nm,流速0.2 mL·min^(-1),对48批野生品和栽培品中的右旋紫草素、乙酰紫草素、β-乙酰氧基异戊酰阿卡宁、异丁酰紫草素、β,β’-二甲基丙烯酰阿卡宁和异戊酰紫草素6个成分进行含量测定,并结合主成分分析(PCA)和正交偏最小二乘-判别分析(OPLS-DA)分析野生品和栽培品中的差异性成分。结果:新疆紫草野生品与栽培品在性状上存在较大差异,建立的含量测定方法线性关系良好,r>0.999,平均加样回收率93.4%~102.9%,RSD<3.0%,不同批次新疆紫草中6个成分含量差异较大,其中野生品中右旋紫草素、β-乙酰氧基异戊酰阿卡宁含量均明显高于栽培品,说明野生品与栽培品还存在一定的差异;建立的PCA模型可区分野生品和栽培品,且通过OPLS-DA确定了异丁酰紫草素和β,β’-二甲基丙烯酰阿卡宁是野生品和栽培品中的2个差异性成分。结论:通过对比野生品和栽培品的木心大小、栓皮卷曲程度以及特异性气味,可对二者进行初步鉴别;建立的含量测定方法重复性好,专属性强,稳定可行;确定了新疆紫草野生品与3个不同地区栽培品的差异性成分,为新疆紫草的质量控制提供依据,为扩大紫草药源提供了思路。

关键词：新疆紫草栽培品野生品差异性分析 β,β’-二甲基丙烯酰阿卡宁 β-乙酰氧基异戊酰阿卡宁异丁酰紫草素

Preclinical and clinical evidence of the association of colibactinproducing Escherichia coli with anxiety and depression in colon cancer

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World Journal of Gastroenterology 2024年第21期30卷 2817-2826页

作者： Fabien Rondepierre maëva Meynier Johan Gagniere Vincent Deneuvy Anissa Deneuvy Gwenaelle Roche Elodie Baudu Bruno Pereira Richard Bonnet Nicolas Barnich Frédéric Antonio Carvalho Denis Pezet mathilde Bonnet Isabelle Jalenques Service de Psychiatrie de l’Adulte A et Psychologie Médicale CHU Clermont-FerrandClermont-Ferrand 63000France M2iSH UMR 1071INSERMUniversity of Clermont AuvergneINRAE USC 1382Clermont-Ferrand 63001France NeuroDol UMR 1107INSERMUniversity of Clermont AuvergneClermont-Ferrand 63001France Department of Digestive Surgery CHU de Clermont-FerrandClermont-Ferrand 63001France Biostatistics Unit Department of Clinical Research and InnovationCHU Clermont-FerrandClermont-Ferrand 63000France Department of Bacteriology CHU de Clermont-FerrandClermont-Ferrand 63001France UniversitéClermont Auvergne INPCNRSClermont Auvergne Institut PascalClermont-Ferrand 63000France

BACKGROUND The association between the intestinal microbiota and psychiatric disorders is becoming increasingly *** gut microbiota contributes to colorectal carcinogenesis(CRC),as demonstrated with colibactin-producing Escherichia coli(CoPEC).AIM To evaluate the association between CoPEC prevalence and anxiety-and depressive-like behaviors with both preclinical and clinical *** Patients followed after a CRC surgery and for whom the prevalence of CoPEC has been investigated underwent a psychiatric *** were compared according to the CoPEC *** parallel C57BL6/J wild type mice and mice with a CRC susceptibility were chronically infected with a CoPEC *** behavior was assessed using the Elevated Plus maze test,the Forced Swimming Test and the Behavior recognition system PhenoTyper®.RESULTS In a limited cohort,all patients with CoPEC colonization presented with psychiatric disorders several years before cancer diagnosis,whereas only one patient(17%)without CoPEC *** result was confirmed in C57BL6/J wildtype mice and in a CRC susceptibility mouse model(adenomatous polyposis colimultiple intestinal neoplasia/+).Mice exhibited a significant increase in anxiety-and depressive-like behaviors after chronic infection with a CoPEC *** This finding provides the first evidence that CoPEC infection can induce microbiota-gut-brain axis disturbances in addition to its procarcinogenic properties.

关键词： Colorectal cancer Colibactin Escherichia coli Colibactin-producing Escherichia coli Infla.ma.ion Anxiety Depression Behavior

CVD-SiC阵列结构对ZrB_(2)/SiC涂层抗烧蚀性影响

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航空学报 2024年第3期45卷 261-274页

作者：高志廷马壮柳彦博北京理工大学材料科学与工程学院北京100081 北京理工大学重庆创新中心重庆401120

采用飞秒激光在化学气相沉积(CVD)-SiC中间层表面制备不同尺寸的阵列,研究了阵列结构对ZrB_(2)/SiC涂层性能的影响。结果表明,随着激光刻蚀频次的增大,阵列结构的深度从30μm增大到150μm。采用氧乙炔烧蚀600 s,ZrB_(2)/SiC涂层烧蚀表... 详细信息

采用飞秒激光在化学气相沉积(CVD)-SiC中间层表面制备不同尺寸的阵列,研究了阵列结构对ZrB_(2)/SiC涂层性能的影响。结果表明,随着激光刻蚀频次的增大,阵列结构的深度从30μm增大到150μm。采用氧乙炔烧蚀600 s,ZrB_(2)/SiC涂层烧蚀表面温度随CVD-SiC微结构深度增大而逐步降低,最低的表面温度达到1700℃,下降了约200℃。烧蚀中心区域的颜色从白色过渡到浅灰色。对于激光刻蚀频次为5的试样,在600 s的单次烧蚀后,质量烧蚀率和线性烧蚀率分别为-7.4×10^(-5)g/s和-13.3μm/s。阵列结构增大了ZrB_(2)/SiC涂层与CVD-SiC中间层的接触面积,从而增强了导热性能,减少了热积聚,进而改善了ZrB_(2)/SiC涂层的抗烧蚀性能。

关键词：阵列结构烧蚀等离子喷涂 C/C复合材料 CVD-SiC 激光刻蚀