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A STUDY OF DRAG COEFFICIENT RELATED WITH VEGETATION BASED ON THE FLUME EXPERIMENT

Journal of Hydrodynamics 2010年第3期22卷 329-337页

作者： HUI Er-qing HU xing-e JIANG Chun-bo ma Fang-kai ZHU zhen-duo China Three Gorges Corporation Yichang 443002 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

This study is focused on the effects of ecological factors （diameter and flexibility） and vegetation community composition on the drag coefficient related with vegetation. The single leafy shrub and three mixed communities （including shrub-grass, shrub-reed and reed-grass community） were studied. The flow velocity and water level were measured and used to calculate the drag coefficient based on the Bernoulli＇s equation, Darcy drag formula and the expression for the drag coefficient related with Darcy drag factor. The trend of the drag coefficient in the vertical direction was analyzed against flow depth, diameter, diameter P（eynolds number, flow depth Reynolds number and relative roughness height in different discharges. The results show that beside the dense leafy shrubs community, the vertical trend of the drag coefficient among other cases against flow depth, diameter, diameter Reynolds number, flow depth Reynolds number and relative roughness height can be approximately expressed by power law functions under different flow discharges. Moreover, in a mixed community with two plants with distinctly different ecological factors, the one with the most distinct variations of ecological factors determines the vertical trend of the drag coefficient; the other one only affects the magnitude of the drag coefficient. Furthermore, if the ecological factors of the vegetation in the vertical direction are kept almost not changed, the drag coefficient can be approximately regarded as a constant.

关键词： vegetated channel drag coefficient flume experiment

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Vitamin B3 inhibits apoptosis and promotes autophagy of isletβcells under high glucose stress

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BIOCELL 2023年第4期47卷 859-868页

作者： YU ZHANG xi’AN ZHOU CHUNYAN ZHANG DENGNI LAI DONGBO LIU YANYANG WU Key Laboratory for Food Science and Biotechnology of Hunan Province College of Food Science and TechnologyHunan Agricultural UniversityChangsha410128China Horticulture and Landscape College Hunan Agricultural UniversityChangsha410128China Hunan Co-Innovation Center for Utilization of Botanical Functional Ingredients Changsha410128China State Key Laboratory of Subhealth Intervention Technology Changsha410128China Hunan Agricultural Products Processing Institute Hunan Food Test and Analysis CenterChangsha410004China

Background:Hyperglycemia is a typical symptom of *** glucose induces apoptosis of isletβ*** autophagy functions in cytoprotection and autophagic cell *** interaction between autophagy and apoptosis is important in the modulation of the function of isletβ*** B3 can induce autophagy and inhibit isletβ***:The mechanism of vitamin B3-mediated protective effect on the function of isletβcells was explored by the method of western blot,immunofluorescence and flow ***:In the present study,high glucose stress increased the apoptosis rate,while vitamin B3 reduced the apoptosis *** effect of vitamin B3 on autophagy flux under normal and high glucose stress was also *** B3 increased the number of autophagosomes and increased the light chain(LC)3-II/LC3-I *** contrast,vitamin B3 decreased sequestosome 1(SQSTM1)/p62 protein expression and inhibited the phosphorylation of mammalian ribosomal protein S6 kinaseβ-1(p70S6K/S6K1),which was a substrate of mammalian target of rapamycin(mTOR)under normal and high glucose *** further verify the protective effect of vitamin B3 on apoptosis,we treated isletβcell RIN-m5F with autophagy inhibitor 3-methyladenine(3-ma).Vitamin B3 decreased the apoptosis rate under high glucose stress,while the inhibition of apoptosis by vitamin B3 was blocked after adding ***:Our data suggested that vitamin B3 reduced the apoptosis rate ofβcells,possibly through inducing autophagy under high glucose stress.

关键词： Vitamin B3 High glucose Autophagy Apoptosis

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鄂尔多斯盆地中东部石炭纪本溪组致密砂岩储层含气性测井综合评价

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科学技术与工程 2024年第13期24卷 5364-5371页

作者：李新虎丁佳萌程光艺刘晓梅马天录西安科技大学地质与环境学院西安710054 自然资源部煤炭资源勘查与综合利用重点实验室西安710021

鄂尔多斯盆地中东部石炭纪本溪组致密砂岩粒度较细,泥质含量较高,孔隙度低、渗透率极差,使测井对其含气性的解释难度增大。基于化验分析资料,重点应用核磁共振、阵列声波、阵列感应等成像测井资料,结合常规测井,建立了4类7种方法的本溪... 详细信息

鄂尔多斯盆地中东部石炭纪本溪组致密砂岩粒度较细,泥质含量较高,孔隙度低、渗透率极差,使测井对其含气性的解释难度增大。基于化验分析资料,重点应用核磁共振、阵列声波、阵列感应等成像测井资料,结合常规测井,建立了4类7种方法的本溪组细粒致密砂岩储层含气性测井评价方法研究,利用测井资料综合开展储层含气性的有效识别。研究表明,综合运用常规和成像测井,对本溪组细粒致密砂岩储层含气性综合评价提供了更加有效的途径。开展本溪组细粒致密砂岩储层含气性测井综合评价研究,对煤系致密砂岩气的勘探和开发具有重要的理论意义和应用价值。

关键词：本溪组致密砂岩含气性成像测井

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Treatment of hepatic cysts by B-ultrasound-guided radiofrequency ablation

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Hepatobiliary & Pancreatic Diseases International 2007年第3期6卷 330-332页

作者： Du, xi-Lin ma, Qing-Jiu Wu, Tao Lu, Jian-Guo Bao, Guo-Qiang Chu, Yan-Kui Fourth Mil Med Univ Dept Gen Surg Tangdu Hosp Xian 710038 Peoples R China

BACKGROUND: The traditional therapy for hepatic cysts has limited success because of recrudescence. Radiofrequency ablation (RFA) has become popular because of its advantages including little damage, therapeutic effect and reduced suffering. This report describes the effects and reliability of RFA in the treatment of 29 patients with hepatic cysts. METHODS: B-ultrasound-guided REA was used to treat hepatic mono-cyst or multi-cysts of 29 patients (63 tumors). Ablative efficiency and complications were assessed by imaging and clinical symptoms. RESULTS: The tumors were abated completely in 34 cysts with a diameter <5 cm and no recurrence was seen after 3 months. In 21 cysts with a diameter of 5-10 cm, tumor volume was decreased by over 70%, then reduction and fiberosis were found. In 8 cysts with a diameter greater than 10 cm, tumor volume was decreased by more than 60%, and in 2 cysts it was increased more slightly than that at I month after REA. In subsequent follow-up (6 and 12 months after REA), tumors <10 cm in diameter were fully ablated. No significant discomfort and complications were found in any patient. CONCLUSION: RFA for the treatment of hepatic cysts is safe, and free from complications.

关键词： hepatic cysts radiofrequency ablation B-ultrasound-guided

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基于雪岭云杉树轮宽度重建中天山巴仑台地区过去565年7~9月NDVI变化

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第四纪研究 2024年第4期44卷 869-881页

作者：马一凡刘禹宋慧明张权蔡秋芳任萌李珮中国科学院地球环境研究所黄土与第四纪地质国家重点实验室陕西西安710061 中国科学院大学北京100049 中国科学院第四纪科学与全球变化卓越创新中心陕西西安710061 西安交通大学人居环境与建筑工程学院陕西西安710054 西安地球环境创新研究院陕西西安710061 中国-巴基斯坦地球科学研究中心中国科学院和巴基斯坦高等教育委员会伊斯兰堡巴基斯坦45320

归一化植被指数(NDVI)对分析植被动态及其对气候的响应至关重要,但是对天山地区而言,现有的短时NDVI数据集不能满足长时间尺度的分析需要。因此,本研究利用天山南坡巴仑台地区雪岭云杉样本建立了树轮宽度年表(STD),发现其与7~9月的NDVI... 详细信息

归一化植被指数(NDVI)对分析植被动态及其对气候的响应至关重要,但是对天山地区而言,现有的短时NDVI数据集不能满足长时间尺度的分析需要。因此,本研究利用天山南坡巴仑台地区雪岭云杉样本建立了树轮宽度年表(STD),发现其与7~9月的NDVI显著相关(r=0.69,n=39,p<0.001),在此基础上,设计线性回归模型,重建了研究区1455~2019年7~9月NDVI变化,方差解释量为46%。结果显示,研究区在1455~2019年期间经历了5个植被覆盖高值期和8个植被覆盖低值期,其中1988~2019年植被生长处于历史最高水平;与周边其他重建序列对比结果表明NDVI变化存在空间差异性,中天山区域近30多年来NDVI呈现增加趋势,而西天山则呈现下降趋势;此外,分析表明降水是研究区NDVI的主要影响因素。天山地区降水主要受到海温异常和遥相关的影响,分析结果显示印度洋海温增暖和东大西洋遥相关型(EA)正相位可以使天山地区降水量增加,进而促进研究区植被的生长。该研究对理解中天山植被覆盖的长期动态变化具有一定的参考意义,并为未来植被动态演化预测提供基础数据。

关键词：树轮宽度归一化植被指数(NDVI) 重建中天山

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大气等离子喷涂Si/Mullite+BSAS/Yb_(2)Si_(2)O_(7)环境障涂层的制备与水氧腐蚀行为

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航空材料学报 2024年第4期44卷 37-45页

作者：崔永静郭孟秋马玉洁周邦阳范尚武焦健成来飞中国航发北京航空材料研究院航空材料先进腐蚀与防护航空科技重点实验室北京100095 西北工业大学超高温结构复合材料重点实验室西安710072

以固相烧结法制备的Yb_(2)Si_(2)O_(7)粉体作为原材料,采用大气等离子喷涂工艺在SiC基体表面制备Si/Mullite+BSAS/Yb_(2)Si_(2)O_(7)三层结构环境障涂层。利用扫描电子显微镜、能谱仪、X射线衍射分析仪、纳米压痕试验机等设备研究涂层... 详细信息

以固相烧结法制备的Yb_(2)Si_(2)O_(7)粉体作为原材料,采用大气等离子喷涂工艺在SiC基体表面制备Si/Mullite+BSAS/Yb_(2)Si_(2)O_(7)三层结构环境障涂层。利用扫描电子显微镜、能谱仪、X射线衍射分析仪、纳米压痕试验机等设备研究涂层的显微组织、相结构和力学性能。结果表明:粉体材料由83%Yb_(2)Si_(2)O_(7)相和17%Yb_(2)SiO_(5)相(质量分数)组成,等离子喷涂获得的Yb_(2)Si_(2)O_(7)层孔隙率为(6.61±0.65)%,涂层结合强度达(22.82±3.55)MPa,涂层断裂韧度达(1.98±0.12)MPa·m1/2。此外,涂层1350℃条件下水氧耦合腐蚀测试结果显示Yb_(2)Si_(2)O_(7)单斜相含量先降低后提高,硅黏结层高温氧化形成的热生长氧化物SiO_(2)与Mullite+BSAS界面相容,未发现Mullite+BSAS与Yb_(2)Si_(2)O_(7)层互扩散现象,硅层的损耗是涂层使用寿命的主要限制环节。

关键词：环境障涂层等离子喷涂碳化硅陶瓷基复合材料 Yb_(2)Si_(2)O_(7)

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Enhancing photostability and power conversion efficiency of organic solar cells by a “sunscreen” ternary strategy

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Science China Chemistry 2023年第4期66卷 1179-1189页

作者： Yongjie Cui Zeng Chen Peipei Zhu Wei ma Haiming Zhu Xunfan Liao Yiwang Chen State Key Laboratory for Modification of Chemical Fibers and Polymer materials&College of materials Science and Engineering Donghua UniversityShanghai 201620China National Engineering Research Center for Carbohydrate Synthesis/Key Lab of Fluorine and Silicon for Energy materials and Chemistry of Ministry of Education Jiangxi Normal UniversityNanchang 330022China Center for Chemistry of High-Performance and Novel materials Department of ChemistryZhejiang UniversityHangzhou 310027China State Key Laboratory for Mechanical Behavior of materials Xi'an Jiaotong UniversityXi'an 710049China

The field has witnessed the rapid growth in the power conversion efficiency(PCE)of organic solar cells(OSCs)over the past decade,reaching the threshold for practical ***,a major issue remains that OSC lifetimes are seriously limited by the ultraviolet(UV)-induced ***,inspired by the superior photostability of car paint under sunlight and ambient air,a“sunscreen”molecule,2-(2-hydroxy-5-tert-octylphenyl)benzotriazole(UV329),is used to construct the PM6:Y6 ternary *** addition of UV329 mainly enhances the ordered stacking of PM6 and increases the light utilization of blend films with the improved crystallization and appropriate phase ***,the ternary device exhibits stronger light response and obviously higher and more balanced carrier mobilities,contributing to higher short-circuit current density,fill factor and *** PCE boost is also verified in PM6:BTP-e C9 and PM6:L8-BO *** photodegradation of PM6 dominates the photo-degradation process of PM6:Y6 systems,while the UV329 can effectively suppress such degradation,and thus the ternary device can retain nearly 90%of the initial PCE under continuous illumination for 120 ***,ternary devices also preserve better thermal stability and shelf-life with the enhanced *** work provides a simple yet effective strategy for simultaneously improving PCE and photostability of OSCs.

关键词： ternary strategy sunscreen UV absorber photostability organic solar cells

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Sequential testis sparing surgery of simultaneous bilateral testicular tumors with different cell types in a Chinese infant:an uncommon presentation

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Asian Journal of Andrology 2019年第4期21卷 419-420页

作者： xiao-xi Li Fang Chen Shou-Lin Li Yi-Chen Huang Yi-Qing Lv Yan Chen Hui-zhen Sun Hua xie Department of Urology Children's Hospital of Shanghai School of Medicine Shanghai Jiao Tong University Shanghai 200062 China Department of Urology Children's Hospital of Shenzhen Shenzhen 518026 China

Dear Editor, Patients of bilateral pediatric testicular tumors and bilateral testicular teratoma or yolk sac tumor (YST) were rarely reported, and there was still no standard therapy. However, synchronous bilateral testicular tumors with different histology were a quite rare situation. We reported the first case of successful radical orchiectomy in the left scrotum and testicular sparing surgery in the right testis sequentially. No atrophy or residual tumor in the right testis and no recurrence in the left scrotum were found after 7 years of follow-up. Ethical approval was obtained from the Institutional Review Board of Childrens Hospital of Shanghai, which was affiliated to the Shanghai Jiao Tong University, School of Medicine, Shanghai, China. Informed consent was obtained from his parents.

关键词： simultaneous bilateral testicular tumors different cell types Chinese infant

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石墨烯场效应晶体管的X射线总剂量效应

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物理学报 2024年第5期73卷 344-350页

作者：李济芳郭红霞马武英宋宏甲钟向丽李洋帆白如雪卢小杰张凤祁湘潭大学材料科学与工程学院湘潭411105 西北核技术研究所西安710024

本文针对不同结构、尺寸的石墨烯场效应晶体管(graphene field effect transistors,GFET)开展了基于10 keV-X射线的总剂量效应研究.结果表明,随累积剂量的增大,不同结构GFET的狄拉克电压V_(Dirac)和载流子迁移率μ不断退化;相比于背栅型... 详细信息

本文针对不同结构、尺寸的石墨烯场效应晶体管(graphene field effect transistors,GFET)开展了基于10 keV-X射线的总剂量效应研究.结果表明,随累积剂量的增大,不同结构GFET的狄拉克电压V_(Dirac)和载流子迁移率μ不断退化;相比于背栅型GFET,顶栅型GFET的辐射损伤更加严重;尺寸对GFET器件的总剂量效应决定于器件结构;200μm×200μm尺寸的顶栅型GFET损伤最严重,而背栅型GFET是50μm×50μm尺寸的器件损伤最严重.研究表明:对于顶栅型GFET,辐照过程中在栅氧层中形成的氧化物陷阱电荷的积累是V_(Dirac)和μ降低的主要原因.背栅型GFET不仅受到辐射在栅氧化层中产生的陷阱电荷的影响,还受到石墨烯表面的氧吸附的影响.在此基础上,结合TCAD仿真工具实现了顶栅器件氧化层中辐射产生的氧化物陷阱电荷对器件辐射响应规律的仿真.相关研究结果对于石墨烯器件的抗辐照加固研究具有重大意义.

关键词：石墨烯场效应晶体管 X射线辐照总剂量效应

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Sintering Complexity of magnesia-chrome Refractories

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China's Refractories 2022年第1期31卷 16-23页

作者： GUO Zongqi ma Ying LI Yong School of materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an 710055China RHI magnesita(Dalian)Co. Ltd.Dalian 116600China School of materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

magnesia-chrome refractories are appropriate to work under cyclic temperatures or atmospheric conditions because some oxides of chrome ore readily release oxygen(are reduced)upon heating and pick up oxygen(are oxidized)upon cooling or upon changing the *** have been ideal lining materials for RH degassers for many years,despite challenging of Cr^(6+) disposal issue after *** varieties of magnesia-chrome refractories depend on their raw materials and burning temperatures,which could be well demonstrated by their *** Indian chrome concentrate cannot be directly used in the production of magnesia-chrome bricks because of reducing sintering *** bonded magnesia-chrome bricks are produced with low purity magnesia after burning at relatively lower temperatures,resulting in liquid film forming as silicate bond around chrome ore *** bonded and rebonded fused-grains magnesia-chrome refractories are made of high purity magnesia or fused magnesia-chrome grains,forming euhedral and intergranular secondary chromite spinels as the main *** amount of secondary spinel increases with the rising burning temperature,leading to increasing hot modulus of rupture and overall hot properties as *** is important to burn magnesia-chrome bricks under weakly reducing *** oxygen content of burning atmosphere from 800℃ to 1650℃ would better controlled below 0.5%to increase the burnt strength and to avoid inner cracks and loose bonding of magnesia-chrome bricks,while the atmosphere contains 3%-6%O_(2) under most economical firing condition.

关键词： magnesia-chrome refractory silicate bond direct bond secondary chromite spinel

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