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磁共振弥散张量成像定量分析复发-缓解型多发性硬化患者表现正常的脑干白质纤维束

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中国医学影像技术 2010年第3期26卷 460-463页

作者：周福庆 zee Chi-Shing 龚洪翰张兴伟 SHIROISHI Mark 南昌大学第一附属医院影像科江西南昌330006 Department of Neuroradiology Keck School of MedicineUniversity of Southern Californialosangeles90033 复旦大学附属中山医院放射科上海200032

目的应用磁共振弥散张量成像(DTI)定量分析复发-缓解型多发性硬化(RRMS)患者表现正常的脑干白质纤维束的改变。方法对50例RRMS患者(RRMS组)及25名年龄和性别相匹配的健康志愿者(对照组)行磁共振扫描,获取常规MR图像和DTI图像。比较两组... 详细信息

目的应用磁共振弥散张量成像(DTI)定量分析复发-缓解型多发性硬化(RRMS)患者表现正常的脑干白质纤维束的改变。方法对50例RRMS患者(RRMS组)及25名年龄和性别相匹配的健康志愿者(对照组)行磁共振扫描,获取常规MR图像和DTI图像。比较两组脑干主要纤维束(皮质脊髓束/皮质脑桥束、小脑上、中、下脚纤维束和内侧丘系纤维束)的部分各向异性分数(FA)和平均弥散系数(MD)的变化。结果排除年龄、性别等因素影响后,经ANCOVA协方差分析,RRMS组患者皮质脊髓束/皮质脑桥束(L:P=0.030;R:P=0.020)、小脑下脚(L:P=0.030;R:P=0.037)、小脑上脚(L:P=0.036;R:P=0.041)、内侧丘系(L:P=0.014;R:P=0.035)的FA值较对照组明显降低。RRMS组患者皮质脊髓束/皮质脑桥束(L:P=0.004;R:P=0.046)、小脑下脚(L:P=0.047;R:P=0.011)、小脑上脚(L:P=0.021;R:P=0.011)、内侧丘系(L:P=0.002;R:P=0.044)的MD值较对照组明显增高。小脑中脚的MD值及FA值两组间差异均无统计学意义(P>0.05)。RRMS患者表现正常脑干白质纤维束的MD值及FA值与脑实质分数(BPF)、T2病灶容积之间均无相关性。结论RRMS患者表现正常脑干白质纤维束DTI的异常发现,提示上述纤维束存在微观病变,推测病变可能是局部隐匿性病灶导致的髓鞘脱失、轴突破坏。

关键词：多发性硬化,复发-缓解型弥散张量成像部分各向异性分数神经纤维脑干

MARTENSITIC AND R PHASE TRANSFOR MATIONS IN NiTiand NiTiHf

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中国有色金属学会会刊：英文版 1999年第S1期9卷 55-64页

作者： Chen zhang a, Paul Thoma b, Bryan Chin a and Ralph zee a a Materials Engineering Program,Auburn University,AL 36849, U.S.A. b Johnson Controls, Inc., Milwaukee, WI 53209, U.S.A.

The ongoing collaborative research between Auburn University and Johnson Controls was described. A Ti rich binary NiTi alloy and two ternary alloys having the compositions Ni 49 Ti 51- x Hf x with 1% and 3%(more fraction) Hf were investigated. The influence of Hf content, cold working(CW) and heat treatment temperature (HT) on the martensitic and R phase transformations was thermally analyzed using differential scanning calorimetry (DSC). The crystal structures of the alloys were examined by X ray diffraction. Results showed that at low HT, the martensitic transformation temperature (TT) decreases with increasing CW for all the alloys studied. In this alloy, for a given CW, the martensite TT increases with increasing HT above 350 ℃. This phenomenon is enhanced by the presence of Hf. Different mechanisms can be responsible for the observed behavior. These mechanisms may involve interaction between phase transformations, dislocations and internal stresses. The effect of Hf substitution is likely due to the atomic size difference between Ti and Hf. A secondary phase,identified as Ti 2Ni in binary NiTi and (TiHf) 2Ni in the two ternary alloys, was observed. The influence of cold work, heat treatment and thermal cycling on the R phase (R) transformation in three alloys was also thermally analyzed. Results showed that such transformation depends on composition as well as CW and HT conditions in a complex manner. Effort was made to identify the microstructure and the factors responsible for the observed behavior in the R phase transformation.

关键词： Ni Ti Ni Ti Hf martensitic transformation R phase transformation

Salt Contents in Soils Under Plastic Greenhouse Gardening in China

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Pedosphere 2001年第4期11卷 359-367页

作者： LIWENQING S．VANDERzee 等 CollegeofResourcesandEnvironment ShandongAgriculturalUniversityTainan271018（China） Sub－DepartmentofSoilScienceandPlantNutrition WageningenAgriculturalUniversityP.O.Box80056700EC

Field experiments were conducted on three main soils, brown soil, meadow soil and cinnamon soil, of Shandong Province to study the effect of plastic greenhouse gardening on soil salt contents. As compared to the open fields, the soil nutrient contents in the fields under plastic greenhouse gardening all increased significantly. The organic matter, quickly available N and P increases were extremely significant and the quickly available K increase was also significant. Along with the nutrient increases the soil salt contents increased clearly in all the soils investigated not only in the top layer but also in the deeper layers, being extremely significant in the 0～10 cm layer and significant in the 10～40 cm layers. The salt contents in the plastic greenhouses had significant correlations with the soil available nitrogen and phosphorous. Soils with longer plastic greenhouse gardening time tended to have more salt. The plastic greenhouse soils contained less CO-3～(2-) and much more NO-3 than the open soils, which indicated a higher influence of human intervention in plastic greenhouses. Among the constituent ions, Cl～(-), NO-3～(-) , Ca～(2+) and Mg～(2+) had positive while HCO-3～(-) had negative significant or extremely significant correlations with total salt, with correlation coefficients being 0.66*, 0.80**, 0.92**, 0.80** and -0.64* , respectively. Nitrate decreased from the top to deeper layers both in the plastic greenhouses and in the open fields. The plastic greenhouse soils contained much more nitrate than the open fields in every layer and even the nitrate contents of the 80～l00 cm layer were still several times those of the top layer in the open fields. The main reason for the salt increases was considered to be the inappropriate fertilization and selective absorption of nutrients by plants in the plastic greenhouses. The methods recommended to avoid soil salt increase in the plastic greenhouses were to apply fertilizers rationally according to the soils, veget

关键词： fertilization nitrate plastic greenhouse salt content vegetable

Risk Measurement of the Malaysian Stock Market

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Risk Measurement of the Malaysian Stock Market

Decomposition mechanism of environmentally friendly insulating medium HFO1234zee/N_(2)gas mixture under partial discharge

2011 International Conference on Sociality and Economics Development（ICSED 2011）

作者： Tze Lin Tan Heng Ghee Khor Mom zee Tan Yen San Yip Universiti Tunku Abdul Rahman Universiti Tunku Abdul Rahman yen

This study aims to model the volatility of risk of the Kuala Lumpur Composite Index （KLCI） in *** estimators were used in modeling the risk of KLCI namely,Close-to-Close estimator,Parkinson estimator,Garmann-Klass estimator and Yang-zhang *** for the KLCI from 2.01.1998 to 30.09.2008 was used to construct a series of 2643 daily observations comprising open,high,low and close *** of variance （ANOVA） will be used in comparing the mean value among different estimators and Pearson Correlation was used to determine the strength of relationship among the *** shown that different estimators are significantly different compared to other *** top of that,the Yang-zhang estimator was found to be weakly correlating to other *** Yang-zhang estimator was concluded to be the best estimator among the four being discussed.

关键词： volatility risk estimator

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High Voltage 2022年第6期7卷 1069-1079页

作者： Lin Lin Qingguo Chen Xinyu Wang Hui zhang Huiyong Li Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbinChina School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbinChina Heilongjiang Institute for Drug Control Harbin HeilongjiangChina

Hydrofluoroolefin HFO1234zee(trans-1,3,3,3-tetrafluoroprop-1-ene)is an environmentally friendly gas insulating medium that has the potential to replace *** clarify the decomposition paths and products of an HFO1234zee/N_(2)gas mixture under partial discharge,the decomposition mechanism is explored with density functional *** results indicate that only HFO1234zee molecules decompose in the range of low-temperature plasma,and electrons with different energies interact with molecules and cause them to decompose through different ***,products are generated by free radical recombination,addition reactions and internal configurational conversions of the *** experimental investigation of decomposition of the HFO1234zee/N_(2)gas mixture with different discharge modes is carried out,and it is found that the products calculated with density functional theory are consistent with those seen *** results show the decomposition mechanism of the insulating gas under partial discharge and provide a theoretical basis for the application of HFO1234zee.

关键词： theory. mixture mechanism

Asymmetric conductivity of the Kondo effect in cold atomic systems

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Frontiers of physics 2022年第1期17卷 71-77页

作者： Yanting Cheng Xin Chen Ren zhang Institute for Advanced Study Tsinghua UniversityBeijing100084China School of Science Xi’an Jiaotong UniversityXi’an710049China

Motivated by recent theoretical and experimental advances in quantum simulations using alkaline earth(AE)atoms,we put forward a proposal to detect the Kondo physics in a cold atomic *** has been demonstrated that the intrinsic spin-exchange interaction in AE atoms can be significantly enhanced near a confinement-induced resonance(CIR),which facilitates the simulation of Kondo *** the Kondo effect appears only for antiferromagnetic coupling,we find that the conductivity of such system exhibits an asymmetry across a resonance of spin-exchange *** asymmetric conductivity can serve as the smoking gun evidence for Kondo physics in the cold atom *** an extra magnetic field ramps up,the spin-exchange process near Fermi surface is suppressed by zee-man energy and the conductivity becomes more and more *** results can be verified in the current experimental setup.

关键词： Kondo effect alkaline earth atom confinement induced resonance

MC1568对胎牛血清诱导的大鼠乳鼠心肌细胞肥大的作用及其机制研究

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实用心脑肺血管病杂志 2023年第11期31卷 58-62页

作者：姬婧张海召朱祥彬陈泽娥欧阳昆富贺松张佳纯高燕北京大学深圳医院心血管外科广东省深圳市518034 广东省深圳市前海蛇口自贸区医院心血管内科 518101 广东省深圳市前海蛇口自贸区医院医学检验科 518101

目的探讨MC1568对胎牛血清(FBS)诱导的大鼠乳鼠心肌细胞肥大的作用及其机制。方法本实验时间为2021年5月至2022年11月。选取出生3 d内的SPF级SD大鼠乳鼠40只,分离并培养其心肌细胞。取原代大鼠乳鼠心肌细胞,将其随机分为对照组(不进... 详细信息

目的探讨MC1568对胎牛血清(FBS)诱导的大鼠乳鼠心肌细胞肥大的作用及其机制。方法本实验时间为2021年5月至2022年11月。选取出生3 d内的SPF级SD大鼠乳鼠40只,分离并培养其心肌细胞。取原代大鼠乳鼠心肌细胞,将其随机分为对照组(不进行干预)、FBS组(加入20%FBS培养48 h以诱导心肌细胞肥大)、曲古抑菌素A(TSA)组(加入20%FBS及200 nmol/L TSA培养48 h)、MC1568组(加入20%FBS及10μmol/L MC1568培养48 h)。采用α-辅肌动蛋白染色检测各组心肌细胞表面积,采用RT-qPCR法检测各组心肌肥大标志物[心房利钠肽(ANP)、β-肌球蛋白重链(MHC)]mRNA表达水平,采用Western blot检测各组心肌细胞中P300、组蛋白去乙酰化酶(HDAC)4、磷酸化HDAC4(pHDAC4)表达水平。结果 FBS组心肌细胞表面积大于对照组、TSA组、MC1568组(P0.05);FBS组心肌细胞中P300表达水平高于对照组、TSA组,pHDAC4表达水平高于对照组、TSA组、MC1568组(P<0.05)。结论 FBS可引起心肌细胞肥大,而MC1568可以抑制心肌细胞肥大,其保护作用可能与抑制HDAC4/MEF2D信号通路有关。

关键词：心肌疾病肌细胞心脏大鼠 MC1568 胎牛血清组蛋白去乙酰化酶

Orthogonal linear polarized lasers (II)——Study on the physical phenomena

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Progress in Natural Science:Materials International 2005年第10期 3-14页

作者： zhang Shulian and LIU Gang (The State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China)

The physical phenomena and corresponding theoretical analysis of orthogonal polarized laser are reviewed. Four lasers (or systems) with orthogonal polarized beams arc involved. For the birefringence dual frequency laser, its physical phenomena discussed include the alternation between strong mode competition and medium mode competition in cavity tuning; the range of frequency difference of strong mode competition (about 0-40 MHz); four polarization statuses (o-light oscillating but e-light extinguishing, both o-light and elight oscillating, e-light oscillating but o-light extinguishing, both o-light and e-light extinguishing) in cavity tuning; the tuning curves of frequency difference; the influence of optical activity of quartz crystal on polarization direction; and the aberrance of frequency splitting. For the Birefringence-zeeman dual frequency laser, we focus on its intensity tuning and frequency difference tuning. For the feedback system of orthogonally polarized laser, we discuss the mutual suppression between two orthogonal frequencies, intensity exchange between two orthogonal frequencies and double of intensity fringe frequency. For orthogonally polarized LD-pumped Nd:YAG microchip laser, its property of the dependence of intensity sensitivity on frequency difference is described.

关键词： orthogonally polarized laser frequency splitting cavity tuning mode competition intra-cavity birefringence zee-man effect frequency difference optical activity optical feedback.

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铝锂合金飞机壁板压缩性能研究

中国民航大学学报 2012年第3期30卷 51-55页

作者：何周理张景新上海飞机设计研究院上海200232

铝锂合金是一种新型合金材料,具有密度低,比强度和比刚度高,以及裂纹扩展速率较低等特点,但是在现有机型上的应用却较少,特别是在机身蒙皮上,缺少工程应用验证。针对典型的飞机壁板结构,即长桁-蒙皮结构,其中蒙皮材料为铝锂合金,长桁为... 详细信息

铝锂合金是一种新型合金材料,具有密度低,比强度和比刚度高,以及裂纹扩展速率较低等特点,但是在现有机型上的应用却较少,特别是在机身蒙皮上,缺少工程应用验证。针对典型的飞机壁板结构,即长桁-蒙皮结构,其中蒙皮材料为铝锂合金,长桁为两种Z型材(钣弯和挤压),分别通过压缩试验、工程计算、数值模拟计算三种不同的方法,分析并比较了两种不同构型的长桁-蒙皮结构的抗压缩性能。三种方法都证明了铝锂合金长桁壁板的抗压缩能力要强于铝合金-7075长桁壁板,为铝锂合金在飞机上的应用积累数据和经验,为飞机结构设计提供参考。

关键词：机身壁板铝锂合金压缩性能典型壁板长桁-蒙皮结构