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21.
陈琳 《安顺师范高等专科学校学报》2010,(5):80-82
设B（H）是维数大于2的复可分Hilbert空间,B（H）代表H上所有有界线性算子全体,假设线性映射Ф：B（H）→B（H）满足对所有A,B∈B（H）,[A^A.,B]=0时,有[Ф（A）^Ф（A）.,B]＋[A^A.,Ф（B）]=0.文中运用可交换迹双线性映射对Ф进行了刻画,证明了存在实数c∈R,算子T∈B（H）且T^＊＋T=cI,使得对任意X∈B（H）,有Ф（X）=XT＋T^＊X． 相似文献
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将TC11钛合金试样经盐酸-硝酸在加热的条件下滴加氢氟酸溶解后,加入锶盐以消除基体钛及其它元素对铁的干扰,采用原子吸收分光光度法对其中铁元素含量进行了测定.结果显示,其RSD为0.7%,加标回收率为99.99%～100.05%,微量Fe的质量百分含量为0.020%.该方法测定速度快,灵敏度高,干扰小,测定结果可靠. 相似文献
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宋文田 《和田师范专科学校学报》2010,29(3):93-94
关于＂面＂字的古文字到小篆字体的发展变化和现代研究结论已经基本定型,都认为其所从部件是从＂目＂到从＂■＂的讹变,本文从古文字各个时代的形体演变实际情况出发,试图推演出它的演变阶段和原因,找到其讹变轨迹,同时也根据发现的＂面＂字材料推断出其发生讹变的两种可能情况。 相似文献
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系统设计采用高性能八位微处理控制器STC89C52RC单片机为核心,信号分别由机器人前后安装的光电传感器和机器人前面安装的触角传感器采集,经主控制器的I/0口处理后,用于机器人的运动控制决策,使其能够寻迹、避障行、抓取物体、搬运物体,同时发出PWM波驱动直流电机对机器人进行加速减速和转弯控制. 相似文献
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Jyoti Aggarwal Akansha Singh Sanjeev Gupta Rajendra Prasad 《Indian journal of clinical biochemistry : IJCB》2021,36(1):120
Psoriasis is a common and an inflammatory skin disease. Trace elements play an important role in the skin metabolism such as keratinisation and melanin formation as well as immunological and inflammatory reactions. Henceforth, the present study was aimed to evaluate the essential metals with special reference to Cu and Zn. In this study, 72 psoriatic patients and 50 controls were enrolled. On the basis of PASI score psoriatic group comprising of 48 mild and 24 severe psoriatic patients were grouped. The serum trace elements analysis in the subjects revealed that serum Cu levels and Cu/Zn ratio was significantly higher in the psoriatic patients as compared to controls. Interestingly, severity of the psoriasis was well correlated with the serum Cu levels. Taking together, all these findings suggest that Cu may be a major culprit in the pathogenesis as well as in the severity of the disease. 相似文献
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云南永平卓潘碱性杂岩体是金沙江-哀牢山富碱斑岩带中的重要岩体,位于兰坪走滑拉分盆地西部.该岩体的主要岩石类型为辉石正长岩、正长岩和霞石正长岩等.岩石地球化学显示高碱、高K2O/Na2O比值、低TiO2、高Al2O3的超钾质钾玄岩系列岩石.微量元素表现为富集K、Rb、Sr、Ba等大离子亲石元素（LILE）,亏损Ta、Nb、Ti、P、Zr等高场强元素（HFSE）,表现为明显的“Ta-Nb-Ti”负异常,同时富集过渡性元素Cr、Ni、Co等.稀土元素为稀土总量高,富集LREE、（La/Yb）N比值高、Eu异常不明显为特征.（^87 Sr/^86 Sr）i比值为0.707611～0.709167、εNd（t）值为-4.89～-6.57,206Pb/204Pb变化于18.6886～18.7022、207Pb/204Pb变化于15.6169～15.63493、208Pb/204Pb变化于38.7972～38.8927,显示岩浆源区具有富集地幔（EM Ⅱ）与下地壳共同作用的壳幔过渡带特征,构造环境判别为大陆弧（CAP）环境.岩体是在碰撞造山过程中大陆板片俯冲,使曾经遭受古洋壳板片流体强烈交代的壳幔过渡带在上升的软流圈熔体的注入而发生部分熔融,在走滑拉分盆地的核心部位沿构造断裂上升侵位而形成. 相似文献
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本文利用Selberg迹公式的方法，通过构造核函数，得到Jacobi尖点形式空间维数的表达式。 相似文献
29.
胡晓华 《湖州师范学院学报》2000,(Z1)
在中学物理的定律教学中,“溯源”法一直被认为是行之有效的方法,它通过对定律形成过程的探索,从而加深学生对定律内容的理解．实际上“溯源”法的意义不仅在于此,它同时还具有培养学生科学的思维方式、热爱科学的良好情趣等功能． 相似文献
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This research compares the strategic processing reported on right after the completion of a reading task with physical traces of the same strategies that were found in the study materials. In addition, both task-specific self-reports and traces of strategies were used to predict performance, both in the task context where the strategy data were generated and in another context. Using a sample of 177 Norwegian tenth-grade students, a quite close correspondence was found between learners’ task-specific self-reports about strategies and the strategies traced in the study materials. Moreover, both self-reports and traces of strategies predicted performance not only on the specific reading task but also beyond that context, on the PISA literacy tests. In both contexts, however, strategy data that traced what learners actually did when working on the reading task seemed to predict performance better than did task-specific self-reports. 相似文献