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A novel endorectal RF coil for high resolution MRI and spectroscopy of the prostate

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Progress in Natural Science:Materials International 2005年第5期15卷 472-476页

作者： ZHANG Hongjie 1.2, SONG Xiaoyu1. WANG Xiaoying3. XU Pingfang1.and BAO Shanglian1.*(1. {1. Key Laboratory of Medical Physics & Engineering, peking university, {1. {3. China 2. Navy General Hospital, {1. 1.003., China 3. peking university First Hospital, {1. 1.003., China) beijing Key Laboratory of Medical Physics & Engineering Peking University Beijing 100871 China Navy General Hospital Beijing 100037 China peking university First Hospital Beijing 100034 China

The diagnosis of prostate diseases by magnetic resonance imaging (MRI) in vivo is sometimes difficult for the lower signal to noise ratio (SNR). To increase the SNR of the prostate image, we designed a RF coil that can be inserted into rectum and was named endorectal coil. The properties of RF coil were evaluated using a network analyzer. Moreover the images and spectroscopy of a special phantom were acquired and the results were compared to those of the commercial TORSO coil (G.E. Medical Systems, USA). Our coil gave a significantly higher SNR at the region of interest (ROI). The achieved high local SNR and resulting high spatial resolution would add more anatomic and biochemical information to the diagnosis of prostate diseases.

关键词： MRI RF coil endorectal coil.

复方碘口腔喷雾原位膜的制备及促口腔溃疡修复评价

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中国药科大学学报 2024年

作者：张小军黄山芩郭潇涵季梦菲沈雁陈大全许颖 1.江苏大学药学院 2.中国药科大学药学院 3.烟台大学药学院江苏大学药学院中国药科大学药学院烟台大学药学院

采用原位凝胶技术，制备了新型复方碘口腔喷雾原位膜，用于发挥缓释作用，并促进口腔溃疡创面修复。首先以喷雾状态和成膜时间为指标，对喷雾药液的处方和工艺进行优化。以成膜时间和药膜黏附性为评价指标对药液混合比例进行考察。并对... 详细信息

采用原位凝胶技术，制备了新型复方碘口腔喷雾原位膜，用于发挥缓释作用，并促进口腔溃疡创面修复。首先以喷雾状态和成膜时间为指标，对喷雾药液的处方和工艺进行优化。以成膜时间和药膜黏附性为评价指标对药液混合比例进行考察。并对最优处方制备的复方碘口腔喷雾药液的药物含量、稳定性、pH、喷雾效果，及原位膜的成膜时间、溶解性、吸湿性、保湿性、体外释放等理化性质进行考察；此外，通过细胞实验考察了成膜材料的生物相容性及复方碘口腔喷雾原位膜的促迁移效果；采用兔口腔溃疡模型，对复方碘口腔喷雾在体成膜效果及促修复效果进行评价。实验结果显示，最优处方制备的药液A和药液B的pH分别为6.21.± 0.02和 6.42 ± 0.03.符合正常口腔黏膜pH范围；稳定性好，具有良好的喷雾状态；药液B中碘含量为（1.96 ± 0.01.mg/mL；原位膜体外成膜时间为（1.8.3.± 3.6）s，口腔内成膜时间为（1.0}.3.± 4.6）s；24 h溶解率为（87.3. ± 1.74）%，吸湿率为（1.4.1. ± 7.1.0}%，保湿率为（26.85 ± 2.50）%；复方碘口腔喷雾原位膜中碘含量为（47.42 ± 0.3.）mg/g；具有良好的柔韧性和黏附性，并具有一定的缓释效果。细胞实验中，原位膜表现出良好的促成纤维细胞迁移作用。兔口腔溃疡实验表明，复方碘口腔喷雾在体可快速成膜，并可显著促进口腔溃疡修复。本研究所开发的复方碘口腔喷雾原位膜，制备工艺稳定，并可有效促进口腔溃疡创面修复，为口腔黏膜制剂的研究和开发提供了新思路，并具有良好的转化前景。

关键词：口腔喷雾原位膜复方碘口腔溃疡缓释促修复

Hausdorff dimension of Julia set of a polynomial with a Siegel disk

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Science China Mathematics 2006年第9期49卷 1284-1296页

作者： SHEN Liang lmam, School of Mathematical Sciences, {1., beijing {3. China lmam School of Mathematical Sciences Peking University Beijing 100871 China

Let f(z) = e2πiθz(1.z/d)d,θ∈R\Q be a polynomial. Ifθis an irrational number of bounded type, it is easy to see that f(z) has a Siegel disk centered at 0. In this paper, we will show that the Hausdorff dimension o... 详细信息

关键词： Hausdorff dimension Siegel disk porous set

Dehydration melting of solid amphibolite at 2.0 GPa: Effects of time and temperature

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Science China Earth Sciences 2005年第8期48卷 1120-1133页

作者： ZHOU Wenge1. XIE Hongsen1. LIU Yonggang1. ZHENG Xiaogang1. ZHAO Zhidan2 & ZHOU Hui3.1. Laboratory of Material in the Earth’s Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China 2. Department of Geology, China {1. of Geosciences, beijing 1.0083. China 3. Department of Geology, peking university, beijing 1.0871. China 1. Laboratory of Material in the Earth’s Interior Institute of Geochemistry Chinese Academy of Sciences 550002 Guiyang China 2. Department of Geology China University of Geosciences 100083 Beijing China 3. Department of Geology Peking University 100871 Beijing China

Two sets of dehydration-melting with a natural solid amphibolite, collected from North Himalayan structure zone, Tibet, have been carried out in multi-anvil apparatus at 2.0 GPa and 800―1.00℃, for 1.―200 h. One is keeping the pressure at 2.0 GPa and the annealing time of 1. h, changing the temperature (800―1.00℃). The other is keeping the pressure at 2.0 GPa and temperature at 850℃, varying the annealing time (1.―200 h). The products are inspected with microscope and electron probe. The results indicate that at 2.0 GPa, annealing time of 1. h, garnets, melts and clinopyroxenes occur in amphibolite gradually with increasing temperature and the chemical compositions of melt vary from tonalite to granodiorite, and then to tonalite. However, at 2.0 GPa and 850℃, with the annealing time increasing, the garnets, melts and cli-nopyroxenes also occur in amphibolite gradually and the chemical compositions of melt vary from tonalite to granodiorite. In both cases, melts interconnect with each other when the contents of melt are over the 5 vol.%. the viscosities of the melt produced in amphibolite at temperature higher than 850℃ are on a level with 1.4 Pa·s. The interconnected melt with such a viscosity may segregate from the source rock and form the magma over reasonable geological time. Therefore, it is believed that at the lower part of the overthickened crust, the tonlitic and grano-dioritic magma may be generated through the dehydration melting of amphibolite.

关键词： solid amphibolite, high pressure, high temperature, time, partial melting.

Pole assignment in descriptor periodic systems

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Science China Mathematics 2005年第10期48卷 1309-1332页

作者： FAN Hung-Yuan~1.LIN Wen-Wei~1.& XU Shufang~2 1. Department of Mathematics,Tsing Hua university,Hsinchu {1.04{1.China 2. lmam,School of Mathematical Sciences,peking university,{{1. 1.0871.China 1. Department of Mathematics Tsing Hua University 30043 Hsinchu China 2. lmam School of Mathematical Sciences Peking University 100871 Beijing China

In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

关键词： descriptor linear periodic system, pole assignment, proportional and derivative feedback, numerical method, periodic Schur decomposition.

Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1.,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Status of study on biological and toxicological effects of nanoscale materials

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Science China Chemistry 2005年第5期48卷 385-394页

作者： WANG Bing1. FENG Weiyue1. ZHAO Yuliang1. XING Gengmei1. CHAI Zhifang1. WANG Haifang2 & JIA Guang3.1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab), Institute of High Energy Physics, Chi-nese Academy of Sciences, {1. 1.0049, China 2. College of Chemistry and Molecular Engineering, peking university, {1. {3. China 3. Department of Occupational and Environmental Health Sciences, School of Public Health, peking university, {1. 1.0083. China 1. Laboratory for Bio-Environmental Health Sciences of Nanoscale Materials (Nanosafety Lab) Institute of High Energy Physics Chinese Academy of Sciences 100049 Beijing China 2. College of Chemistry and Molecular Engineering Peking University 100871 Beijing China 3. Department of Occupational and Environmental Health Sciences School of Public Health Peking University 100083 Beijing China

Because the physical and chemical properties of nanosized materials mostly differ from the existing microsized materials, their potential impacts on human health and the envi-ronment will be topics under the serious discussions in press and in a number of international scientific journals. We analyze and summarize the existing data of the experimental study on the biological activities and adverse effects of nanoscale materials/particles including single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron powders. Though some biological behaviors of nanoscale materials observed cannot be understood on the basis of the current knowledge, as the existing data are mostly preliminary, it is too early to make some ex-clusive conclusions on biological activities (or the toxicity) of any of nanoscale materials. The experimental techniques, the current topics, and the future research directions for this new re-search field are also discussed.

关键词： nanomaterials, single wall carbon nanotubes, multi wall carbon nanotubes, titanium oxide and iron, biological activity and toxicological effect.

On multiply of sections of line bundles on compact Riemann surfaces

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Science China Mathematics 2008年第4期51卷 721-727页

作者： TAN XiaoJiang lmam and School of Mathematical Sciences {1. beijing {3.China 1. lmam and School of Mathematical Sciences Peking University Beijing 100871 China

In this paper,we give some conditions on the surjective of multiply maps H^0(R,L)×H^0(R,K)→H^0(R,L(?)K).Here R is a compact Riemann surface,L a line bundle on R and K is the canonical line bundle.

关键词： compact Riemann surfaces line bundles 1.E20 1.F24

Petrogenesis of Songshugou dunite body in the Qinling orogenic belt, Central China: Constraints from geochemistry and melt inclusions

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Science China Earth Sciences 2005年第8期48卷 1146-1157页

作者： SU Li1.2, SONG Shuguang3.& ZHOU Dingwu1.1. Key Laboratory of Continental Dynamics of the Ministry of Education, Department of Geology, Northwestern {1., Xi’an 71.069, China 2. The Geological Lab Center, China {1. of Geosciences (beijing), beijing 1.0083. China 3. Key Laboratory of Orogenic Belts of the Ministry of Education, Department of Geology, peking university, beijing 1.0871. China 1. Key Laboratory of Continental Dynamics of the Ministry of Education Department of Geology Northwestern University 710069 Xi’an China 2. The Geological Lab Center China University of Geosciences 100083 (Beijing)Beijing China 3. Key Laboratory of Orogenic Belts of the Ministry of Education Department of Geology Peking University 100871 Beijing China

The Songshugou dunite body, which occupies an area of about 20 km2, is the largest ultramafic massif in the eastern Qinling orogenic belt, Central China. The major compo-nent of this body is dunitic rocks including mylonitic dunite and coarse-grained dunite; they oc-cupy about 95 vol% of the total body. Petrography, mineral composition, major and trace ele-ments and primitive melt inclusions have been investigated in this paper; all revealed that this dunite body is the product of melt-rock interaction by porous percolation flow. In comparison with dunite sills or veins in harzburgite from the basal part of Oman ophiolite, this dunite body is characterized by lower contents of Al2O3. CaO and HREE but higher content of highly incom-patible elements and Zr and Hf. The LREE enriched patterns and primitive mantle normalized spidergrams of trace elements are also different from the Oman dunite. Combining with melt in-clusions observed in olivines, we conclude that this dunite body is the product of large- scale porous percolation flow of high-MgO melts within depleted mantle peridotites. The high-MgO magma, in essence, was most probably produced at the hot head of an upwelling mantle plume. The occurrence of the Songshugou dunite body is closely associated with the activity of mantle super-plume in Neo-Proterozoic era in the Yangtze Craton.

关键词： Songshugou dunite body, geochemistry, melt inclusion, mantle plume, Qinling orogenic belt.