检索结果-南通市图书馆

The role of CALYPSO in the discovery of high-T_c hydrogen-rich superconductors

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第10期28卷 56-61页

作者： Wenwen Cui yinwei li Laboratory of Quantum Materials Design and Application School of Physics and Electronic EngineeringJiangsu Normal University

Hydrogen-rich compounds are promising candidates for high-Tc or even room-temperature superconductors. The search for high-Tc hydrides poses a major experimental challenge because there are many known hydrides and even more unknown hydrides with unusual stoichiometries under high pressure. The combination of crystal structure prediction and first-principles calculations has played an important role in the search for high-Tc hydrides, especially in guiding experimental synthesis. Crystal structure AnaLYsis by Particle Swarm Optimization(CALYPSO) is one of the most efficient methods for predicting stable or metastable structures from the chemical composition alone. This review summarizes the superconducting hydrides predicted using CALYPSO. We focus on two breakthroughs toward room-temperature superconductors initiated by CALYPSO: the prediction of high-Tc superconductivity in compressed hydrogen sulfide and lanthanum hydrides, both of which have been confirmed experimentally and have set new record Tc values. We also address the challenges and outlook in this field.

关键词： CALYPSO structure prediction hydrogen-rich superconductors

Application of endoscopic techniques in orbital blowout fractures

在线全文

学校读者我要写书评

暂无评论

Frontiers of Medicine 2013年第3期7卷 328-332页

作者： Shu Zhang yinwei li Xianqun Fan Department of Ophthalmology the Ninth People’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200011China Institute of Eye&Vision Science Shanghai Jiao Tong UniversityShanghai 200011China

Minimally invasive surgical techniques,particularly endoscopic techniques,have revolutionized otolaryngeal *** techniques have been gradually applied in orbital surgery through the sinus inferomedial to the orbit and the orbital subperiosteal *** techniques help surgeons observe fractures and soft tissue of the posterior orbit to precisely place implants and protect vital structures through accurate,safe,and minimally invasive *** reviewed the development of endoscopic techniques,the composition of endoscopic systems for orbital surgery,and the problems and developmental prospects of endoscopic techniques for simple orbital wall fracture repair.

关键词： orbital fractures endoscope restoration surgery

面部渐进性隆起伴视力下降的骨纤维异常增殖症1例

在线全文

学校读者我要写书评

暂无评论

中国眼耳鼻喉科杂志 2024年第S1期24卷 42-46,52页

作者：方怜非李寅炜周慧芳上海交通大学医学院附属第九人民医院眼科上海200011

20岁女性,因“左侧眶周渐进性隆起伴眼球突出20年,左眼视力下降1年”就诊。查体提示患者眼球突出度12 mm>90 mm<16 mm,左眼最佳矫正视力0.8,伴周边视野轻度受损和左眼眼球运动受限,色觉正常。结合眼眶CT表现,考虑为“左侧眶周多骨性骨... 详细信息

20岁女性,因“左侧眶周渐进性隆起伴眼球突出20年,左眼视力下降1年”就诊。查体提示患者眼球突出度12 mm>90 mm<16 mm,左眼最佳矫正视力0.8,伴周边视野轻度受损和左眼眼球运动受限,色觉正常。结合眼眶CT表现,考虑为“左侧眶周多骨性骨纤维异常增殖症”。遂于内镜导航引导下,眼科与口腔科联合手术,行眶缘修整术、眼眶减压术和颌骨修整术、颧弓缩窄术,术后病理和分子学检测进一步确诊为骨纤维异常增殖症。患者术后左眼眼球突出和外观畸形均显著改善,最佳矫正视力恢复至1.0,眼球运动受限明显好转;术后4年,患者病灶骨稍有缓慢增长,无症状复发。讨论体会:骨纤维异常增殖症的治疗难点在于手术时机和手术方案的选择。手术时机的选择需综合考虑患者年龄、病灶骨增长速率、功能受损情况以及患者心理因素;手术方案的确定需要综合考虑病灶数目、部位和引发功能障碍的原因。

关键词：骨纤维异常增殖症畸形眼球突出视力下降牵拉性视神经病变眼眶减压术复发

一种基于度量优化的深度网络SAR自聚焦方法

在线全文

学校读者我要写书评

暂无评论

运筹与模糊学 2024年第3期14卷 653-664页

作者：毛倩倩詹梦洋李银伟上海理工大学光电信息与计算机工程学院上海

相位误差是引起合成孔径雷达图像散焦的主要原因,受到目标场景与算法参数的影响,基于度量优化的传统自聚焦方法迭代次数多,计算量大。鉴于卷积神经网络在图像特征提取与特征分类方面的优越性,本文提出了一种基于度量优化的深度网络SAR... 详细信息

相位误差是引起合成孔径雷达图像散焦的主要原因,受到目标场景与算法参数的影响,基于度量优化的传统自聚焦方法迭代次数多,计算量大。鉴于卷积神经网络在图像特征提取与特征分类方面的优越性,本文提出了一种基于度量优化的深度网络SAR自聚焦方法。首先,利用卷积神经网络的特征提取能力,将不同程度的离焦图像通过特征分类来实现离焦图像到相位误差系数的映射。其次,网络估计的相位误差系数被建模成相应的相位误差多项式,构成相应的误差向量来补偿离焦图像。通过使用度量函数作为损失函数进行网络训练,实现SAR离焦图像的误差更新和补偿。相比于传统自聚焦方法,基于深度网络的方法,训练完成后,不需要进行反复迭代,且不依赖于场景强散射点,具有更快的聚焦速度和稳定的聚焦性能。

关键词：深度网络特征提取自聚焦度量优化

太赫兹条带SAR的PFA成像与误差补偿方法

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

建模与仿真 2024年第3期13卷 3449-3461页

作者：罗绍文王秋艳李银伟上海理工大学光电信息与计算机工程学院上海

由于成像分辨率高、成像帧频高等优势,太赫兹合成孔径雷达(Synthetic Aperture Radar,SAR)正日益受到广泛的关注。而太赫兹波束窄使得其成像幅宽相对较小,这也正好符合极坐标格式算法(Polar Format Algorithm,PFA)的应用场景。然而PFA... 详细信息

由于成像分辨率高、成像帧频高等优势,太赫兹合成孔径雷达(Synthetic Aperture Radar,SAR)正日益受到广泛的关注。而太赫兹波束窄使得其成像幅宽相对较小,这也正好符合极坐标格式算法(Polar Format Algorithm,PFA)的应用场景。然而PFA是针对聚束SAR成像的,不能直接应用于条带SAR;同时随着太赫兹SAR分辨率的提升,PFA对运动误差的二维空变影响无法忽视。为解决以上问题,本文提出了一种太赫兹条带SAR的PFA成像与误差补偿方法。首先通过确定条带SAR与聚束SAR之间的补偿函数实现二者的等效转换,拓宽PFA的应用范围;其次在PFA处理前采用互相关方法进行运动误差的粗补偿以减小PFA对运动误差的二维耦合影响;最后在PFA之后采用最大对比度自聚焦算法进行运动误差精补偿来满足太赫兹SAR的成像要求。仿真实验结果验证了该方法的有效性和鲁棒性。

关键词：极坐标格式算法合成孔径雷达最大对比度算法条带探测

Stoichiometric evolutions of PH3 under high pressure:implication for high-Tc superconducting hydrides

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

National Science Review 2019年第3期6卷 524-531页

作者： Ye Yuan yinwei li Guoyong Fang Guangtao liu Cuiying Pei Xin li Haiyan Zheng Ke Yang lin Wang Center for High Pressure Science and Technology Advanced Research School of Physics and Electronic Engineering Jiangsu Normal University Key Laboratory of Carbon Materials of Zhejiang Province College of Chemistry and Materials Engineering Wenzhou University Department of Physics Fudan University Shanghai Institute of Applied Physics Chinese Academy of Sciences

The superconductivity of hydrides under high pressure has attracted a great deal of attention since the recent observation of the superconducting transition at 203 K in strongly compressed *** has been realized that the stoichiometry of hydrides might change under high pressure,which is crucial in understanding the superconducting *** this study,PH3was studied to understand its superconducting transition and stoichiometry under high pressure using Raman,IR and X-ray diffraction measurements,as well as theoretical ***3is stable below 11.7 GPa and then it starts to dehydrogenate through two dimerization processes at room temperature and pressures up to 25 *** resulting phosphorus hydrides,P2H4and P4H6,were verified experimentally and can be recovered to ambient *** further compression above 35 GPa,the P4H6directly decomposed into elemental *** temperature can greatly hinder polymerization/decomposition under high pressure and retains P4H6up to at least 205 *** superconductivity transition temperature of P4H6is predicted to be 67 K at 200 GPa,which agrees with the reported result,suggesting that it might be responsible for superconductivity at higher *** results clearly show that P2H4and P4H6are the only stable P–H compounds between PH3and elemental phosphorus,which is helpful for shedding light on the superconducting mechanism.

关键词： high pressure hydrides superconductivity stoichiometric evolution

Helium incorporation induced direct-gap silicides

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

npj Computational Materials 2021年第1期7卷 809-816页

作者： Shicong Ding Jingming Shi Jiahao Xie Wenwen Cui Pan Zhang Kang Yang Jian Hao lijun Zhang yinwei li Laboratory of Quantum Functional Materials Design and Application School of Physics and Electronic EngineeringJiangsu Normal UniversityXuzhouChina State Key Laboratory of Superhard Materials Key Laboratory of Automobile Materials of MOEand College of Materials Science and EngineeringJilin UniversityChangchunChina Shandong Key Laboratory of Optical Communication Science and Technology School of Physical Science and Information Technology of Liaocheng UniversityLiaochengChina

The search of direct-gap Si-based semiconductors is of great interest due to the potential application in many technologically relevant *** work examines the incorporation of He as a possible route to form a direct band gap in *** predictions and first-principles calculations show that He and Si,at high pressure,form four dynamically stable phases of Si_(2)He(oP36-Si_(2)He,tP9-Si_(2)He,mC18-Si_(2)He,and mC12-Si_(2)He).All phases adopt host–guest structures consisting of a channel-like Si host framework filled with He guest *** Si frameworks in oP36-Si2He,tP9-Si2He,and mC12-Si_(2)He could be retained to ambient pressure after removal of He,forming three pure Si *** them,oP36-Si_(2)He and mC12-Si_(2)He exhibit direct band gaps of 1.24 and 1.34 eV,respectively,close to the optimal value(~1.3 eV)for solar cell *** shows that mC12-Si_(2)He with an electric dipole transition allowed band gap possesses higher absorption capacity than cubic diamond Si,which makes it to be a promising candidate material for thin-film solar cell.

关键词： allowed filled ambient

玻璃体切除术联合睫状体光凝治疗外伤性青光眼的效果观察

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国实用医刊 2024年第1期51卷 41-43页

作者：徐良马玉红于文英张林李龙李寅伟南阳市眼科医院眼外伤科南阳473000

目的研究玻璃体切除术(PPV)联合睫状体光凝(ECP)治疗外伤性青光眼的效果。方法随机对照研究。抽取2020年1月至2023年1月南阳市眼科医院收治的外伤性青光眼患者50例,按随机数字表法分为对照组和研究组,每组25例。对照组采用PPV治疗,研究... 详细信息

目的研究玻璃体切除术(PPV)联合睫状体光凝(ECP)治疗外伤性青光眼的效果。方法随机对照研究。抽取2020年1月至2023年1月南阳市眼科医院收治的外伤性青光眼患者50例,按随机数字表法分为对照组和研究组,每组25例。对照组采用PPV治疗,研究组采用PPV联合直视下ECP治疗。比较两组术后6个月视力,比较两组术后7 d、1个月、3个月、6个月眼压变化,比较两组并发症发生率。结果术后6个月,研究组视力提高率(72.00%,18/25)高于对照组(36.00%,9/25),P0.05)。结论PPV联合直视下ECP治疗外伤性青光眼的效果显著,能扩大光凝范围,缩短激光持续时间,提升患者视力,降低眼压,减少并发症的发生。

关键词：青光眼玻璃体切除术睫状体光凝眼压

Medical culture in the disease narrative of modern Chinese literature

在线全文

学校读者我要写书评

暂无评论

Medical culture in the disease narrative of modern Chinese l...