检索结果-南通市图书馆

有翼飞行器有限时间时变编队跟踪控制方法研究

同方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

战术导弹技术 2024年第3期 123-135页

作者：徐星光郭鸿飞张科南任章北京机电工程研究所北京100074 北京航空航天大学自动化科学与电气工程学院北京100191

有翼飞行器执行编队协同突防任务时,领导者飞行器需要通过变轨机动飞行提高突防概率,要求飞行器编队能够快速调整,提升编队保持的整体效果。针对有翼飞行器编队协同突防作战中编队保持的任务目标,研究了多枚有翼飞行器有限时间时变编队... 详细信息

有翼飞行器执行编队协同突防任务时,领导者飞行器需要通过变轨机动飞行提高突防概率,要求飞行器编队能够快速调整,提升编队保持的整体效果。针对有翼飞行器编队协同突防作战中编队保持的任务目标,研究了多枚有翼飞行器有限时间时变编队跟踪控制问题。在领导者飞行器具有未知输入条件下,利用积分滑模控制方法、自适应控制方法,基于邻居飞行器相互间的局部信息设计了有限时间时变编队跟踪控制器。基于有限时间控制性理论,证明了时变编队跟踪误差在有限时间内的收敛性。采用数值仿真对比的方法,验证了有限时间时变编队跟踪控制方法在有翼飞行器编队协同突防中的可行性与有效性。

关键词：有翼飞行器有限时间编队跟踪控制未知输入积分滑模编队保持协同突防

在线全文

学校读者我要写书评

暂无评论

脑胶质瘤抗血管治疗现况与耐药机制研究进展

神经疾病与精神卫生 2024年第5期24卷 305-312页

作者：李卓群张克难陈婧北京市神经外科研究所 100070

血管结构异常增生是各类实体肿瘤中的常见现象,在高级别脑胶质瘤中尤为显著。目前,已发现多种血管结构的形成机制,这些机制促进肿瘤内血管结构增殖,并在高级别胶质瘤中被验证。基于此机制,贝伐珠单抗被广泛应用于脑胶质瘤抗血管治疗,但... 详细信息

血管结构异常增生是各类实体肿瘤中的常见现象,在高级别脑胶质瘤中尤为显著。目前,已发现多种血管结构的形成机制,这些机制促进肿瘤内血管结构增殖,并在高级别胶质瘤中被验证。基于此机制,贝伐珠单抗被广泛应用于脑胶质瘤抗血管治疗,但仍面临诸多挑战,如贝伐珠单抗可提升患者的生活质量,延长患者无进展生存期,但是患者总体生存期无获益,且部分患者在治疗后无影像学改善,此外还存在耐药问题。既往研究认为耐药机制主要包括促进肿瘤细胞恶性表型进展和促进异常血管增生两种方式,可能为未来提高抗血管治疗效果、改善患者预后提供有效线索。

关键词：胶质瘤血管生成抗血管治疗贝伐珠单抗耐药机制综述

血浆致动脉粥样硬化指数与高血压合并冠心病的相关性

在线全文

学校读者我要写书评

暂无评论

延边大学医学学报 2024年第1期47卷 25-30页

作者：玲玲张克男李传奇玄春花延边大学附属医院全科医学科吉林延吉133000

[目的 ]探讨血浆致动脉粥样硬化指数(AIP)与高血压合并冠心病的相关性,旨在为AIP预测高血压合并冠心病患者冠状动脉病变程度提供依据.[方法 ]选择因原发性高血压合并冠心病行冠状动脉造影术的患者558例,根据检查结果分为高血压未合并冠... 详细信息

[目的 ]探讨血浆致动脉粥样硬化指数(AIP)与高血压合并冠心病的相关性,旨在为AIP预测高血压合并冠心病患者冠状动脉病变程度提供依据.[方法 ]选择因原发性高血压合并冠心病行冠状动脉造影术的患者558例,根据检查结果分为高血压未合并冠心病组(151例)和高血压合并冠心病组(407例).按照SYNTAX评分标准对冠状动脉病变程度进行评分,再将高血压合并冠心病组分为低危组(230例)、中危组(122例)及高危组(55例).比较各组一般资料、血糖及血脂水平,运用ROC曲线预测高血压合并冠心病患者的AIP值.应用多因素Logistic回归分析影响冠状动脉狭窄程度的独立危险因素,并使用ROC曲线评价AIP对高血压合并冠心病患者冠状动脉狭窄程度的预测价值.[结果 ]高血压合并冠心病组与高血压未合并冠心病组性别、民族、饮酒、身高、体质量、体质量指数(BMI)及总胆固醇(TC)间差异均无统计学意义(P> 0.05),而吸烟、年龄、三酰甘油(TG)、高密度脂蛋白胆固醇(HDL-C)、AIP及空腹血糖水平间差异均具有统计学意义(P 2.29时高血压合并冠心病的风险升高.高血压合并冠心病组中SYNTAX评分与BMI、TG、低密度脂蛋白胆固醇、AIP及空腹血糖水平呈正相关(P 2.43时中危及以上冠状动脉狭窄程度风险升高,AIP> 2.66时高危及以上冠状动脉狭窄程度风险升高.[结论 ]AIP可为评估高血压合并冠心病患者冠状动脉病变程度提供依据.

关键词：冠心病高血压血浆致动脉粥样硬化指数 SYNTAX评分

Temperature-dependent Photoluminescence of Silicon Nanocrystals Embedded in SiO2 Matrix

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2018年第4期34卷 513-516页

作者： zhang Tianning zhang kenan CHEN Xiren WANG Shuxia zhang Rongjun SHAO Jun CHEN Xin DAI Ning National Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 P. R. China Department of Optical Science and Engineering School of Information Science and Engineering Fudan University Shanghai 200433 P. R. China University of Chinese Academy of Sciences Beijing 100049 P. R. China

Nanostructured silicon plays a key role in the fidds of microelectronics, optoelectronics and photonics. Since near-infrared photolummescence（PL） was first observed in nanoporous silicon at room temperature, silicon nanocrystals（Si-NCs） have attracted considerable attention due to their tunable structures and properties. Considerable efforts have recently been devoted to obtaining deeper insight in the PL emission of colloidal and solid Si-NCs and the applications of these materials.

关键词： Silicon nanocrystal Photohtminescence Red-shift

Vertically coupled ZnO nanorods on MoS2 monolayers with enhanced Raman and photoluminescence emission

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

Nano Research 2015年第3期8卷 743-750页

作者： kenan zhang Yun zhang Tianning zhang Wenjing Dong Tiaoxing Wei Yan Sun Xin Chen Guozhen Shen Ning Dai National Laboratory for Infrared Physics Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China State Key Laboratory for Superlattices and Microstructures Institute of Semiconductors Chinese Academy of Sciences Beijing 100083 China

Hybrid structures composed of layered materials have received much attention due to their exceptional tunable optical, electronic and catalytic properties. Here, we describe a hydrothermal strategy for coupling vertical ZnO nanorods on MoS2 monolayers without a catalyst. These vapor-solid-grown MoS2 monolayers aid in growing vertical ZnO nanorods via epitaxy. Enhanced Raman and photoluminescence emissions were observed from the MoS2 monolayers under the ZnO nanorods in these coupled structures, which was attributed to the light antenna effect of the ZnO nanorods. These hybrid and incorporation protocols for layered materials will provide new perspectives and opportunities for promoting the construction of heterojunctions with adjustable layered structures leading to fascinating fundamental phenomena and advanced devices.

关键词： MoS2 monolayers ZnO nanorods Raman photoluminescence

A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large‑Size Ultrathin Nonlayered Two‑Dimensional Materials

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

Nano-Micro Letters 2021年第11期13卷 79-91页

作者： Mei Zhao Sijie Yang kenan zhang Lijie zhang Ping Chen Sanjun Yang Yang Zhao Xiang Ding Xiaotao Zu Yuan Li Yinghe Zhao Liang Qiao Tianyou Zhai School of Physics University of Electronic Science and Technology of China(UESTC)Chengdu 610054People’s Republic of China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074People’s Republic of China School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006People’s Republic of China Key Laboratory of Carbon Materials of Zhejiang Province Institute of New Materials and Industrial TechnologiesCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035People’s Republic of China

Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication ***,owing to the inherent strong covalent bonds,the direct synthesis of 2D planar structure from nonlayered materials,especially for the realization of large-size ultrathin 2D nonlayered materials,is still a huge ***,a general atomic substitution conversion strategy is proposed to synthesize large-size,ultrathin nonlayered 2D *** nonlayered CdS as a typical example,large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method,where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition *** size and thickness of CdS flakes can be controlled by the CdI2 *** growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS,which has been evidenced by experiments and theoretical *** atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials,providing a bridge between layered and nonlayered materials,meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.

关键词： Nonlayered 2D materials Large-size ultrathin CdS flakes Atomic substitution conversion Layered-nonlayered structural transformation

Electronic structure of molecular beam epitaxy grown 1T’-MoTe2 film and strain effect

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2019年第10期28卷 210-214页

作者： Xue Zhou Zeyu Jiang kenan zhang Wei Yao Mingzhe Yan Hongyun zhang Wenhui Duan Shuyun Zhou State Key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing 100084China Collaborative Innovation Center of Quantum Matter Beijing 100084China

Atomically thin transition metal dichalcogenide films with distorted trigonal(1T') phase have been predicted to be candidates for realizing quantum spin Hall effect. Growth of 1T' film and experimental investigation of its electronic structure are critical. Here we report the electronic structure of 1T'-MoTe2 films grown by molecular beam epitaxy(MBE).Growth of the 1T'-MoTe2 film depends critically on the substrate temperature, and successful growth of the film is indicated by streaky stripes in the reflection high energy electron diffraction(RHEED) and sharp diffraction spots in the low energy electron diffraction(LEED). Angle-resolved photoemission spectroscopy(ARPES) measurements reveal a metallic behavior in the as-grown film with an overlap between the conduction and valence bands. First principles calculation suggests that a suitable tensile strain along the a-axis direction is needed to induce a gap to make it an insulator. Our work not only reports the electronic structure of MBE grown 1T'-MoTe2 films, but also provides insights for strain engineering to make it possible for quantum spin Hall effect.

关键词： quantum spin Hall effect 1T'-MoTe2 molecular beam epitaxy(MBE) transition metal dichalcogenides(TMDCs)

Clinical management and survival outcomes of patients withdifferent molecular subtypes of diffuse gliomas in China(2011–2017):a multicenter retrospective study from CGGA

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & Medicine 2022年第10期19卷 1460-1476页

作者： kenan zhang Xing Liu Guanzhang Li Xin Chang Shouwei Li Jing Chen Zheng Zhao Jiguang Wang Tao Jiang Ruichao Chai Department of Molecular Pathology Beijing Neurosurgical InstituteCapital Medical UniversityBeijing 100070China Department of Neuropathology Beijing Neurosurgical InstituteCapital Medical UniversityBeijing 100070China Department of Neurosurgery Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China Department of Neurosurgery Beijing Sanbo Brain HospitalCapital Medical UniversityBeijing 100093China Division of Life Science and State Key Laboratory of Molecular Neuroscience Department of Chemical and Biological EngineeringThe Hong Kong University of Science and TechnologyClear Water BayKowloonHong Kong SAR 999077China Hong Kong Center for Neurodegenerative Diseases Hong Kong Science ParkHong Kong SAR 999077China HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute FutianShenzhen 518057China

Objective:We aimed to summarize the clinicopathological characteristics and prognostic features of various molecular subtypes of diffuse gliomas(DGs)in the Chinese ***:In total,1,418 patients diagnosed with DG between 2011 and 2017 were classified into 5 molecular subtypes according to the 2016 WHO classification of central nervous system *** IDH mutation status was determined by immunohistochemistry and/or DNA sequencing,and 1p/19q codeletion was detected with fluorescence in situ *** median clinical follow-up time was 1,076 days.T-tests and chi-square tests were used to compare clinicopathological ***‒Meier and Cox regression methods were used to evaluate prognostic ***:Our cohort included 15.5%lower-grade gliomas,IDH-mutant and 1p/19q-codeleted(LGG-IDHm-1p/19q);18.1%lowergrade gliomas,IDH-mutant(LGG-IDHm);13.1%lower-grade gliomas,IDH-wildtype(LGG-IDHwt);36.1%glioblastoma,IDHwildtype(GBM-IDHwt);and 17.2%glioblastoma,IDH-mutant(GBM-IDHm).Approximately 63.3%of the enrolled primary gliomas,and the median overall survival times for LGG-IDHm,LGG-IDHwt,GBM-IDHwt,and GBM-IDHm subtypes were 75.97,34.47,11.57,and 15.17 months,*** 5-year survival rate of LGG-IDHm-1p/19q was 76.54%.We observed a significant association between high resection rate and favorable survival outcomes across all subtypes of primary *** also observed a significant role of chemotherapy in prolonging overall survival for GBM-IDHwt and GBM-IDHm,and in prolonging post-relapse survival for the 2 recurrent GBM ***:By controlling for molecular subtypes,we found that resection rate and chemotherapy were 2 prognostic factors associated with survival outcomes in a Chinese cohort with DG.

关键词： Diffuse glioma IDH 1p/19q molecular pathology temozolomide

Growth of large scale PtTe,PtTe_(2) and PtSe_(2) films on a wide range of substrates

在线全文

学校读者我要写书评

暂无评论

Nano Research 2021年第6期14卷 1663-1667页

作者： kenan zhang Meng Wang Xue Zhou Yuan Wang Shengchun Shen Ke Deng Huining Peng Jiaheng Li Xubo Lai Liuwan zhang Yang Wu Wenhui Duan Pu Yu Shuyun Zhou State key Laboratory of Low Dimensional Quantum Physics and Department of Physics Tsinghua UniversityBeijing100084China Department of Mechanical Engineering and Tsinghua-Foxconn Nanotechnology Research Center Tsinghua UniversityBeijing100084China Collaborative Innovation Center of Quantum Matter Beijing100084China

1T phase of transition metal dichalcogenides(TMDCs)formed by group 10 transition metals(***,Pd)have attracted increasing interests due to their novel properties and potential device *** of large scale thin films with controlled phase is critical especially considering that these materials have relatively strong interlayer interaction and are difficult to *** we report the growth of centimeter-scale PtTe,1T-PtTe2 and 1T-PtSe2 films via direct deposition of Pt metals followed by tellurization or *** find that by controlling the Te flux,a hitherto-unexplored PtTe phase can also be obtained,which can be further tuned into PtTe2 by high temperature annealing under Te *** films with different thickness can be grown on a wide range of substrates,including NaCl which can be further dissolved to obtain free-standing PtTe2 or PtSe2 ***,a systematic thickness dependent resistivity and Hall conductivity measurements show that distinguished from the semiconducting PtSe2 with hole carriers,PtTe2 and PtTe films are *** work opens new opportunities for investigating the physical properties and potential applications of group 10 TMDC films and the new monochalcogenide PtTe film.

关键词： transition metal dichalcogenides(TMDCs) selenization tellurization PtSe2 PtTe2 PtTe