检索结果-南通市图书馆

Double [5]carbohelicene: facile synthesis, chiroptical properties,isomerization study, and lasing application

Science China Chemistry 2025年第1期 233-240页

作者： Peipei Liu Yantong Li Meng-Xiang Wu hao kang Xiao-Li Zhao Lin Xu Linlin Liu Xiaodong Li Junfeng Fang Zhiwei Fang Ya Cheng Hai-Bo Yang Huakang Yu Xueliang Shi State Key Laboratory of Petroleum Molecular & Process Engineering Shanghai Key Laboratory of Green Chemistry and Chemical ProcessesSchool of Chemistry and Molecular Engineering East China Normal University School of Physics and Optoelectronics South China University of Technology Institute of Polymer Optoelectronic Materials & Devices State Key Laboratory of Luminescent Materials & Devices South China University of Technology School of Physics and Electronic Science Engineering Research Center of Nanophotonics & Advanced Instrument Ministry of EducationEast China Normal University State Key Laboratory of Precision Spectroscopy School of Physics and Electronic Science East China Normal University

Double carbohelicenes have attracted considerable attention due to their aesthetic structures, distinct π-conjugation extension, inherent chirality, and intriguing optical and electronic properties. Herein, the concise de novo synthesis of a new double[5]carbohelicene 1 together with its chiroptical properties, isomerization process and lasing application is presented. 1 was synthesized by a simple protocol involving the formation of a 6,6′-bipentacene as the key intermediate. It is worth noting that1 existed as two diastereomers 1-PP/MM and 1-PM, which were successfully isolated and unambiguously confirmed by Xray crystallography. The optical resolution of the racemic 1-PP/MM was successfully achieved by chiral-phase highperformance liquid chromatography（HPLC）, and 1-PP and 1-MM were characterized by circular dichroism. Interestingly, it was found that 1-PP/MM could be completely isomerized to 1-PM upon heating, and the detailed thermodynamics and kinetics of the isomerization process were systematically investigated. 1-PM exhibited deep-red luminescence with emission maximum at 723 nm and fluorescence quantum yield as high as 32.95%. Consequently, we can showcase the lasing application of 1-PM by doping with epoxy resin to assemble a bottle microlaser spontaneously, which the lasing wavelength is 796.6 nm at a threshold of 0.8 m J cm-2. We believe that our studies, including the facile synthesis methodology, detailed isomerization studies, and lasing application, will shed some light on the design and synthesis of novel carbohelical systems with more functions.

关键词：

来源：

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Mode-localized accelerometer with ultrahigh sensitivity

引用

Science China(Information Sciences) 2022年第4期65卷 238-250页

作者： hao kang Bing RUAN Yongcun hao Honglong CHANG Ministry of Education Key Laboratory of Micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University

The mode localization phenomenon is an effective technique to enhance sensor sensitivity,and some low noise floor mode-localized sensors,including accelerometers,mass sensors,and electrometers,have been successfully *** further improve the performance of the mode-localized accelerometer,we report a microelectromechanical system mode-localized accelerometer based on 4-degree of freedom （DoF） weakly coupled resonators （WCRs） with a stress-relief structure eliminating the thermal stress generated during the silicon-on-glass fabrication *** results show that compared with the state-of-the-art 3-DoF mode-localized accelerometer (4.40 g-1),the amplitude ratio-based sensitivity of the proposed accelerometer(119.36 V·g-1) is improved by 2612%.Moreover,the noise floor is 0.64μg·Hz-1/2from 0.01 to 3 Hz under the closed-loop *** the authors’best knowledge,this is the lowest measured noise floor for mode-localized accelerometers.

关键词： mode localization weakly coupled resonators accelerometer degree-of-freedom microelectromechanical system

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Effect of boron on hot strips of low carbon steel produced by compact strip production

引用

Journal of University of Science and Technology Beijing 2008年第2期15卷 138-142页

作者： hao Yu Yonglin kang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The effect of boron on hot strips of low carbon steel produced by compact strip production （CSP） to reduce the strength to a certain degree was investigated, which is quite different from that of high-strength low alloy steel. The mechanical properties and microstructural evolution of the hot strip were studied using optical microscopy and tensile tests. By means of an electrolytic dissolution technique and Thermo-Cal calculation, the precipitates containing boron were analyzed and detected. From the electron backscattered diffraction analysis, it can be deciphered whether the microstructure has recrystallized or not. Furthermore, the effect of boron segregation on the recrystallization or non-recrystallization conditions can be distinguished. The segregation behavior of boron was investigated in boron-containing steel. The nonequilibrium segregation of boron during processing was discussed on the basis of the forming complexes with vacancies that migrate to the boundaries prior to annihilation, which was confirmed by the subsequent cold rolling with annealing experiments.

关键词： compact strip production boron segregation electrolytic dissolution technique nonequilibrium segregation recrystallization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Microstructure and mechanical properties of automobile beam steels produced by EAF-CSP process

引用

Journal of University of Science and Technology Beijing 2006年第6期13卷 508-511页

作者： Zhengzhi Zhao Yonglin kang hao Yu Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The microstructure, mechanical properties, and misorientation of automobile beam steels produced by EAF-CSP process were studied using optical microscopy （OM） and electron back-scattered diffraction （EBSD）. It is shown that the microstructure of strips is mainly polygonal ferrite, and the average grain size is about 5-8 μm. The electron back-scattered diffraction results show that grain boundaries in ferrite are basically high-angle grain boundaries without remarkable preferred orientation. Hot strips of automobile beam steels possess a good combination of strength and plasticity because of their fine microstructures and low quantity of impurities.

关键词： steel CSP microstructure mechanical property electron back-scattered diffraction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Clinical utility of cytokine analysis in the diagnosis and efficacy monitoring of vitreoretinal lymphoma

引用

International Journal of Ophthalmology(English edition) 2022年第12期15卷 1893-1902页

作者： hao kang Yong Tao Department of Ophthalmology Beijing Chaoyang HospitalCapital Medical UniversityBeijing 100020China

AIM:To investigate the value of cytokine analysis in aqueous humor(AH)for discriminating vitreoretinal lymphoma(VRL)from uveitis and for evaluating the efficacy of intravitreal methotrexate(MTX)***:This retrospective study was done on 28 VRL patients between 2013 and *** interleukin(IL)-10,IL-6,IL-8,vascular endothelial growth factor(VEGF),and vascular cell adhesion molecules(VCAM)were measured in 28 VRL patients and 38 uveitis *** to the respective examinations for distinguishing VRL from uveitis,the diagnostic accuracy was evaluated by receiver operating characteristic(ROC)curve *** response to treatment was monitored by observing changes in bestcorrected visual acuity(BCVA),ocular manifestation,and AH cytokine levels in 21 patients with VRL who had undergo multiple intravitreal injections of ***:Compared with uveitis patients,VRL patients had higher IL-10 level(P1.55 and 88.2%and 81.1%,respectively,for IL-10>76.7 pg/m *** 21 patients who had undergo repeated injections,improvements in BCVA,clinical remission of VRL and continuous decrease in cytokine levels over time were *** those patients,the BCVA correlated with the aqueous levels of IL-10 and IL-6 during the course of disease ***:The combination of the aqueous cytokine profiles can be instrumental for conventional diagnostic methods and for progression monitoring and treatment response.

关键词： vitreoretinal lymphoma intraocular lymphoma primary central nervous system lymphoma cytokine methotrexate

来源：

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

Map composition generalized to coherent collections of maps

引用

Frontiers of Mathematics in China 2015年第3期10卷 547-565页

作者： Herng Yi CHENG kang hao CHEONG National University of Singapore High School of Mathematics and Science Singapore 129957 Singapore Tanglin Secondary School Singapore 127391 Singapore

Relation algebras give rise to partial algebras on maps, which are generalized to partial algebras on polymaps while preserving the properties of relation union and composition. A polymap is defined as a map with every point in the domain associated with a special set of maps. Polymaps can be represented as small subcategories of Set＊, the category of pointed sets. Map composition and the counterpart of relation union for maps are generalized to polymap composition and sum. Algebraic structures and categories of polymaps are investigated. Polymaps present the unique perspective of an algebra that can retain many of its properties when its elements （maps） are augmented with collections of other elements.

关键词： Relation algebra partial algebra composition

来源：

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

Surface Temperature Change of U75V 60 kg/m Heavy Rail During Heat Treatment

引用

Journal of Iron and Steel Research International 2013年第2期20卷 33-37,67页

作者： kang hao WU Di Zhao Xian-ming State Key Laboratory of Rolling and Automation Northeastern University

The U75V 60 kg/m heavy rail samples were heated to 900 ℃ in a resistance furnace for a fixed duration of 50 min. Under this condition, the samples were austenitized totally. Then, the samples were dragged out of furnace and cooled for 25 s in the open air. After that, the samples entered into the air spraying channel, and were cooled from the top and both sides by compressed air. During this period, main technical parameters were changed such as the distance between spray nozzles and surface of rail head, air pressure, air spraying time and air temperature. So under laboratory condition, optimal heat-treating parameters of U75V 60 kg/m heavy rail were determined as the distance between spray nozzles and surface of rail head of 15 mm, air pressure of 0.26 MPa, cooling time of 80 s, and air temperature of 28 ℃. The surface temperature at different positions of heavy rail was measured before and after heat treatment, and the temperature changing law was determined. The self tempering occurred on the surface of rail head after heat treatment, and the tempering temperature became the largest （about 3 min） after heat treatment, separately 528, 524 and 536 ℃ at the center, top fillet and bottom fillet of rail head. The heavy rail was cooled in open air after heat treatment; during this period, the temperature gap on the surface of heavy rail became smaller and smaller, and was reduced to zero when being cooled for 20 min.

关键词： temperature change heavy rail heat treatment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Non-adiabatic holonomic quantum operations in continuous variable systems

引用

Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 12-19页

作者： hao-Long Zhang Yi-hao kang Fan Wu Zhen-Biao Yang Shi-Biao Zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350116China

Quantum operations by utilizing the underlying geometric phases produced in physical systems are favoured due to their potential *** a system in a non-degenerate eigenstate undergoes an adiabatically cyclic evolution dominated by its Hamiltonian,it will get a geometric phase,referred to as the Berry *** a non-adiabatically cyclic evolution produces an Aharonov-Anandan geometric *** two types of Abelian geometric phases are extended to the non-Abelian cases,where the phase factors become matrix-valued and the transformations associated with different loops are *** and non-Abelian(holonomic)operations are prevalent in discrete variable systems,whose limited(say,two)energy levels,form the *** their developments in continuous systems have also been investigated,mainly due to that,bosonic modes(in,such as,cat states)with large Hilbert spaces,provide potential advantages in fault-tolerant quantum *** we propose a feasible scheme to realize non-adiabatic holonomic quantum logic operations in continuous variable systems with cat *** construct arbitrary single-qubit(two-qubit)gates with the combination of single-and two-photon drivings applied to a Kerr Parametric Oscillator(KPO)(the coupled KPOs).Our scheme relaxes the requirements of the previously proposed quantum geometric operation strategies in continuous variable systems,providing an effective way for quantum control.

关键词： cat qubit continuous variable systems non-Abelian

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of Air Pressure on Hardened Layer of U75V 60 kg/m Heavy Rail after Heat Treatment

引用

Journal of Harbin Institute of Technology(New Series) 2013年第1期20卷 52-56页

作者： hao kang Xian-Ming Zhao Di Wu State Key Lab of Rolling and Automation Northeastern University

The samples cut from U75V 60 kg/m heavy rail are heated to 900 ℃ in resistance furnace and then put into air spraying channel to be cooled for 80 s, and change air pressure from 0.16 MPa to 0.33 MPa, and observe the effect of air pressure on hardened layer. The thickness and hardness of hardened layer increases with the increase of air pressure, and the thickness is more than 24 mm at the center and top fillets of rail head, and more than 15 mm at the blow fillets of rail head when air pressure is more than 0.26 MPa. During the tempering after heat treatment, tempering temperature of rail head is more than 570 ℃ when air pressure is separately 0.16 MPa, 0.20 MPa and 0.23 MPa, which is higher than finishing temperature of pearlite transformation at the cooling rate of 3 ℃/s according to CCT curve of U75V steel. When air pressure is separately 0.26, 0.30 and 0.33 MPa, the tempering temperature is 529 ℃ lower than finishing temperature of pearlite transformation at the cooling rate of 3 ℃/s. Under this condition, pearlite transformation is finished totally, so in order to reduce air consumption and control the cost, proper air pressure for U75V 60 kg/m heavy rail heat treating should be 0.26 MPa; the cooling rate increases with the increase of air pressure, and the average cooling rate on the surface of rail head is more than 3.21 ℃/s when air pressure is more than 0.26 MPa, and the largest cooling rate occurs at the top fillets of rail head.

关键词： air pressure hardened layer heavy rail heat treatment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the pointing model of a slant-axis terahertz antenna

引用

Research in Astronomy and Astrophysics 2020年第4期20卷 115-122页

作者： Yu Wang Zheng Lou Ying-Xi Zuo hao-Ran kang Ming-Zhu Zhang Purple Mountain Observatory Chinese Academy of SciencesNanjing 210034China Key Laboratory for Radio Astronomy Chinese Academy of SciencesNanjing 210034China Shanghai Normal University Shanghai 201400China University of Science and Technology of China Hefei 230026China

This paper describes the establishment and verification of an accurate pointing model for a1.2 m aperture slant-axis terahertz antenna.A new analytical pointing model for the slant-axis antenna is presented based on an analogy to that of the alt-azimuth ***,extra error terms are added to the pointing model based on the structure and mechanical analysis of the slant-axis *** verify the pointing model experimentally,a pointing error measurement method based on photogrammetric techniques is *** this method,pointing behaviors of the antenna are accurately measured without the aid of astronomical observations,and major sources of the pointing errors are measured individually by photogrammetry and their respective coefficients are compared with those in the analytical pointing *** results show that an extended pointing model consisting 21 error terms can significantly reduce the residual systematic errors compared with the traditional model,more details are given in the following sections.

关键词： telescopes slant-axis antenna photogrammetry pointing models

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：