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Science China Chemistry 2017年第10期60卷 1340-1348页

作者： Shaoqing Zhang Liyan Yang Delong Liu chang he Jianqi Zhang Yun Zhang Jianhui Hou School of Chemistry and Biology Engineering University of Science and Technology Beijing Beijing 100083 China State Key Laboratory of Polymer Physics and Chemistry Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and Technology Beijing 100190 China

Two benzo[1,2-b:4,5-b￠]dithiophene(BDT)-based small molecule(SM) donor materials with identical conjugated backbones but different substitution groups, named as DRTB-O and DRTB-T, were well explored to demonstrate the influence of the replacement of alkoxy with alkylthienyl on their photovoltaic properties in fullerene-based and fullerene-free organic solar cells(OSCs). The study shows that the two SM donors possess similar absorption spectra and energy levels but different crystalline structures in solid films. The carrier transport property and phase separation morphologies of the blend films have also been fully *** employing PC71 BM as the acceptor, the power conversion efficiency(PCE) of DRTB-O:PC71BM and DRTB-T:PC71BM based devices were 4.91% and 7.08%, respectively. However, by blending with IDIC, the two SM donors exhibited distinctly different photovoltaic properties in fullerene-free OSCs, and the PCE of DRTB-O:IDIC and DRTB-T:IDIC based devices were 0.15% and9.06%, respectively. These results indicate that the replacement of alkoxyl with alkylthienyl in designing SM donor materials plays an important role in the application of fullerene-free OSCs.

关键词： organic solar cells small molecule fullerene-free side chain molecular design

Polynomial Convergence of Primal-Dual Path-Following Algorithms for Symmetric Cone Programming Based on Wide Neighborhoods and a New Class of Directions

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Journal of the Operations Research Society of China 2017年第3期5卷 333-346页

作者： chang-he Liu Yuan-Yuan Huang You-Lin Shang School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang 471023HenanChina

This paper presents a class of primal-dual path-following interior-point algorithms for symmetric cone programming(SCP)based on wide neighborhoods and new directions with a parameterθ.When the parameterθ=1,the direction is exactly the classical Newton *** the parameterθis independent of the rank of the associated Euclidean Jordan algebra,the algorithm terminates in at most O(κr logε−1)iterations,which coincides with the best known iteration bound for the classical wide neighborhood *** the parameterθ=√n/βτand Nesterov–Todd search direction is used,the algorithm has O(√r logε−1)iteration complexity,the best iteration complexity obtained so far by any interior-point method for solving *** our knowledge,this is the first time that a class of interior-point algorithms including the classical wide neighborhood path-following algorithm is proposed and analyzed over symmetric cone.

关键词： Path-following interior-point algorithm Wide neighborhood Symmetric cone programming Euclidean Jordan algebra Polynomial complexity

Effect of Asynchronous Adjustments of Clamping Cylinders on Triangular Crack of Slab Castings Under Application of Soft Reduction

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Journal of Iron and Steel Research International 2013年第2期20卷 38-47页

作者： LIU Ke chang Yun-he HAN Zhan-guang ZHANG Jia-quan State Key Laboratory of Advanced Metallurgy School of Metallurgical and Ecological EngineeringUniversity of Science and Technology Beijing

Soft reduction is known to be one of the best ways to improve the internal quality of slab castings such as center segregation, center porosity, centerline or triangular zone cracks, which is based on a proper adoption of the amount of reduction upon the given final solidification zone through roll gap adjustments. The synchronization of the clamping cylinders for roll gap adjustments should be very important to the application of soft reduction, including the synchronization of the clamping cylinders adjustments in the same and different segments. The synchronization of clamping cylinders adjustments is mainly affected by the adjustable accuracy of the four position-controlled clamping cylinders mounted in the upper frames of the segments according to a predetermined transformation relationship between the signals of displacement sensors and aimed roll gap, which, however, is also influenced by the installation accuracy, the precision of displacement sensors, the deformation of the segment frames and/or its bearing pedestals. Due to the actual asynchronous adjustments of the four clamping cylinders, the dynamic soft reduction operation is normally applied at non-ideal mechanical conditions. here 7 possible situations of asynchronous adjustments of the local segments which may induce gap deviation have been presented. The roll gap deviation in the soft reduction region of a slab casting has been studied by a 3-D visco-elastic plastic FEM model, through which the additional inter-roll bulging, the related triangular cracks induced by one kind of the possible asynchronous adjustment situation and the effectiveness of soft reduction have been analyzed. A critical tolerance for the gap adjustments has been proposed for better contribution of soft reduction to the internal quality of slabs.

关键词： slab casting soft reduction clamping cylinder asynchronous adiustment

Research and Realization of a Master-Slave Robotic System for Retinal Vascular Bypass Surgery

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Chinese Journal of Mechanical Engineering 2018年第4期31卷 48-57页

作者： chang-Yan he Long Huang Yang Yang Qing-Feng Liang Yong-Kang Li School of Mechanical Engineering and Automation Beihang University Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing Key Laboratory of Ophthalmology and Visual Sciences

Retinal surgery continues to be one of the most technical demanding surgeries for its high manipulation accuracy requirement, small and constrained workspace, and delicate retinal tissue. Robotic systems have the potential to enhance and expand the capabilities of surgeons during retinal surgery. Thus, focusing on retinal vessel bypass surgery, a master-slave robot system is developed in this paper. This robotic system is designed based on characteristics of retinal vascular bypass surgery and analysis of the surgical workspace in eyeball. A novel end-effector of two degrees of freedom is designed and a novel remote center of motion mechanism is adopted in the robot *** kinematics and the mapping relationship are then established, the gravity compensation control strategy and the hand tremor elimination algorithm are applied to achieve the high motion accuracy. The experiments on an artificial eyeball and an in vitro porcine eye are conducted, verifying the feasibility of this system.

关键词： Retinal robotic system Mechanism design Kinematics Gravity compensation

Study on Focal Mechanism changing Characteristics of the 2013 Zogang-Markam Ms6. 1 Earthquake Sequence

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Earthquake Research in China 2016年第1期30卷 13-21页

作者： he chang Zhu Hang Earthquake Administration of Sichuan Province Chengdu 610041 China

The M_S6. 1 earthquake was a foreshock-mainshock-aftershock type which occurred in the boundary region between Zogang and Markam counties on August 12,2013. Within 9hours before the main shock seven earthquakes of greater than M_L2. 0 occurred,with a maximum of M_L4. 7. In this paper,the earthquake focal mechanism changing process of the Zogang-Markam M_S6. 1 earthquake sequence is studied by calculating the correlation coefficient of body wave spectral amplitudes,and the result shows that the correlation coefficients of spectral amplitude of foreshocks present high value fluctuation with an average value of 0. 86,which shows that the focal mechanism of foreshocks are similar;and the correlation coefficients of spectral amplitude of aftershocks present low value,which shows that the possibility of a large earthquake is not high after a time.

关键词： Zogang-Markam Ms6. 1 earthquake Earthquake sequence Focal mechanismSpectral amplitude correlation coefficient

Tuning of Magnetic Properties of α-RuCl3 Single Crystal by Cr Doping

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Chinese Physics Letters 2020年第6期37卷 90-93页

作者： Yu-Jie Yuan Cheng-he Li Shang-Jie Tian he-chang Lei Xiao Zhang State Key Laboratory of Information Photonicsx and Optical Communications and School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano DevicesRenmin University of ChinaBeijing 100872China

We study the influence of Cr doping on magnetic properties ofα-RuCl3 single crystals in *** increasing Cr content,the c-axial lattice parameter increases gradually,implying that the Cr doping may weaken the interlayer *** magnetism of Ru1-xCrxCl3 single crystals evolves from a long-range AFM order to a possible spin-glass state with Cr *** appearance of a possible spin-glass state can be explained by the introduction of FM interaction by Cr3+ions,which competes with the AFM interaction between Ru3+***,the larger magnetic moment of Cr3+ion with S=3/2 than Ru3+ion with Jeff=1/2 also results in a monotonic increase of the effective moment of Ru1-xCrxCl3 single crystal.

关键词： doping interaction moment

Probing molecular orientation at bulk heterojunctions by polarization-selective transient absorption spectroscopy

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Science China Chemistry 2021年第9期64卷 1569-1576页

作者： Cankun Zhang Yuzhe Zhang Zhiye Wang Yuming Su Zhixiang Wei Jianhui Hou Shan he Kaifeng Wu chang he Jianqi Zhang Cheng Wang State Key Laboratory for Physical Chemistry of Solid Surfaces iChEMCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China Innovation Laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) FuzhouChina CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanosciecneNational Center for Nanoscience and TechnologyBeijing100190China State Key Laboratory of Polymer Physics and Chemistry Institute of ChemistryChinese Academy of SciencesBeijing100190China State Key Laboratory of Molecular Reaction Dynamics and Dynamics Research Center for Energy and Environmental Materials Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian116023China

A bulk heterojunction in organic solar cells is where charge separation and recombination *** orientation at the interface is one of the key factors that dictate solar cell *** X-ray scattering-based methods can determine donor/acceptor domain orientations between an anisotropic phase and an isotropic fullerene-based phase,the rise of nonfullerene solar cells presents a new challenge in delineating local molecular directions at the interface between two anisotropic donor/acceptor ***,we determine interfacial molecular orientations of three high-efficiency small molecule solar cells(ZR1:Y6,B1:BO-4 Cl,and BTR:BO-4 Cl)using polarization-selective transient absorption *** polarization anisotropy of charge separation dynamics indicates an angle of~90°between ZR1 and Y6 molecules at the interface,an angle close to 0°between B1 and BO-4 Cl,and random orientations between BTR and BO-4 *** observations provide complementary information to X-ray scattering measurements and highlight polarization-selective transient absorption spectroscopy as a tool to probe interfacial structure and dynamics of key photophysical steps in energy conversion.

关键词： polarization-selective transient absorption spectroscopy bulk heterojunction organic solar cell molecular orientation

Metal-organic frameworks bonded with metal N-heterocyclic carbenes for efficient catalysis

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National Science Review 2022年第6期9卷 64-73页

作者： chang he Jun Liang Yu-Huang Zou Jun-Dong Yi Yuan-Biao Huang Rong Cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences University of Chinese Academy of Sciences Science and Technology Innovation Laboratory for Optoelectronic Information of China

Metal N-heterocyclic carbenes(M-NHCs) on the pore walls of a porous metal-organic framework(MOF)can be used as active sites for efficient organic catalysis. Traditional approaches that need strong alkaline reagents or insoluble Ag2O are not, however, suitable for the incorporation of NHCs on the backbones of MOFs because such reagents could destroy their frameworks or result in low reactivity. Accordingly,development of facile strategies toward functional MOFs with covalently bound M-NHCs for catalysis is needed. herein, we describe the development of a general and facile approach to preparing MOFs with covalently linked active M-NHC(M = Pd, Ir) single-site catalysts by using a soluble Ag salt AgOC(CF3)3as the source and subsequent transmetalation. The well-defined M-NHC-MOF(M = Pd, Ir) catalysts obtained in this way have shown excellent catalytic activity and stability in Suzuki reactions and hydrogen transfer reactions. This provides a general and facile strategy for anchoring functional M-NHC single-site catalysts onto functionalized MOFs for different reactions.

关键词： metal-organic framework N-heterocyclic carbene MIL-101 Suzuki reaction transfer

Modulation of terminal alkyl chain length enables over 15% efficiency in small-molecule organic solar cells

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Science China Chemistry 2021年第7期64卷 1200-1207页

作者： Qianglong Lv Cunbin An Tao Zhang Jianqi Zhang Shaoqing Zhang Pengxin Zhou chang he Jianhui Hou Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing 100190China College of Chemistry and Chemical Engineering Northwest Normal UniversityLanzhou 730070China Key Laboratory of Nanosystem and Hierarchical Fabrication National Center for Nanoscience and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

In small-molecule organic solar cells(SM-OSCs),it remains a big challenge to obtain favorable bulk heterojunction morphology by donor material ***,we design and synthesize three small-molecule donors BPF3T-C4,BPF3T-C6 and BPF3T-C8,with different terminal alkyl *** they possess similar absorption profiles and molecular energy levels,their crystallinity gradually decreases with the chain length of the terminal alkyl *** blending with an electron acceptor of BO-4Cl,the crystallinity is suppressed and the packing orientations of these donors changed from edge-on to ***,the crystallinity of BO-4Cl is gradually weakened with the chain length of the terminal alkyl chain of donor ***,The BPF3T-C6 with moderate crystallinity exhibits the best phase-separation morphology among these blend *** a result,the BPF3T-C6:BO-4Cl-based SM-OSC shows an impressive power conversion efficiency of 15.1%.

关键词： small-molecule donor non-fullerene acceptor intermolecular interaction terminal alkyl chain small-molecule organic solar cells

Comparison of using polyurethane foam passive samplers and tree bark samples from Western China to determine atmospheric organochlorine pesticide

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Journal of Environmental Sciences 2016年第3期28卷 90-98页

作者： Qiuxu Li Yao Lu Jun Jin Guangyao Li Peng Li chang he Ying Wang College of Life and Environmental Sciences Minzu University of ChinaBeijing 100081China Engineering Research Center for Food Environment and health Beijing 100081China

Polyurethane foam（PUF）passive samplers were deployed and tree bark samples were collected at 15 sites across western China in 2013,and the organochlorine pesticide（OCP）concentrations in the samples were *** and its degradation products（collectively called DDTs）,hexachlorocyclohexanes（HCHs）,and hexachlorobenzene（HCB）were the dominant OCPs in the PUF samples and tree bark *** mean DDTs,HCHs and HCB concentrations were 33,22 and 18 ng/sample in the PUF samples,and 428,74,and 43 ng/（g lipid weight（lw））in the tree bark,*** OCP concentrations in the air,calculated using PUF–air and tree-bark–air partitioning models,were of the same order of *** sample types showed that relatively fresh inputs of DDT and HCHs to the environment have occurred in western ***,PUF passive samplers were compared with the use of tree bark samples as passive *** OCP compositions in the PUF and tree bark samples were *** the relatively stable OCPs（such as HCB,β-HCH and p,p′-dichlorodiphenyldichloro-ethylene（DDE））were consistent in the PUF and tree bark samples.

关键词： Organochlorine pesticides Polyurethane foam Tree bark Passive sampler Western China