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Synthesis of vinylferrocene and the ligand-exchange reaction between its copolymer and carbon nanotubes

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Frontiers of Chemical Science and Engineering 2014年第2期8卷 171-178页

作者： ran shi Hai WANG Ping TANG Yuezhen BIN Department of Polymer Materials and Engineering Dalian University of Technology Dalian 116024 China Department of Future Industry-Oriented Basic Science and Materials Toyota Technological Institute Tempaku Nagoya 468-8511 Japan

To improve the dispersibility of carbon nanotubes （CNTs）, poly（vinylferrocene-co-styrene）（poly （Vf-co-St））, was grafted onto the surface of CNTs by a ligand-exchange reaction. Poly（Vf-co-St） was obtained by a radical copolymerization reaction using styrene and vinylferrocene as the monomers. The vinylferrocene was synthesized from ferrocene via a Friedel-Crafts acylation. The molecular weight, molecular weight distribution, and amount of Vf in the poly（Vf-co-St） were 1.32 × 104, 1.69 and 17.6% respectively. The degree of grafting of the copolymer onto the CNTs surface was calculated from thermogravimetric analysis and varied from 27.1% to 79.7%. The addition of the poly（Vf-co-St） greatly promoted the dispersibility of the modified CNTs in anhydrous alcohol. The electrical conductivity of compo- sites prepared from the polymer-grafted CNTs and copolymer （acrylonitrile, 1,3-butadiene and styrene, ABS） strongly depended on the degree of grafting. These results show that the amount of polymer grafted onto the surface of CNTs can be controlled and that the electrical properties of composites prepared with these grafted polymers can be tuned.

关键词： vinylferrocene poly (Vf-co-St) CNTs dis-persibility

Improved spatio-SNR FGS video coding scheme using motion compensation on enhancement-layer

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Journal of Systems Engineering and Electronics 2006年第1期17卷 37-42页

作者： Jiang Tao Zhang Zhaoyang Ma ran shi Xuli Dept. of Electronic & Information Engineering School of Communication Shanghai Univ. Shanghai 200072 P. R. China

MPEG-4 fine-granularity-scalable （FGS） technology is an effective solution to resolve the network bandwidth varying because FGS provides very fine granular SNR scalability. However, this scalability is obtained with sacrifice of coding efficiency. An one-loop FGS structure is presented based on motion compensation （MC ＋ FGS） to improve the coding efficiency of base FGS. Then it describes and discusses the hybrid spatial-SNR FGS （FGSS） structure that extends SNR scalability of FGS to spatial scalability （spatio-SNR scalability）. FGSS structure inherent the low coding efficiency of FGS structure. Combining MC ＋ FGS structure with FGSS structure, a structure of MC ＋ FGSS structure is obtained which acquires both structures＇ advantages and counteracts both structures＇ defects. Experimental results prove the MC＋ FGSS structure not only obtains fine granular spatio-SNR scalability, but also achieves high coding efficiency.

关键词： fine-granularity-scalable coding efficiency motion compensation spatial scalability MPEG-4.

A New Route to the Interpretation of Hopf Invariant

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Communications in Theoretical Physics 2008年第7期50卷 53-58页

作者： REN Ji-Rong LI ran DUAN Yi-shi Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

We discuss an object from algebraic topology,Hopf invariant,and reinterpret it in terms of the φ-mappingtopological current *** main purpose of this paper is to present a new theoretical framework,which can directlygive the relationship between Hopf invariant and the linking numbers of the higher dimensional submanifolds of Euclideanspace R^(2n-1).For the sake of this purpose we introduce a topological tensor current,which can naturally deduce the(n-1)-dimensional topological defect in R^(2n-1) *** these (n-1)-dimensional topological defects are closed orientedsubmanifolds of R^(2n-1),they are just the (n-1)-dimensional *** linking number of these knots is well *** the inner structure of the topological tensor current,the relationship between Hopf invariant and the linkingnumbers of the higher-dimensional knots can be constructed.

关键词： Hopf invariant higher-dimensional knot linking number

Polarons in alkaline-earth-like atoms with multiple background Fermi surfaces

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Frontiers of physics 2018年第4期13卷 185-193页

作者： Jin-Ge Chen Yue-ran shi Xiang Zhang Wei Zhang Department of Physics Renmin University of China Beijing 100872 China Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of China Beijing 100872 China

We study the impurity problem in a Fermi gas of 173Yb atoms near an orbital Feshbach resonance （OFR）, where a single moving particle in the 3p0 state interacts with two background Fermi seas of particles in different nuclear states of the ground 1S0 manifold. By employing wave function ansatz to molecule and polaron states, we investigate various properties of the molecule, the attractive polaron, and the repulsive polaron states. In comparison to the case where only one Fermi sea is populated, we find that the presence of an additional Fermi sea acts as an energy shift between the two channels of the OFR. In addition, quantum fluctuations near the Fermi level can also induce sizable effects to various properties of the attractive and repulsive polarons.

关键词： Fermi gas alkaline-earth atoms orbital Feshbach resonance polaron

Healthcare for Patients with Hepatitis B Virus:Analysis of 367381 Inpatient Cases in China

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Current Medical Science 2022年第3期42卷 658-665页

作者： Da ZHOU shi-ran SUN Yang SUN Rui MIN Center for Health Information and Statistics of Hubei Wuhan 430079China Department of Hepatobiliary Surgery Union HospitalTongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430022China School of Politics and Management Wuhan UniversityWuhan 430072China School of Public Health Tongji Medical CollegeHuazhong University of Science and TechnologyWuhan 430030China

Objective Hepatitis B virus(HBV)infection,which has been recognized as an international public health challenge,has caused significant morbidity for the entire *** research focused on patients with HBV in China to examine health utilization and *** Patients hospitalized with HBV from 2017 to 2019 in tertiary hospitals in Hubei,a province located in central China,were selected as the study *** information was collected from the provincial inpatient electronic system *** and regression analyses were performed to describe the basic situation of healthcare services and determine the influencing indicators of inpatient service *** A total of 367381 cases of HBV infection were identified in the study *** of these cases were patients who were married(90.2%)and males(63%).With the great efforts by the universal coverage of the basic medical insurance(BMI)in China,the increasing rate of inpatient hospitalization for HBV was 3.5 times higher than that of the total inpatient health service cases in the study *** average age of this group was 52.84±14.10 years and 11.1%of patients paid for their own medical expenditures without *** average length of stay(LOS)was 11.10 days,and the average cost per patient was 15712.05 *** values were higher than the average level in study ***,marital status,career,payment type,and kind of hospitals significantly influenced healthcare *** and the elderly might incur higher healthcare costs than their *** The BMI operated by government has played a role in the utilization release of health services for HBV ***,researchers must pay more attention to the continuing increase in the medical expenses of this group.

关键词： healthcare utilization expenditure hepatitis B virus infection inpatients hospitalization

Takotsubo cardiomyopathy associated with bronchoscopic operation:A case report

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World Journal of Clinical Cases 2020年第24期8卷 6517-6523页

作者： Bi-Feng Wu Jia-ran shi Liang-Rong Zheng Department of Cardiology The First Affiliated HospitalCollege of MedicineZhejiang UniversityHangzhou 310000Zhejiang ProvinceChina

BACKGROUND Takotsubo cardiomyopathy(TTC),a syndrome of acute left ventricular(LV)dysfunction,is characterized by transitory hypokinesis of LV apices with compensatory hyperkinesis of the LV basal *** symptoms of TTC mimic acute myocardial infarction,without significant coronary stenoses on coronary *** plays a key role in the diagnosis and prognosis of *** indicators from echocardiograms may be helpful in disease *** SUMMARY A 67-year-old man with a 10-year history of non-small cell lung cancer was admitted to our hospital for emerging facial edema and dry *** lavage,brushing,and biopsy were performed to evaluate tumor *** this procedure,he complained of left chest pain,nausea,and vomiting,with elevated troponin *** showed sinus bradycardia with ST-segment elevation in I,AVL,and V4 to V6 *** angiography revealed mild stenosis in the right coronary *** showed hypokinesis of LV apices with compensatory hyperkinesis of the LV basal *** the 7-d follow-up,echocardiographic pressure-strain analysis showed a normal LV ejection fraction,but partial recovery of LV myocardial work,which fully recovered 5 mo *** This is a case of TTC caused by bronchoscopic *** strongly recommend noninvasive myocardial work measured by echocardiographic pressure-strain analysis as a necessary supplementary test for the long-term follow-up of TTC.

关键词： Takotsubo cardiomyopathy Bronchoscope Left ventricular myocardial work Case report Non-small cell lung cancer

Developments and challenges in neoadjuvant therapy for locally advanced pancreatic cancer

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World Journal of Gastroenterology 2023年第35期29卷 5094-5103页

作者： Bo Zhou shi-ran Zhang Geng Chen Ping Chen Department of Hepatobiliary Surgery Daping HospitalArmy Medical UniversityChongqing 400042China

Pancreatic ductal adenocarcinoma(PDAC)remains a significant public health challenge and is currently the fourth leading cause of cancer-related mortality in developed *** advances in cancer treatment,the 5-year survival rate for patients with PDAC remains less than 5%.In recent years,neoadjuvant therapy(NAT)has emerged as a promising treatment option for many cancer types,including locally advanced PDAC,with the potential to improve patient *** analyze the role of NAT in the setting of locally advanced PDAC over the past decade,a systematic literature search was conducted using PubMed and Web of *** results suggest that NAT may reduce the local mass size,promote tumor downstaging,and increase the likelihood of *** findings are supported by the latest evidence-based medical literature and the clinical experience of our *** the potential benefits of NAT,there are still challenges that need to be *** such challenge is the lack of consensus on the optimal timing and duration of *** criteria for patient selection are needed to further identify PDAC patients likely to respond to *** conclusion,NAT has emerged as a promising treatment option for locally advanced ***,further research is needed to optimize its use and to better understand the role of NAT in the management of this challenging *** continued advances in cancer treatment,there is hope of improving the outcomes of patients with PDAC in the future.

关键词： Neoadjuvant therapy Pancreatic ductal adenocarcinoma Locally advanced pancreatic cancer Chemoradiotherapy Immunotherapy Vaccine therapy

Efficient passivation of DY center in CH_(3)NH_(3)PbBr_(3) by chlorine:Quantum molecular dynamics

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Nano Research 2022年第3期15卷 2112-2122页

作者： ran shi Wei-Hai Fang Andrey S.Vasenko Run Long Oleg V.Prezhdo College of Chemistry Key Laboratory of Theoretical&Computational Photochemistry of Ministry of EducationBeijing Normal UniversityBeijing 100875China National Research University Higher School of Economics(HSE)University 101000 MoscowRussia Donostia International Physics Center(DIPC) Paseo Manuel de Lardizabal 4San Sebastián/Donostia20018 Basque CountrySpain Department of Chemistry University of Southern CaliforniaLos AngelesCA 90089USA

MAPbBr_(3)(MA=CH_(3)NH_(3)^(+))doping with bismuth increases electric conductivity,charge carrier density and photostability,reduces toxicity,and expands light ***,Bi doping shortens excited-state lifetimes due to formation of DY−charge recombination *** nonadiabatic molecular dynamics and time-domain density functional theory,we demonstrate that the DY−center forms a deep,highly localized hole trap,which accelerates nonradiative relaxation ten-fold and is responsible for 90%of carrier *** trapping occurs by coupling between the valence band and the trap state,facilitated by the Br atoms surrounding the Bi *** of the DY−center with chlorines heals the local geometry distortion,eliminates the trap state,and makes the carrier lifetimes longer than even in pristine MAPbBr_(3).The decreased charge recombination arises from reduced nonadiabatic coupling and shortened coherence time,due to diminished electron–hole overlap around the passivated *** study demonstrates accelerated nonradiative recombination in Bi-doped MAPbBr_(3),suggests a strategy for defect passivation and reduction of nonradiative energy losses,and provides atomistic insights into unusual defect properties of metal halide perovskites needed for rational design of high-performance perovskite solar cells and optoelectronic devices.

关键词： Hybrid organic-inorganic perovskite DY−center and Cl passivation charge trapping and recombination nonadiabatic molecular dynamics time-domain density functional theory.

Non-universal Fermi polaron in quasi two-dimensional quantum gases

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Chinese Physics B 2022年第8期31卷 246-251页

作者： Yue-ran shi Jin-Ge Chen Kui-Yi Gao Wei Zhang Department of Physics Renmin University of ChinaBeijing 100872China Beijing Academy of Quantum Information Sciences Beijing 100193China Beijing Key Laboratory of Opto-electronic Functional Materials and Micro-nano Devices Renmin University of ChinaBeijing 100872China

We consider an impurity problem in a quasi-two-dimensional Fermi gas, where a spin-down impurity is immersed in a Fermi sea of N spin-up atoms. Using a variational approach and an effective two-channel model, we obtain the energy for a wide range of interaction strength and for various different mass ratios between the impurity and the background fermion in the context of heteronuclear mixture. We demonstrate that in a quasi-two-dimensional Fermi gas there exists a transition of the ground state from polaron in the weakly interacting region to molecule in the strongly interacting *** critical interaction strength of the polaron–molecule transition is non-universal and depends on the particle density of the background Fermi sea. We also investigate the excited repulsive polaron state, and find similar non-universal behavior.

关键词： Fermi gas polaron problem two-channel model