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Monte Carlo simulation of neutron sensitivity of microfission chamber in neutron flux measurement

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Nuclear Science and Techniques 2022年第6期33卷 128-138页

作者： Ze-Peng Wu Xin-Biao Jiang Wen-Shou Zhang Chun-Lei Su Yong-Gang Zhang-Sun li-hong bao State Key Laboratory of Simulation and Effect for Intense Pulse Radiation Northwest Institute of Nuclear TechnologyXi’an 710024China

Microfission chambers loaded with highly enriched fissile materials are widely used for measuring power in reactors. The neutron sensitivity of the microfission chamber is a key parameter that determines the accuracy of the power measurement. To evaluate the performance of the FC4A microfission chamber, in this work, we introduced an accurate and validated model of the microfission chamber, a performed Monte Carlo simulation of the neutron sensitivity of the microfission chamber with GEANT4 code, and conducted an irradiation experiment on the neutron irradiation effect platform #3 of the Xi’an Pulsed Reactor. We compared the simulated sensitivity with the experimental results, which showed that the sensitivity obtained from the simulation was in good agreement with the experimental results. In addition, we studied the impact of the design parameters of the fission chamber on the calculated neutron sensitivity of the microfission chamber.

关键词： Microfission chamber Neutron sensitivity Monte Carlo simulation GEANT4

The first catalytic asymmetric addition of diethylzinc to aldehyde promoted by chiral thiourea

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Chinese Chemical Letters 2011年第11期22卷 1265-1268页

作者： Zhi Guo Qiao Tian Hua Shen Zhen Fang Fu Jun Qi li hong Wang Qing bao Song The State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology College of Chemical Engineering and Materials Science Zhejiang University of Technology Hangzhou 310032 China

A series of C_2-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial *** of the new compounds have been fully characterized by IR,~1H NMR,^（13）C NMR,MS spectra and elemental *** chiral thioureas were used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc,the corresponding sec-alcohols were gained with excellent enantioselectivities（up to 87.1%ee） and high yields（up to 76.7%） after the conditions were optimized.

关键词： Chiral thiourea Diethylzinc Amino alcohol C_2-symmetric Enantioselective addition

Low-temperature growth of large-scale,single-crystalline graphene on Ir(111)

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Chinese Physics B 2019年第5期28卷 11-15页

作者： Hui Guo Hui Chen Yande Que Qi Zheng Yu-Yang Zhang li-hong bao li Huang Ye-liang Wang Shi-Xuan Du hong-Jun Gao Institute of Physics and University of Chinese Academy of Sciences CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

Iridium is a promising substrate for self-limiting growth of graphene. However, single-crystalline graphene can only be fabricated over 1120 K. The weak interaction between graphene and Ir makes it challenging to grow graphene with a single orientation at a relatively low temperature. Here, we report the growth of large-scale, single-crystalline graphene on Ir(111) substrate at a temperature as low as 800 K using an oxygen-etching assisted epitaxial growth method. We firstly grow polycrystalline graphene on Ir. The subsequent exposure of oxygen leads to etching of the misaligned *** growth cycle, in which the leftover aligned domain serves as a nucleation center, results in a large-scale and single-crystalline graphene layer on Ir(111). Low-energy electron diffraction, scanning tunneling microscopy, and Raman spectroscopy experiments confirm the successful growth of large-scale and single-crystalline graphene. In addition, the fabricated single-crystalline graphene is transferred onto a SiO_2/Si substrate. Transport measurements on the transferred graphene show a carrier mobility of about 3300 cm^2·V^(-1)·s^(-1). This work provides a way for the synthesis of large-scale,high-quality graphene on weak-coupled metal substrates.

关键词： graphene low-temperature growth single-crystalline Ir(111)

Monolayer MoS_(2)of high mobility grown on SiO_(2)substrate by two-step chemical vapor deposition

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Chinese Physics B 2022年第8期31卷 183-189页

作者： Jia-Jun Ma Kang Wu Zhen-Yu Wang Rui-Song Ma li-hong bao Qing Dai Jin-Dong Ren hong-Jun Gao Institute of Physics Chinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesChinese Academy of SciencesBeijing 100190China CAS Key Laboratory of Nanophotonic Materials and Devices CAS Key Laboratory of Standardization and Measurement for Nano-technologyNational Center for Nanoscience and TechnologyBeijing 100190China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100190China

We report a novel two-step ambient pressure chemical vapor deposition(CVD)pathway to grow high-quality Mo S_(2)monolayer on the Si O_(2)substrate with large crystal size up to 110μ*** large specific surface area of the pre-synthesized Mo O_(3)flakes on the mica substrate compared to Mo O_(3)powder could dramatically reduce the consumption of the Mo *** electronic information inferred from the four-probe scanning tunneling microscope(4P-STM)image explains the threshold voltage variations and the n-type behavior observed in the two-terminal transport ***,the direct van der Pauw transport also confirms its relatively high carrier *** study provides a reliable method to synthesize high-quality Mo S_(2)monolayer,which is confirmed by the direct 4P-STM measurement *** methodology is a key step toward the large-scale growth of transition metal dichalcogenides(TMDs)on the Si O_(2)substrate and is essential to further development of the TMDs-related integrated devices.

关键词： chemical vapor deposition(CVD) scanning tunneling microscope(STM) MoS_(2) transport

Local probe of the interlayer coupling strength of few-layers SnSe by contact-resonance atomic force microscopy

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Frontiers of physics 2020年第6期15卷 105-113页

作者： Zhi-Yue Zheng Yu-Hao Pan Teng-Fei Pei Rui Xu Kun-Qi Xu Le Lei Sabir Hussain Xiao-Jun liu li-hong bao hong-Jun Gao Wei Ji Zhi-Hai Cheng State Key Laboratory of Digital Manufacturing Equipment and Technology School of Mechanical Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China Beijing Key Laboratory of Optoelectronic Functional Materials&Micro-nano Devices Department of PhysicsRenmin University of ChinaBeijing 100872China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Inorganic Functional Materials and Devices Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China CAS Key Laboratory of Standardization and Measurement for Nanotechnology CAS Center for Excellence in NanoscienceNational Center for Nano science and TechnologyBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China China North Vehicle Research Institute BeijingChina

The interlayer bonding in two-dimensional(2D)materials is particularly important because it is not only related to their physical and chemical stability but also afects their mechanical,thermal,elec-tronic,optical,and other *** address this issue,we report the direct characterization of the interlayer bonding in 2D SnSe using contact-resonance atomic force microscopy(CR-AFM)*** ***-specific CR spectroscopy and CR force spectroscopy measurements are performed on both SnSe and its supporting SiO2/Si substrate *** on the cantilever and contact mechanic models,the contact stifness and vertical Young's modulus are evaluated in comparison with SiO2/Si as a reference *** interlayer bonding of SnSe is further analyzed in combination with the semi-analytical model and density functional theory *** direct characteriza-tion of interlayer interactions using this non-destructive methodology of CR-AFM would facilitate a better understanding of the physical and chemical properties of 2D layered materials,specifically for interlayer intercalation and vertical heterostructures.

关键词： 2D materials interlayer bonding contact-resonance atomic force microscopy density functional theory

Intrinsic charge transport behaviors in graphene-black phosphorus van der Waals heterojunction devices

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Chinese Physics B 2018年第7期27卷 480-485页

作者： Guo-Cai Wang liang-Mei Wu Jia-Hao Yan Zhang Zhou Rui-Song Ma Hai-Fang Yang Jun-Jie li Chang-Zhi Gu li-hong bao Shi-Xuan Du hong-Jun Gao Institute of Physics Chinese Academy of Sciences Beijing 100190 China University of Chinese Academy of Sciences Beijing 100190 China

Heterostructures from mechanically-assembled stacks of two-dimensional materials allow for versatile electronic device applications. Here, we demonstrate the intrinsic charge transport behaviors in graphene-black phosphorus heterojunction devices under different charge carrier densities and temperature regimes. At high carder densities or in the ON state, tunneling through the Schottky barrier at the interface between graphene and black phosphorus dominates at low temperatures. With temperature increasing, the Schottky barrier at the interface is vanishing, and the channel current starts to decrease with increasing temperature, behaving like a metal. While at low carder densities or in the OFF state, thermal emission over the Schottky barrier at the interface dominates the carriers transport process. A barrier height of ～ 67.3 meV can be extracted from the thermal emission-diffusion theory.

关键词： black phosphorus heterojunction contact barrier height

Quantum public-key crypto via EPR pairs

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 58-63页

作者： Xiang-Qun Fu hong-Wei li Jian-hong Shi Tan li Wan-Su bao Henan Key Laboratory of Quantum Information and Cryptography Information Engineering University Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China

With the development of quantum computing technology, quantum public-key cryptography is gradually becoming an alternative to the existing classical public-key cryptography. This paper designs a quantum trapdoor one-way function via EPR pairs and quantum measurements. Based on this, a new quantum public-key cryptosystem is presented, which offers forward security,and can resist the chosen-plaintext attack and chosen-ciphertext attack. Compared with the existing quantum public-key cryptos,eavesdropping can be automatically detected in this new quantum public-key cryptosystem under a necessary condition, which is also detailed in the paper.

关键词： quantum public-key crypto trapdoor one-way function EPR pairs

InSe-Te van der Waals heterostructures for current rectification and photodetection

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Chinese Physics B 2023年第8期32卷 415-420页

作者：王昊冼国裕刘丽刘轩冶郭辉鲍丽宏杨海涛高鸿钧 Institute of Physics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

As the basis of modern electronics and optoelectronics,high-performance,multi-functional p-n junctions have manifested and occupied an important ***,the performance of the silicon-based p-n junctions declines gradually as the thickness approaches to few *** heterojunction constructed by two-dimensional(2D)materials can significantly improve the device performance compared with traditional ***,we report the In Se-Te type-II van der Waals heterostructures with rectification ratio up to 1.56×10^(7) at drain-source voltage of±2 *** p-n junction exhibits a photovoltaic and photoelectric effect under different laser wavelengths and densities and has high photoresponsivity and detectivity under low irradiated light ***,the heterojunction has stable photo/dark current states and good photoelectric switching *** high-performance heterostructured device based on 2D materials provides a new way for futural electronic and optoelectronic devices.

关键词： indium selenium tellurium van der Waals heterostructure transport photodetection

Surgical treatment for hepatocellular carcinoma and secondary hypersplenism

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Hepatobiliary & Pancreatic Diseases International 2006年第3期5卷 396-400页

作者： Qian Wang, Kai Sun, Xiang-hong li, bao-Gang Peng and li-Jian liang Department of Hepatobiliary Surgery, First Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510080, China Department of Hepatobiliary Surgery First Affiliated Hospital Sun Yat-Sen University Guangzhou 510080 China. wangqian00@***

BACKGROUND: Hepatocellular carcinoma (HCC) is a common disease with high mortality and serious effect on the life quality of patients. Operation is still the most effective treatment. Currently, in China, patients with HCC are often complicated by hepatitis B related liver cirrhosis and secondary hypersplenism. This study was undertaken to evaluate the effect and indications of synchronous hepatectomy and splenectomy for HCC patients with hypersplenism. METHODS: The clinical records and treating processes of 24 patients with HCC and hypersplenism during the period of January 1991 to July 2004 were analyzed retrospectively. RESULTS: Sixteen patients underwent hepatectomy and splenectomy, including extensive devascularizasion around the cardia (9 patients). Seven patients were treated with microwave ablation and splenectomy plus extensive esophagogastric devascularization. One patient underwent hepatectomy combined with microwave ablation and splenectomy plus extensive esophagogastric devascularization. There were no deaths during the operation. During the first week after operation, the symptoms of hypersplenism disappeared and the platelet (Plt) and white blood cell (WBC) counts were significantly elevated (Plt: 247×109/L vs. 45.9×109/L, WBC: 13.0×109/L vs.3.3×109/L,Plications. Splenectomy enhances patients' immunity against tumor in a long period as well.

关键词： hepatocellular carcinoma hypersplenism hepatectomy splenectomy