分类： 工程与技术科学 >> 物理学相关工程与技术 分类： 工程与技术科学 >> 仪器仪表技术 分类： 电子与通信技术 >> 电子技术 分类： 物理学 >> 交叉学科物理及相关领域的科学与技术 提交时间： 2023-12-03
摘要：本文提出了一种用于低温扫描隧道显微镜(CryoSTM)的跨阻放大器(TIA)设计方案。在CryoSTM中带有尖端样品成分的TIA称为CryoSTM-TIA。该CryoSTM-TIA的跨阻增益在1Gohm，而其带宽大于300kHz。所提出的CryoSTM-TIA的独特特点是其前置放大器由单个低温高电子迁移率晶体管(HEMT)制成，因此在100kHz时仪器等效输入噪声电流功率谱密度低于4(fA)2/Hz。此外，应用“偏置冷却法”可用于原位控制HEMT掺杂区冻结DX-中心的密度，改变其结构以降低器件噪声。利用该仪器，可以进行高能量分辨率的快速扫描隧道光谱测量。并且，它能够测量各种量子系统在原子尺度上的扫描隧道散粒噪声谱(STSNS)，即使散粒噪声非常低。它为通过测量STSNS来研究新的量子态提供了一个强大的工具，例如检测拓扑量子系统中马约拉纳束缚态的存在。
分类： 物理学 >> 核物理学 提交时间： 2023-11-29 合作期刊: 《Nuclear Science and Techniques》
摘要：The phenomenology involved in severe accidents (SA) in nuclear reactors is highly complex. Currently, integrated analysis programs used for severe accident analysis heavily rely on custom empirical parameters, which introduce considerable uncertainty. Therefore, in recent years, the field of severe accidents has shifted its focus toward applying uncertainty analysis methods to quantify uncertainty in safety assessment programs, known as "best estimate plus uncertainty (BEPU)." This approach aids in enhancing our comprehension of these programs and their further development and improvement. This study concentrates on a third-generation pressurized water reactor (Gen-III PWR) equipped with advanced active and passive mitigation strategies. Through an Integrated Severe Accident Analysis Program (ISAA), numerical modeling and uncertainty analysis were conducted on severe accidents resulting from large break loss of coolant accidents (LBLOCA). Seventeen uncertainty parameters of the ISAA program were meticulously screened. Using Wilks' formula, the developed uncertainty program code, SAUP, was employed to carry out Latin hypercube sampling (LHS), while ISAA was employed to execute batch calculations. Statistical analysis was then conducted on two figures of merit (FOMs), namely, hydrogen generation and the release of fission products (FP) within the pressure vessel. Uncertainty calculations revealed that hydrogen production and the fraction of fission product released exhibited a normal distribution, ranging from 182.784 kg to 329.581 kg and from 15.6% to 84.3%, respectively. The ratio of hydrogen production to reactor thermal power fell within the range of 0.0578 to 0.104. A sensitivity analysis was performed for uncertain input parameters, revealing significant correlations between the failure temperature of the cladding oxide layer, maximum melt flow rate, size of the particulate debris, and porosity of the debris with both hydrogen generation and the release of fission products.
分类： 物理学 >> 核物理学 提交时间： 2023-11-25
Yijie Wang
Fenhai Guan
Qianghua Wu
Xinyue Diao
Yan Huang
Liming Lyu
Yuhao Qin
Zhi Qin
Dawei Si
Zhen Bai
Fangfang Duan
Limin Duan
Zhihao Gao
Qiang Hu
Rongjiang Hu
Genming Jin
Shuya Jin
Junbing Ma
Peng Ma
Jiansong Wang
摘要：The intensity interferometry is applied as a chronometer of the particle emission of hydrogen isotopes from the intermediate velocity source formed in $^{40}$Ar+$^{197}$Au reactions at 30 MeV/u. The dynamic emission order of $ tau_{ rm p}> tau_{ rm d}> tau_{ rm t}$ is evidenced via the correlation functions of nonidentical particle pairs. Assuming the similar source size, the same emission order is inferred from the correlation functions of identical particle pairs, where $ tau_{ rm p} approx 100 { rm ~fm/c}$ is extracted by the fit of Koonin-Pratt equation to p-p correlation function. Transport model simulations demonstrate that the dynamic emission order of light charged particles depends on the stiffness of the nuclear symmetry energy.
分类： 物理学 >> 核物理学 提交时间： 2023-11-25
Fen-Hai Guan
Xin-Yue Diao
Qiang-Hua Wu
Xiang-Lun Wei
He-Run Yang
Peng Ma
Zhi Qin
Yu-Hao Qin
Dong Guo
Rong-Jiang Hu
Li-Min Duan
Zhi-Gang Xiao
Yi-Jie Wang
摘要：The Compact Spectrometer for Heavy Ion Experiment (CSHINE) is under construction for the study of isospin chronology via the Hanbury Brown$-$Twiss (HBT) particle correlation function and the nuclear equation of state of asymmetrical nuclear matter. The CSHINE consists of silicon strip detector (SSD) telescopes and large-area parallel plate avalanche counters, which measure the light charged particles and fission fragments, respectively. In phase I, two SSD telescopes were used to observe 30 MeV/u $^{40}$Ar +$^{197}$Au reactions. The results presented here demonstrate that hydrogen and helium were observed with high isotopic resolution, and the HBT correlation functions of light charged particles could be constructed from the obtained data.
分类： 物理学 >> 核物理学 提交时间： 2023-11-25 合作期刊: 《原子核物理评论》
摘要：本工作基于国产𝜙2″ ×2″ LaBr3(Ce) 晶体耦合滨松R13089 型快时间响应光电倍增管定制了LaBr3(Ce) 探测器。研究结果表明，定制LaBr3(Ce) 快时间探测器对662 keV 𝛾 射线的能量分辨率和全能峰探测效率分别为3.6% 和0.09%，对60Co 中1173-1332 keV 级联𝛾 射线的时间分辨率为270 (22) ps。该探测器的本征辐射计数率为4824 (69) Counts/h/cm3。本文同时展示了圣戈班B380 和B390 探测器的测试结果作为参考。
分类： 物理学 >> 核物理学 提交时间： 2023-11-23
摘要：The supercritical CO2 Brayton cycle is considered a promising energy conversion system for Generation IV reactors for its simple layout, compact structure, and high cycle efficiency. Mathematical models of four Brayton cycle layouts are developed in this study for different reactors to reduce the cost and increase the thermohydraulic performance of nuclear power generation to promote the commercialization of nuclear energy. Parametric analysis, multi-objective optimizations, and four decision-making methods are applied to obtain each Brayton scheme’s optimal thermohydraulic and economic indexes. Results show that for the same design thermal power scale of reactors, the higher the core’s exit temperature, the better the Brayton cycle’s thermo-economic performance. Among the four-cycle layouts, the recompression cycle (RC) has the best overall performance, followed by the simple recuperation cycle (SR) and the intercooling cycle (IC), and the worst is the re-heating cycle (RH). However, RH has the lowest total cost of investment (Ctot) of $1619.85 million, and IC has the lowest levelized cost of energy (LCOE) of 0.012$/(kWh). The nuclear Brayton cycle system’s overall performance has been improved due to optimization. The performance of the Molten Salt Reactor combined with the intercooling cycle (MSR-IC) scheme has the greatest improvement, with the net output power (Wnet), thermal efficiency ηt, and exergy efficiency (ηe) improved by 8.58%, 8.58%, and 11.21% respectively. The performance of the Lead-cooled Fast Reactor combined with the simple recuperation cycle scheme was optimized to increase Ctot by 27.78%. In comparison, the internal rate of return (IRR) increased by only 7.8%, which is not friendly to investors with limited funds. For the nuclear Brayton cycle, the Molten Salt Reactor combined with the recompression cycle scheme should receive priority, and the Gas-cooled Fast Reactor combined with the re-heating cycle scheme should be considered carefully.
分类： 物理学 >> 核物理学 提交时间： 2023-11-22 合作期刊: 《Nuclear Science and Techniques》
摘要：
分类： 物理学 >> 核物理学 提交时间： 2023-11-22 合作期刊: 《Nuclear Science and Techniques》
Qin Xu
Hua-Ting Kong
Ke Liu
Huan Zhou
Kun-Hao Zhang
Wei-Wei Wang
Min-Jun Li
Qiang-Yan Pan
Xing-Ya Wang
Yu-Zhu Wang
Feng Yu
Xing-Yu Gao
Qi-Sheng Wang
摘要：BL10U2 is an undulator-based macromolecular crystallography (MX) beamline located at the 3.5-GeV Shanghai Synchrotron Radiation Facility. BL10U2 is specifically designed for conducting routine and bio safety level-2 (BSL-2) MX experiments utilizing high-flux tunable X-rays with energies from 7 to 18 keV, providing a beam spot size of 20 µm (horizontal) × 10 µm (vertical) at the sample point. Certification by the Shanghai Pudong Municipal Health Commission confirmed the capability to perform BSL-2 MX experiments. The beamline is currently equipped with an Eiger X 16M detector and two newly developed in-house high-precision diffractometers that can be switched to perform conventional or in situ crystal diffraction experiments. An automatic sample changer developed in-house allows fast sample exchange in less than 30s, supporting high-throughput MX experimentation and rapid crystal screening. Data collection from both the diffractometer and detector was controlled by an in-house developed data collection software (Finback) with a user-friendly interface for convenient operation. This study presents a comprehensive overview of the facilities, experimental methods, and performance characteristics of the BL10U2 beamline.
分类： 物理学 >> 核物理学 提交时间： 2023-11-21 合作期刊: 《Nuclear Science and Techniques》
Liangliang Wang
Jianing Dong
Mingyi Dong
Qinglin Geng
Min Luo
Yan Niu
Anqing Wang
Chenxu Wang
Meng Wang
Lei Zhang
Liang Zhang
Ruikai Zhang
Yao Zhang
Minggang Zhao
Yang Zhou
Yi Liu
Xiaocong Ai
Guangyan Xiao
Yaxuan Li
Linghui Wu
摘要：The reconstruction of the tracks of charged particles with high precision is crucial for HEP experiments to
achieve their physics goals. The BESIII drift chamber, which is used as the tracking detector of the BESIII
experiment, has suffered from aging effects resulting in degraded tracking performance after operation for ap-
proximately 15 years. To preserve and enhance the tracking performance of BESIII, one of the proposals is to
add one layer of a thin cylindrical CMOS pixel sensor based on state-of-the-art stitching technology between
the beam pipe and the drift chamber. The improvement in the tracking performance of BESIII with such an
additional pixel detector compared to that with only the existing drift chamber was studied using the modern
common tracking software ACTS , which provides a set of detector-agnostic and highly performant tracking
algorithms that have demonstrated promising performance for a few high-energy physics and nuclear physics
experiments.
分类： 物理学 >> 核物理学 提交时间： 2023-11-18 合作期刊: 《Nuclear Science and Techniques》
摘要：The estimation of model parameters is an important subject in engineering. In this area of work, the prevailing approach is to estimate or calculate these as deterministic parameters. In this study, we consider the model parameters from the perspective of random variables and describe the general form of the parameter distribution inference problem. Under this framework, we propose an ensemble Bayesian method by introducing Bayesian inference and the Markov chain Monte Carlo (MCMC) method. Experiments on a finite cylindrical reactor and a 2D IAEA benchmark problem show that the proposed method converges quickly and can estimate parameters effectively, even for several correlated parameters simultaneously. Our experiments include cases of engineering software calls, demonstrating that the method can be applied to engineering, such as nuclear reactor engineering.
分类： 物理学 >> 核物理学 提交时间： 2023-11-16
Hua Ai
Xinmei Yang
Huajian Liu
Bingchuan Chen
Ling Han
Hua Sun
Yanjun Chen
Yuan Qian
Jian-Qiang Wang
摘要：The corrosion behavior of 316H stainless steel (SS) in the impure and purified NaCl-KCl-MgCl2 salt was investigated at 700 °C . Results indicate that the main deleterious impurity induced corrosion in the impure salt was the absorbed moisture, present in the form of MgCl2·6H2O. 316H SS occurred severe intergranular corrosion with a corrosion depth of 130 μm for 1000 h in the impure NaCl-KCl-MgCl2 salt. In contrast, the purification treatment of molten chloride salt by the dissolved Mg metal can remove the absorbed moisture, and the corresponding reactions were also discussed. As a result, the corrosiveness of NaCl-KCl-MgCl2 salt is reduced significantly. 316H SS occurred slight uniform corrosion with a depth of less than 5 μm for 3000 h in the purified NaCl-KCl-MgCl2 salt.
分类： 物理学 >> 电磁学、光学、声学、传热、经典力学和流体动力学 提交时间： 2023-11-16
Ji, Jianfeng
Guo Han
Xue Yanling
Chen Rongchang
Fu Yanan
Du Guohao
Deng Biao
Xie Honglan
Xiao Tiqiao
摘要：A new X-ray imaging and biomedical application beamline (BL13HB) has been implemented at the Shanghai Radiation Synchrotron Facility (SSRF) as an upgrade to the old X-ray imaging and biomedical application beamline (BL13W1). This is part of the Phase II construction project of the SSRF. The BL13HB is dedicated to 2D and 3D static and dynamic X-ray imaging, with a field of view of up to 48.5 × 5.2 mm2 and spatial resolution as high as 0.8 μm. A super-bending magnet is used as the X-ray source in BL13HB, which has a maximum magnetic field of 2.293 T. The energy range of monochromatic X-ray photons from a double-multiplayer monochromator was 8-40 keV, and the white beam mode was provided on the beamline for dynamic X-ray imaging and dynamic X-ray micro-CT. While maintaining the previous experimental setup of BL13W1, new equipment was added to the beamline experimental station. The beamline is equipped with different sets of X-ray imaging detectors for several experimental methods such as micro-CT, dynamic micro-CT, and pair distribution function (PDF). The experimental station of BL13HB is designed specifically for various in situ dynamic experiments, and BL13HB has been open to users since June 2021.
分类： 物理学 >> 核物理学 提交时间： 2023-11-15
Ke Liu
Huan Zhou
Qin Xu
Huating Kong
Kunhao Zhang
Weiwei Wang
Minjun Li
Zhijun Wang
Qiangyan Pan
Xingya Wang
Feng Yu
Qisheng Wang
摘要：Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated, upgraded, and given a new ID (BL02U1). It now delivers X-rays in the energy range of 6–16 keV, with a focused beam of 11.6 µm × 4.8 µm and photon flux greater than 10^12 phs/s. The high credibility and stability of the beam and good timing synchronization of the equipment significantly improve the experimental efficiency. Since June 2021, when it officially opened to users, over 4200 h of beamtime have been provided to over 200 research groups to collect data at the beamline. Its good performance and stable operation have led to the resolution of several structures based on data collected at the beamline.
分类： 物理学 >> 核物理学 提交时间： 2023-11-15
Yijie Wang
Mengting Wan
Xinyue Diao
Sheng Xiao
Yuhao Qin
Zhi Qin
Dong Guo
Dawei Si
Boyuan Zhang
Baiting Tian
Fenhai Guan
Qianghua Wu
Xianglun Wei
Herun Yang
Peng Ma
Rongjiang Hu
Limin Duan
Fangfang Duan
Junbing Ma
Shiwei Xu
摘要：The neutron rich neck zone created in heavy ion reaction is experimentally probed by the production of the $A=3$ isobars. The energy spectra and angular distributions of triton and $^3$He are measured with the CSHINE detector in $^{86}$Kr +$^{208}$Pb reactions at 25 MeV/u. While the energy spectrum of $^{3}$He is harder than that of triton, known as "$^{3}$He-puzzle", the yield ratio $R({ rm t/^3He})$ presents a robust rising trend with the polar angle in laboratory. Using the fission fragments to reconstruct the fission plane, the enhancement of out-plane $R({ rm t/^3He})$ is confirmed in comparison to the in-plane ratios. Transport model simulations reproduce qualitatively the experimental trends, but the quantitative agreement is not achieved. The results demonstrate that a neutron rich neck zone is formed in the reactions. Further studies are called for to understand the clustering and the isospin dynamics related to neck formation.
分类： 物理学 >> 核物理学 提交时间： 2023-11-14
Yijie Wang
Fenhai Guan
Dawei Si
Sheng Xiao
Boyuan Zhang
Yaopeng Zhang
Baiting Tian
Xianglun Wei
Herun Yang
Peng Ma
Rongjiang Hu
Limin Duan
Fangfang Duan
Qiang Hu
Junbing Ma
Shiwei Xu
Zhen Bai
Yanyun Yang
Jiansong Wang
Wenbo Liu
摘要：Two-body correlations of the isotope-resolved light and heavy clusters are measured in 86Kr+ 208Pb reactions at 25 MeV/u. The yield and kinetic variables of the A = 3 isobars, triton and 3He, are analyzed in coincidence with the heavy clusters of 7 ≤ A ≤ 14 emitted at the earlier chance. While the velocity spectra of both triton and 3He exhibit scaling behavior over the type of the heavy clusters, the yield ratios of t/ 3He correlate reversely to the neutron-to-proton ratio N/Z of the latter, showing the ping-pong modality of the N/Z of emitted clusters. The commonality that the N/Z of the residues keeps the initial system value is extended to the cluster emission in heavy ion reactions. The comparison of transport model calculations to the data is discussed.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2023-11-11
摘要：In this paper we followed the idea in Ref. 1 to discuss the Doppler frequency shift of photons and the Compton scattering between photons and electrons, pointing out that followingthe idea we have to modify the usual quantum relation of massless particle. But due to limitedinformation and knowledge, we couldn’t yet determine the specific expression for the correctioncoefficient of the quantum relation of massless particle. However, the phenomenon of spontaneous radiation in a cyclotron maser give us an opportunity to see what the expression for this correctioncoefficient might look like, as the phenomenon of spontaneous radiation in a cyclotron maser canbe explained by the effect of Doppler frequency shift of virtual photons and Compton scatteringbetween virtual photons and electrons. Therefor, under some restrictive conditions, we construct a very concise expression for this correction coefficient by discussing different cases. And then we used this expression to analyze the wavelength of radiation in the cyclotron maser, which tends toa limited value at v→c, rather than to 0 as in the Lorentz model. This paper still inherits the idea inRef. 1 that the energy and momentum of particles cannot be infinite, otherwise it will make some equations meaningless, and this view is also from the idea in some quantum gravity models. This paper also provides us with a possible experimental scheme to determine the value of Qin Ref. 1 , but it still requires extremely high experimental energy.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2023-11-10 合作期刊: 《应用力学学报》
摘要：随着各学科交叉融合不断深化,有限元法因其高效、精确、便捷等优点被广泛用于下肢肌骨系统生物力学研究,促进了临床个体化治疗、康复辅具、智能可穿戴等领域的发展,具有广阔的应有前景。以Web of science、PubMed、CNKI数据库为数据来源,“finite element and(lower limb or lower extremity or leg)”为英文检索词, “有限元、下肢”为中文检索词检索2018—2022年以下肢为重点的有限元研究。本研究系统阐述了有限元法在骨折预测及风险评估、骨折固定方法及固定器械力学分析、关节置换术评估中的临床应用,并探究了有限元法在骨应力分析、康复辅具力学分析、下肢-织物模型力学分析中的研究及应用。结果表明:有限元法可以建立符合生物力学理论的下肢模型,模拟计算各种工况,反映人体组织内部结构的应力应变情况,推动了临床医学个体化治疗研究的深入,促进了下肢康复辅具、智能可穿戴产品向智能化发展。未来的研究应着重提高有限元计算精度,将高精度测量技术、多体动力学肌骨模型与有限元法结合、建立人体-织物有限元模型,进一步促进下肢肌骨系统生物力学研究的广度和深度。
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2023-11-10 合作期刊: 《应用力学学报》
摘要：
依据经典Flügge壳体理论,利用功能梯度材料(FGM)和均匀材料物理性质和力学行为相似性的均匀化转换计算方法,研究了静水压力下FGM圆柱壳临界压力的预测方法。针对水下FGM圆柱壳耦合系统的振动问题,考虑流体影响,采用波动法推导出相应的振动方程,使用了牛顿迭代法,以确定在静水压力下FGM圆柱壳的固有频率。根据临界载荷与固有频率为零的载荷水平线性相关性,运用拟合曲线法和均匀化转换后的公式法对静水压力下FGM圆柱壳临界压力进行了预测分析,并讨论了FGM圆柱壳各项参数对静水压力下FGM圆柱壳临界压力的影响。结果表明,FGM圆柱壳的材料弹性模量E合值、几何尺寸h/R和L/R,以及不同边界条件改变对临界压力影响较大。通过对多组算例的对比分析,证明了本研究方法的正确性和有效性。使用该方法进行预测的精度高,计算量小,能够为非均匀结构力学行为的分析提供新的研究途径。
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2023-11-10 合作期刊: 《应用力学学报》
摘要：选取典型的钢筋混凝土(RC)深梁受剪试验,开发并运用三维刚体弹簧元法(3D RBSM)模拟了大尺寸截面深梁的受剪破坏过程,以及箍筋对深梁抗剪性能的影响。结果表明,3D RBSM不仅能够较准确地计算RC深梁的开裂荷载、名义抗剪强度以及箍筋的增强作用,而且能够模拟裂缝的开展以及构件的破坏。相比于有限元法,3D RBSM具有以下优势:大幅度提高了名义抗剪强度的计算精度,实现了散布裂缝模拟的可视化以及混凝土裂缝宽度的直观、定量评价; 能够更好地捕捉峰值荷载后的软化行为。因此,3D RBSM为大尺寸截面深梁的受剪破坏模拟、明晰抗剪性能尺寸效应机理和完善大尺寸RC构件设计提供了有效研究手段。
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2023-11-10 合作期刊: 《应用力学学报》
摘要：带数值耗散的算法因其能有效过滤虚假高频响应的影响而备受关注。基于离散控制理论Z变换,提出一类带数值耗散的结构动力学显式算法。该算法采用CR法的速度和位移递推式,满足零振幅衰减率,且对线性系统和非线性刚度软化系统为无条件稳定,对刚度硬化系统则是条件稳定的; 该算法由单个参数ρ控制数值耗散能力。通过对振幅衰减和周期延长的理论分析表明,系数a可调节算法的精度和非线性稳定区间,给出精度最优时系数的取值。对特定的系数取值该算法可转变为CR法。通过算例对线性系统和非线性系统的分析验证了新算法具有良好的精度、稳定性和数值耗散,表明新算法是正确有效的。
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