分类： 核科学技术 >> 核材料与工艺技术 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： The electrochemical properties of perrhenate were studied in hydrochloric acid solution via cyclic voltammetry by disk glassy carbon electrode. The electroreduction of perrhenate was performed at a constant potential -0.33 V (vs. Ag/AgCl) with a potentiostat by a flow type electrolysis cell. It was found that the change of rhenium ion concentration before and after electrolysis was negligible. This means almost no rhenium or rhenium oxides were deposited on the carbon fiber electrode during the electroreduction. The rhenium ion solution changed from colorless into yellow-brown after electrolysis process. UV-Visible spectrophotometry was used to characterize the oxidation states of Re before and after electrolysis. Some obvious peaks were detected after electrolysis, indicating that Re(VII) was reduced to Re(V). The complex behavior and stability of Re(V)-HEDP were discussed for the purpose of electroreduction of Re(VII) or Tc(VII) on radiopharmaceuticals production.
分类： 核科学技术 >> 粒子加速器 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Terahertz vibrational spectroscopy has recently been demonstrated as a novel noninvasive technique for the characterization of biological molecules. But the interpretation of the experimentally measured terahertz absorption bands requires robust computational method. In this paper, we present a statistical method for predicting the absorption peak positions of a macromolecule in the terahertz region. The essence of this method is to calculate the absorption spectra of a biological molecule based on multiple short scale molecular dynamics trajectories instead of using a long time scale trajectory. The method was employed to calculate the absorption peak positions of the protein, thioredoxin from Escherichia coli (E.coli), in the range of 1025 cm1 to verify the reliability of this statistical method. The predicted absorption peak positions of thioredoxin show good correlation with measured results demonstrating that the proposed method is effective in terahertz absorption spectra modeling. Such approach can be applied to predict characteristic spectral features of biomolecules in the terahertz region.
分类： 物理学 >> 核物理学 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： Molecularly thin water layer, with a hydrogen bonding network different from those in bulk water and ice, has unique properties and is generally involved in many important processes such as wetting, erosion, atmosphere chemical reaction, protein folding and biomolecular interaction. Here, we report a new water layer structure at room temperature, which is found inside nanobubbles by using synchrotron based scanning transmission soft X-ray microscopy (STXM). The three peaks 535.0, 536.8 and 540.9 eV at O K edge inside the nanobubbles show a novel characteristics of very thin water layers, which has never been observed before.
提交时间： 2017-05-02
Yang, ZH [Yang, Zhenhai][ 1,2,3,4 ]
Li, XF [Li, Xiaofeng][ 1,2,3,4 ]
Wu, SL [Wu, Shaolong][ 1,2,3,4 ]
Gao, PQ [Gao, Pingqi][ 5 ]
Ye, JC [Ye, Jichun][ 5 ]
摘要： We present a crystalline siliconthin-film [5 mu m] solar cell decorated by a front nanobowled texture and a rear truncated- nanopyramid silver reflector. This design substantially suppresses the overall light reflection and enhances the optical resonances
分类： 核科学技术 >> 粒子加速器 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
摘要： In this paper, we present a theoretical study on excitonic absorption spectra of one-dimensional semiconductor quantum wires. The carrier-carrier scattering is treated by the second Born approximation in the Markovian limit. The absorption spectra of different carrier densities and temperatures are discussed. The excitonic absorption peak position and width show complicated dependence on carrier density and temperature, indicating the importance of carrier-carrier scattering. The behavior can be understood by the cooperative effects of exchange self-energy and Coulomb correlation due to carrier-carrier scattering.
分类： 农、林、牧、渔 >> 土壤学 提交时间： 2024-07-31 合作期刊: 《干旱区科学》
摘要： The eastern foothills of the Helan Mountains in China are a typical mountainous region of soil and gravel, where gravel could affect the water movement process in the soil. This study focused on the effects of different gravel contents on the water absorption characteristics and hydraulic parameters of stony soil. The stony soil samples were collected from the eastern foothills of the Helan Mountains in April 2023 and used as the experimental materials to conduct a one-dimensional horizontal soil column absorption experiment. Six experimental groups with gravel contents of 0%, 10%, 20%, 30%, 40%, and 50% were established to determine the saturated hydraulic conductivity (Ks), saturated water content (θs), initial water content (θi), and retention water content (θr), and explore the changes in the wetting front depth and cumulative absorption volume during the absorption experiment. The Philip model was used to fit the soil absorption process and determine the soil water absorption rate. Then the length of the characteristic wetting front depth, shape coefficient, empirical parameter, inverse intake suction and soil water suction were derived from the van Genuchten model. Finally, the hydraulic parameters mentioned above were used to fit the soil water characteristic curves, unsaturated hydraulic conductivity (Kθ) and specific water capacity (C(h)). The results showed that the wetting front depth and cumulative absorption volume of each treatment gradually decreased with increasing gravel content. Compared with control check treatment with gravel content of 0%, soil water absorption rates in the treatments with gravel contents of 10%, 20%, 30%, 40%, and 50% decreased by 11.47%, 17.97%, 25.24%, 29.83%, and 42.45%, respectively. As the gravel content increased, inverse intake suction gradually increased, and shape coefficient, Ks, θs, and θr gradually decreased. For the same soil water content, soil water suction and Kθ gradually decreased with increasing gravel content. At the same soil water suction, C(h) decreased with increasing gravel content, and the water use efficiency worsened. Overall, the water holding capacity, hydraulic conductivity, and water use efficiency of stony soil in the eastern foothills of the Helan Mountains decreased with increasing gravel content. This study could provide data support for improving soil water use efficiency in the eastern foothills of the Helan Mountains and other similar rocky mountainous areas.
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： 2017-05-02
Tu, CJ [Tu, C. J.][ 1,2 ]
Gao, JH [Gao, J. H.][ 2 ]
Hui, S [Hui, S.][ 1,2 ]
Lou, D [Lou, D.][ 1 ]
Zhang, HL [Zhang, H. L.][ 2 ]
Liang, LY [Liang, L. Y.][ 2 ]
Jin, AP [Jin, A. P.][ 3 ]
Zou, YS [Zou, Y. S.][ 1 ]
Cao, HT [Cao, H. T.][ 2 ]
摘要： This paper focuses on the enhancement of thermal stability of Ag-Al2O3 nanocermet films by means of alloying of Ag nanoparticles with Al element. The optical analysis demonstrated the AgAl embedded Al2 O3 cermet films (namely, AgAl-Al2O3) possess excellent thermal tolerance even at 500◦C for 260h under nitrogen ambient. The evolution of microstructural and chemical properties of Al2O3/AgAl-Al2O3/Al2O3 stack layers during the annealing process was comprehensively investigated, in order to grasp the thermal stability mechanism. It is believed that the enhanced thermal stability was ascribed to the formation of fresh alumina as capping layer riveted on the Ag nanoparticles surfaces, which acted as the pinning points to prevent silver element from migrating so as to maintain the expected optical properties.
分类： 物理学 >> 核物理学 提交时间： 2021-02-25
摘要： In high energy resolution X-ray spectroscopy beamlines of synchrotron radiation (SR) facilities and laboratory XAS/XES spectrometer, it is important to keep X-ray spectrometer operating in optimal conditions. The adjusting process is normally very time consuming due to the irregular light source beam point, and it is difficult to get global optimum. This study aims to develop an intelligent adjusting system based on global optimization algorithm for spectrometers on SR beamlines and on laboratory x-ray source. First of all, based on the two dimensional experimental data, automatic adjustment process was established. Then the automatic optimization was applied to adjust X-ray spectrometer practically, and upgraded iteratively. The online testing is carried out on a self-developed laboratory XAS spectrometer. Online tests results show that this automatic adjustment process converges to the optimal solution quickly, and the convergence time is about several dozens to hundreds steps, more efficient than manual optimization process. After automatic adjustment, we can get correct X-ray absorption spectrum based on the adjusted spectrometer.
分类： 物理学 >> 核物理学 提交时间： 2025-06-18
Luo, Mr. Haotian
Zhang, Dr. Qiwei
Ruan, Dr. Xichao
Luan, Dr. Guangyuan
Wu, Dr. Hong-Yi
Ren, Dr. Jie
Chen, Mr. Xuanbo
Jiang, Dr. Wei
Fan, Dr. Ruirui
摘要： In this study, the neutron radiative capture cross section of 93Nb was measured using the GTAF gamma spectrometer at the Back-n beamline of the China Spallation Neutron Source (CSNS), employing the time-of-flight (TOF) method. A comprehensive data processing approach was implemented, including background subtraction, neutron flux normalization, dead time correction, and yield spectrum calculation. The uncertainties were evaluated from statistical counting, neutron flux, sample thickness, and flight path correction. The excitation function of 93Nb was obtained up to 2 keV. Resonance parameters below 200 eV were analyzed using the SAMMY code. The results show good agreement with evaluated nuclear data libraries such as ENDF/B-VIII.0, JENDL-5, and TENDL-2023 in the main resonance regions, while discrepancies in low cross-section regions were attributed to large statistical uncertainties, possible changes in the RPI function, and impurities such as 181Ta. This work provides valuable experimental data and methodological insight for the cross-section measurement and resonance analysis of 93Nb.
提交时间： 2017-05-02
Shen, B [Shen, Bin][ 1 ]
Li, Y [Li, Yang][ 1 ]
Yi, D [Yi, Da][ 2 ]
Zhai, WT [Zhai, Wentao][ 1 ]
Wei, XC [Wei, Xingchang][ 2 ]
Zheng, WG [Zheng, Wenge][ 1 ]
摘要： As reported, the foaming of layered graphene films into porous graphene foams could improve their performance for absorbents, catalysis and supercapacitors. Herein, to emphasize the impact of porous structure on electromagnetic interference [EMI] shieldin
分类： 物理学 >> 核物理学 提交时间： 2025-01-20
Yang, Dr. Shumin
Guo, Dr. Ling-Ling
Nan, Dr. Bing
Zhao, Dr. Ying
Wu, Dr. Yan-Qing
Guo, Prof. Zhi
Tian, Dr. Chen
Zhao, Dr. Bo
Xue, Dr. Chao-Fan
Zhao, Dr. Jun
Song, Miss Shuang
Liang, Mr. Zhen-Ye
Li, Prof. Li-Na
Wang, Prof. Yong
Tai, Prof. Renzhong
摘要： The tender energy spectroscopy beamline (BL16U1) is one of the phase-II beamline at the Shanghai Synchrotron Radiation Facility (SSRF). The design and performance of the tender energy spectroscopy beamline at SSRF are described in this paper. Based on a 26 mm-period in vacuum undulator (IVU) source, the beamline is to give an operable energy range between 2.1 and 16 keV, covering the K-edges of those elements from P to Rb and the L3-edges of those elements from Zr to Bi. The principal optical elements of the beamline consist of a toroidal mirror, a liquid-nitrogen cooled double-crystal monochromator, a high harmonic rejection mirror and two pairs of Kirkpatrick–Baez (KB) mirrors. Three end-stations, including the non-focusing, microprobe and sub-microprobe end-stations, are installed on the beamline. X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS) including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS), have been achieved under vacuum or He atmosphere at the non-focusing end-station with a spot size of ~ 670×710 μm2. Based on two KB mirrors systems, micro-X-ray fluorescence (μXRF) mapping studies and micro-X-ray absorption near-edge structure (μXANES) will be operated with a spot size of nearly ~ 3.3×1.3 μm2 at the microprobe end-station, and with a smaller spot size of ~ 0.5×0.25 μm2 at the sub-microprobe end-station. Up to now, the non-focusing end-station of the BL16U1 is officially opened to users in Jan. 2024. The microprobe and sub-microprobe end-stations will be opened to users in the near future. This paper describes the characteristics, short-term technical developments and a few of the early experimental results of this new beamline.
分类： 物理学 >> 核物理学 提交时间： 2024-12-12
Yang, Dr. Shumin
Guo, Dr. Ling-Ling
Nan, Dr. Bing
Zhao, Dr. Ying
Wu, Dr. Yan-Qing
Guo, Prof. Zhi
Tian, Dr. Chen
Zhao, Dr. Bo
Xue, Dr. Chao-Fan
Zhao, Dr. Jun
Song, Miss Shuang
Liang, Mr. Zhen-Ye
Li, Prof. Li-Na
Wang, Prof. Yong
Tai, Prof. Renzhong
摘要： The tender energy spectroscopy beamline (BL16U1) is a phase-II beamline project at the Shanghai Synchrotron Radiation Facility (SSRF). The design and performance of the tender energy spectroscopy beamline at SSRF are described in this paper. Based on a 26 mm-period in vacuum undulator (IVU) source, the beamline is to give an operable energy range between 2.1 and 16 keV, covering the K-edges of those elements from P to Rb and the L3-edges of those elements from Zr to Bi. The principal optical elements of the beamline consist of a toroidal mirror, a liquid-nitrogen cooled double-crystal monochromator, a high harmonic rejection mirror and two pairs of Kirkpatrick–Baez (KB) mirrors. Three end-stations, including the non-focusing, microprobe and sub-microprobe end-stations, are installed on the beamline. X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS) including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine-structure (EXAFS), have been achieved under vacuum or He atmosphere at the non-focusing end-station with a spot size of ~ 670×710 μm2. Based on two KB mirrors systems, micro-X-ray fluorescence (μXRF) mapping studies and micro-X-ray absorption near-edge structure (μXANES) will be operated with a spot size of nearly ~ 3.3×1.3 μm2 at the microprobe end-station, and with a smaller spot size of ~ 0.5×0.25 μm2 at the sub-microprobe end-station. Up to now, the non-focusing end-station of the BL16U1 is officially opened to users in Jan. 2024. The microprobe and sub-microprobe end-stations will open to users in the near future. This paper describes the characteristics, short-term technical developments and a few of the early experimental results of this new beamline.
分类： 核科学技术 >> 辐射物理与技术 提交时间： 2024-04-29
摘要： The layout and characteristics of the hard X-ray spectroscopy beamline (BL11B) at the Shanghai Synchrotron Radiation Facility are described herein. BL11B is a bending-magnet beamline dedicated to conventional millisecond-scale quick-scanning X-ray absorption fine structures. It is equipped with a cylindrical collimating mirror, a double-crystal monochromator comprising Si(111) and Si(311), a channel-cut quick-scanning Si(111) monochromator, a toroidal focusing mirror, and a high harmonics rejection mirror. It can provide 5–30 keV of X-rays with a photon flux of ~5 × 1011 photons/s and an energy resolution of ~ 1.31 × 10-4 at 10 keV. The performance of the beamline can satisfy the demands of users in the fields of catalysis, materials, and environmental science. This paper presents an overview of the beamline design and a detailed description of its performance and capabilities.
分类： 物理学 >> 核物理学 提交时间： 2025-02-13
摘要： The thin window of a gas detector is crucial for allowing X-rays or other radiation to penetrate the detector. Today, the thin window at the entrance of the gas detector relies mainly on imports. The penetration performance of polyester films as incident windows for thin-window gas detectors was improved through the combination of plasma treatment and an organic-inorganic hybrid coating. Plasma modification provides an efficient way to achieve surface etching and polar group formation, therefore, the organic-inorganic hybrid coating fastness on the film could be efficiently increased. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray spectroscopy (EDS), and contact angle measurements were employed to analyze the surface morphology, chemical composition, and hydrophilicity of the modified films. Experimental results revealed that increased plasma treatment power and duration improved surface roughness and hydrophilicity, and significantly improved coating adhesion and uniformity. X-ray fluorescence spectroscopy confirmed a marked reduction in particle loss, demonstrating the coating films’ improved suitability for high-sensitivity particle detection applications. This approach shows potential for further optimization, offering a viable pathway to advance thin-window gas detector technologies.
分类： 核科学技术 >> 粒子加速器 提交时间： 2023-06-18 合作期刊: 《Nuclear Science and Techniques》
ZHANG Li-Li
YAN Shuai
JIANG Sheng
YANG Ke
WANG Hua
HE Shang-Ming
LIANG Dong-Xu
ZHANG Ling
HE Yan
LAN Xu-Ying
MAO Cheng-Wen
WANG Juan
JIANG Hui
ZHENG Yi
DONG Zhao-Hui
ZENG Le-Yong
Li Ai-Guo
摘要： The hard X-ray micro-focusing beamline (BL15U1) of SSRF is dedicated to hard X-ray micro/nano-spectrochemical analysis consisting of X-ray fluorescence (XRF), X-ray absorption spectroscopy (XAS) and X-ray diffraction (XRD) techniques. It is one of the most versatile instruments in hard X-ray microscopy science. Since its commission in 2009, BL15U1 has allocated over 25000 h beamtime for users, and about 700 proposals have been executed. The beamline and the experimental end-station were upgraded for several times to facilitate the users experimental needs and make it more convenient to operate. In this paper, we give a review on the beamline, describing its characteristics, recent technical developments, and a few examples of scientific progresses achieved in recent years on BL15U1.
分类： 天文学 >> 天体物理学 提交时间： 2023-02-21
Chaojun Wang
B. Luo
W. N. Brandt
D. M. Alexander
F. E. Bauer
S. C. Gallagher
Jian Huang
Hezhen Liu
D. Stern
摘要： We utilize recent NuSTAR observations (co-added depth 55-120 ks) of PG 1001+054, PG 1254+047, and PHL 1811 to constrain their hard X-ray (≳5 keV) weakness and spectral shapes, and thus to investigate the nature of their extreme X-ray weakness. These quasars showed very weak soft X-ray emission, and they were proposed to be intrinsically X-ray weak, with the X-ray coronae producing weak continuum emission relative to their optical/UV emission. However, the new observations suggest an alternative explanation. The NuSTAR 3-24 keV spectral shapes for PG 1001+054 and PHL 1811 are likely flat (effective power-law photon indices \Gamma_{\rm eff}=1.0^{+0.5}_{-0.6} and \Gamma_{\rm eff}=1.4^{+0.8}_{-0.7}, respectively), while the shape is nominal for PG 1254+047 (\Gamma_{\rm eff}=1.8\pm0.3). PG 1001+054 and PHL 1811 are significantly weak at hard X-ray energies (by factors of 26-74 at rest-frame 8 keV) compared to the expectations from their optical/UV emission, while PG 1254+047 is only hard X-ray weak by a factor of 3. We suggest that X-ray obscuration is present in all three quasars. We propose that, as an alternative to the intrinsic X-ray weakness + X-ray obscuration scenario, the soft and hard X-ray weakness of these quasars can be uniformly explained under an obscuration-only scenario. This model provides adequate descriptions of the multi-epoch soft and hard X-ray data of these quasars, with variable column density and leaked fraction of the partial-covering absorber. We suggest that the absorber is the clumpy dust-free wind launched from the accretion disk. These quasars probably have super-Eddington accretion rates that drive powerful and high-density winds.
分类： 生物学 >> 生态学 提交时间： 2017-11-17
Hui Xie
Saogao Zeng
Lili Zeng
Xiaobing Lan
Guicheng Zhang
Li Liu
Xin Lu
Na Chen
Zhiyuan Li
Zengzhao Tu
Hongjiang Xu
Ling Yang
Xiquan Zhang
Wenhui Hu
摘要： Followed pharmacological evaluation exposed an extensive hepatic first pass effect within our recently disclosed DPP-IV inhibitors bearing thienopyrimidine scaffold. Through scaffold replacement with pyrrolopyrimidine, compound 1a had substantially improved the metabolic stability (from 6.6% to 65.07%), yet with severely poor absorptive property. Further modification by incorporation with varied substituents and structure conversion yielded both permeable and metabolic stable compounds. The whole pharmacokinetic- property based optimization had succeeded in balancing overall properties and resulted in the compound 1j, that with excellent efficacy to be a potential anti-diabetic candidate.
分类： 物理学 >> 核物理学 提交时间： 2024-01-21
Chong ZOU
Qi SUN
Xiaoyu WANG
Mengxiao KANG
Jincheng WANG
Yingyi LIU
Haolan YANG
Xuanbo CHEN
Qiwei ZHANG
Jie REN
Guangyuan LUAN
Haotian LUO
Hongyi WU
Xichao RUAN
Hanxiong HUANG
Zhaohui WANG
Guozhu HE
Jie BAO
摘要： To fulfill the needs of neutron capture reaction cross-section measurement in keV energy scale in the field of nuclear astrophysics and advanced nuclear energy system development, the 4 BaF2 Gamma-ray Total Absorption Facility (GTAF) developed by the Key Laboratory of Nuclear Data of the China Institute of Atomic Energy (CIAE) has been transplanted and installed at the Back-streaming White Neutron Source (Back-n) of the China Spallation Neutron Source (CSNS) in 2019. A series of results has been achieved and published based on the GTAF since then, and due to which the needs of reducing backgrounds are becoming increasingly urgent. In order to understand the origins of backgrounds and to optimize the facilities, a detailed simulation program using GEANT4 toolkits was established and presented in this paper. To demonstrate the availability of the proved codes, several practical examples of assisting the process of experimental data and helping verify the optimization proposition are also shown in this paper.
分类： 农、林、牧、渔 >> 农业基础学科 提交时间： 2023-10-17 合作期刊: 《干旱区科学》
摘要： The unreasonable nitrogen (N) supply and low productivity are the main factors restricting the sustainable development of processing tomatoes. In addition, the mechanism by which the N application strategy affects root growth and nitrate distributions in processing tomatoes remains unclear. In this study, we applied four N application levels to a field (including 0 (N0), 200 (N200), 300 (N300), and 400 (N400) kg/hm2) based on the critical N absorption ratio at each growth stage (planting stage to flowering stage: 22%; fruit setting stage: 24%; red ripening stage: 45%; and maturity stage: 9%). The results indicated that N300 treatment significantly improved the aboveground dry matter (DM), yield, N uptake, and nitrogen use efficiency (NUE), while N400 treatment increased nitrate nitrogen (NO3-N) residue in the 2060 cm soil layer. Temporal variations of total root dry weight (TRDW) and total root length (TRL) showed a single-peak curve. Overall, N300 treatment improved the secondary root parameter of TRDW, while N400 treatment improved the secondary root parameter of TRL. The grey correlation coefficients indicated that root dry weight density (RDWD) in the surface soil (020 cm) had the strongest relationship with yield, whereas root length density (RLD) in the middle soil (2040 cm) had a strong relationship with yield. The path model indicated that N uptake is a crucial factor affecting aboveground DM, TRDW, and yield. The above results indicate that N application levels based on critical N absorption improve the production of processing tomatoes by regulating N uptake and root distribution. Furthermore, the results of this study provide a theoretical basis for precise N management.
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： 2017-05-02
Zhou, Y [Zhou, Yu][ 1,2 ]
Chen, GF [Chen, Guofei][ 1 ]
Wang, W [Wang, Wei][ 1 ]
Wei, LH [Wei, Lihong][ 1 ]
Zhang, QJ [Zhang, Qiuju][ 1 ]
Song, LP [Song, Liping][ 2 ]
Fang, XZ [Fang, Xingzhong][ 1 ]
摘要： Two series of poly(ester imide)s derived from bis(trimellitic acid anhydride) phenyl ester (TAHQ) and bis[(3,4- dicarboxylic anhydride) phenyl] terephthalate (PAHP), as well as poly(ether imide)s based on hydroquinone diphthalic anhydride (HQDPA), were synthesized with aromatic diamines via solution polycondensation. These polyimide films were transparent with an ultraviolet-visible absorption cut-off wavelength below 375 nm, and with tensile strengths of 42.0–83.8 MPa, tensile moduli of 2.5–4.7 GPa and elongations at break of 2.1–5.4%. Compared with the poly(ether imide)s, the poly(ester imide)s showed higher glass transition temperatures (Tg), lower water absorption (WA) and lower temperature of 5% weight loss (Td5%). Moreover, the poly(ester imide)s derived from PAHP with a low electron affinity of 2.04 eV by theoretical calculation achieved better transparency, lower WA and slightly lower Tg than the corresponding TAHQ- based poly(ester imide)s.
点击量
通过
点击量
下载量
评论
待评议
