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Modeling of cascaded high isolation bidirectional amplification in long-distance fiber-optic time and frequency synchronization system

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Chinese Physics B 2021年第7期30卷 294-302页

作者： Kuan-Lin Mu Xing Chen zheng-kang wang Yao-Jun Qiao Song Yu The State Key Laboratory of Information Photonics and Optical Communications School of Information and Communication EngineeringBeijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

We propose a physical model of estimating noise and asymmetry brought by high isolation Bi-directional erbiumdoped fiber amplifiers(Bi-EDFAs),no spontaneous lasing even with high gain,in longdistance fiber-optic time and frequency(T/F)synchronization *** is found that the Rayleigh scattering noise can be suppressed due to the high isolation design,but the amplified spontaneous emission(ASE)noise generated by the high isolation Bi-EDFA and the bidirectional asymmetry of the transmission link caused by the high isolation Bi-EDFA will deteriorate the stability of the *** calculated results show that under the influence of ASE noise,the frequency instability of a 1200 km system composed of 15 high isolation Bi-EDFAs is 1.773×10^(-13)/1 *** the instability caused by asymmetry is 2.6064×10^(-16)/30000–35000 s if the total asymmetric length of the bidirectional link length is 30 *** intensity noises originating from the laser and detector,the transfer delay fluctuations caused by the variation in ambient temperature and the jitter in laser output wavelength are also *** experiment composed of three high isolation Bi-EDFAs is done to confirm the theoretical *** summary,the paper shows that the short-term instability of the T/F synchronization system composed of high isolation Bi-EDFAs is limited by the accumulation of ASE noise of amplifiers and the laser frequency drift,while the long-term instability is limited by the periodic variation in ambient temperature and the asymmetry of the *** research results are useful for pointing out the direction to improve the stability of the fiber-optic T/F synchronization system.

关键词： time and frequency synchronization erbium-doped fiber amplifier instability Allan deviation

Fracture behavior and mechanism of highly fragmented steel cylindrical shell under explosive loading

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Defence Technology（防务技术） 2024年第6期36卷 122-132页

作者： kang wang Peng Chen Xingyun Sun Yufeng Liu Jiayu Meng Xiaoyuan Li Xiongwei zheng Chuan Xiao Xi'an Modern Chemistry Research Institute Xi'an 710065China Shanxi Jiangyang Chemical Company Limited Taiyuan 030051China Central Iron&Steel Research Institute Company Limited Beijing 100081China China Research and Development Academy of Machinery Equipment Beijing 100089China

An in-depth understanding of the fracture behavior and mechanism of metallic shells under internal explosive loading can help develop material designs for warheads and regulate the quantity and mass distribution of the fragments *** study investigated the fragmentation performance of a new high-carbon silicon-manganese(HCSiMn)steel cylindrical shell through fragment recovery *** with the conventional 45Cr steel shell,the number of small mass fragments produced by the HCSi Mn steel shell was significantly increased with a scale parameter of 0.57 g fitted by the Weibull distribution *** fragmentation process of the HCSi Mn shell exhibited more brittle tensile fracture characteristics,with the microcrack damage zone on the outer surface being the direct cause of its high *** the one hand,the doping of alloy elements resulted in grain refinement by forming metallographic structure of tempered sorbite,so that microscopic intergranular fracture reduces the characteristic mass of the fragments;on the other hand,the distribution of alloy carbides can exert a"pinning"effect on the substrate grains,causing more initial cracks to form and propagate along the brittle carbides,further improving the shell *** the killing power radius for light armored vehicles was slightly reduced by about 6%,the dense killing radius of HCSiMn steel projectile against personnel can be significantly increased by about 26%based on theoretical *** results provided an experimental basis for high fragmentation warhead design,and to some extent,revealed the correlation mechanism between metallographic structure and shell fragmentation.

关键词： Projectile fragmentation Fragment mass distribution Fracture mode Metallographic structure Damage power

Polarization dependence of gain and amplified spontaneous Brillouin scattering noise analysis for fiber Brillouin amplifier

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Chinese Physics B 2019年第9期28卷 253-257页

作者： Kuan-Lin Mu Jian-Ming Shang Li-Hua Tang zheng-kang wang Song Yu Yao-Jun Qiao School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China Institute of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China

The polarization dependences of gain and amplified spontaneous Brillouin scattering(ABS) noise for fiber Brillouin amplifier(FBA) are analyzed through theories, simulations, and *** vector propagation equations for calculating the gain of the probe signal and the ABS noise are derived and analyzed in the Stokes *** simulations and experiments, we prove that the gain of the probe signal and the ABS noise are strongly dependent on the relative state of polarization(SOP) of the pump and probe *** closer the relative SOP of the pump and probe signals is, the more obvious ABS noise suppression effect will be brought by increasing the power of the input probe signal.

关键词： fiber Brillouin amplifier state of polarization stimulated Brillouin scattering spontaneous Brillouin scattering

Structural engineering of Sb-based electrode materials to enhance advanced sodium-ion batteries

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Rare Metals 2024年第10期43卷 4777-4806页

作者： zheng Yang Qiao-Ling kang Rui-wang Li-Jing Yan Xian-He Meng Ting-Li Ma College of Materials and Chemistry Jiliang University

Antimony （Sb） is recognized as a potential electrode material for sodium-ion batteries （SIBs） due to its huge reserves,affordability,and high theoretical capacity(660 mAh·g-1).However,Sb-based materials experience significant volume expansion during cycling,leading to comminution of the active substance and limiting their practical use in ***,the volume expansion issue of Sb-based materials during charging/discharging must be solved to create high-performance *** paper presents a detailed review of structural engineering of Sb-based electrode materials,focusing on the performance effects of different kinds of structures on advanced performance ***,the future development and the challenges of Sb-based materials are *** paper can provide specific perspectives on the structure construction and optimization of Sb-based anode materials so as to promote the rapid development and practical applications of SIBs.

关键词： Sb-based electrode Sodium-ion batteries Structural engineering

An improved installation of 2-hydroxy-4-methoxybenzyl(iHmb)method for chemical protein synthesis

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Chinese Chemical Letters 2024年第5期35卷 145-150页

作者： Ying Li Long-Jie wang Yong-kang Zhou Jun Liang Bin Xiao Ji-Shen zheng The First Affiliated Hospital of USTC MOE Key Laboratory for Membraneless Organelles and Cellular DynamicsDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefei 230001China Department of Chemistry University of Science and Technology of ChinaHefei 230027China

The 2-hydroxy-4-methoxybenzyl(Hmb)backbone modification can prevent amide bond-mediated sidereactions(e.g.,aspartimide formation,peptide aggregation)by installing the removable Hmb group into a peptide bond,thus improving the synthesis of long and challenging peptides and ***,its use is largely precluded by the limited Hmb’s installation *** this report,an improved installation of Hmb(iHmb)method was developed to achieve the flexible installation and the convenient removal of *** iHmb method involves two critical steps:(1)oxidative diazotization of the readily installed 2-hydroxy-4-methoxy-5-amino-benzyl(Hmab)to give 2-hydroxy-4-methoxy-5-diazonium-benzyl(Hmdab)by combining soamyl nitrite(IAN)/HBF_(4),and(2)reductive elimination of Hmdab to give the desired Hmb by 1,2-ethanedithiol(EDT).The iHmb method enables the installation of Hmb at any primary amino acid including the highly sterically hindered amino acids(e.g.,valine and isoleucine).The practicality and utility of the iHmb method was demonstrated by one-shot solid-phase synthesis of a challenging aspartimide-prone peptide,the mirror-image version of a hydrophobic peptide and a long-chain peptide up to ***,the iHmb method can be utilized to facilitate chemical protein ligation,as exemplified by the synthesis of the single-spanning membrane protein *** iHmb method expands the toolkit for peptide synthesis and ligation and facilitates the preparation of peptides/proteins.

关键词： Chemical protein synthesis Solid-phase peptide synthesis Removable backbone modification 2-Hydroxy-4-methoxybenzyl(Hmb)group Aspartimide-prone peptides Difficult peptides Membrane proteins

Steel-refractory reactions in lanthanum-,cerium-,and ytrium-added steels

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Journal of Iron and Steel Research International 2024年第6期31卷 1473-1485页

作者： Jian kang Hong-po wang Yu wang College of Materials Science and Engineering Chongqing UniversityChongqing 400044China The State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China

A systematic experimental study was conducted on the similarities and differences in the reactions between commonly used rare earth elements(REEs)and frequently used refractories in the steelmaking *** results indicate that the reaction behaviors of La,Ce,and Y with MgO,Al_(2)O_(3),and MgO·Al_(2)O_(3) crucibles differed *** consumption rates of La,Ce,and Y in the molten steel were in descending order of La>Ce>Y for smelting with all three kinds of *** the REEs reacted with the crucible,the contents of Mg and Al showed a trend of first increasing and then *** laboratory-scale smelting conditions,the reactions related to REEs were dominated by steel-crucible reactions,and the contact area between the unit mass of molten steel and refractory materials mainly determined the consumption rates of ***-and Ce-crucible reactions generated loose and porous reaction interfaces;however,Y-crucible reactions generated a dense Y_(2)O_(3) layer,dramatically suppressing the consumption rate of *** calculation indicated that the reactions between rare earth and different refractory materials were first-order *** crucible materials significantly affected the product type and morphology of the steel-crucible reaction interfaces,thereby influencing the consumption rate of *** reactions between REEs and refractories must be seriously considered,especially for small-scale smelting.

关键词： Rare earth Inclusion Refractory Thermodynamics Dynamics

Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties

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Chinese Journal of Chemical Engineering 2024年第2期66卷 19-30页

作者： kang He Liangyu Zhu Yanmei wang CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored *** mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force *** mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon *** the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1%,and 93.5%,*** is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=10^(-3)mol·L^(-1)for pepsin,and pH 5,I=10^(-5)mol·L^(-1)for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=10^(-1)mol·L^(-1)for pepsin,and pH 9,I=10^(-1)mol·L^(-1)for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=10^(-5)mol·L^(-1),while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-10^(-1)mol·L^(-1).However,alkaline protein(lysozyme,whose isoelectric point was higher than

关键词： Switchable conformation transition Controllable protein adsorption Mixed brushes Isoelectric point Antibacterial surface

Hepatocellular SETDB1 Regulates Hepatic Ischemia-Reperfusion Injury through Targeting Lysine Methylation of ASK1 Signal

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Research 2024年第3期6卷 305-317页

作者： kang Xia Tianyu wang Zhongbao Chen Jiayu Guo Bo Yu Qi Chen Tao Qiu Jiangqiao Zhou Shusen zheng Department of Organ Transplantation Renmin Hospital of Wuhan UniversityWuhanChina Department of Urology Renmin Hospital of Wuhan UniversityWuhanChina. Department of general surgery Renmin Hospital of Wuhan UniversityWuhanChina Division of Hepatobiliary and Pancreatic Surgery Department of SurgeryFirst Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhouChina Key Laboratory of Combined Multi-Organ Transplantation Ministry of Public HealthHangzhouChina Key Laboratory of Organ Transplantation HangzhouZhejiang ProvinceChina Key Laboratory of the Diagnosis and Treatment of Organ Transplantation CAMSHangzhouChina.

Background: Hepatic ischemia-reperfusion injury (HIRI) stands as an unavoidable complication arising from liver surgery, profoundly intertwined with its prognosis. The role of lysine methyltransferase SET domain bifurcated 1 (SETDB1) in HIRI remains elusive, despite its confirmation as a potential therapeutic target for diverse diseases. Here, we investigated the mechanism by which SETDB1 regulated HIRI. Methods: RNA sequencing data were used to identify the expression and potential targets of SETDB1 through bioinformatics analysis. To elucidate the impact of SETDB1 on HIRI, both an in vivo model of HIRI in mice and an in vitro model of hepatocyte hypoxia/reoxygenation were established. Biochemical and histological analyses were used to investigate the influence of SETDB1 on liver damage mediated by HIRI. Chromatin immunoprecipitation and coimmunoprecipitation were implemented to explore the in-depth mechanism of SETDB1 regulating HIRI. Results: We confirmed that hepatocellular SETDB1 was up-regulated during HIRI and had a close correlation with HIRI-related inflammation and apoptosis. Moreover, inhibition of SETDB1 could mitigate HIRI-induced liver damage, inflammation, and apoptosis. Through our comprehensive mechanistic investigation, we revealed that SETDB1 interacts with apoptosis-signal-regulating kinase 1 (ASK1) and facilitates the methylation of its lysine residues. Inhibition of SETDB1 resulted in reduced phosphorylation of ASK1, leading to a marked suppression of downstream c-Jun N-terminal kinase (JNK)/p38 signaling pathway activation. The therapeutic effect on inflammation and apoptosis achieved through SETDB1 inhibition was nullified by the restoration of JNK/p38 signaling activation through ASK1 overexpression. Conclusions: The findings from our study indicate that SETDB1 mediates lysine methylation of ASK1 and modulates the activation of the ASK1–JNK/p38 pathway, thus involved in HIRI-induced inflammation and apoptosis. These results suggest that SETD

关键词： SETDB1 inflammation ASK1

Disturbance Observer-based Pointing Control of Leighton Chajnantor Telescope

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Research in Astronomy and Astrophysics 2024年第1期24卷 135-150页

作者： Weirui Chen zheng wang School of Automation Southeast UniversityNanjing 210096China Key Laboratory of Measurement and Control of Complex Systems of Engineering Ministry of EducationSoutheast UniversityNanjing 210096China

Leighton Chajnantor Telescope(LCT), i.e., the former Caltech Submillimeter Observatory telescope, will be refurbished at the new site in Chajnantor Plateau, Chile in 2023. The environment of LCT will change significantly after its relocation, and the telescope will be exposed to large wind disturbances directly because its enclosure will be completely open during observation. The wind disturbance is expected to be a challenge for LCT's pointing control since the existing control method cannot reject this disturbance very well. Therefore, it is very necessary to develop a new pointing control method with good capability of disturbance rejection. In this research, a disturbance observer—based composite position controller(DOB-CPC) is designed, in which an H∞feedback controller is employed to compress the disturbance, and a feedforward linear quadratic regulator is employed to compensate the disturbance precisely based on the estimated disturbance signal. Moreover, a controller switching policy is adopted, which applies the proportional controller to the transient process to achieve a quick response and applies the DOB-CPC to the steady state to achieve a small position error. Numerical experiments are conducted to verify the good performance of the proposed pointing controller(i.e., DOB-CPC) for rejecting the disturbance acting on LCT.

关键词： instrumentation:miscellaneous methods:analytical methods:numerical telescopes