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金丝桃素-β-环糊精络合物的制备及其在小龙虾保鲜膜中的应用

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食品安全质量检测学报 2024年第3期15卷 46-58页

作者：白顺杰姜紫薇白婵涂子仪廖涛邱亮潘晖金士威中南民族大学化学与材料科学学院/国家民委分析化学重点实验室武汉430074 湖北省农业科学院农产品加工与核农技术研究所/农业农村部农产品冷链物流技术重点实验室武汉430064 湖北省小龙虾产业技术研究院有限公司武汉433100 荆州市食品药品检验所荆州434099

目的探究魔芋葡甘露聚糖(konjac glucomannan,KGM)、海藻酸钠(sodium alginate,SA)、巴西棕榈蜡(carnaubawax,CW)与金丝桃素-β-环糊精络合物(hypericin-β-cyclodextrin complex,Hyp-β-cd)制备的光敏性保鲜膜在4℃储藏条件下对小龙虾的品质影响。方法将制备的Hyp-β-cd加入到KGM、SA与CW溶液中,采用流延法制备光动力杀菌保鲜膜(KGM/SA/CW/Hyp-β-cd膜),通过核磁共振光谱(nuclear magnetic resonance spectroscopy,NMR)与荧光猝灭法验证了Hyp-β-cd的形成和活性氧(reativ oxygen species,ROS)的生成能力,然后用正交实验法对复合膜的制备进行优化。通过扫描电子显微镜(scanning electron microscope,SEM)、傅里叶红外光谱(Fourier transform infrared spectroscopy,FTIR)、X射线衍射(X-ray diffrction,XRD)进行表征,最后,以pH、总挥发性盐基氮(total volatile basic nitrogen,TVB-N)、菌落总数及硫代巴比妥酸反应物(thiobarbituric acid reactants,TBARS)值做为指标对保鲜效果进行评估。结果NMR及荧光猝灭的结果表明Hyp-β-cd的形成和ROS的生成,通过正交实验法对复合膜的制备进行优化:KGM含量为0.7%(m/V,下同)、SA含量为1.2%、CW含量为0.6%、Hyp-β-cd含量为0.4%时,复合膜有最优机械性能,拉伸强度为51.84MPa,断裂伸长率为14.27%。SEM证明了各物质在复合膜中的均匀分布。FTIR与XRD结果表明,随着SA、CW与Hyp-β-cd的加入,KGM与SA之间形成氢键,提高了复合膜的物理性能,CW的加入减少了复合膜的微孔隙,其中水接触角从67.5°增加到88.7°,氧气透过率从32.96降低到22.37 m^(3)·μm/m^(2)·day·kPa。由KGM/SA/CW/Hyp-β-cd膜包裹且在黄色LED光源照射处理后的小龙虾,在第8d时TVB-N值为20.37mg/g,菌落总数为6.14lgCFU/g,TBARS值为0.85 mg/kg,pH超过7.6。结论KGM/SA/CW/Hyp-β-cd复合膜具有作为光敏性抗菌包装材料的潜在应用价值。

关键词：金丝桃素-β-环糊精络合物光动力灭菌小龙虾保鲜膜

Suitable region of dynamic optimal interpolation for efficiently altimetry sea surface height mapping

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Geodesy and Geodynamics 2024年第2期15卷 142-149页

作者： Jiasheng shi Taoyong jin School of Geodesy and Geomatics Hubei Luojia LaboratoryWuhan UniversityWuhan 430079China MOE Key Laboratory of Geospace Environment and Geodesy Wuhan UniversityWuhan 430079China

The dynamic optimal interpolation(DOI)method is a technique based on quasi-geostrophic dynamics for merging multi-satellite altimeter along-track observations to generate gridded absolute dynamic topography(ADT).Compared with the linear optimal interpolation(LOI)method,the DOI method can improve the accuracy of gridded ADT locally but with low computational ***,considering both computational efficiency and accuracy,the DOI method is more suitable to be used only for regional *** this study,we propose to evaluate the suitable region for applying the DOI method based on the correlation between the absolute value of the Jacobian operator of the geostrophic stream function and the improvement achieved by the DOI *** verifying the LOI and DOI methods,the suitable region was investigated in three typical areas:the Gulf Stream(25°N-50°N,55°W-80°W),the Japanese Kuroshio(25°N-45°N,135°E-155°E),and the South China Sea(5°N-25°N,100°E-125°E).We propose to use the DOI method only in regions outside the equatorial region and where the absolute value of the Jacobian operator of the geostrophic stream function is higher than1×10^(-11).

关键词： Dynamic optimal interpolation Linearoptimal interpolation Satellite altimetry Sea surface height Suitable region

Wavelength Variation of a Random Laser with Concentration of a Gain Material

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Chinese Physics Letters 2011年第10期28卷 91-94页

作者： CHEN Shu-jing shi jin-wei ZHAI Tian-Rui WANG Zhao-Na LIU Da-He CHEN Xiao Applied Optics Beijing Area Major Laboratory Department of PhysicsBeijing Normal UniversityBeijing 100875 Key Laboratory of Nondestructive Test(Ministry of Education) Nanchang Hang Kong UniversityNanchang 330063 College of Science Minzu University of ChinaBeijing 100081

The wavelength variation of a laser-dye-type random laser is observed *** is found that the emitting wavelength of a random laser changes with the change of concentration of the gain ***,the actual radiation wavelengt... 详细信息

关键词： material pumping laser

High-Temperature Stability of Mg-1Al-12Y Alloy Containing LPSO Phase and Mechanism of Its Portevin-Le Chatelier(PLC)Effect

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 982-998页

作者： Qian-Long Ren Shuai Yuan shi-Yu Luan jin-Hui Wang Xiao-wei Li Xiao-Yu Liu Qinghai Provincial Key Laboratory of New Light Alloys Qinghai Provincial Engineering Research Center of High Performance Light Metal Alloys and FormingQinghai UniversityXining810016China School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China

In this study,the high-temperature stability and the generation mechanism of the Portevin-Le Chatelier(PLC)effect in solid-solution Mg-1Al-12Y alloy with different heat treatment processes were investigated by adjusting the content of long-period stacking ordered(LPSO)*** was found that the content of LPSO phases in the alloys differed the most after heat treatment at 530℃for 16 h and 24 h,with values of 13.56%and 3.93%***,high-temperature tensile experiments were conducted on these two alloys at temperatures of 150℃,200℃,250℃,and 300℃.The results showed that both alloys exhibited the PLC effect at temperatures ranging from 150 to 250℃.However,at a temperature 300℃,only the alloy with a greater concentration of LPSO phases exhibited the PLC effect,whereas the alloy with a lower proportion of LPSO phases did not exhibit this ***,both alloys exhibited remarkable high-temperature stability,with the alloy containing a greater percentage of LPSO phases also demonstrating superior *** underlying mechanism for this phenomenon lies in the exceptional high-temperature stability exhibited by the second phase within the ***,the LPSO phase effectively obstructs the movement of dislocations,and it also undergoing kinking to facilitate plastic deformation of the *** results indicate that the PLC effect can be suppressed by reducing dislocation pile-up at grain boundaries,which leads to a decrease in alloy plasticity but an increase in *** presence of the PLC effect in the WA121 alloy is attributed to the abundant dispersed second phase within the alloy,which initially hinders the movement of dislocations,leading to an increase in stress,and subsequently releases the dislocations,allowing them to continue their movement and thereby reducing in stress.

关键词： Magnesium alloy Long-period stacking ordered(LPSO)phase Portevin-Le Chatelier effect High temperature

Motion-pressure coupled control and simulation of long-endurance capability for multicapsule stratospheric airships

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Chinese Journal of Aeronautics 2024年第6期37卷 137-150页

作者： Zhiguang shi wei HUO Zongyu ZUO School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100191China Beijing Near Space Airship Technology Development Co. LtdBeijing 100070China

The current study focuses on the motion-pressure coupled control for a multicapsule stratospheric airship and transforms the path-tracking and heading-hold control of airships into guidance tracking with a time-varying weighted sum of longitudinal and lateral velocities by the definition of compound ***,an improved nonlinear predictive control method is provided to reduce the control energy consumption by the rolling optimization of controller parameters based on finite time intervals,ensuring infinite-time path-tracking ***,combined with the proposed cyclic regulation process of safe pressure between internal and external capsules,this study can fully reflect the force-thermal coupled rule of airships under the actions of atmospheric environment and maneuvering force,while evaluating the long-endurance capability of airships under the conditions of safe superheating and *** effectiveness of the motionpressure coupled controller was verified through numerical simulations,which can overcome the influence of environmental wind and achieve a tracking effect for the desired cruise path and compound *** airspeed provided during the cyclic circadian time caused the maximum superheating of the helium controlled within 30*** helium in the internal and external capsules achieved circadian *** equivalent micropore diameter of the capsule of 5 mm can achieve 55 days of long-endurance *** controller satisfies the requirements of cruise-flight application modes for multicapsule stratospheric airships with important engineering value.

关键词： Compound speed Nonlinear predictive control Cyclic pressure regulation Long-endurance capability Stratospheric airship

High performance 2T0C DRAM cells based on atomic-layer-deposited InAlZnO FETs

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Science China(Information Sciences) 2024年第9期67卷 344-345页

作者： Wen XIONG Binbin LUO wei MENG Bao ZHU Xiaohan WU shi-jin DING School of Microelectronics Fudan University

Recently, the oxide semiconductor-based 2T0C dynamic random-access memory(DRAM) has shown great potential in monolithic three-dimensional(M3D)-integrated memory,owing to some unique advantages of oxide semiconductors,such as high electron mobility, wide band gap, and compatibility with back-end-of-line(BEOL) processes [1, 2].

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Tunable magneto-Seebeck effect in Co_(2)FeSi/MgO/Co_(2)FeSi heterostructure via optimized interfacial engineering

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Science China(Physics,Mechanics & Astronomy) 2024年第3期67卷 128-135页

作者： jingyu Li Xianbiao shi Yurong jin Le Ma Liuming wei Chi Zhang Hang Li Peng-Fei Liu International Joint Research Laboratory of New Energy Materials and Devices of Henan Province School of Physics and ElectronicsHenan UniversityKaifeng 475004China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Defence Industry Secrecy Examination and Certification Center Beijing 100089China School of Materials Science and Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Network Security Henan Police CollegeZhengzhou 450046China College of Electrical Engineering Henan University of TechnologyZhengzhou 450001China

Enhancing the tunneling magneto-Seebeck(TMS) ratio and uncovering its underlying mechanism are greatly demanded in spin *** magnitude and sign of the TMS effect depend on the type of atom and the stacking order of atoms at the ***,we demonstrate that TMS ratios can be effectively manipulated by altering heterogonous or homogeneous interface through decoration on the CoFeSi(001) surface inserted on the MgO insulating *** maximum TMS ratio of pure Co_(2)/O termination is 4565% at 800 ***,the TMS ratio of the FeSi/O termination has two peak values,of which the maximum could reach up to-3290% at 650 *** comparing two different atom arrangements at the interface,we reveal that the sign and symbol of the TMS ratio can be controlled by the temperature and different atomic configurations at the Co_(2)FeSi/MgO ***,the spin-Seebeck coefficient up to ~150 μV/K is also possible when we select suitable terminations and *** findings will provide useful insights into how to control the sign and symbol of the TMS ratio and accordingly stimulate the development field of magneto-thermoelectric power and spin caloritronic devices based on the magneto-Seebeck effect in Heusler-based metallic multilayers.

关键词： magneto-Seebeck effect interface spintronics electronic structure spin-Seebeck effect

Production induced fracture closure of deep shale gas well under thermo-hydro-mechanical conditions

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Petroleum Science 2024年第3期21卷 1796-1813页

作者： shi-Ming wei Yang Xia Yan jin Xu-Yang Guo jing-Yu Zi Kai-Xuan Qiu Si-Yuan Chen College of Science China University of Petroleum(Beijing)Beijing102249China CNOOC Research Institute Ltd Beijing100028China The University of Hong Kong Hong Kong999077China

Deep shale gas reservoirs have geological characteristics of high temperature,high pressure,high stress,and inferior ability to pass through *** multi-stage fractured horizontal well is the key to exploiting the deep shale gas ***,during the production process,the effectiveness of the hydraulic fracture network decreases with the closure of fractures,which accelerates the decline of shale gas *** this paper,we addressed the problems of unclear fracture closure mechanisms and low accuracy of shale gas production prediction during deep shale gas *** we established the fluid—solid—heat coupled model coupling the deformation and fluid flow among the fracture surface,proppant and the shale *** the fluid—solid—heat coupled model was applied to the fracture network,it was well solved by our numerical method named discontinuous discrete fracture *** with the conventional discrete fracture method,the discontinuous discrete fracture method can describe the three-dimensional morphology of the fracture while considering the effect of the change of fracture surface permeation coefficient on the coupled fracture—matrix flow and describing the displacement discontinuity across the *** simulations revealed that the degree of fracture closure increases as the production time proceeds,and the degree of closure of the secondary fractures is higher than that of the primary *** creep and proppant embedment both increase the degree of fracture *** reduction in fracture surface permeability due to proppant embedment reduces the rate of fluid transfer between matrix and fracture,which has often been overlooked in the ***,it significantly impacts shale gas production,with calculations showing a 24.7%cumulative three-year yield *** study is helpful to understand the mechanism of hydraulic fracture ***,it provides the theoretical guidance for maintaining the long

关键词： Shalegas Fracture closure Fluid-solid-heat coupling Discontinuous discrete fracture

MHz cut-off frequency and permeability mechanism of iron-based soft magnetic composites

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Chinese Physics B 2024年第9期33卷 560-564页

作者： Xiao-wei jin Tong Li Hui-Gang shi De-Sheng Xue Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education LanzhouUniversityLanzhou 730000China

The lack of soft magnetic composites with high power density in MHz frequency range has become an obstacle in the efficient operation of the electrical and electronic ***,a promising method to increase the cut-off frequency of iron-based soft magnetic composites to hundreds of MHz is *** cut-off frequency is increased from 10 MHz to 1 GHz by modulating the height of the ring,the distribution of particles,and the particle *** mechanism of cut-off frequency and permeability is the coherent rotation of domain modulated by inhomogeneous field due to the eddy current *** empirical formula for the cut-off frequency in a magnetic ring composed of iron-based particles is established from experimental *** work provides an effective approach to fabricate soft magnetic composites with a cut-off frequency in hundreds of MHz.

关键词： cut-off frequency permeability eddy current effect soft magnetic composites