摘要：As one of the key characteristics in cognitive wireless networks(CWNs),network environment awareness techniques have received much attention *** of traditional spectrum sensing technology that suffers from problems of miss detection,false alarm,hidden node,and inefficiency,cognitive pilot channel(CPC) technology has been proposed as one of the candidate solutions for an efficient and accurate network information delivery scheme to user equipment(UE).The aim of the CPC technology is to provide the necessary information for the reconfiguration of the UE using the public signaling *** ensure the efficient information delivery,the whole geographical area covered by the CPC is divided into square meshes of the same ***,two typical network information transmission modes for CPC deployment are also proposed:broadcast CPC mode and on-demand CPC *** further improve the efficiency of network information delivery,an efficient dynamic mesh grouping scheme has been designed which is based on the fractal theory for the broadcast CPC mode,where adaptive rectangular sized meshes are used to approximately cover the whole *** to the traditional fixed size mesh division strategy,results show that the proposed dynamic mesh grouping scheme significantly reduces the number of meshes by grouping similar meshes together,and the average delay of receiving CPC information on the UE side is therefore reduced.

摘要：In order to enhance the glutathione peroxidase（GPX） catalytic activity of the selenium-containing single-chain variable fragments（Se-scFv）, a novel human scFv was designed on the basis of the structure of human antibody and optimized via bioinformatics methods such as homologous sequence analysis, three-dimensional（3D） model building, binding-site analysis and docking. The DNA sequence of the new human scFv was synthesized and cloned into the expression vector pET22b（＋）, then the scFv protein was expressed in soluble form in Escherichia coli BL21（DE3） and purified by Ni2＋-immobilized metal affinity chromatography（IMAC）. The serine residue of scFv in the active site was converted into selenocysteine（Sec） with the chemical modification method, thus, the human Se-scFv with GPX activity was obtained. The GPX activity of the Se-scFv protein was characterized. Compared with other Se-scFv, the new human Se-scFv showed similar efficiency for catalyzing the reduction of hydrogen peroxide by glutathione. It exhibited pH and temperature dependent catalytic activity and a typical ping-pong kinetic mechanism.

摘要：聚焦于星载固态功率放大器的高频化,设计并实现了Q频段20W、V频段10W以及W频段2W的固态功率放大器。基于氮化镓功率单片技术,提升了单元的功率和效率;基于魔T和径向线的高效率、低插损多路功率合成技术,实现了整机高功率输出;铜金刚石和热管的应用和工艺攻关,克服了多热源、高热流的工程瓶颈。Q频段和W频段固放首次在轨应用,以及V频段固放在地面发射机中的应用。考虑到严苛的空间考核条件以及器件为满足在轨长寿命的降额要求,产品均性能优良稳定。文中的Q频段和W频段固放是我国首次开发并在轨搭载验证的星载连续波固态功率放大器,为我国后续极高频段高通量卫星的载荷实现提供了有力技术支撑。

摘要：The stability control of surrounding rock for large or super-large section chamber is a difficult technical problem in deep mining *** on the in-site geological conditions of Longgu coal mine,this paper used the dynamic module of FLAC3D to study the response characteristics of deep super-large section chamber under dynamic and static combined loading *** showed that under the static loading condition,the maximum vertical stress,deformation and failure range are large,where the stress concentration coefficient is *** maximum roof-to-floor and two-sides deformations are 54.6 mm and 53.1 mm,***,under the dynamic and static combined loading condition:(1)The influence of dynamic load frequency on the two-sides is more obvious;(2)The dynamic load amplitude has the greatest influence on the stress concentration degree,and the plastic failure tends to develop to the deeper;(3)With the dynamic load source distance increase,the response of surrounding rock is gradually *** this basis,empirical equations for each dynamic load conditions were obtained by using regression analysis method,and all correlation coefficients are greater than *** research provided reference for the supporting design of deep super-large section chamber under same or similar conditions.

摘要：Lithium bis(fluorosulfonyl)imide(LiFSI) is a promising replacement for lithium hexafluorosphate due to its excellent properties. A solution to the corrosion of aluminum(Al) current collectors by LiFSI at elevated temperatures is essential. The mechanisms of Al corrosion in LiFSI-based electrolyte at 45 ℃ were studied with density functional theory calculations and spectroscopic investigations. It is found that the irregular, loose and unprotected AlF3 materials caused by the dissolution of co-generated Al(FSI)3 can exacerbate Al corrosion with the increase of temperature. Lithium bis(oxalate)borate(LiBOB) can effectively inhibit the Al corrosion with a robust and protective interphase;this can be attributed to the interfacial interactions between the Al foil and electrolyte. Boron-containing compounds promote the change from AlF3 to LiF, which further reinforces interfacial stability. This work allows the design of an interface to Al foil using LiFSI salt in lithium-ion batteries.

摘要：The intrinsic sluggish conversion kinetics and severe shuttle effect in lithium-sulfur(Li-S)batteries are responsible for their poor reversible capacity and cycling longevity,which have greatly hindered their practical *** address these drawbacks,herein,we design and construct a heterostructured Ni/Ni_(2)P embedded in a mesoporous carbon nanosphere composite(Ni/Ni_(2)P-MCN)for boosting polysulfide catalytic conversion in Li-S *** Ni/Ni_(2)PMCN-modified separator could not only prevent the shuttle effect significantly through abundant chemical adsorptive sites,but also demonstrate superior catalytic reactivities for the conversion of *** importantly,the conductive carbon matrix with an exposed mesoporous structure can serve as an effective physical barrier to accommodate deposited insoluble Li_(2)***,the cells with the Ni/Ni_(2)P-MCN-modified separator exhibit greatly boosted rate capability(431 mA h g^(-1) at 5 C)and cycling stability(a capacity decay of 0.031% per cycle after 1500 cycles).Even at an enhanced sulfur loading of 4.2 mg cm^(-2),a stable and superior areal capacity(about 3.5 mA h cm^(-2))has been *** envision that the unique Ni/Ni_(2)P heterostructure in the porous carbon matrix could offer great potential for highperformance and sustained energy storage devices.

摘要：A mathematical model of gear tooth profiles using the ellipse curve, whose curvature is convenient to control by changing the mathematical parameters as its line of action, was built based on the meshing theory. The equation of undercutting condition was derived from the model. A special epicycloidal tooth profile was also presented. An example gear drive with variation of the ellipse parameters was taken to illustrate the proposed method. The contact ratio of the gear drive designed by the proposed method was analyzed. A comparison of the property of the gear drive designed with the involute gear drive was also carried out. The results confirm that the proposed gear drive has higher contact ratio in comparison with the involute gear drive.

摘要：Using staggered-grid finite difference method to solve seismic wave equation,large spatial grid and high dominant frequency of source cause numerical dispersion,staggeredgrid finite difference method,which can reduce the step spatial size and increase the order of difference,will multiply the calculation amount and reduce the efficiency of solving wave *** optimal nearly analytic discrete(ONAD)method can accurately solve the wave equation by using the combination of displacement and gradient of spatial nodes to approach the spatial partial derivative under rough grid and high-frequency *** this study,the ONAD method is introduced into the field of reverse-time migration(RTM)for performing forward-and reverse-time extrapolation of a two-dimensional acoustic equation,and the RTM based on ONAD method is realized via normalized cross-correlation imaging condition,effectively suppressed the numerical dispersion and improved the imaging *** ONAD method to image the groove model and SEG/EAGE salt dome model by RTM,and comparing with the migration sections obtained by staggered-grid finite difference method with the same time order 2 nd and space order 4 th,results show that the RTM based on ONAD method can effectively suppress numerical dispersion caused by the high frequency components in source and shot records,and archive accurate imaging of complex geological structures especially the fine structure,and the migration sections of the measured data show that ONAD method has practical application value.

摘要：In the paper, we propose a surface wave suppression method in time-frequency domain based on the wavelet transform, considering the characteristic difference of polarization attributes, amplitude energy and apparent velocity between the effective signals and strong surface waves. First, we use the proposed method to obtain time-frequency spectra of seismic signals by using the wavelet transform and calculate the instantaneous polarizability at each point based on instantaneous polarization analysis. Then, we separate the surface wave area from the signal area based on the surface-wave apparent velocity and the average energy of the signal. Finally, we combine the polarizability, energy, and frequency characteristic to identify and suppress the signal noise. Model and field data are used to test the proposed filtering method.

摘要：The process of wound healing is routinely evaluated by histological evaluation in the clinic,which may cause scarring and secondary *** confocal microscopy(RCM)represents a noninvasive,real-time imaging technique that allows in vivo evaluation of the *** RCM was wide-probe-based,which limited its application on uneven and covered *** this study,we report the development of a portable reflectance confocal microscope(PRCM)in which all components were assembled in a handheld *** the size and weight of the PRCM were reduced based on the use of a microelectromechanical system,the resolution was kept at 0.91μm,and the field of view of the system was 343μm×532μ*** used in vivo,the PRCM was able to visualize cellular and nuclear morphology for both mouse and human *** evaluations were then performed on wounds after topically applied mesenchymal stem cells(MSCs)or saline *** PRCM allowed visualization of the formation of collagen bundles,re-epithelization from the wound edge to the wound bed,and hair follicle regeneration,which were consistent with histological ***,we offer new insights into monitoring the effects of topically applied MSCs on the process of wound healing by using *** study illustrates that the newly developed PRCM represents a promising device for real-time,noninvasive monitoring of the dynamic process of wound healing,which demonstrates its potential to diagnose,monitor,or predict disease in clinical wound therapy.