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一种基于小波变换图像压缩编码方法

武汉汽车工业大学学报 1999年第6期21卷 33-36,59页

作者：杭小庆张素文王天珍武汉测绘科技大学武汉汽车工业大学

提出了一种新的小波变换图像编码方案，即改进的零树法混合量化编码方案。先对图像进行四层小波变换，再舍去第一层小波变换后的高频分量，然后对余下的数据进行零树法量化编码，最后，对零树法量化编码的结果进行游程编码。实验结果表... 详细信息

提出了一种新的小波变换图像编码方案，即改进的零树法混合量化编码方案。先对图像进行四层小波变换，再舍去第一层小波变换后的高频分量，然后对余下的数据进行零树法量化编码，最后，对零树法量化编码的结果进行游程编码。实验结果表明，该方案优于直接零树法量化编码方案。

关键词：图像编码小波变换图像压缩量化编码零树法

pH值和表面活性剂对桦褐孔菌降解甘蔗渣效率的影响

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浙江理工大学学报（自然科学版） 2021年第5期45卷 704-710页

作者：张超王天珍陈肖肖徐向群浙江理工大学生命科学与医药学院杭州310018

为了提高桦褐孔菌(Inonotus obliquus)液体发酵选择性降解甘蔗渣木质素的效率,采用两因素多水平的方法进行正交实验,并通过正交实验确定发酵条件参数,对不同发酵时间处理后的甘蔗渣进行糖化水解,分析pH值和表面活性剂(Tween-80)对桦褐... 详细信息

为了提高桦褐孔菌(Inonotus obliquus)液体发酵选择性降解甘蔗渣木质素的效率,采用两因素多水平的方法进行正交实验,并通过正交实验确定发酵条件参数,对不同发酵时间处理后的甘蔗渣进行糖化水解,分析pH值和表面活性剂(Tween-80)对桦褐孔菌降解甘蔗渣的影响。结果表明:当pH值为6.0,Tween-80添加量为0.1%时,桦褐孔菌表现出较强的选择性降解效率,最高木质素降解率由对照的21.3%提升到76.6%,并且达到最高木质素降解率的发酵时间由10 d缩短至2 d,最高产糖量和糖化效率也分别由对照的188.0 mg/g、22.8%提升至246.4 mg/g、30.5%;pH值6.0和0.1%Tween-80对桦褐孔菌选择性降解甘蔗渣木质素有较好的促进作用。

关键词：桦褐孔菌液体发酵选择性降解 pH值 Tween-80 糖化作用

Performance analysis of two-way relay mixed RF/FSO system with co-channel interference

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Optoelectronics Letters 2025年第2期21卷 85-89页

作者： wang Zhuo School of Optoelectronic Engineering Changchun University of Science and Technology

In this paper,the performance of a two-way relay (TWR) mixed radio frequency/free space optical (RF/FSO) system with co-channel interference (CCI) is *** from interference-limited one-way relay (OWR) system,CCIs should be considered at both relay and users in TWR ***,opportunistic user schedule is applied to select the user with the largest signal to interference plus noise ratio (SINR).Exact and asymptotic outage probability (OP) is *** bit error rate (BER) is further presented to evaluate the overall *** results show that the performance of a TWR system is dominated by the uplink or downlink whose performance is severer.

关键词： Bit error rate

Wafer‑Scale Vertical 1D GaN Nanorods/2D MoS_(2)/PEDOT:PSS for Piezophototronic Effect‑Enhanced Self‑Powered Flexible Photodetectors

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Nano-Micro Letters 2025年第3期17卷 102-116页

作者： Xin Tang Hongsheng Jiang Zhengliang Lin Xuan wang Wenliang wang Guoqiang Li State Key Laboratory of Luminescent Materials and Devices South China University of TechnologyGuangzhou 510640People’s Republic of China Department of Electronic Materials School of Materials Science and EngineeringSouth China University of TechnologyGuangzhou 510640People’s Republic of China

van der Waals(vdW)heterostructures constructed by lowdimensional(0D,1D,and 2D)materials are emerging as one of the most appealing systems in next-generation flexible ***,hand-stacked vdW-type photodetectors are not compatible with large-areaarray fabrication and show unimpressive performance in self-powered ***,vertical 1D GaN nanorods arrays(NRAs)/2D MoS_(2)/PEDOT:PSS in wafer scale have been proposed for self-powered flexible photodetectors arrays *** as-integrated device without external bias under weak UV illumination exhibits a competitive responsivity of 1.47 A W^(−1)and a high detectivity of 1.2×10^(11)Jones,as well as a fast response speed of 54/71μs,thanks to the strong light absorption of GaN NRAs and the efficient photogenerated carrier separation in type-II ***,the strain-tunable photodetection performances of device have been ***,the device at−0.78%strain and zero bias reveals a significantly enhanced photoresponse with a responsivity of 2.47 A W^(−1),a detectivity of 2.6×10^(11)Jones,and response times of 40/45μs,which are superior to the state-of-the-art self-powered flexible *** work presents a valuable avenue to prepare tunable vdWs heterostructures for self-powered flexible photodetection,which performs well in flexible sensors.

关键词： Vertical nanorod arrays van der Waals heterostructure Piezophototronic effect Self-powered photodetection Flexible sensors

Silk damping in scalar-induced gravitational waves: a novel probe for new physics

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 79-85页

作者： Yan-Heng Yu Sai wang Theoretical Physics Division Institute of High Energy Physics Chinese Academy of Sciences School of Physics University of Chinese Academy of Sciences

Silk damping is well known in the study of cosmic microwave background（CMB） and accounts for suppression of the angular power spectrum of CMB on large angular multipoles. In this article, we study the effect of Silk damping on the scalar-induced gravitational waves（SIGWs）. Resulting from the dissipation of cosmic fluid, the Silk damping notably suppresses the energydensity spectrum of SIGWs on scales comparable to a diffusion scale at the decoupling time of weakly-interacting particles. The effect offers a novel observable for probing the underlying particle interaction, especially for those mediated by heavy gauge bosons beyond the standard model of particles. We anticipate that pulsar timing arrays are sensitive to gauge bosons with mass ～10～3-10～4 GeV, while space-and ground-based interferometers to those with mass ～10～7-1012GeV, leading to essential complements to on-going and future experiments of high-energy physics.

关键词： scalar-induced gravitational waves Silk damping new physics

Mechanism of inflammatory response and therapeutic effects of stem cells in ischemic stroke:current evidence and future perspectives

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Neural Regeneration Research 2025年第1期20卷 67-81页

作者： Yubo wang Tingli Yuan Tianjie Lyu Ling Zhang Meng wang Zhiying He Yongjun wang Zixiao Li Vascular Neurology Department of NeurologyBeijing Tiantan HospitalCapital Medical UniversityBeijingChina China National Clinical Research Center for Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Shanghai Engineering Research Center of Stem Cells Translational Medicine ShanghaiChina National Center for Healthcare Quality Management in Neurological Diseases Beijing Tiantan HospitalCapital Medical UniversityBeijingChina Institute for Regenerative Medicine Shanghai East HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina Chinese Institute for Brain Research BeijingChina Research Unit of Artificial Intelligence in Cerebrovascular Disease Chinese Academy of Medical SciencesBeijingChina Beijing Engineering Research Center of Digital Healthcare for Neurological Diseases BeijingChina

Ischemic stroke is a leading cause of death and disability worldwide,with an increasing trend and tendency for onset at a younger ***,in particular,bears a high burden of stroke *** recent years,the inflammatory response after stroke has become a research hotspot:understanding the role of inflammatory response in tissue damage and repair following ischemic stroke is an important direction for its *** review summarizes several major cells involved in the inflammatory response following ischemic stroke,including microglia,neutrophils,monocytes,lymphocytes,and ***,we have also highlighted the recent progress in various treatments for ischemic stroke,particularly in the field of stem cell ***,understanding the complex interactions between inflammation and ischemic stroke can provide valuable insights for developing treatment strategies and improving patient *** cell therapy may potentially become an important component of ischemic stroke treatment.

关键词： cell therapy immune cell inflammatory ischemic stroke stem cell

Distribution and mapping of temperate savanna in the sandy lands of eastern China

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Science China Earth Sciences 2025年第1期68卷 128-141页

作者： Xiaoya LI Feng wang Tao DUAN Kaijie YANG Bin YANG Chunmei wang Xin TIAN Qi LU Institute of Ecological Conservation and Restoration Institute of Desertification Studies Chinese Academy of Forestry Institute of Desertification Institute of Desertification Studies Chinese Academy of Forestry Institute of Great Green Wall Satellite Application Centre for Ecology and Environment MEE Institute of Microelectronics Chinese Academy of Sciences Aerospace Information Research Institute Chinese Academy of Sciences Institute of Forest Resource Information Techniques Chinese Academy of Forestry

Savannas are distributed globally across various *** perform a significant socioeconomic role in regulating net primary productivity and the terrestrial carbon *** to the high spatial heterogeneity induced by the mixed distribution of trees and grasses,current global land-cover classification maps often classify savannas as forests or grasslands Temperate savannas in China cover a vast area,yet their spatial patterns and extent remain poorly *** study developed a novel remote sensing temperate savannas mapping method by integrating very high-resolution （VHR） unmanned aerial vehicle （UAV） and GF-6 satellite imagery based on the vegetation structure characteristics of temperate savannas using the FAO definition of *** and validation datasets were collected from VHR UAV imagery covering the main temperate savannah types with a ground area of 1818 *** fractional woody vegetation cover （FWVC） and fractional herbaceous vegetation cover （FHVC） in temperate savannas were estimated by integrating Classification and Regression Tree and Random Forest *** current distribution of temperate savannas in the Horqin and Otindag Sandy Lands of Eastern China was mapped to a unit area of 0.5 *** root-mean-square error （RMSE） values for the FWVC and FHVC models were 10.69% and 11.67%,and the R2values were 0.66 and 0.63,*** assessment indicated that the new temperate savanna map had high identification accuracy,with a Kappa coefficient of 0.70,overall accuracy of 0.88,and average accuracy of *** savannas in the sandy lands of eastern China were primarily distributed in the northern Horqin Sandy Land the central and eastern regions of the Otindag Sandy Land,and the transition zone from the southern slopes of the Greater Khingan Mountains to the plains,covering a total area of 3.27×10～6 *** main savannah types were elm,oak/maple,and shrub *** savannas were widely distributed in the Otindag Sandy

关键词： Temperate savanna UAV imagery GF-6 Fractional woody vegetation cover Fractional herbaceous vegetation cover Machine learning

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Simulations of electron zebra stripes in the inner radiation belt using a composite empirical electric field model

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Science China Earth Sciences 2025年第1期68卷 27-38页

作者： Ziyang wang Ying LIU Qiugang ZONG Hong ZOU Yuguang YE Xuzhi ZHOU Chao YUE Shan wang Institute of Space Physics and Applied Technology Peking University State Key Laboratory of Lunar and Planetary Science Macau University of Science and Technology

The phenomenon termed “zebra stripes” manifests as regular patterns in the energy-space(L shell) spectrum of energetic electrons(ranging from tens to hundreds ke V) within the inner radiation belt. These structures exhibit drift-periodic behavior and commonly arise from large-scale electric field perturbations near the substorm onsets. In this study, we introduce a composite electric field model and replicate the formation, structure, and evolution of zebra stripes using a bounce-averaged test particle code under this electric field model. High-resolution measurements of energetic electrons obtained from the Van Allen Probes and the recently launched Macao Science Satellites-1 are used as initial conditions and served to validate our test particle simulations. Comparative analyses between observed data and simulations demonstrate our test particle method's efficacy in capturing zebra stripes' general behavior. Moreover, the composite model proves capable of reproducing realistic variations in the electric field within the inner radiation belt to a certain extent. Nevertheless, subtle differences emerge in the flux strength and the positions of stripes. These disparities primarily stem from limitations inherent in the electric field model and the initial conditions of the simulation. Acknowledging that the model represents an average case, it is conceivable that real-world scenarios may deviate from the average, thereby introducing variations in the observed phenomena.

关键词： Zebra stripes Inner radiation belt Large-scale electric fields Van Allen Probes Macao Science Satellite

受激辐射光子与引起受激辐射光子同模的全量子力学证明

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陕西师大学报(自然科学版) 1985年第2期 48-55页

作者：付克德王天真郇宜贤陕西师大物理系

在量子力学中处理光的发射和吸收问题时,由于对外来电磁场采用了经典描述,所得结果不令人满意。如,它不能解释受激辐射光子与引起受激辐射光子二者为什么处于同一量子态或同模;与它们相联系的电磁波为什么在频率、相位、偏振状态和传播... 详细信息

在量子力学中处理光的发射和吸收问题时,由于对外来电磁场采用了经典描述,所得结果不令人满意。如,它不能解释受激辐射光子与引起受激辐射光子二者为什么处于同一量子态或同模;与它们相联系的电磁波为什么在频率、相位、偏振状态和传播方向是完全相同的或同模。而这正是激光理论中最基本的问题。本文将对实物粒子和电磁场都采用量子力学描述,从而对上述问题提供一种全量子力学证明。

关键词：受激辐射模场量子力学光子玻色子