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Intramolecular energy transfer between chromophores separated by a rigid steroid bridge Ⅱ.Energy transfer as a probe to determine the ratio of two epimers

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Chinese Journal of Chemistry 1990年第1期8卷 61-67页

作者： TONG zhen-he yang Guo-Qiang WU Shi-Kang Institute of Photographic Chemistry,Academia Sinica,Beijing 100012 Institute of Photographic Chemistry Academia Sinica Beijing 100012

The singlet-singlet intramolecular energy transfer between naphthalene moiety and dansyl group held apart by a rigid steroid bridge was investigated for two molecules:3β-(1-naphthyl)acetoxy- 17α-dansyl-△~5androstene(3a)and 3β-(1-naphthyl)acetoxy-17β-dansyl-△~5androstene(3b).The rates of energy transfer for 3a and 3b in cyclohexane are 6.9×10~6 and 1.1×10~8s^(-1) *** difference in energy transfer rate between 3a and 3b is attributed to the different donor-acceptor separation and *** ratio of the two epimers in the synthesized product mixture was obtained from the fluorescence decay measurements.

关键词： Energy transfer as a probe to determine the ratio of two epimers

Reconstructing forest and grassland cover changes in China over the past millennium

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Science China Earth Sciences 2025年第1期68卷 94-110页

作者： Fanneng he Fan yang Yafei WANG Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Key Research Institute of Yellow River Civilization and Sustainable Development Henan University University of Chinese Academy of Sciences

Historical forest and grassland cover changes not only are critical indicators for quantifying ecological and environmental change processes but also serve as fundamental data for long-term climate change simulations and terrestrial ecosystem carbon emission assessments. However, because of limitations in historical data, quantitative estimations and spatially gridded reconstructions of these changes remain challenging, necessitating further methodological exploration. This study focused on China's present-day land area over the past millennium, objectively capturing the characteristics and drivers of forest and grassland cover changes. On this basis, using the forest transition theory and the space-for-time substitution method, we depicted the historical deforestation process as an inverted “S” curve and developed a model to reconstruct historical forest area changes based on the functional relationship between the forest area and population size dynamics. Subsequently, a gridded forest allocation model was established on the basis of deforestation tendencies. For the grassland cover, we implemented regionspecific methods, such as the cropland area deduction method and the habitat constraint method, to quantitatively reconstruct historical changes. Consequently, we obtained provincial forest and grassland area changes over the past millennium and mapped 10-km-resolution gridded data of forest and grassland cover. The results indicated the following.(1) The methods developed using population data as a proxy objectively reproduced the spatiotemporal evolution of forest and grassland cover in China over the past millennium. These feasible methods offer a novel pathway for the quantitative reconstruction of historical forest and grassland cover changes.(2) The data indicated that China's forest area generally decreased over the past millennium, characterized by a “decrease-then-increase” pattern. The forest area experienced three distinct phases: a slow decline(AD 1000

关键词： Land use and land cover change Forest Grassland Quantitative reconstruction Gridded reconstruction China historical period

Joint Estimation of SOH and RUL for Lithium-Ion Batteries Based on Improved Twin Support Vector Machineh

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Energy Engineering 2025年第1期122卷 243-264页

作者： Liyao yang HongyanMa Yingda Zhang Wei he School of Electrical and Information Engineering Beijing University of Civil Engineering and ArchitectureBeijing100044China Institute of Distributed Energy Storage Safety Big Data Beijing100044China Beijing Key Laboratory of Intelligent Processing for Building Big Data Beijing100044China

Accurately estimating the State of health(SOH)and Remaining Useful Life(RUL)of lithium-ion batteries(LIBs)is crucial for the continuous and stable operation of battery management ***,due to the complex internal chemical systems of LIBs and the nonlinear degradation of their performance,direct measurement of SOH and RUL is *** address these issues,the Twin Support Vector Machine(TWSVM)method is proposed to predict SOH and ***,the constant current charging time of the lithium battery is extracted as a health indicator(HI),decomposed using Variational Modal Decomposition(VMD),and feature correlations are computed using Importance of Random Forest Features(RF)to maximize the extraction of critical factors influencing battery performance ***,to enhance the global search capability of the Convolution Optimization Algorithm(COA),improvements are made using Good Point Set theory and the Differential Evolution *** Improved Convolution Optimization Algorithm(ICOA)is employed to optimize TWSVM parameters for constructing SOH and RUL prediction ***,the proposed models are validated using NASA and CALCE lithium-ion battery *** results demonstrate that the proposed models achieve an RMSE not exceeding 0.007 and an MAPE not exceeding 0.0082 for SOH and RUL prediction,with a relative error in RUL prediction within the range of[-1.8%,2%].Compared to other models,the proposed model not only exhibits superior fitting capability but also demonstrates robust performance.

关键词： State of health remaining useful life variational modal decomposition random forest twin support vector machine convolutional optimization algorithm

Na^+和K^+对水泥基材料早期收缩性能的影响

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水利学报 2016年第11期47卷 1345-1351页

作者：何真李洋蔡新华陈晓润武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072

利用压汞、纳米压痕以及27Al固体核磁共振方法,系统研究了不同碱金属离子(Na^+和K^+)与含量对水泥基材料早期自收缩和干燥收缩性能的影响规律。结果表明,超量的Na^+或K^+均促进了水泥基材料早期自收缩和干燥收缩,但K^+的促进作用明显大... 详细信息

利用压汞、纳米压痕以及27Al固体核磁共振方法,系统研究了不同碱金属离子(Na^+和K^+)与含量对水泥基材料早期自收缩和干燥收缩性能的影响规律。结果表明,超量的Na^+或K^+均促进了水泥基材料早期自收缩和干燥收缩,但K^+的促进作用明显大于Na^+,其机制在于:(1)K^+比Na^+更易促进水泥基材料中小于50纳米孔数量的增加,这使得超量K^+水泥基材料在干燥时具有更大的收缩驱动力;(2)虽然K^+比Na^+更易促进水泥基材料生成高密度水化硅酸钙(HD C-S-H),但同时超量K^+水泥基材料中C-S-H总量也较高,大量的C-S-H是导致较高早期收缩的根源;(3)与Na^+相比,K^+更明显地阻碍了钙矾石(AFt)晶体的形成,削弱了AFt的骨架作用,且K^+可促使AFt向单硫型水化硫铝酸钙(AFm)转变,因而导致超量K^+水泥基材料更易发生收缩变形。

关键词：收缩碱类型孔结构水化硅酸钙纳米压痕核磁共振

Effect of Progressive Substitution of Cement and Lime by Powdered Shells Used as a Curing Agent for Dredged Soil in a Port Area

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期40卷 88-102页

作者： SUN yang WANG Faxin SU Yaying LI Yiwei he Feng College of Harbour Coastal and Offshore EngineeringHohai UniversityNanjing 210098China Huai'an Research Institute Hohai UniversityHuai'an 223025China Jiangsu Fangyang Industrial Investment Corp.Ltd. Lianyungang 210098China

This study aimed to address the challenges of solid waste utilization,cost reduction,and carbon reduction in the treatment of deep-dredged soil at Xuwei Port in Lianyungang city of *** research in this area was ***,a curing agent made from powdered shells was used to solidify the dredged soil in *** employed laboratory orthogonal tests to investigate the physical and mechanical properties of the powdered shell-based curing *** was collected by conducting experiments to assess the role of powdered shells in the curing process and to determine the optimal ratios of powdered shells to solidified soil for different *** development of strength in solidified soil was studied in both seawater and pure water *** study revealed that the strength of the solidified soil was influenced by the substitution rate of powdered shells and their interaction with *** cement content had a positive effect on *** high-strength solidified soil,the recommended ratio of wet soil:cement:lime:powdered shells were 100:16:4:4,while for low-strength solidified soil,the recommended ratio was 100:5.4:2.4:***,under appropriate conditions,improved short-term strength by promoting the formation of expansive ettringite minerals that contributed to cementation and *** findings suggest that the combination of cement and powdered shells is synergistic,positively affecting the strength of solidified *** recommended ratios provide practical guidance for achieving desired strength levels while considering factors such as cost and carbon *** role of seawater in enhancing short-term strength through crystal formation is noteworthy and can be advantageous for certain *** conclusion,this research demonstrates the potential of using a powdered shell-based curing agent for solidifying dredged soil in an environmentally friendly and cost-effective *** recommended ratios for different str

关键词： carbon reduction and solidification dredged soil abandoned shells orthogonal test chemical additives(lime and cement) unconfined compressive strength(UCS)

Characteristic changes in astrocyte properties during astrocyte-to-neuron conversion induced by NeuroD1/Ascl1/Dlx2

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Neural Regeneration Research 2025年第6期20卷 1801-1815页

作者： Qing he zhen Wang Yuchen Wang Mengjie Zhu Zhile Liang Kanghong Zhang Yuge Xu Gong Chen GHM Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina

Direct in vivo conversion of astrocytes into functional new neurons induced by neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocytes into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study, we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocytes in mouse cortices subjected to stab injury, resulting in a series of significant changes in astrocyte properties. Initially, the three neural transcription factors were exclusively expressed in the nuclei of astrocytes. Over time, however, these astrocytes gradually adopted neuronal morphology, and the neural transcription factors was gradually observed in the nuclei of neuron-like cells instead of astrocytes. Furthermore,we noted that transcription factor-infected astrocytes showed a progressive decrease in the expression of astrocytic markers AQP4(astrocyte endfeet signal), CX43(gap junction signal), and S100β. Importantly, none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively convert reactive astrocytes into neurons in the adult mammalian brain.

关键词： aquaporin-4 Ascl1 astrocyte cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 reprogramming

The detection, extraction and parameter estimation of extreme-mass-ratio inspirals with deep learning

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 86-96页

作者： Qianyun Yun Wen-Biao Han Yi-yang Guo he Wang Minghui Du Hangzhou Institute for Advanced Study University of Chinese Academy of Sciences Shanghai Astronomical Observatory Chinese Academy of Sciences School of Physics and Astronomy Shanghai Jiao Tong University School of Astronomy and Space Science University of Chinese Academy of Sciences Taiji Laboratory for Gravitational Wave Universe (Beijing/Hangzhou) University of Chinese Academy of Sciences Lanzhou Center for Theoretical Physics Key Laboratory of Theoretical Physics of Gansu Province Key Laboratory of Quantum Theory and Applications of MoE Lanzhou University Institute of Theoretical Physics & Research Center of Gravitation Lanzhou University International Centre for Theoretical Physics Asia-Pacific (ICTP-AP) University of Chinese Academy of Sciences (UCAS) Center for Gravitational Wave Experiment National Microgravity Laboratory Institute of Mechanics Chinese Academy of Sciences

One of the primary goals of space-borne gravitational wave detectors is to detect and analyze extreme-mass-ratio inspirals(EMRIs). This task is particularly challenging because EMRI signals are complex, lengthy, and faint. In this work, we introduce a2-layer convolutional neural network(CNN) approach to detect EMRI signals for space-borne detectors, achieving a true positive rate(TPR) of 96.9% at a 1% false positive rate(FPR) for signal-to-noise ratio(SNR) from 50 to 100. Especially, the key intrinsic parameters of EMRIs such as the mass, spin of the supermassive black hole(SMBH) and the initial eccentricity of the orbit can also be inferred directly by employing a neural network. The mass and spin of the SMBH can be determined at 99% and 92% respectively. This will greatly reduce the parameter spaces and computing cost for the following Bayesian parameter *** model also has a low dependency on the accuracy of the waveform model. This study underscores the potential of deep learning methods in EMRI data analysis, enabling the rapid detection of EMRI signals and efficient parameter estimation.

关键词： gravitational wave EMRIs deep-learing

Intramolecular energy transfer between chromophores separated by a rigid steroid bridge——Ⅰ.Singlet and triplet energy transfer in 3β(1-naphthyl)acetoxy-⊿~5-androsten-17-one

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Acta Chimica Sinica English Edition 1989年第5期7卷 450-457页

作者： TONG zhen-he yang Guo-Qiang WU Shi-Kang Institute of Photographic Chemistry,Academia Sinica,Beijing Institute of Photographic Chemistry Academia Sinica Beijing

Intramolecular transfer of both singlet and triplet electronic excitation between the naphthalene moiety and the carbonyl group in 3β-(1-naphthyl)acetoxy-⊿~5-androsten-17-one was *** with 280 nm light selectively leads to excitation of the naphthalene moiety. Transfer of the singlet excitation from the naphthalene moiety to the carbonyl group occurs by dipole- dipole resonance *** measured rates for such energy transfer in several solvents agree with that calculated from Frster *** efficient intersystem crossing,the carbonyl group transfers triplet excitation back to the naphthalene moiety via electron exchange *** combination of singlet and triplet energy transfer with the high efficiency of intersystcm crossing of carbonyl group results in the phosphorescence enhancement of naphthalene moiety.

关键词： naphthyl)acetoxy Singlet and triplet energy transfer in 3 androsten-17-one

泛素对小鼠急性肺损伤肺组织细胞黏附分子及肿瘤坏死因子-α水平的影响

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实用医学杂志 2010年第15期26卷 2711-2713页

作者：邢娟何振扬海南省人民医院加强治疗科海口市570311

目的:研究泛素对盲肠结扎穿孔(CLP)致小鼠急性肺损伤时肺组织细胞间黏附分子-1(ICAM-1)、血管细胞黏附分子-1(VCAM-1)和肿瘤坏死因子-α(TNF-α)水平的影响。方法:60只小鼠随机分为CLP组、假手术组、泛素1组(10mg/kg,UB1)、泛素2组(5mg/... 详细信息

目的:研究泛素对盲肠结扎穿孔(CLP)致小鼠急性肺损伤时肺组织细胞间黏附分子-1(ICAM-1)、血管细胞黏附分子-1(VCAM-1)和肿瘤坏死因子-α(TNF-α)水平的影响。方法:60只小鼠随机分为CLP组、假手术组、泛素1组(10mg/kg,UB1)、泛素2组(5mg/kg,UB2)和泛素3组(1mg/kg,UB3),每组12只。除假手术组外,其他组小鼠均行CLP。手术后6h,UB1、2、3组尾静脉给予泛素,CLP组和假手术组则给予等体积氯化钠溶液。手术后7h,所有小鼠眼眶采血后处死,收集肺组织。ELISA法测定9%肺组织匀浆ICAM-1、VCAM-1、TNF-α水平和血清TNF-α水平。结果:3个UB组肺组织ICAM-1、VCAM-1和TNF-α水平较CLP组及假手术组低,部分两两间的差异达到统计学意义。3个UB组血清TNF-α水平较CLP组略低,但远高于假手术组。UB3组肺组织ICAM-1、VCAM-1水平和血清TNF-α低于UB1、2组,其中与UB1组VCAM-1的差异具有统计学意义;UB3组肺组织TNF-α水平则略高于UB1、2组。结论:外源性泛素不仅对CLP导致的肺组织ICAM-1、VCAM-1和TNF-α水平的增高有显著的抑制作用,同时,对手术创伤等其他因素引起的升高亦有一定的抑制作用;但泛素对血清TNF-α水平影响较小。

关键词：呼吸窘迫综合征,成人泛素细胞间黏附分子-1 血管细胞黏附因子-1 肿瘤坏死因子-α