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Comparative study of pulsed laser diode end-pumped thulium-doped 2-µm Q-switched lasers

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Chinese Physics B 2021年第3期30卷 293-299页

作者： Ya wen Zhen fan Lin-Hao Shang Guang-Yong Jin Wang Chao Xin-Yu Chen Chun-ting Wu Jilin Key Laboratory of Solid Laser Technology and Application College of ScienceChangchun University of Science and TechnologyChangchun 130022China

We report pulsed laser diode(LD)end-pumped acoustic Q-switched Tm:YAG laser,Tm:LuAG laser,and Tm:LuYAG laser and the physical properties and spectra of Tm:YAG,Tm:LuAG,and Tm:LuYAG are *** Tm:LuYAG laser is pumped by 785-nm and 788-nm pulses separately,and is compared with Tm:YAG *** output energy values and output wavelengths of Tm:LuAYG lasers pumped by LDs with different wavelengths are obtained and compared with each *** the repetition frequency is 100 Hz,the pulsed Tm:YAG laser has single pulse energy of 15.9 mJ,pulse width of 126.7 ns,and the center wavelength of 2013.36 nm,and the pulsed Tm:LuAG laser possesses single pulse energy of 11.8 mJ,pulse width of 252.4 ns,and the center wavelength of 2023.65 nm,and the pulsed Tm:LuYAG laser output energy values are 12.32 mJ and 12.25 mJ with the slope efficiencies of 12.5%and 11.85%,the center wavelengths of 2017.89 nm and 2027.11 nm,respectively,while the pump sources are 785-nm and 788-nm pulsed LDs,respectively.

关键词： thulium-doped crystal bonded crystal mixed crystal 2-µm laser

The nature of the γ-ray flare associated with blazar 3C 454.3

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Research in Astronomy and Astrophysics 2015年第9期15卷 1455-1466页

作者： wen Hu Zhong-Hui fan Ben-Zhong Da Department of Astronomy Yunnan University Key Laboratory of Astroparticle Physics Yunnan Province

We have studied the simultaneous spectral energy distributions （SEDs） of the 2009 December flare and those of the quiescent state of blazar 3C 454.3 by con- structing a multi-component model We find that all six SEDs can be explained by a one-zone leptonic model involving synchrotron self-Compton （SSC） plus external Compton emission from an accretion disk （ECD） and that from a broad-line region （ECC）. X-ray emission is dominated by the SSC mechanism, and the γ-ray spectrum is well represented by a combination of ECD and ECC processes. Our results indicate that the energy density of the magnetic field and electrons decrease with distance from the central engine, and the Doppler factor increases with the blob moving outward in the development of the 2009 December flare. The increase in the observed flux density is possibly due to the increase in the Doppler factor of the blob. The relation between the Doppler factor σb and the distance from the central black hole suggests the magnetically driven jets span a sub-pc scale, and the relation between the magnetic field Bt and the dimension of the emission region R＇b is in good agreement with what is required by conservation of magnetic flux. The weak ＂harder-when-brighter＂ behavior of the γ-ray spectrum could be a result of the increase in Doppler factor during the outward motion of the blob. The parameters during the quiescent state obviously deviate from those during the flare state. We propose that the flare was likely caused by the ejection of a new blob. The gamma-ray emissions in different states are associated with the evolution of the blob.

关键词： radiation mechanisms: non-thermal -- methods: numerical -- galaxies:active -- quasars: individual (3C 454.3)

Transient neurogenesis in ischemic cortex from Sox2^(+)astrocytes

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Neural Regeneration Research 2023年第7期18卷 1521-1526页

作者： Jia-Lei Yang Hong fan fan-fan Fu Bao-Lin Guo Ying Huang Li Sun wen-ting Wang Jun-Ling Xing Xin-Tian Hu Yu-Qiang Ding Kun Zhang Ying-Zhou Hu Ya-Zhou Wang Department of Neurobiology and Institute of Neurosciences School of Basic MedicineFourth Military Medical UniversityXi’anShaanxi ProvinceChina China National Clinical Research Center for Neurological Diseases Department of NeurologyBeijing Tiantan HospitalBeijingChina Department of Neurology The Second Affiliated Hospital of Xi’an Jiaotong UniversityXi’anShaanxi ProvinceChina State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science Institute of Brain ScienceFudan UniversityShanghaiChina Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences&Yunnan Province Kunming Institute of ZoologyChinese Academy of SciencesKunmingYunnan ProvinceChina

The adult cortex has long been regarded as *** injury can induce neurogenesis in the adult cortex is still ***,we report that focal ischemia stimulates a transient wave of local *** 5′-bromo-2′-deoxyuridine labeling,we demonstrated a rapid generation of doublecortin-positive neuroblasts that died quickly in mouse cerebral cortex following ***-Cre^(ER)-based cell ablation and fate mapping showed a small contribution of neuroblasts by subventricular zone neural stem *** a mini-photothrombotic ischemia mouse model and retrovirus expressing green fluorescent protein labeling,we observed maturation of locally generated new ***,fate tracing analyses using PDGFRα-,GFAP-,and Sox2-Cre^(ER) mice showed a transient wave of neuroblast generation in mild ischemic cortex and identified that Sox2-positive astrocytes were the major neurogenic cells in adult *** addition,a similar upregulation of Sox2 and appearance of neuroblasts were observed in the focal ischemic cortex of Macaca *** findings demonstrated a transient neurogenic response of Sox2-positive astrocytes in ischemic cortex,which suggests the possibility of inducing neuronal regeneration by amplifying this intrinsic response in the future.

关键词： adult astrocyte cortex fate-mapping ischemia local neurogenesis neural stem cells Sox2

Genuine tripartite entanglement and geometric quantum discord in entangled three-body Unruh-DeWitt detector system

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Frontiers of physics 2024年第5期19卷 49-56页

作者： tingting fan Cuihong wen Jiliang Jing Jieci Wang Department of Physics and Collaborative Innovation Center for Quantum Effects and ApplicationsHunan Normal UniversityChangsha 410081China

We studied the quantum correlations of a three-body Unruh-DeWitt detector system using genuine tripartite entanglement(GTE)and geometric quantum discord(GQD).We considered two representative three-body initial entangled states,namely the GHZ state and the W *** demonstrated that the quantum correlations of the tripartite system are completely destroyed at the limit of infinite *** particular,it is found that the GQD of the two initial states exhibits“sudden change”behavior with increasing *** is shown that the quantum correlations of the W state are more sensitive than those of the GHZ state under the effect of Unruh thermal *** GQD is a more robust quantum resource than the GTE,and we can achieve robustness in discord-type quantum correlations by selecting the smaller energy gap in the *** findings provide guidance for selecting appropriate quantum states and resources for quantum information processing tasks in a relativistic setting.

关键词： Unruh-DeWitt detector Unruh effect relativistic quantum information geometric quantum discord

The Research of Customer Loyalty Improvement in Telecom Industry Based on NPS Data Mining

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China Communications 2017年第11期14卷 260-268页

作者： Lili Tong Yiting Wang fan wen Xiaowen Li Beijing University of Posts and Telecommunications Beijing 100876 China School of Economics and Management Beijing University of Posts and Telecommunications Beijing 100876 China School of Computer Science Beijing University of Posts and Telecommunications Beijing 100876 China China Mobile Communications Co. Ltd. Enterprise Customer Branch Beijing 100032 China

In recent years, the telecommunications have used the concept of NPS(Net Promoter Score) for customer relationship management, but there is neither definite theory research nor instructive instance research. However, this paper summarizes an approach with instance case analysis to improve customer loyalty via NPS data mining, which has extensive and practical significance for tele-companies. First, this paper finds some driven forces of customer loyalty, which are relative to customer consumption such as the call duration, the usage of data, ARPU, etc., by using some innovative reasoning-analysis based on IG(Information Gain) and xg-boost decision-making tree model, so the tele-companies can predict the role of individual customer and form daily monitoring on big data, which will save a lot of NPS survey cost. Second, this paper summarizes how customer group feature impacts the relationship between NPS and financial performance. Taking ARPU value as the performance goals, we divide the sample customers into 6 groups and summarize their characteristics based on k-means clustering, and give targeted suggestion of each group.

关键词： net promoter NPS customer loyalty data mining

Efect of Post-Irrigation Aeration on Growth and Quality of Greenhouse Cucumber

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Pedosphere 2013年第6期23卷 790-798页

作者： NIU wen-Quan fan wen-Tao N.PERSAUD ZHOU Xiao-Bo Institute of Soil and Water Conservation Northwest A&F University College of Water Resources and Architectural Engineering Northwest A&F University Department of Crop and Soil Environmental Sciences Virginia Polytechnic Institute and State University Department of Agricultural & Biosystems Engineering Iowa State University

Rhizosphere aeration, irrigation with aerated water, and post-irrigation aeration would positively impact crop growth and yield. The objective of this study was to determine the effect of 4 post-irrigation aeration levels on plant growth, yield, irrigation-use efficiency （IUE）, and fruit market and nutritional quality of greenhouse cucumber under subsurface drip irrigation （SDI） and furrow irrigation （FI）. The post-irrigation aeration levels were 0.00, 0.50, 0.75, and 1.00 times half the estimated porosity of the plot rhizosphere. The experimental design was a two-faetor split-plot in randomized complete blocks with irrigation （FI and SDI） as the main treatments and 4 aeration levels as the sub-treatments. Ridge and furrow main plots （2.4 m ~ 2.4 m） with 4 ridges were replicated 5 times. Each of the 4 ridges （1.44 m2 in area） in the main plots was used as a sub-treatment plot. The results showed that post-irrigation aeration enhanced greenhouse cucumber plant growth, yield, IUE, and fruit market and nutritional quality. These parameters generally increased with increasing aeration levels under both FI and SDI. The aeration effect was generally higher under SDI than FI, and the IUE under SDI was almost twice that under FI. Further investigation would be required to elucidate the plant physiological mechanisms and soil processes responsible for the observed effects.

关键词： fruit quality furrow irrigation irrigation-use efficiency rhizosphere subsurface drip irrigation

Biological Cycles of Mineral Elements in a Young Mixed Stand in Abandoned Mining Soils

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Journal of Integrative Plant Biology 2007年第9期49卷 1284-1293页

作者： Da-Lun Tian wen-Hua Xiang wen-De Yan wen-Xing Kang Xiang-wen Deng Zhu fan Research Section of Ecology Central-South University of Forestry & Technology Changsha 410004 China

Phytoremediation as a sustainable and inexpensive technology based on the removal of pollutants from the environment by plants is becoming an increasingly important objective in plant research. In this study, biological cycles of five nutrient elements （N, P, K, Ca, and Mg） and eight heavy metal elements （Fe, Cu, Zn, Mn, Cd, Ni, Pb and Co） were examined in young paniculed goldraintree （Koelreuteria paniculata Laxm） and common elaeocarpus （Elaeocarpus decipens） mixed stands in an abandoned mining area. We found that after vegetation restoration in abandoned mining areas, the organic matter and concentrations of nutrient elements were significantly increased and the heavy metal elements were significantly decreased, the annual retention, uptake and return were 75.0, 115.4, and 40.3 kg/hm^2 for nutrient elements, and 1 878.0, 3 231.0 and 1 353.0 g/hm^2 for heavy metal elements, respectively, with the utilization coefficient, cycling coefficient and turnover rate of 0.92, 0.35 and 0.32 for nutrient elements, and 1.24, 0.42 and 1.92 for heavy metal elements, respectively. Our results suggested that the vegetation restoration in abandoned mining areas had significant effects in improving environmental conditions, enhancing soil available nutrients, and ensuring human health.

关键词： abandoned mining areas biological cycle common elaeocarpus (Elaeocarpus decipens) heavy metal elements mixed stand paniculed goldraintree (Koelreuteria paniculata).

Effect of Transverse Grain Boundary on Microstructure,Texture and Mechanical Properties of Drawn Copper Wires

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Journal of Materials Science & Technology 2014年第2期30卷 184-191页

作者： Jian Chen Xiaoguang Ma wen Yan Feng Xia Xinhui fan School of Mat Science and Chemical Engineering Xi'an Technological University

In the present study, microstructure and texture of drawn copper wires with a large number of transverse grain boundaries have been characterized and their mechanical properties have been analyzed. The results show that the texture evolution is accelerated by transverse grain boundary and the saturation value 60% of volume fraction of 〈111〉 fiber texture component is reached rapidly with increasing strain. For the microstructure of drawn wires with a large number of transverse grain boundaries, the critical strain, where lamellar boundaries form, is less than that for wires with equiaxed grains or columnar grains （all grain boundaries parallel to axis direction）. Since transverse grain boundary accelerates grain subdivision and dislocation density increases rapidly in drawn wires with a large number of transverse grain boundaries, there are a higher flow stress and a higher work hardening rate.

关键词： Transverse grain boundary Cold drawing Texture Microstructure Ultimate tensile strength

Synthesis of fluorescent multisubstituted polyquinolines by cascade C–H activation-based polyannulations of isonicotinamides and diynes

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Science China Chemistry 2023年第4期66卷 1139-1149页

作者： Dongyang fan Fei Zhang Jie Cui Dong Wang ting Han Ben Zhong Tang Center for AIE Research Shenzhen Key Laboratory of Polymer Science and TechnologyGuangdong Research Center for Interfacial Engineering of Functional MaterialsCollege of Materials Science and EngineeringShenzhen UniversityShenzhen 518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China School of Science and Engineering Shenzhen Institute of Aggregate Science and TechnologyThe Chinese University of Hong KongShenzhen 518172China

The development of new and efficient polymerization strategies for the synthesis of multisubstituted fused heterocyclic polymers with attractive properties is of great ***,a rhodium-catalyzed polyannulation route is developed for the in situ generation of multisubstituted polyquinolines with efficient aggregate-state *** on the cascade C-H activation of isonicotinamides and their annulations with internal diynes,a series of high molecular weight polyquinolines are efficiently produced in high yields of up to 99%in a facile and atom-economical *** conventional two-component stepwise polymerizations,these polyannulation reactions are tolerant to monomer non-stoichiometric conditions and proceed even more thoroughly in the presence of an excess amount of the isonicotinamide *** from the unique multisubstituted polyquinoline structures,the obtained polymers show high thermal and morphological stability,useful aggregation-induced emission(AIE)properties,and tunable aggregated-state fluorescence *** AIE-active polyquinoline is demonstrated to be a good lysosome-specific fluorescent probe with low cytotoxicity and excellent photostability.

关键词： fused heterocyclic polymers polyannulation polyquinolines aggregation-induced emission bioimaging