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Quantitative division of succession and spatial patterns among different stand developmental stages in Changbai Mountains

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Journal of Mountain Science 2019年第9期16卷 2063-2078页

作者： GONG zhi-wen KANG xin-gang GU Li College of Economics and Management Research Center of Resource Economics and Environment Management Northwest A8J7 University Yangling 712100 China College of Forestry Northwest A&F University Yang ling 712100 China College of Forestry Beijing Forestry University Beijing 100083 China

Broadleaf-Korean pine forests exhibit high species richness and distinctive species composition, which are currently becoming more dominant among natural forests in Changbai Mountains of northeastern China. Understanding the ecological process of restored vegetation is quite important for ecosystem reconstruction. Distinguishing stand development stages and analyzing the dynamic spatial patterns could provide insights into significant community coexistence mechanisms. In the present study, eight permanent study areas were established according to the substituting space for time method in Changbai Mountains of north-eastern China. The optimal division method was used to quantify the successional series into different stand development stages, and the point pattern analysis method(L(r) function) was used to analyse the dynamic changes in spatial patterns and interspecific associations. Our results suggested that:(1) The stand development process was divided into five stages: the first three stages were poplar-birch secondary forests in different stages of recovery, the fourth stage was thespruce-fir mixed forest, and the last stage was the primary broadleaf-Korean pine forest;(2) The spatial pattern showed an aggregated distribution at a small scale and changed to a random distribution as the scale increased in poplar-birch secondary forests, but the spatial pattern appeared to be randomly distributed in spruce-fir mixed forest and broadleafKorean pine forest;(3) The interspecific associations between pioneer species and climax species changed from negative to positive among the different stand stages, and environmental resources were shared among these species. Interspecific differences in shade tolerance among the tree species were key determinants of forest dynamics and structure. Our study is vital to the understanding of the forest development;thus, the spatial change features should receive greater attention when forest management is being planned and restoratio

关键词： Dynamic spatial patterns Interspecific association Optimal division method Stand developmental stages Space for time substitution

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hh-transforms of Positivity Preserving Semigroups and Associated Markov Processes

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Acta Mathematica Sinica,English Series 2011年第2期27卷 369-376页

作者： xin Fang HAN zhi-Ming MA Wei SUN School of Mathematical Science and Computing Technology Central South University Changsha 410083 P. R. China Institute of Applied Mathematics AMSS Chinese Academy of Sciences Beijing 100190 P. R. China Department of Mathematics and Statistics Concordia University Montreal H3G 1M8 Canada

The hh-transforms of positivity preserving semigroups and their associated Markov processes are investigated in this paper. In particular, it is shown that any quasi-regular positivity preserving coercive form is hh-a... 详细信息

关键词： hh-transform positivity preserving semigroup positivity preserving coercive form Markov process weak duality

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Hyperbaric oxygen preconditioning improves postoperative cognitive dysfunction by reducing oxidant stress and inflammation

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Neural Regeneration Research 2017年第2期12卷 329-336页

作者： zhi-xin Gao Jin Rao Yuan-hai Li Department of Anesthesiology First Affiliated Hospital of Anhui Medical University

Postoperative cognitive dysfunction is a crucial public health issue that has been increasingly studied in efforts to reduce symptoms or prevent its occurrence. However, effective advances remain lacking. Hyperbaric oxygen preconditioning has proved to protect vital organs, such as the heart, liver, and brain. Recently, it has been introduced and widely studied in the prevention of postoperative cognitive dysfunction, with promising results. However, the neuroprotective mechanisms underlying this phenomenon remain controversial. This review summarizes and highlights the definition and application of hyperbaric oxygen preconditioning, the perniciousness and pathogenetic mechanism underlying postoperative cognitive dysfunction, and the effects that hyperbaric oxygen preconditioning has on postoperative cognitive dysfunction. Finally, we conclude that hyperbaric oxygen preconditioning is an effective and feasible method to prevent, alleviate, and improve postoperative cognitive dysfunction, and that its mechanism of action is very complex, involving the stimulation of endogenous antioxidant and anti-inflammation defense systems.

关键词： nerve regeneration brain injury hyperbaric oxygenation preconditioning antioxidants antiinflammation reactive oxygen species oxidant stress inflammation protection post-operation cognitive dysfunction neural regeneration

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RANKL signaling in bone marrow mesenchymal stem cells negatively regulates osteoblastic bone formation

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Bone Research 2018年第4期6卷 418-425页

作者： Xiao Chen xin zhi Jun Wang Jiacan Su Department of Orthopedics Trauma Shanghai Changhai Hospital Second Military Medical University Department of Chemistry Fudan University School of Basic Medical Sciences Second Military Medical University College of Life Science Fudan University

RANKL signaling is essential for osteoclastogenesis. Its role in osteoblastic differentiation and bone formation is unknown. Here we demonstrate that RANK is expressed at an early stage of bone marrow mesenchymal stem cells(BMSCs) during osteogenic differentiation in both mice and human and decreased rapidly. RANKL signaling inhibits osteogenesis by promoting β-catenin degradation and inhibiting its synthesis. In contrast, RANKL signaling has no significant effects on adipogenesis of ***, conditional knockout of rank in BMSCs with Prx1-Cre mice leads to a higher bone mass and increased trabecular bone formation independent of osteoclasts. In addition, rank: Prx1-Cre mice show resistance to ovariectomy-(OVX) induced bone loss. Thus, our results reveal that RANKL signaling regulates both osteoclasts and osteoblasts by inhibition of osteogenic differentiation of BMSCs and promotion of osteoclastogenesis.

关键词： BMSCs RANKL signaling in bone marrow mesenchymal stem cells negatively regulates osteoblastic bone formation

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Preparative separation and quantitative determination of two kaurenoic acid isomers in root barks ofAcanthopanax gracilistylus

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Chinese Journal of Natural Medicines 2017年第8期15卷 625-630页

作者： XIE xin-xin JIANG Ze-Jing CHENG zhi-Hong CHEN Dao-Feng Department of Pharmacognosy School of PharmacyFudan UniversityShanghai 201203China

The kaurenoic acid-type diterpenoids in Acanthopanacis Cortex have been reported to be the major active components. However, the diterpenoids are present as position isomers that exacerbate the challenges in obtaining standards compounds. Little work has been done on the quantitative analysis of the diterpenoids in the herb. In the present study, two diterpenoid isomers ent-16βH,17-isovalerate-kauran-19-oic acid(1) and ent-16βH,17-methyl butanoate-kauran-19-oic acid(2) with high purity were separated by analytical HPLC, followed by recrystallization in acetone. Furthermore, an HPLC-ELSD method was developed and validated for simultaneous determination of 1 and 2 in 9 batches of Acanthopanacis Cortex samples. The HPLC separation and quantification was achieved in 40 min using an Agela Promosil C18 column eluted with a gradient of water and acetonitrile. The calibration curves showed good linearity(r^2 ≥ 0.999 9) within the test ranges. The LOD ranged from 0.407 2 to 0.518 0 mg and LOQ ranged from 1.018 0 to 1.295 0 mg. The precisions(%RSD) were within 1.47% for the two isomers. The recovery of the assay was in the range of 98.78%-99.11% with RSD values less than 2.76%. It is the first time to establish a quantitative HPLC method for the analysis of the bioactive kaurenoic acid isomers in the herb.

关键词： Acanthopanax gracilistylus Kaurenoic Acid Quantification HPLC-ELSD

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Bandwidth Allocation with Minimum Rate Constraints in Cluster-based Femtocell Networks

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International Journal of Automation and computing 2015年第1期12卷 77-82页

作者： Kai Ma Liang Li Jie Yang zhi-xin Liu xin-Bin Li xin-Ping Guan School of Electrical Engineering Key Laboratory of Industrial Computer Control Engineering of Hebei Province Yanshan University Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information ProcessingMinistry of Education

Inter-femtocell interference becomes serious when femtocells are densely deployed. To mitigate the inter-femtocell interference, this paper proposes a cluster-based bandwidth allocation algorithm. We create femtocell clusters by constructing a weighted interference graph and allocate bandwidth to each cluster based on a Nash bargaining solution(NBS). Simulation results show that the cluster-based bandwidth allocation algorithm can reduce the inter-femtocell interference and meet the minimum rate constraint of each cluster.

关键词： Femtocell cluster inter-femtocell interference bandwidth allocation Nash bargaining solution(NBS)

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Preface: Key technologies for enhancing the performance of FAST

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Research in Astronomy and Astrophysics 2020年第5期20卷 63-64页

作者： Peng Jiang zhi-Qiang Shen Ren-xin Xu CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Department of Radio Science and Technology Shanghai Astronomical ObservatoryShanghai 200030China School of Physics and Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)passed its national acceptance inspection on 2020 January *** special issue includes a total of 15 papers,which are selected to introduce the status of FAST’s performance and demonstrate the key technologies applied to *** presented performance parameters can provide an important reference for scientists to propose observations with *** key technologies presented in these papers include design and implementation in the measurement and control system,electromagnetic compatibility system,and receiver ***,scientific achievements obtained by FAST during the commissioning phase are also reported.

关键词： telescope techniques:radar astronomy methods:data analysis methods:observational techniques:interferometric

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Pure phase MoN: preparation by chemical-diffused permeation and enhanced conductivity with rare earth Gd

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Rare Metals 2015年第2期34卷 137-142页

作者： xin Li Chao Gao Yu-zhi Jiang Xi-Kun Li School of Materials Science and Engineering Shenyang Ligong University

MoN was prepared by rare earth Gd thermaldiffused permeation method via solid–gas interface reaction using（NH_4）_4[NiMo6O_24H_6]·7H_2O（abbreviated as NiMo6） as the precursor. Thermo-gravimetric differential thermal analysis（TG–DTA） was used to study the product＇s stability. The results of X-ray diffractometer（XRD）and X-ray photoelectron spectroscopy（XPS） indicate that a new hexagonal crystal MoN forms after the rare earth gas permeation and Gd3＋are diffused as substitution ions into the crystal lattice of MoN, and the surface valence of elemental content was measured by XPS. The conductivity results by direct current（DC） four-probe method show that MoN obtained from the Gd thermal permeation exhibits conductor character in the temperature range of 298–740 K and semiconductor behavior in 740–800 K.

关键词： Rare earth permeation MoN Conductivity Gd

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基质金属蛋白酶9和血管内皮生长因子表达在大鼠肺血栓栓塞症模型肺损伤中的作用

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国际呼吸杂志 2008年第19期28卷 1166-1170页

作者：朱敏王辰张黎明庞宝森翟振国杨媛华牛淑洁毛燕玲马力翁心植首都医科大学附属北京朝阳医院北京呼吸疾病研究所 100020

目的通过颈外静脉注入自体血栓建立大鼠急性肺血栓栓塞症（pulmonary thromboembolism，PTE）模型，观察急性PTE后基质金属蛋白酶9（matrix metalloproteinases-9，MMP-9）和血管内皮生长因子（vascular endothelial growth factor，VEGF）的水平变化和表达，及其在PTE后肺组织病理改变中的作用。方法56只健康雄性SD大鼠随机均分为PTE组及假手术（sham）组。于制模后2h、6h、24h及72h处死大鼠。应用苏木精-伊红染色方法观察肺组织病理改变。采用酶联免疫吸附试验法测定血清及支气管肺泡灌洗液（BAI，F）中MMP-9和VEGF浓度；考马斯亮兰法测定BALF中总蛋白浓度并进行细胞计数；免疫组织化学染色观察MMP-9和VEGF在肺组织中的表达。结果①病理结果：PTE组栓塞区肺组织有肺损伤改变；sham组未见上述病理变化；②血清学结果：PTE组MMP-9和VEGF浓度在6h、24h和72h显著高于sham组（P〈0．01）；③BALF结果：PTE组MMP-9浓度24h时显著高于sham组（P〈0．01）；VEGF2h和24h均显著高于sham组（P〈O．05，P〈0．01）；PTE组BALF中总蛋白浓度和细胞数2h和24h组均显著高于sham组（P值均〈0．01）；④免疫组织化学结果：显示PTE组MMP-9和VEGF表达显著高于sham组。结论急性PTE可引起肺损伤。PTE可引起血液中MMP-9和VEGF细胞因子释放及其肺组织中显著表达，促进炎性细胞和蛋白渗出，参与PTE相关肺损伤的发生。

关键词：肺血栓栓塞症肺损伤基质金属蛋白酶血管内皮生长因子

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Waste heat recovery and denitrification of flue gases from gas-fired boilers

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Science China(Technological Sciences) 2016年第12期59卷 1874-1881页

作者： ZHAO Yan ZHU Xiao Lei MENG Ji An LI zhi xin Thermal Research Institute Tianjin UniversityTianjin300072China Beijing Yuanshen Energy Saving Technology Co.Ltd. BeijingChina Key Laboratory of Thermal Science and Power Engineering of Ministry of Education School of Aerospace Tsinghua UniversityBeijing 100084China

A waste heat recovery and denitrification system was developed for improving energy conservation and emissions control especially for control of PM2.5 particles and haze. The system uses enhanced heat and mass transfer techniques in a packed heat exchange tower with self-rotation and zero-pressure spraying, low temperature NO oxidation by ozone, and neutralization with an alkali solution. Operating data in a test project gave NOx in the exhaust flue gas of less than 30 mg/Nm3 with an ozone addition rate of 8 kg/h and spray water p H of 7.5–8, an average heat recovery of 3 MW, and an average heat supply of 7.2 MW.

关键词： flue gas waste heat recovery denitrification ozone oxidation of NO neutralization with alkali solution heat pump

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