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Seed,cutting and air-layering reproductive inefficiency of noxious woody vine Merremia biosiana and its implications for management strategy

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Frontiers in Biology 2009年第3期4卷 342-349页

作者： Mingguang LI Haiyang liu Fenglan LI Xiuyuan CHENG bin GUO Zhiwei FAN State Key Laboratory of Biocontrol Sun Yat-sen UniversityGuangzhou 510275China Environment and Plant Protection Institute Chinese Academy of Tropical Agricultural SciencesDanzhou 571737China

Merremia boisiana(Gagnep)van *** a noxious fast growing woody vine and is able to grow overtop other plants,causing the death of plants underneath and forming monospecies *** formulate management responses,we assessed its seed and vegetative reproduction efficacy through indoor and field *** number of flowers counted from bagged infructescences in Guangzhou ranged from 25 to 172,with an average of *** the seeds of bagged infructescences had shown that there were only 1.58 hard testa seeds in each *** vitality tests using red ink indicated that only 68.6%of hard testa and filled seeds were *** emergence rate of scarified hard testa seeds in the sand bed was 31.96%.Under imitated natural conditions,8%of hard testa seeds could germinate,and 9%still retained their germination potential in one ***,seedlings should be monitored and removed in a timely fashion after any attempt of *** soil or transplanting plant from infested patches should be strictly prohibited at least for several *** considered,an infructescence contributed 0.3 *** investigation in the field found no seedlings either inside or at the perimeter of the patch,suggesting scant expansion by means of seed ***,the elimination effort could be focused on a relatively restricted scale of *** 630 cuttings of young shoots,old shoots and old lying shoots with or without growth regulators,there were only four(or 0.63%)established ***-layering shoots all died in two *** cuttings and airlayering reproduction indicated that regeneration from fragments of removed stems or accidentally dropped ones was quite unlikely,and thus mechanical removal was safe.

关键词： Merremia boisiana seed vitality germination rate vegetative reproduction management

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High Data Rate OFDM System with Simplified DAPSK Demodulation

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The Journal of China Universities of Posts and Telecommunications 2005年第2期12卷 30-34页

作者： liu Kai-ming WANG wen-bo liu Yuan-an Center for Wireless Communications Beijing University of Posts and Telecommunications Beijing 100876 P.R. China

In this paper, a simplified differential amplitude demodulation scheme for high-level Differential Amplitude and Phase Shift Keying （DAPSK） techniqus is proposed, which requires fewer thresholds for demodulation and thus has lower complexity. The performance of the Orthogonal Frequency Division Multiplexing （OFDM） system combined with the simplified DAPSK scheme is investigated over frequency-selective fading channels, then. Compared with coherent QAM-OFDM system, DAPSK-OFDM system has much lower complexity since channel estimation and equalization are unnecessary. Further more, under the condition of the same data rate, DAPSK-OFDM can achieve the performance close to or even better than that of QAM-OFDM system which adopts pilot symbols for channel estimation, by employing the concatenated code and utilizing the additional redundancy for outer coding at high Signal-to-Noise Ratios （SNRs）.

关键词： DAPSK OFDM flat fading frequency-selective fading

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Microstructure and nanoindentation hardness of shot-peened ultrafine-grained low-alloy steel

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Journal of Iron and Steel Research International 2019年第5期26卷 472-482页

作者： Xiao-wei Feng Juan Xie wen-ying Xue Yong-feng Shen Hong-bo Wang Zhen-yu liu Institute of Systems Engineering of China Academy of Engineering Physics Mianyang 621999 Sichuan China Key Laboratory for Anisotropy and Texture of Materials (MOE) School of Materials Science and Engineering Northeastern University Shenyang 110819 Liaoning China The State Key Lab of Rolling and Automation Northeastern University Shenyang 110819 Liaoning China

The effect of shot peening (SP) on microstructure and hardness of ultrafine-grained (UFG) low-alloy steel was investigated. With increasing shot-peening time from 0.5 to 1.5 h, grain size of UFG low-alloy steel decreases from 400 to 280 nm at surface whilst that of the layer with a depth of 160μm decreases from (230 ± 15) to (75 ± 5) nm. Interestingly, nanoindentation shows that hardness increases linearly with increasing the SP duration, reaching a value as high as (7.10 ± 0.1) GPa at the depth of 160 μm after the SP duration of 1.5 h. The thickness of the SP treated layer is measured as^300 μm. The Hall-Petch (H-P) relationship was established for the hardening layer. Correspondingly, abrasion resistance should be ~51% higher than that of as-prepared UFG low-alloy steel. As shown in SP processing, grain refinement is the key factor responsible for the strengthening of the studied steel.

关键词： Low-alloy steel Shot peening Grain refinement Nanoindentation Hardness

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Large-scale characteristics of thermokarst lakes across the source area of the Yellow River on the Qinghai-Tibetan Plateau

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Journal of Mountain Science 2023年第6期20卷 1589-1604页

作者： liu wen-hui ZHOU Guang-hao liu Hai-rui LI Qing-peng XIE Chang-wei LI Qing ZHAO Jian-yun ZHANG Qi State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining 810016China Department of Geological Engineering Qinghai UniversityXining 810016China College of Eco-Environmental Engineering Qinghai UniversityXining 810016China Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryosphere SciencesNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73ooooChina

As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and *** the Sources Area of the Yellow River(SAYR),permafrost degradation has accelerated since the 1980s,and numerous thermokarst lakes have been *** this paper,we use Sentinel-2 images to extract thermokarst lake boundaries and perform a regional-scale study on their geometry across the permafrost region in the *** also explored the spatiotemporal variations and potential drivers from the perspectives of the permafrost,climate,terrain and vegetation *** results showed that there were 47,518 thermokarst lakes in 2021 with a total area of 190.22×106 m^(2),with an average size of 4,003.3 m^(2).The 44,928 ponds(≤10,000 m^(2))predominated the whole lake number(94.1%)but contributed to a small portion of the total lake area(28.8%).With 2,590 features(5.9%),small-sized(10,000 to 100,000 m^(2))and large-sized lakes(>100,000 m^(2))constituted up to 71.2%of the total lake *** lakes developed more significantly in warm permafrost regions than in cold permafrost areas;74.1%of lakes with a total area of 119.6×106 m^(2)(62.9%),were distributed in warm permafrost *** thermokarst lakes were likely to develop within the elevation range of 4,500~4,800 m,on flat terrain(slope<10°),on SE and S aspects and in alpine meadow *** thermokarst lakes in the study region experienced significant shrinkage between 1990 and 2021,characterized by obvious lake drainage;the lake numbers decreased by 5418(56.1%),with a decreasing area of 58.63×106 m^(2)(49.0%).This shrinkage of the thermokarst lake area was attributable mainly to the intensified degradation of rich-ice permafrost thawing arising from continued climate warming,despite the wetting climatic trend.

关键词： Thermokarst lake Spatial characteristic Influencing factor Source area of the Yellow River

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Effect of Chain Extender on Hydrogen Bond and Microphase Structure of Biodegradable Thermoplastic Polyurethanes

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Chinese Journal of Polymer Science 2018年第4期36卷 514-520页

作者： wen-Kai liu Yun Zhao Rong Wang Feng Luo Jian-Shu Li Jie-Hua Li Hong Tan College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University

Thermomechanical properties of polyurethanes（PUs） strongly depend on the molecular interactions and microphase structure. In this work, two chain extenders with different ratios, flexile 1,4-butanediol（BDO） and branched trimethylolpropane mono allyl ether（TMPAE）, are used to tune the molecular interactions and microphase structures of a series of biodegradable thermoplastic polyurethanes（TPUs）. In TPUs, the biodegradable polycaprolactone（PCL, M_n of 2000） is used as soft segment while 1,6-diisocyanatohexane（HDI） and chain extenders are used as hard segment. Fourier transform infrared spectroscopy（FTIR）, proton nuclear magnetic resonance spectroscppy（~1 H-NMR）, gel permeation chromatography（GPC）, differential scanning calorimetry（DSC）, dynamic mechanical analysis（DMA） and mechanical tests were performed to characterize the bulk structure and properties of TPUs. Compared with BDO, the steric bulk of TMPAE is larger. The increment of TMPAE can help to increase the hydrogen bond content, microphase separation, and the elastic modulus ratio（R）, which would strongly affect the thermomechanical property of the TPUs. The results of this work verify the importance of the structure of chain extender on the properties of TPUs. It provides valuable information for further understanding the structure-property relationships of these polyurethanes.

关键词： Chain extender Hydrogen bond Crystallinity Polyurethane

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Cholesterol as a functional metabolite cooperates with metadherin in cancer cells

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Chinese Chemical Letters 2020年第7期31卷 1831-1834页

作者： wen Wang Xiaolong liu Huan Chen Ting Ling Tian Xia Xiumei liu Jing liu Wuxiyar Otkur Xianzhe Shi Huan Qi Di Chen Hai-Long Piao CAS Key Laboratory of Separation Science for Analytical Chemistry Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China

Protein-metabolite interactions(PMIs)play important roles in various biological processes,especially in disease ***,due to the complexity of living cells,it is very difficult to identify specific ***,we chose one oncogenic factor,metadherin(MTDH),as a bait to identify its in vivo interacting metabolites in cancer *** is an important metabolite and essential structural component of cell *** could also drive several diseases including ***,we found that cholesterol robustly interacted with MTDH and downregulated the expression of MTDH in cancer ***,MTDH disturbed metabolite alterations under cholesterol treatment in MTDH transduced cancer ***,our results uncover an undescribed PMI where MTDH,as an oncogenic factor,might positively regulate cancer progression by interacting with choleste *** study interprets the theoretical basis of PMI-oriented cancer progression and targeting therapies in clinic.

关键词： Metabolite-protein interaction Cholesterol Metadherin Mass spectrometry

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2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes migration ability of primary cultured rat astrocytes via aryl hydrocarbon receptor

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Journal of Environmental Sciences 2019年第2期31卷 368-376页

作者： Yangsheng Chen Rui Sha Li Xu Yingjie Xia Yiyun liu Xuejun Li Heidi Qunhui Xie Naijun Tang bin Zhao State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of Sciences University of Chinese Academy of Sciences Department of Occupational and Environmental Health sTianjin Medical University

Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin(TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed woundhealing assay and Transwell? motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations(10^(-10) and/or 10^(-9) mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mR NA expression of two promigratory genes, including cell division cycle 42(CDC42) and matrix metalloproteinase 2(MMP2)was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor(AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.

关键词： 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) Astrocyte Migration Gene expression Aryl hydrocarbon receptor (AhR) pathway

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MoS_2 saturable absorber prepared by chemical vapor deposition method for nonlinear control in Q-switching fiber laser

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Chinese Physics B 2018年第8期27卷 7-12页

作者： Meng-Li liu Yu-Yi OuYang Huan-Ran Hou Ming Lei wen-Jun liu Zhi-Yi Wei State Key Laboratory of Information Photonics and Optical Communications School of ScienceBeijing University of Posts and TelecommunicationsBeijing 100876China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China

Due to the remarkable carrier mobility and nonlinear characteristic, MoS2 is considered to be a powerful competitor as an effective optical modulated material in fiber lasers. In this paper, the MoS2 films are prepared by the chemical vapor deposition method to guarantee the high quality of the crystal lattice and uniform thickness. The transfer of the films to microfiber and the operation of gold plated films ensure there is no heat-resistant damage and anti-oxidation. The modulation depth of the prepared integrated microfiber-MoS2 saturable absorber is 11.07%. When the microfiber-MoS2 saturable absorber is used as a light modulator in the Q-switching fiber laser, the stable pulse train with a pulse duration of 888 ns at 1530.9 nm is obtained. The ultimate output power and pulse energy of output pulses are 18.8 mW and 88 nJ, respectively. The signal-to-noise ratio up to 60 dB indicates the good stability of the laser. This work demonstrates that the MoS2 saturable absorber prepared by the chemical vapor deposition method can serve as an effective nonlinear control device for the Q-switching fiber laser.

关键词： nonlinear optical materials fiber laser Q-switching

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Microstructure and corrosion behavior of Zr–1.0Cr–0.4Fe–xMo alloys

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Rare Metals 2015年第2期34卷 118-124页

作者： Tian-Guo Wei Lu Zhang Zhi Miao Hong liu Bai-Feng Luan wen Wang Chong-Sheng Long Reactor Fuel and Materials Key Laboratory Nuclear Power Institute of China Nuclear and Radiation Safety Ministry of Environmental Protection Institute of Material Science and Technology Chongqing University

Possibility of using Mo as an alloying element in Zr-based alloys was attractive in terms of microstructure refinement and mechanical properties strengthening. In this research, Zr–1.0Cr–0.4Fe–xMo（0, 0.2, 0.4, and 0.6） alloys with different Mo contents were prepared by vacuum arcmelting method, the microstructure and the corrosion resistance of these alloys were investigated. Addition of Mo has a refinement effect on the microstructure; with the increase of Mo content, the a-laths in the as-cast samples and the grain size in the annealed samples decrease. Zr–1.0Cr–0.4Fe–xMo alloys have large numbers of fine second-phase particles（SPPs） in the matrix, the area fraction of the SPPs is more than 10 %. With the increase of Mo content, the population density of the SPPs increases significantly, while the average diameter of the SPPs decreases. Mo addition also affects the texture; the intensity of basal pole texture aligning normal direction decreases with the increase of Mo content in the *** with Zr-4 and Zr–1Nb, Zr–1.0Cr–0.4Fe–xMo alloys have excellent corrosion resistance in 500 ℃/10.3 MPa steam. The corrosion rates of Mo-containing alloys are higher than that of Mo-free alloy, which is mainly attributed to the solute Mo atoms in the Zr *** of the SPPs features due to the increase of Mo content alleviates the degradation of corrosion resistance in some degree, but it is not the dominant factor.

关键词： Zr-based alloys Mo addition Microstructures Second-phase particles Corrosion behavior

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Antibacterial ability and cytocompatibility of Cu-incorporated Ni–Ti–O nanopores on NiTi alloy

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Rare Metals 2019年第6期38卷 552-560页

作者： Jia-Ming Zhang Yong-Hua Sun Ya Zhao Yan-Lian liu Xiao-Hong Yao bin Tang Rui-Qiang Hang Research Institute of Surface Engineering College of Materials Science and Technology Taiyuan University of Technology

Nearly equiatomic nickel–titanium(NiTi) alloy is an ideal implant biomaterial because of its shape memory effect, superelasticity, low elastic modulus as well as other desirable ***, it is prone to infection because of its poor antibacterial *** present work incorporated Cu into Ni–Ti–O nanopores(NP–Cu) anodically grown on the NiTi alloy to enhance its antibacterial ability, which was realized through *** results show that incorporation of Cu(0.78 at%–2.37 at%)has little influence on the NP diameter, length and *** release level of Cu ions is in line with loadage which may be responsible for the improved antibacterial ability of the NiTi alloy to combat possible bacterial infection in ***, the NP–Cu shows better cytocompatibility and even can promote proliferation of bone marrow mesenchymal stem cells(BMSCs),up-regulate collagen secretion and extracellular matrix mineralization when compared with Cu-free *** antibacterial ability and cytocompatibility of the NP–Cu render them to be promising when serving as NiTi implant coatings.

关键词： Nickel–titanium alloy Nickel–titanium–oxygen nanopores Copper Antibacterial ability Cytocompatibility

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