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Alterations to biological soil crusts with alpine meadow retrogressive succession affect seeds germination of three plant species

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Journal of Mountain Science 2016年第11期13卷 1995-2005页

作者： LI Yi-kang OUYANG Jing-zheng LIN Li XU Xing-liang zhang fa-wei DU Yan-gong LIU Shu-li CAO Guang-min HAN fa Key Laboratory of Adaptation and Evolution of Plateau Biota Northwest Institute of Plateau BiologyChinese Academy of SciencesXining 810001China University of Chinese Academy of Sciences Beijing 100049China Institute of Geographic Sciences&Natural Resources Research the Chinese Academy of SciencesBeijing 100101China Liancheng National Nature Reserve of Gansu Province Yongdeng Country 730000China

Biological soil crusts(BSCs) are the important components of alpine meadow *** extent and morphology of BSCs vary greatly with alpine meadow retrogressive succession due to grazing *** is significant interest in impacts of crust composition on plant seed germination,especial l y in(semi-) arid ***,little is known about the influences of BSCs,and their associations with alpine meadow succession,on germination of typical alpine meadow vascular plant *** a full factorial common-gardenexperiment,we studied effects of:(1) crust type,(2) seed position,and(3) surface texture on seed *** chose three typical alpine meadow plant species(*** pratensis,Tibetia himalaica and Potentillen nivea),which belonged to different functional groups(graminoids,legumes,and forbs) and play important roles in all alpine meadow succession *** type and seed position influenced seed germination,and the inhibitory effects of BSCs depended on the crust type and seed species *** major factors influencing seed germination were BSC type,seed position,soil texture,and the interactions between BSC type and seed position; species and seed position; species andsurface texture; and species,crust type,and surface *** crust significantly inhibited germination of all *** position also had a significant effect on seed germination(p face than below the surface,this was especially true for *** within cyanobacteria and lichen *** germination rates of *** on the soil surface were significantly correlated with plant occurrence frequency within the alpine meadow *** poor correlation for the other two species is possibly that they are *** results clearly demonstrated that BSCs can be biological filters during seed germination,depending on the BSC succession *** their influences on seed germination,BSCs can strongly

关键词： Crust type Seed position Microenvironment Germination Tibetan Plateau Vascular plants

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Distribution of soil carbon in different grassland types of the Qinghai-Tibetan Plateau

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Journal of Mountain Science 2016年第10期13卷 1806-1817页

作者： LIU Shu-li DU Yan-gong zhang fa-wei LIN Li LI Yi-kang GUO Xiao-wei LI Qian CAO Guang-min Northwest Institute of Plateau Biology Chinese Academy of SciencesQinghai 810001China University of Chinese Academy of Sciences Beijing 100049China

Accurate estimate of soil carbon storage is essential to reveal the role of soil in global carbon cycle. However, there is large uncertainty on the estimation of soil organic carbon(SOC) storage in grassland among previous studies, and the study on soil inorganic carbon(SIC) is still lack. We surveyed 153 sites during plant peak growing season and estimated SOC and SIC for temperate desert, temperate steppe, alpine steppe, steppe meadow, alpine meadow and swamp, which covered main grassland in the Qinghai Plateau during 2011 to 2012. The results showed that the vertical and spatial distributions of SOC and SIC varied by grassland types. The SOC amount mainly decreased from southeast to northwest, whereas the SIC amount increased from southeast to northwest. The magnitude of SOC amount in the top 50 cm across grassland types ranked by: swamp > alpine meadow >steppe meadow > temperate steppe > alpine steppe > temperate desert, while the SIC amount showed an opposite order. There was a great deal of variation in proportion of SOC and SIC among different grassland types(from 55.17 to 94.59 for SOC and 5.14 to 44.83 for SIC). The total SOC and SIC storage was 5.78 Pg and 1.37 Pg, respectively, in the top 50 cm of soil in Qinghai Province. The mixed linear model revealed that grassland types was the predominant factor in spatial variations of SOC amount while grassland types and soil p H accounted for those of SIC amount. Our results suggested that the community shift of alpine meadow towards alpine grassland induced by climate warming would decrease carbon sequestration capacity by 6.0 kg C m2.

关键词： Soil organic carbon Soil inorganic carbon Different grassland types Carbon distribution Storage

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Effects of continuous tracheal gas insufflation during pressure limited ventilation on pulmonary surfactant in rabbits with acute lung injury

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Chinese Medical Journal 2006年第17期119卷 1415-1420页

作者： ZHU Guang-fa zhang wei ZONG Hua LIANG Ying Department of Respiratory Medicine Beijing Anzhen HospitalCapital University of Medical Science Beijing 100029 China

Background Pulmonary surfactant dysfunction may contribute to the development of ventilator induced lung injury （VILI）. Tracheal gas insuffiation （TGI） is a technique in which fresh gas is introduced into the trachea and augment ventilation by reducing the dead space of ventilatory system, reducing ventilatory pressures and tidal volume （VT） while maintaining constant partial arterial CO2 pressure （PaCO2）. We hypothesised that TGI limited peak inspiratory pressure （PIP） and VT and would minimize conventional mechanical ventilation （CMV） induced pulmonary surfactant dysfunction and thereby attenuate VILI in rabbits with acute lung injury （ALI）. Methods ALI was induced by intratracheal administration of lipopolysaccharide in anaesthetized, ventilated healthy adult rabbits randomly assigned to continuous TGI at 0.5 L/min （TGI group） or CMV group （n=8 for each group）, and subsequently ventilated with limited PIP and VT to maintain PaCO2 within 35 to 45 mmHg for 4 hours. Physiological dead space to VT ratio （VD/VT）, dynamic respiratory compliance （Cdyn） and partial arterial O2 pressure （PaO2） were monitored. After ventilation, lungs were analysed for total phospholipids （TPL）, total proteins （TP）, pulmonary surfactant small to large aggregates ratio （SA/LA） in bronchoalveolar lavage fluid （BALF） and for determination of alveolar volume density （Vv）, myeloperoxidase and interleukin （IL）-8. Results TGI resulted in significant （P〈0.05 or P〈0.01） decrease in PIP [（22.4±1.8） cmH20 vs （29.5±1.1） cmH2O], VT [（6.9±1.3） ml/kg vs （9.8±1.11） ml/kg], VD/VT [（32±5）% vs （46±2）%], TP [（109±22） mg/kg vs （187±25） mg/kg], SA/LA （2.5±0.4 vs 5.4±0.7）, myeloperoxidase [（6.2±0.5） U/g tissue vs （12.3±0.8） U/g tissue] and IL-8 [（987±106） ng/g tissue vs （24±3） mN/m] of BALF, and significant （P〈0.05） increase in Cdyn [（0.47±0.02） ml·cmH2O^-1·kg^-1 vs （0.31±0.02） ml·cmH2O^-1·kg^-1], PaO2 [（175±24） mmHg vs （135±26） mmHg], TPL/TP （52±8 vs 33±11） and Vv （0.65±0.05 vs 0.44±0.07） as compared with CMV

关键词： tracheal gas insufflation acute lung injury pulmonary surfactant ventilator induced lung injury mechanical ventilation

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Effects of long-term grazing exclusion on vegetation structure,soil water holding capacity,carbon and nitrogen sequestration capacity in an alpine meadow on the Tibetan Plateau

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Journal of Mountain Science 2023年第3期20卷 779-791页

作者： YANG Yong-sheng zhang fa-wei XIE Xian-rong WANG Jun-bang LI Ying-nian HUANG Xiao-tao LI Hui-ting ZHOU Hua-kun Key Laboratory of Adaptation and Evolution of Plateau Biota and Key Laboratory of Restoration Ecology in Cold Region of Qinghai Province Northwest Institute of Plateau BiologyChinese Academy of SciencesXining 810008China Qinghai Haibei National Field Research Station of Alpine Grassland Ecosystem Xining 810008China Xi Ning Municipal Beishan Forestry farm Xining 810003China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Grazing exclusion is one of the primary management practices used to restore degraded grasslands on the Tibetan ***,to date,the effects of long-term grazing exclusion measures on the process of restoring degraded alpine meadows have not been *** this study,moderately degraded plots,in which the vegetation coverage was approximately 65%and the dominant plant species was Potentilla anserina L,with grazing exclusion for 2 to 23 years,were selected in alpine meadows of Haibei in Qinghai-Tibet *** coverage,plant height,biomass,soil bulk density,saturated water content,soil organic carbon(SOC)and total nitrogen(TN)were *** results were as follows:(1)With aboveground biomass and total saturated water content at 0-40 cm depth,the average SOC and TN contents in moderately degraded alpine meadows increased as a power function,and the plant height increased as a log function.(2)The average soil bulk density at 0-40 cm depth first decreased and then increased with increasing grazing exclusion duration,and the minimum value of 0.90 g·cm^(-3) was reached at 15.23 *** plant coverage,total belowground biomass at 0-40 cm depth,total aboveground and belowground biomass first increased and then decreased,their maximum values(80.49%,2452.92g·m^(-2),2891.06 g·m^(-2))were reached at 9.41,9.46 and 10.25 years,***-term grazing exclusion is apparently harmful for the sustainable restoration of degraded alpine *** optimal duration of grazing exclusion for the restoration of moderately degraded alpine meadows was 10 *** research suggests that moderate disturbance should be allowed in moderately degraded alpine meadows after 10years of grazing exclusion.

关键词： Long-term grazing exclusion Soil water holdingcapacity Soilcarbonand nitrogen sequestration Biomass Alpine meadow

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Effectiveness and safety of noninvasive positive-pressure ventilation for severe hypercapnic encephalopathy due to acute exacerbation of chronic obstructive pulmonary disease:a prospective case-control study

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Chinese Medical Journal 2007年第24期120卷 2204-2209页

作者： ZHU Guang-fa zhang wei ZONG Hua XU Qiu-fen LIANG Ying Department of Respiratory Medicine Beijing Anzhen HospitalCapital Medical University Beijing 100029 China

Background Although severe encephalopathy has been proposed as a possible contraindication to the use of noninvasive positive-pressure ventilation （NPPV）, increasing clinical reports showed it was effective in patients with impaired consciousness and even coma secondary to acute respiratory failure, especially hypercapnic acute respiratory failure （HARF）. To further evaluate the effectiveness and safety of NPPV for severe hypercapnic encephalopathy, a prospective case-control study was conducted at a university respiratory intensive care unit （RICU） in patients with acute exacerbation of chronic obstructive pulmonary disease （AECOPD） during the past 3 years. Methods Forty-three of 68 consecutive AECOPD patients requiring ventilatory support for HARF were divided into 2 groups, which were carefully matched for age, sex, COPD course, tobacco use and previous hospitalization history, according to the severity of encephalopathy, 22 patients with Glasgow coma scale （GCS）〈10 served as group A and 21 with GCS 〉10 as group B. Results Compared with group B, group A had a higher level of baseline arterial partial CO2 pressure （（102±27） mmHg vs （74±17） mmHg, P〈0.01）, lower levels of GCS （7.5±1.9 vs 12.2±1.8, P〈0.01）, arterial pH value （7.18±0.06 vs 7.28±0.07, P〈0.01） and partial 02 pressure/fraction of inspired 02 ratio （168±39 vs 189±33, P〈0.05）. The NPPV success rate and hospital mortality were 73% （16/22） and 14% （3/22） respectively in group A, which were comparable to those in group B （68% （15/21） and 14% （3/21） respectively, all P〉0.05）, but group A needed an average of 7 cmH20 higher of maximal pressure support during NPPV, and 4, 4 and 7 days longer of NPPV time, RICU stay and hospital stay respectively than group B （P〈0.05 or P〈0.01）. NPPV therapy failed in 12 patients （6 in each group） because of excessive airway secretions （7 patients）, hemodynamic instability （2）, worsening of dyspnea and deterioration of gas exchange （2）, and gastric content aspiration （1）.

关键词： acute respiratory failure hypercapnia encephalopathy chronic obstructive pulmonary disease noninvasive positive pressure ventilation

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斯木塔斯台阶式陡槽溢洪道水力特性模型试验研究

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中国农村水利水电 2011年第1期 93-96页

作者：张为法刘韩生西北农林科技大学水利与建筑工程学院陕西杨凌712100

斯木塔斯水电站原设计方案泄水建筑物中溢洪道采用了台阶式消能方式,为了论证在高水头,小单宽流量下台阶式溢洪道应用的合理性,有必要对设计方案进行模型试验的研究。借助大比尺的模型试验,对该溢洪道段的流态,压强,掺气,消能率等进行... 详细信息

斯木塔斯水电站原设计方案泄水建筑物中溢洪道采用了台阶式消能方式,为了论证在高水头,小单宽流量下台阶式溢洪道应用的合理性,有必要对设计方案进行模型试验的研究。借助大比尺的模型试验,对该溢洪道段的流态,压强,掺气,消能率等进行了观测。试验结果表明各项水力特性良好,消能效果显著,满足工程实际的需要,为工程决策提供了科学依据。模型试验验证了台阶消能工在高水头,小单宽流量下应用的可行性,对类似工程具有一定的参考价值。

关键词：台阶溢洪道掺气浓度时均压强消能率

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台阶式溢洪道滑行水流消能特性研究

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长江科学院院报 2014年第6期31卷 37-40页

作者：张峰刘韩生张为法西北农林科技大学水利与建筑工程学院陕西杨凌712100 中国水电工程顾问集团西北勘察设计研究院西安710000

台阶式溢洪道消能率无法详细反映其消能特性,为了突出反映台阶消能作用,从总消能水头中扣除光滑溢洪道原有消能水头得到纯台阶消能部分,计算了单位高度纯台阶消能率,以及台阶消能所占总消能的比重。结果表明:滑行水流的单位高度纯台阶... 详细信息

台阶式溢洪道消能率无法详细反映其消能特性,为了突出反映台阶消能作用,从总消能水头中扣除光滑溢洪道原有消能水头得到纯台阶消能部分,计算了单位高度纯台阶消能率,以及台阶消能所占总消能的比重。结果表明:滑行水流的单位高度纯台阶消能率约为0.80%/m^0.83%/m,与单宽流量和台阶数目均无关,随台阶高度增大增幅为4.5%;纯台阶消能所占总消能比重随单宽流量增大而增加,随台阶数目增多而减小;此外,还对单宽流量增加时消能率下降的原因进行了探讨。结果分析表明:大单宽流量消能率下降是由于光滑溢洪道能作用降低而纯台阶消能不变导致的。

关键词：台阶式溢洪道滑行水流单宽流量台阶高度消能率

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高寒草甸表层土壤和优势植物叶片的化学计量特征对降水改变和氮添加的响应

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植物生态学报 2023年第7期47卷 922-931页

作者：李红琴张法伟仪律北洛阳师范学院生命科学学院河南洛阳471934 中国科学院三江源国家公园研究院西宁810008 国家生态科学数据中心北京100101 中国科学院西北高原生物研究所高原生物适应与进化重点实验室西宁810008 青海省林业和草原局林业碳汇服务中心西宁810008

降水格局改变和氮沉降增加是草地生态系统结构及功能演变的重要影响因素,其对高寒草甸土壤和植物的化学计量的影响存在很大变异,限制了对高寒草甸生态功能预测的准确性。该研究基于祁连山东段南麓高寒草甸降水改变(减雨50%和增雨50%)和... 详细信息

降水格局改变和氮沉降增加是草地生态系统结构及功能演变的重要影响因素,其对高寒草甸土壤和植物的化学计量的影响存在很大变异,限制了对高寒草甸生态功能预测的准确性。该研究基于祁连山东段南麓高寒草甸降水改变(减雨50%和增雨50%)和氮添加(10 g·m^(-2)·a^(-1))的控制实验平台,分析了2017-2020年表层(0-10 cm)土壤有机碳、全氮、全磷含量和优势植物麻花艽(Gentiana straminea)、垂穗披碱草(Elymus nutans)、黄花棘豆(Oxytropis ochrocephala)和矮生嵩草(Kobresia humilis)的叶片碳(LC)、氮(LN)、磷(LP)和钾(LK)含量等变化,以明晰土壤和植物的化学计量特征对降水改变和氮添加的响应。结果表明,土壤化学计量特征的变异存在显著年际效应,与实验处理无显著关系。地上活体生物量(PB)存在显著的年际差异,并受到氮添加的显著影响。优势物种叶片化学计量特征的变异因物种而异。垂穗披碱草叶片化学计量特征的变化均不显著,属于资源保守型物种,而矮生嵩草的变化显著,敏感性较强。基于处理样地与对照样地每年指标相对变化(Δ)的分析表明,氮添加显著提高了ΔPB达15.6%。降水减少显著降低了黄花棘豆ΔLC达6.8%,增加了矮生嵩草ΔLP达19.8%。研究表明仅氮添加提高了PB,降水减少改变了部分物种LC和LP含量,土壤和植物叶片的化学计量特征变异的年际效应或物种效应大于实验处理效应,凸显了高寒草甸生态系统对降水改变和氮添加响应的复杂性。

关键词：高寒草甸降水改变氮添加化学计量优势植物

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Zeros of the Jones Polynomial for Torus Knots and 2-bridge Knots

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Chinese Quarterly Journal of Mathematics 2014年第4期29卷 612-619页

作者： HAN You-fa zhang Rong-wei WANG Lin-lin MA Xiao-sha School of Mathematics Liaoning Normal University Dalian 116029 China

We study zeros of the Jones polynomial and their distributions for torus knots and 2-bridge knots. We prove that e(2m+1)πi/2and e(2m+1)πi/4(m is a positive integer)can not be the zeros of Jones polynomial for torus knots T p,q by the knowledge of the trigonometric function. We elicit the normal form of Jones polynomials of the 2-bridge knot C(-2, 2, ···,(-1)r2) by the recursive form and discuss the distribution of their zeros.

关键词： Jones polynomial zeros torus knot 2-bridge knot

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Joint Probabilistic Scheduling and Resource Allocation for Wireless Networked Control Systems

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IEEE/CAA Journal of Automatica Sinica 2025年第1期 258-260页

作者： Meng Zheng Lei zhang wei Liang IEEE the State Key Laboratory of Robotics and the Key Laboratory of Networked Control Systems Shenyang Institute of Automation Chinese Academy of Sciences the University of Chinese Academy of Sciences

Dear Editor,This letter presents a joint probabilistic scheduling and resource allocation method(PSRA) for 5G-based wireless networked control systems(WNCSs). As a control-aware optimization method, PSRA minimizes the linear quadratic Gaussian(LQG) control cost of WNCSs by optimizing the activation probability of subsystems, the number of uplink repetitions, and the durations of uplink and downlink phases. Simulation results show that PSRA achieves smaller LQG control costs than existing works.

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