Mycelial culture of wild Inonotus hispidus parasitizing the jujube tree and the cultivation conditions of its fruit body on rice medium北大核心CSCD

Inonotus hispidus is a kind of rare medicinal fungus, and its natural resources are very scarce. Currently, the artificial cultivation technology of I. hispidus is not completely developed, and this reflects on its extremely low biological conversion rate and long cultivation period. In order to improve the bioconversion rate and shorten the production cycle of I. hispidus, we first analyzed the mycelia culture conditions of the collected I. hispidus, and then we further explore the method of domesticated cultivation of its fruiting body in rice medium. During the process of mycelial culture, the suitable temperature, pH, carbon source, and nitrogen source for mycelial growth were selected using the mycelial growth rate as index. During the domesticated cultivation of the fruiting body, the suitable culture medium for its growth was selected using the bioconversion rate as index. Screening results of mycelial culture conditions showed that the optimal culture conditions for the growth of mycelium of the wild I. hispidus were: temperature of 25 °C, initial pH of 6.0, glucose as the carbon source, and yeast extract powder as the source of nitrogen. The results of the domesticated cultivation showed that the biotransformation rate of I. hispidus was higher when using rice as the main medium substrate. The optimal cultivation conditions were: a 0.2% yeast extract content in the nutrient solution, a 1:1.6 ratio of rice to nutrient solution, and a 4 mL inoculum of the liquid strain. Under these conditions, it took about 4 days for the mycelium to grow over the cultivation medium. The time required for the differentiation of the primordium to form fruit bodies was about 20 days, and the bioconversion rate reached 28.70% ± 5.05%. The results of this study indicate the feasibility of using rice as the main substrate for the cultivation of I. hispidus, and it also provide new insights for the finding of new cultivation substrates for other rare medicinal fungi. © 2018 Science Press. All rights reserved.     

突发事件下城市群应急医疗床位共享建模

为给突发事件下城市群应急医疗床位共享提供理论依据,针对突发事件下城市群应急医疗床位共享问题,阐述突发事件下城市群应急医疗床位共享的必要性和可行性,并运用Multi-Hub理论,建立应急医疗床位在城市群集中的优化网络模型,并分析其内涵。在此基础上,采用基于层次分析法的线性回归方法,对多出救点、单个资源、多受灾点的应急医疗床位共享进行优化与讨论,并采用排队分配原则进行应急医疗床位具体去向的落实。研究结果表明:基于Multi-Hub理论的应急医疗床位区域集中优化模型与基于层次分析法的线性规划应急医疗床位调配优化模型,对突发事件下城市群应急医疗床位的共享具有优化和指导作用,能够提高突发事件下城市群应急医疗床位共享的效率,排队分配法能够在不超过医院容纳限度的前提下,保障应急救援的有序性和及时性。     

基于文本故障视角的通信保障应急预案有效性评估研究

应急通信预案作为应急通信保障的行动纲领,其文本有效性将直接影响预案有效性,进而影响到整个应急救援行动的有效性。针对预案文本有效性问题,从文本故障视角出发,基于故障树分析法构建通信保障应急预案有效性评估模型;采用语句成分分析法和伪代码转换法对预案进行故障形式诊断,结合标准故障树,计算预案的有效性并给出具体评估步骤;最终,通过4个样本预案对模型进行实例分析,结果表明:该模型能够提高预案文本故障的识别效率,对预案的编制或修订具有参考意义。     

Spontaneous Interspecific Hybridization and Patterns of Pollen Dispersal in Ex Situ Populations of a Tree Species (Sinojackia xylocarpa) that is Extinct in the Wild

Abstract:  For endangered plants interspecific hybridization occurring in ex situ collections may lead to failure of reintroduction actions. We used Sinojackia xylocarpa , a well documented Chinese endemic species that is extinct in the wild, as a model case to address this concern. We used paternity analyses to assess the spontaneous hybridization and patterns of pollen flow between S. xylocarpa and its congener species, S. rehderiana , in conserved populations in Wuhan Botanic Garden. Interspecific hybridization events were detected in seven out of eight maternal trees of S. xylocarpa , and an average of 32.7% seeds collected from maternal trees of S. xylocarpa were hybrids. The paternity of 93 out of 249 seedlings from S. xylocarpa assigned to S. rehderiana provided convincing evidence that spontaneous interspecific hybridization occurred extensively in the living garden collection we studied. Different patterns of pollen dispersal (predominantly short-distance vs. long-distance pollination) were observed between intra- and interspecific hybridization events in the garden. Pollen dispersal within the ex situ populations was not restricted by distance, as evidenced by a lack of significant correlations between the average effective pollen dispersal distance (δ) and the geographic distances (d1 and d2) between maternal and paternal trees. The interspecific pollen-dispersal distance ranged from 10 to 620.1 m (mean 294.4 m). Such extensive hybridization in ex situ collections could jeopardize the genetic integrity of endangered species and irrevocably contaminate the gene pool if such hybrids are used for reintroduction and restoration. We recommend strongly that measures be taken to minimize the genetic risks of this kind of hybridization, including establishing buffer zones in ex situ collections, manipulating flowering phenology, testing seed lots before use in reintroduction programs, and controlling pollination for seed purity.     

天津市东疆港区绿化树种适应性评价

筛选适生树种是盐碱地绿化工作的技术关键。天津市东疆港区的土壤是淤泥质盐渍土,在该区域绿化树种现场调查的基础上,依据树种的适生能力、生态效益和实际生长效果建立了综合评价多级指标体系。通过确定各指标因子的权重和评判标准,计算出各树种的综合指数,并依次划分为骨干树种、重要树种、辅助和补充树种以及不适宜树种4个级别,该综合评价多级指标体系为类似盐碱地绿化建设工程提供了实践和理论依据。     

糠醛厂生产过程安全评价

对企业生产过程中的危险有害因素进行安全评价,是当前企业预防事故发生的有效手段。安全评价技术在国内外已有较长的发展历史,但关于糠醛生产过程的安全评价方法及研究还比较匮乏。在糠醛生产过程中存在着火灾、爆炸、中毒、噪声等危险因素,极易造成大量的人员伤亡和财产损失。根据某糠醛厂的实际情况,结合安全评价的基本程序,采用重大危险源辨识及事故树分析评价法,对危险有害因素进行辨识和评价。结果显示,糠醛厂存在着锅炉超压爆炸的危险,利用事故树分析法可以及时的找出预防途径,有针对性地提出安全改进的合理建议,从而进一步改善糠醛厂生产过程中的环境。评价的结果对糠醛生产企业进行安全决策、减少事故隐患,具有积极的指导意义。     

Estimating the vulnerability of fifteen tree species under changing climate in Northwest North America

In the Pacific northwestern (PNW) region of North America, climatic conditions have significantly warmed since a predominantly cool phase of the Pacific North American circulation patterns between 1950 and 1975. What are the implications of this shift in climate for the vulnerability of native tree species? To address this question, we combined mechanistic and statistical models to assess where a variety of native tree species might be more vulnerable within their recorded ranges and where they might potentially migrate. For long-lived species that are well adapted to compete, seasonal differences in photosynthesis and water use offer insights helpful in predicting their distributions. To evaluate the general response of conifers to climatic variation across the region, we previously applied a process-based model (3-PG), to simulate the growth and maximum leaf area index that Douglas-fir could attain within recognized forested areas. We then constructed automated decision tree models to define and map the ecological distributions of 15 tree species based on differences in how photosynthesis was constrained by drought, daytime temperatures, high evaporative demand, and the frequency of frost. For the baseline climate period (1950-1975), the decision tree models predicted presence and absence of each species at ∼23,000 observations with an average accuracy of 81%, with an average kappa statistic of 0.74. In this paper the same models were run annually for the period between 1976 and 2006 for each species, and the areas defined as remaining suitable or becoming vulnerable to disturbance were identified based on whether more or less than half of the years fell within the originally defined limits. Based on these criteria, 70% of the species recorded ranges remained suitable, with 30% deemed vulnerable. Results varied notably by species with western red cedar and western hemlock remaining highly adapted, with potential for range expansion in area of up to 50% relative to the baseline period. In contrast, ponderosa pine, lodgepole pine, grand, and noble fir were classified as vulnerable with potential net contractions in their ranges. The analysis was extended through the rest of the 21st century using climatic projections from the Canadian global circulation model with a high fossil fuel emission scenario (A2) and compared to other previously published species range predictions.     

北京建成区道路绿化空间结构和行道树健康状况

采用实地普查测量方法,定量研究了北京建成区188条道路行道树的树种结构、径级分布、立木层次和健康状况。结果表明,国槐（Sophora japonica）、毛白杨（Populus alba）、银杏（Ginkgo biloba）是建成区主要行道树种,使用量分别占研究区树木总株数的54．7％、13．7％和7．4％。建成区树木...     

温带阔叶红松林中不同树种和倒木对土壤性质的影响

以长白山温带阔叶红松林为研究对象,通过野外采集土壤样品,综合研究老龄树及倒木对周边表层土壤性质的影响。研究结果显示,在本研究样地条件下,不同树种周边的表层土壤性质存在显著性差异,红松（Pinus koraiensis）周边土壤中水溶性有机碳WSOC的质量分数和特征吸光系数SUVA254值都高于紫椴（乃砌amurensis）和水曲柳（Fraxinus mandshurica）,但是土壤水溶性总氮WSTN和交换性无机氮的质量分数却是红松低于紫椴和水曲柳。对倒木影响的森林表层土壤性质的研究结果显示,倒木下方森林表层土壤中WSOC、WSTN以及交换性矿质氮的质量分数都明显地高于林间土壤,说明在小尺度空间区域内,倒木可能是森林表层土壤活性碳、氮库的重要输入源。此外,本研究还利用主成分分析探讨了受树种影响的森林表层土壤不同性质之间的关联性,并对树种和倒木影响周边土壤性质的可能性机制进行分析。     

生态系统服务约束关系界定及影响机制分析

以长江经济带为研究对象,选择InVEST模型对长江经济带代表性的5种生态系统服务进行评估,根据两两配对关系原理进行约束线提取,并构建生态系统服务约束关系与影响因素相互作用模型,对其作用机制进行探究.结果表明,2000~2015年长江经济带5种生态系统服务两两间共表现出矩形型,对数型,抛物线型和驼峰型4种约束类型;7种影响因素与配对的10对约束关系间均呈弱相关性;影响因子与约束关系作用关系曲线的空间变化呈现较大差异,总体为上下波动的趋势;影响因子对约束关系的贡献程度情况各异.辐射对约束关系的平均贡献率最高,达21.43%,其中对粮食供给-生境质量的贡献率最高,为33.10%;NDVI的平均贡献率最低,为7.55%,其中对粮食供给-生境质量的贡献率最低,为5.70%;各因素间相互作用、彼此制约的关系是生态系统服务约束关系变化的内在机制.