Results 21 to 30 of about 13,463 (225)

Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
Pengpeng Wang   +4 more
wiley   +1 more source

Copyrolysis of biomass and synthetic polymer mixtures and gas chromatographic analysis of gaseous hydrocarbons(生物质与聚合物共裂解及其气态烃类的气相色谱分析)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2010
设计的生物质与聚合物共裂解工艺,共裂解产物中C3-C4烃成分占气态烃类的大部分,为可燃气的开发提供理论基础.从生物质与聚合物共裂解产物中气态烃类的分布可见:生物质与聚合物常压共裂解气体转化率更高;相对生物质与聚合物高压无氧共裂解, C1和C2烃类生成相对减少,常压共裂解有利于C3和C4烃烃类的生成,占总气态烃的64.6%(质量比).将毛细管柱与氢火焰离子化检测器(FID)联用,研究了生物质与聚合物共裂解产物中气态烃类的气相色谱分析.通过控制分析条件,有效地使各类烃获得有效的分离.柱温:程序升温 ...
CUIYan-li(崔艳丽)   +4 more
doaj   +1 more source

羧甲基纤维素-丁苯橡胶复合黏结剂在硅基锂离子电池中的应用 [PDF]

open access: yes, 2018
黏结剂是影响锂离子电池性能的重要因素之一,将羧甲基纤维素(CMC)和丁苯橡胶(SBR)联合使用,有利于缓解锂离子电池电极的体积效应,但SBR的导电性较差不利于提升电池的电化学性能.为此,制备了不同取代度(0.23~0.86)的低聚合度CMC,并和4种高聚合度CMC分别应用于硅负极,进行循环性能的比较;采用低聚合度CMC-SBR制备电极,进行电化学性能测试.结果表明,采用低聚合度CMC制备的电极的电化学性能优于高聚合度CMC,且不添加SBR时表现出相对优异的电化学性能,其中取代度为0 ...
刘健   +4 more
core  

Functional homogenization of terrestrial mammals outside protected areas in the Hengduan Mountains, China

open access: yesConservation Biology, EarlyView.
Abstract Despite the crucial role of human impacts on biodiversity loss, many assessments of this loss focus on single metrics, such as species richness, and overlook the multidimensional effects of human activities. Because of its importance to ecosystem functioning, we investigated the functional diversity of medium‐ and large‐sized mammal ...
Xueyou Li   +8 more
wiley   +1 more source

To prepare antimicrobial bamboo fabric by oxidization method and the research of related properties [PDF]

open access: yes, 2016
根据相关文献和世界卫生组织报告,目前在世界范围内仍然有多于8.8亿的人口不能获得安全、卫生的饮用水源,这一情况主要集中在不发达地区。到目前为止,世界上每年仍有大约220万人死于饮用不卫生水导致的痢疾等其他疾病,这其中大部分是儿童。造成这一问题的主要原因是缺乏安全可靠、廉价的水处理技术。 大量文献表明,磺胺嘧啶银对皮肤烧伤、溃疡等伤口处易感染细菌具有较好的杀灭效果,可对伤口化脓及感染情况进行有效控制。但是磺胺嘧啶银及其他低浓度银盐对体液或者水不具有耐受性,极容易流失,使得其使用范围受到一定的限制。研究发现,
秦光辉
core  

Calibration of the species threat abatement and restoration metric's threat abatement component in a Costa Rican landscape

open access: yesConservation Biology, EarlyView.
Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair   +17 more
wiley   +1 more source

漫反射光谱法检测变压器绝缘纸聚合度

open access: yesGaoya dianqi, 2016
检测变压器绝缘纸聚合度是判断其固体绝缘老化程度最直接有效的方法,实验室制取了53个不同聚合度的变压器绝缘纸样,采用国标法(粘度法)检测其聚合度。通过漫反射光谱仪对所有纸样进行扫描,结合偏最小二乘回归法建立了绝缘纸聚合度与光谱参数间的定量模型,模型相关系数为0.951 9,预测均方根误差RMSEP为67.5。该方法检测绝缘纸聚合度的精密度和准确度基本满足工程应用要求,为变压器固体绝缘状态提供了一种快捷、无损的检测方式。
蔡德华   +3 more
doaj  

Study on the Sulfonation of Straw Powder and The Application as High-effect Water Reducer [PDF]

open access: yes, 2015
农作物秸秆中富含纤维素、半纤维素、木质素等光合作用产物,目前没有得到很好利用,是值得开发的可再生生物资源库。2015年我国的秸秆产生量将达到9亿多吨。焚烧秸秆不仅浪费资源,而且加重了雾霾等环境污染。因此,开发以秸秆等天然可再生资源为原料的减水剂等高附加值产品,对保护环境、推动生态产业的发展及减少化石类资源的消耗意义重大。 本论文利用本课题组开发的三氧化硫/1,2-二氯乙烷体系,开发了以不经分离和纯化的秸秆粉为原料,合成水溶性混合生物高分子硫酸单酯盐新工艺。成功获得了具有很好水溶性 ...
阙元昌
core  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

壳聚糖与Ⅰ型胶原制备组织工程复合支架材料的扫描电镜研究

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2006
【目的】 通过扫描电镜观察壳聚糖和Ⅰ型胶原在不同温度下以不同比例制备成冻干状组织工程复合支架材料的微观结构, 以获得最佳浓度、比例、温度匹配组合, 制备理想的组织工程复合支架材料。【方法】在- 5 ℃、- 20 ℃和- 80 ℃将不同浓度的壳聚糖、Ⅰ型胶原以及它们不同比例的混合液冷冻 12 h 后冻干 24 h, 扫描电镜观察不同材料表面和内部的微观结构, 并计算其平均孔径和孔隙率。【结果】壳聚糖、Ⅰ型胶原以及它们的混合液冻干后都形成白色海绵状固体, 冷冻温度越低冻干后材料的孔径越小, 孔隙率越低 ...
李容林
doaj  

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