湖北九宫山甜槠群落结构与优势种的空间分布格局研究

通过对湖北九宫山国家级自然保护区甜槠群落建立的1ha固定森林样地进行植物群落调查,分析了样地内木本植物物种组成、区系成分、种群径级结构和空间分布格局,结果表明:(1)样地内木本植物(DBH≥1 cm)共有132种,隶属于42科78属,其中,杜鹃花科、壳斗科、樟科、蔷薇科、冬青科等是优势科,短柄袍、鹿角杜鹃、青冈、长叶石栎、甜槠等是优势种.(2)样地内植物科、属的分布类型均以泛热带分布类型为主,分别为30.95％和20.51％.(3)样地内所有木本植物个体的径级结构均呈倒"J"型,幼龄个体数量大,森林群落更新状况良好.(4)样地内木本植物个体的空间分布格局以聚集分布为主,部分优势物种在小尺度上呈聚集分布,而在较大尺度上则为随机分布.     

海外新闻

美国消防员要求对防护装备中有害物进行检测2021年1月底,美国马萨诸塞州楠塔基特岛消防局的肖恩·米切尔,联合国际消防员协会(IAFF)的其他成员,要求协会对消防员个体防护装备中的全氟烷基和聚氟烷基物质(PFAS)开展独立检测,并呼吁协会拒绝装备制造商和化学行业的赞助。     

g-C_3N_4/C@Bi_2MoO_6复合光催化剂的制备及其光催化活性

通过水热合成法和液相沉积法制备g-C_3N_4/C@Bi_2MoO_6复合光催化剂,并采用X射线衍射、扫描电子显微镜、氮气吸脱附、紫外-可见漫反射等技术对其进行表征。研究了可见光下g-C_3N_4/C@Bi_2MoO_6催化降解罗丹明B(Rh B)的影响因素,并对其光催化反应机理进行初步探讨。实验结果表明:g-C_3N_4掺杂量为60%(w)时g-C_3N_4/C@Bi_2MoO_6的光催化活性最高;在60%g-C_3N_4/C@Bi_2MoO_6的投加量为1.00 g/L、初始Rh B质量浓度为2.50 mg/L、可见光照射150 min的条件下,Rh B的降解率达到97.90%;在g-C_3N_4/C@Bi_2MoO_6光催化降解体系中,h~+和·O_2~-是主要活性物种。     

天津市地表水体与沉积物中7种高关注酚类化合物的污染特征与生态风险分析

为探究地表水体与沉积物中酚类化合物的污染分布特征和生态风险,选择天津市3个水源地与6条主要河流,采集了26个地表水样与6个沉积物样品,利用固相萃取与超声萃取、高效液相色谱-串联质谱法(HPLC-MS/MS)测定了水样及沉积物中1-萘酚(1-naphthol)、壬基酚(nonylphenol, NP)、双酚A(bisphenol A, BPA)、2-苯基苯酚(biphenyl-2-ol)、3,4-二氯酚(3,4-dichlorophenol)、四溴双酚A(tetrabromobisphenol A, TBBPA)和对叔丁基苯酚(p-tert-butylphenol, PTBP)等7种高关注酚类化合物的浓度水平,并应用物种敏感性分布(species sensitivity distribution, SSD)法和熵值法(ecological risk quotient, RQ)评估7种酚类化合物水环境和沉积物的生态风险。结果表明,地表水样中7种酚类化合物均全部检出;其中壬基酚的检出浓度最高,其次为四溴双酚A、对叔丁基苯酚、1-萘酚、2-苯基苯酚、3,4-二氯酚和双酚A。沉积物中酚类化合物的污染分布规律与水样相似,除双酚A外的目标物全部检出。其中,壬基酚浓度比其他物质浓度高2个数量级。风险评估结果显示,壬基酚对水环境与沉积物存在不可接受的风险;而四溴双酚A、对叔丁基苯酚、1-萘酚、2-苯基苯酚、3,4-二氯酚和双酚A则对环境具有较低风险或者存在一定的风险。     

生气时不要做10件事,三步“浇灭”怒火

<正>"皱着眉、撅着嘴、张大鼻孔",这是一张被研究证实世界通用的"愤怒脸"。俗话说"气大伤身",生气给身体带来的伤害是全方位的,却很少有人能在怒火冲头的时候做到心平气和。近日,美国《赫芬顿邮报》刊文总结生气时最不该做的10件事。带"气"入睡西方有句俗语:"永远不要带着怒气上床。"一项发表在美国《神经学杂志》上的研究发现,与清醒的状态相比,睡眠可能让你对糟糕经历的记忆更加牢固,那些让你     

斯道拉恩索将在美国投资建造生物质可再生材料示范工厂

近日,全球性生物质材料、纸张、包装和林木制品的创想者斯道拉恩索（Stora Enso）宣布,将投资3200万欧元（约合2．53亿元人民币）在美国路易斯安那州雷斯兰市建造一家生物质可再生材料示范性市场开发工厂,以对其新近全资收购的美国生物技术公司Virdia所开发的先进纤维素类生物质提取分离技术进行工业验证,助力斯道拉恩索生物质材料事业部在生物化学和生物质材料领域的发展壮大。     

荒野：希望与文明相处——评《荒野与美国思想》

山川、河流、瀑布、小溪、田野、猛兽、花丛、飞虫、蓝天、白云,这些动态或是静态的景物是否能够让你感受到自然给予你的爱意？自然的关,自然的诱惑,是否让你感受到她的魅力？自然中的风起云涌,荆棘丛生,狼群野兽,是否可以唤醒你那原始的冲动？荒野是自然最为客观的那一部分,没有人类对自然的渲染,没有人类对自然的指点,没有人类对自然的修饰,调动你身上每个细胞感受那最纯粹的自然——荒野!     

Molecular characterization and developmental expression patterns of thyroid hormone receptors (TRs) and their responsiveness to TR agonist and antagonist in Rana nigromaculata

Considering some advantages of Rana nigromaculata as an experimental species, we propose that this species, like Xenopus laevis, could be used to assay thyroid hormone（TH） signaling disrupting actions. To validate the utilizability of R. nigromaculata, we investigated the responsiveness of R. nigromaculata to a TH receptor（TR） agonist（T3） and antagonist（amiodarone） by analyzing expression, based on characterizing TR cDNA and developmental expression patterns. With high levels of identity with the corresponding genes in X. laevis, both TRα and TRβ in R. nigromaculata exhibited roughly similar developmental expression patterns to those of X. laevis, in spite of some species-specific differences. Both TRα and TRβ expression had greater changes in the liver and intestine than in the tail and brain during metamorphosis. T3 exposure for 2 days induced more dramatic increases of TRβ expression in stage 27 than in stage34 tadpoles but not in stage 42 tadpoles, showing that the responsiveness of R. nigromaculata to TH decreased with development and disappeared at the onset of metamorphic climax.Corresponding to greater changes of TRβ expression in the liver and intestine than in the tail and brain during metamorphosis, the liver and intestine had higher responsiveness to exogenous T3 than the tail and brain. Amiodarone inhibited T3-induced TRβ expression. Our results show that R. nigromaculata can be used as a model species for assaying TH signaling disrupting actions by analyzing TRβ expression, and intestine tissues at stage 27 are ideal test materials due to high responsiveness and easy accessibility.     

Evaluation of accuracy of linear regression models in predicting urban stormwater discharge characteristics

Stormwater runoff has been identified as a source of pollution for the environment, especially for receiving waters. In order to quantify and manage the impacts of stormwater runoff on the environment, predictive models and mathematical models have been developed. Predictive tools such as regression models have been widely used to predict stormwater discharge characteristics. Storm event characteristics, such as antecedent dry days （ADD）, have been related to response variables, such as pollutant loads and concentrations. However it has been a controversial issue among many studies to consider ADD as an important variable in predicting stormwater discharge characteristics. In this study, we examined the accuracy of general linear regression models in predicting discharge characteristics of roadway runoff. A total of 17 storm events were monitored in two highway segments, located in Gwangju, Korea. Data from the monitoring were used to calibrate United States Environmental Protection Agency＇s Storm Water Management Model （SWMM）. The calibrated SWMM was simulated for 55 storm events, and the results of total suspended solid （TSS） discharge loads and event mean concentrations （EMC） were extracted. From these data, linear regression models were developed. R2 and p-values of the regression of ADD for both TSS loads and EMCs were investigated. Results showed that pollutant loads were better predicted than pollutant EMC in the multiple regression models. Regression may not provide the true effect of site-specific characteristics, due to uncertainty in the data.     

罗萨利·巴罗·艾格

<正>罗萨利·巴罗·艾格(Rosalie Barrow Edge,1877年11月3日—1962年11月30日),纽约社会活动家,环境保护主义者,观鸟爱好者,终生致力于鸟类保护事业。罗萨利女士1877年出生于纽约,是家里五个孩子里最小的一个,她的父亲是英国一位富有的商人和会计,也是英国作家查尔斯?狄更斯的表弟。在自然教育经历上,罗萨利没有经过正式的培训,但从师于不少顶级野生动物学专家,在野生动物种保护领域上取得了深厚的知识修养。