A new Jurassic theropod from China documents a transitional step in the macrostructure of feathers

Genuine fossils with exquisitely preserved plumage from the Late Jurassic and Early Cretaceous of northeastern China have recently revealed that bird-like theropod dinosaurs had long pennaceous feathers along their hindlimbs and may have used their four wings to glide or fly. Thus, it has been postulated that early bird flight might initially have involved four wings (Xu et al. Nature 421:335–340, 2003; Hu et al. Nature 461:640–643, 2009; Han et al. Nat Commun 5:4382, 2014). Here, we describe Serikornis sungei gen. et sp. nov., a new feathered theropod from the Tiaojishan Fm (Late Jurassic) of Liaoning Province, China. Its skeletal morphology suggests a ground-dwelling ecology with no flying adaptations. Our phylogenetic analysis places Serikornis, together with other Late Jurassic paravians from China, as a basal paravians, outside the Eumaniraptora clade. The tail of Serikornis is covered proximally by filaments and distally by slender rectrices. Thin symmetrical remiges lacking barbules are attached along its forelimbs and elongate hindlimb feathers extend up to its toes, suggesting that hindlimb remiges evolved in ground-dwelling maniraptorans before being co-opted to an arboreal lifestyle or flight.     

美国环保产业政策分析及经验借鉴

美国在全球环保产业中占据着十分重要的位置。美国环保产业的蓬勃发展,得益于其行之有效的产业政策与激励措施,其环保产业政策的发展对很多国家都产生了重要影响。介绍了美国环保产业的范围和发展现状,从环境管控、环保技术、产业化、财税支持和环保贸易等方面分析了美国环保产业政策框架。最后,结合美国环保产业发展的经验与教训对我国未来环保产业的发展提出了政策建议。     

Distribution and mobility of metals in agricultural soils near a copper smelter in South China

The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH₂OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl₂ extractable fraction. A large proportion of Cu was bound to the acidic H₂O₂ extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier’s procedure, and the order of mobility was Zn > Cd > Cu  > Pb.     

脉冲调制介质阻挡放电和催化联用技术降解甲苯

利用低温等离子体处理挥发性有机化合物(VOCs)废气是目前国内外研究的热点。研究利用脉冲调制介质阻挡放电和催化联用技术降解甲苯,对比分析了连续放电和脉冲调制对去除甲苯的影响;研究了脉冲调制后在有无催化剂的情况下的能量效率,比较了两种情况下的臭氧浓度以及中间产物的不同。结果表明:脉冲调制有效提高了甲苯的降解能效,其能量效率几乎是连续放电时的2倍～3倍;在有催化剂的情况下,能量效率是没催化剂的1.5倍～2倍,臭氧浓度明显降低,结焦产物中含苯环的衍生物的量少于无催化的结焦产物。     

水蒸气/氨活化在脉冲电晕脱硫工业中试装置上的应用

在工业中试装置上进行了水蒸气／氨活化实验,同时开展了脉冲电源的调试运行、脱硫副产物收集一体化、工艺参数以及对副产物成份分析等实验。在烟气流量4500～11000m^3／h、反应器入口温度60-70℃、氨硫化学计量比约1：1、系统连续运行和采用一体化的单电场进行脱硫副产物收集的条件下．得到结果：水蒸气／氨活化脱硫效果明显,并且有较好的副产物收集功能,收集效率20％～30％;副产物中SO4^2-：SO3^2-大于95：5,脱硫效率稳定大于90％,副产物收率大于85％。     

HgCl2对斑马鱼SOD,AChE酶活性和基因相对转录量的影响

以HgCl2为实验毒物,研究其对斑马鱼的毒性效应,经染毒后,分别在第1天和第7天取斑马鱼的肌肉测定超氧化物歧化酶(SOD)、乙酰胆碱酯酶(AChE)活性,半定量RT-PCR检测肌肉中乙酰胆碱酯酶、细胞色素P450(CYP 1A)和超氧化物歧化酶(Cu/Zn-SOD)基因的相对转录量.结果显示HgCl2对斑马鱼的毒性很强...     

包含详细微物理过程的一维辐射雾模式

本文建立一个包含详细微物理过程的一维雾模式.模式包括动量方程、热量方程、水汽方程、雾滴凝结增长方程和浓度变化方程等.大气长波辐射采用Roach的五波段模式,微物理过程采用分档技术.试验结果表明,该模式可用于辐射雾的研究.     

矿石铅同位素示踪成矿物质来源综述

矿石铅同位素是示踪成矿物质来源的重要手段之一。本文综述了矿石铅同位素示踪成矿物质来源的基本原理和主要方法 ,并指出 :单阶段模式年龄、特征参数示踪已逐步淘汰 ,铅构造模式示踪遭质疑 ,Δβ Δγ图解示踪还需要接受更多矿床实例的检验 ,全方位对比是矿石铅示踪成矿物质来源的首选方法。     

灰水喷雾增湿简易脱硫工艺的工业试验研究

本文介绍了以灰水作为增湿剂的喷雾增湿简易脱硫工艺的原理、流程、工程概况和工业试验 ,分析并研究了运行效果 ,探讨了存在的主要问题 ,进行了技术和经济评价