Detailed analysis of fan-shaped jets in three dimensional numerical simulation

We performed three dimensional resistive magnetohydrodynamic simulations to study the magnetic reconnection using an initially shearing magnetic field configuration(force free field with a current sheet in the middle of the computational box).It is shown that there are two types of reconnection jets:the ordinary reconnection jets and fan-shaped jets,which are formed along the guide magnetic field.The fan-shaped jets are significantly different from the ordinary reconnection jets which are ejected by magneti...     

矿物收藏漫谈(五)这些矿物杂志和书籍,实在精彩

<正>上期中提到了一些关于矿物标本的书籍,这里再列出几本实在精彩的有关矿物收藏知识的书籍和杂志,因为他们实在是精彩。     

综合应用低温扫描电镜和核磁共振波谱法研究油和盐水在砂岩中的分布

本文主要叙述了６１００－ＩＺ涡轮轮增压汽油机增压后，发动机特性的变化以及在不同大气条件和不同的海拔高度上发动机的功率修正和性能预测的方法，即根据已知标准状态下的输出功率计算出在其它海拔地区的功率指标，汉及在同一海拔高度下大气状况改变后功率将会产生的变化。     

Surface wave tomography on a large-scale seismic array combining ambient noise and teleseismic earthquake data

We discuss two array-based tomography methods,ambient noise tomography (ANT) and two-planewave earthquake tomography (TPWT),which are capable of taking advantage of emerging large-scale broadband seismic arrays to generate high resolution phase velocity maps,but in complementary period band:ANT at 8-40 s and TPWT at 25-100 s period.Combining these two methods generates surface wave dispersion maps from 8 to 100 s periods,which can be used to construct a 3D v S model from the surface to ～200 km depth.As an i...     

Setting priorities for land management to mitigate climate change

Background

No consensus has been reached how to measure the effectiveness of climate change mitigation in the land-use sector and how to prioritize land use accordingly. We used the long-term cumulative and average sectorial C stocks in biomass, soil and products, C stock changes, the substitution of fossil energy and of energy-intensive products, and net present value (NPV) as evaluation criteria for the effectiveness of a hectare of productive land to mitigate climate change and produce economic returns. We evaluated land management options using real-life data of Thuringia, a region representative for central-western European conditions, and input from life cycle assessment, with a carbon-tracking model. We focused on solid biomass use for energy production.

Results

In forestry, the traditional timber production was most economically viable and most climate-friendly due to an assumed recycling rate of 80% of wood products for bioenergy. Intensification towards "pure bioenergy production" would reduce the average sectorial C stocks and the C substitution and would turn NPV negative. In the forest conservation (non-use) option, the sectorial C stocks increased by 52% against timber production, which was not compensated by foregone wood products and C substitution. Among the cropland options wheat for food with straw use for energy, whole cereals for energy, and short rotation coppice for bioenergy the latter was most climate-friendly. However, specific subsidies or incentives for perennials would be needed to favour this option.

Conclusions

When using the harvested products as materials prior to energy use there is no climate argument to support intensification by switching from sawn-wood timber production towards energy-wood in forestry systems. A legal framework would be needed to ensure that harvested products are first used for raw materials prior to energy use. Only an effective recycling of biomaterials frees land for long-term sustained C sequestration by conservation. Reuse cascades avoid additional emissions from shifting production or intensification.     

Metallothionein induction by Cu, Cd and Hg in Dicentrarchus labrax liver: assessment by RP-HPLC with fluorescence detection and spectrophotometry

Metallothionein was quantified in sea bass Dicentrarchus labrax intraperitoneally (i.p.) injected with different Cu, Cd and Hg doses (50-250 microg kg(-1) wet wt) after 48 h exposure. A distinct peak with 16.8 min retention time was obtained by reversed-phase high performance liquid chromatography coupled to fluorescence detection (RP-HPLC-FD) with the three metals. Total metallothionein levels assayed in unheated liver extracts by RP-HPLC-FD were significantly higher (1.3-1.95-fold) than those obtained by the well-established spectrophotometric method. In the RP-HPLC-FD method, metallothionein increased linearly with Cu and Hg doses, being saturated beyond 100 mug kg(-1) Cd. Maximum induction was obtained at 100 microg kg(-1) Cd (5.3-fold), and 250 microg kg(-1) Cu or Hg (8- and 5.1-fold, respectively). At low doses no metallothionein induction was shown by the less sensitive spectrophotometric assay.     

The tropical brown alga Lobophora variegata as a bioindicator of mining contamination in the New Caledonia lagoon: a field transplantation study

Previous field and laboratory studies have identified the alga Lobophora variegata as a good candidate for biomonitoring metal contamination in the New Caledonia lagoon which is subjected to intensive and extensive metal inputs from land-based mining activities. The aim of this work was to further assess the bioindicative potential of this species by investigating, in the field, its bioaccumulation capacity for local key contaminants, i.e. Ag, As, Cd, Co, Cr, Cu, Mn, Ni and Zn. Algae from clean and contaminated sites were cross-transplanted for a period of three months in order to determine the in situ uptake and depuration kinetics of the nine elements. Results indicate that algae transplanted to the contaminated site displayed a significant linear increase in concentration with time for Ag, As, Cd, Co, Cr, Cu, Mn and Ni. In contrast, algae transplanted to the clean site did not show major depuration of these elements, except for Co. Overall, L. variegata showed a rapid temporal response in metal uptake, especially for the elements intensively released into the coastal environment of New Caledonia (viz., Co, Cr, Mn and Ni). This species appears therefore as an excellent bioindicator species of metal contamination in this area. Our results also provide background information necessary for using L. variegata under in situ experimental conditions so as to provide better quantitative information on ambient metal contamination levels. The wide distribution of L. variegata in tropical areas further enhances its potential as a bioindicator species of metal contamination in other tropical coastal environments.     

日本海洋民用工程概况

1 前言 一般来说,海域利用有空间、能源开发、海洋增长和矿产资源利用等4种类型。日本的海域利用重点在空间利用方面。 日本四周环海,由于地理条件所限,长期以来海域利用一直强调渔业和海上运输基地的建设,最近又强调作为国际贸易基地的港口建设。为了扩大有限的陆地,对于海滨土地围垦也予以同等重视。