梁山县破解"双保双赢"难题

近年来,梁山县正确处理保护耕地与保障发展的关系,积极破解“双保双赢”难题,切实加大土地开发整理和复垦力度,走节约集约用地之路,实现了保护耕地与保障发展的“双保双赢”。     

Comparative oxygen radical formation and toxicity of BDE 47 in rainbow trout cell lines

The polybrominated diphenyl ethers (PBDEs) constitute a class of flame retardants whose residues have markedly increased in fish and human tissues during the last decade. In particular, the levels of certain PBDE congeners in salmon have raised concern regarding potential risks associated with dietary PBDE exposures. However, little is known regarding PBDE-mediated cell injury in relevant in vitro cell models. We conducted a comparative study of oxyradical production and cell injury in rainbow trout gill (RTgill-W1) and trout liver cells (RTL-W1) exposed to 2,2',4,4'-tetrabromodiphenyl ether (BDE 47), a predominant BDE residue found in fish tissues such as salmonids. Exposure to low micromolar concentrations of BDE 47 elicited a significant loss in RTgill-W1 and RTL-W1 cell viability as measured by alamarBlue assay. The dose-response of BDE toxicity differed among the two cell lines, with the RTL-W1 liver cells showing greater resistance to toxicity at lower BDE 47 doses, but a more dramatic loss of viability relative to gill cells when challenged with higher (50 microM) doses. The sensitivity of the trout liver cells at higher BDE 47 exposures was reflected by a higher basal production of oxygen radical production by 6-carboxy-2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) fluorescence that was markedly enhanced in the presence of BDE 47, suggesting an overwhelming of trout liver cell antioxidant defense pathways. Collectively, our data indicate that RTgill-W1 and RTL-W1 liver cells are sensitive to BDE 47-mediated cell injury through a mechanism that may involve oxidative stress. Our data also provide an in vitro basis for potential tissue differences in BDE 47-mediated cell injury.     

A numerical scheme for morphological bed level calculations

The typical equation for bed level change in sediment transport in river, estuary and near shore systems is based on conservation of sediment mass. It is generally a nonlinear conservation equation for bed level. The physics here are similar to shallow water wave equations and gas dynamics equation which will develop shock waves in many circumstances. Many state-of-art morphological models use classical lower order Lax–Wendroff or modified Lax–Wendroff schemes for morphology which are not very stable for long time sediment transport processes simulation. Filtering or artificial diffusion are often added to achieve stability. In this paper, several shock capturing schemes are discussed for simulating bed level change with different accuracy and stability behaviors. The conclusion is in favor of a fifth order Euler-WENO scheme which is introduced to sediment transport simulations here over other schemes. The Euler-WENO scheme is shown to have significant advantages over schemes with artificial viscosity and filtering processes, hence is highly recommended especially for phase-resolving sediment transport models.     

几种大型珍珠贝人工苗网箱式中间培育的研究

采用网箱式和传统式2种方法,在3个不同类型的海区(内湾性的陵水县黎安港、半开放性的雷州市流沙港、开放性的三亚市六道湾),进行几种大型珍珠贝人工苗的中间培育.经90d的中间培育后,结果表明:网箱式培育与传统式培育相比较,几种珍珠贝的生长速率和成活率都有较大幅度的提高.其壳高生长速率的增幅分别为:珠母贝18.9%、18.2%、19.9%;大珠母贝22.8%、20.6%、23.5%;企鹅珍珠贝21.8%、20.7%、21.7%;均为差异显著(P＜0.05)或差异极显著(P＜0.01).成活率的增幅分别为:珠母贝175.0%、147.9%、133.9%;大珠母贝172.8%、159.0%、127.4%;企鹅珍珠贝122.5%、118.2%、102.2%,均为差异显著(P＜0.05)或差异极显著(P＜ 0.01).     

珠母贝人工繁育优化技术的研究

在室内水泥池分别进行了移池培育、不同种类附着器、光照强度、水流和冲洗对珠母贝附着幼虫变态和稚贝存活的研究,结果表明:附着密度为2.18个/cm~2±0.50个/cm~2时,移池培育,其变态幼虫密度为0.95个/cm~2±0.13个/cm~2,20 d稚贝存活密度0.41个/~2±0.08个/cm~2,移池培育显著提高附着幼虫变态和稚贝存活;附着板、附着绳、网片、小石块变态幼虫密度分别为0.70个/cm~2±0.08个/cm~2、1.38个/cm~2±0.15个/cm~2、0.97个/cm~2±0.12个/cm~2、1.04个/cm~2±0.28个/cm~2,稚贝存活密度分别为0.36个/cm~2±0.06个/cm~2、0.62个/cm~2±0.07个/cm~2、0.45个/cm~2±0.07个/cm~2、0.60个/cm~2±0.08个/cm~2,附着绳显著提高附着幼虫变态和稚贝存活;光照强度为300～600 lx时变态幼虫密度为0.87个/cm~2±0.07个/cm~2,20 d稚贝存活密度0.45个/cm~2±0.08个/cm~2,强光不利于幼虫的变态和稚贝存活;水流速为2.3 cm/s时变态幼虫密度为1.08个/cm~2±0.07个/cm~2,20 d稚贝存活密度0.87个/cm~2±0.07个/cm~2,冲洗的变态幼虫密度为1.64个/cm~2±0.19个/cm~2,20 d稚贝存活密度1.00个/cm~2±0.12个/cm~2,水流或冲洗显著提高附着幼虫变态和稚贝存活.     

企鹅珍珠贝游离珠培育技术的初步研究

2006 年 5 - 12 月,在广东省、湛江市、徐闻县芳华珍珠养殖场,采用贝龄 2 ～ 4 a 的企鹅珍珠贝作植核贝,以 1 ～ 3 a 贝作小片贝,进行游离珍珠培育试验.结果表明,植核母贝经 15 ～ 40 d 的术前处理,成活率为 95.33 % ～ 97.00 %;施术贝经过 6 个月培育后,吐核率为 63.00 % ～ 71.88 %,死亡率为 26.17 % ～ 35.00 %,成珠率为 1.95 % ～ 3.33 %.企鹅珍珠贝合适的植核母贝为 2 ～ 3 龄贝,小片贝为 1 ～ 2 龄贝.     

舟山潮间带生态学研究：Ⅱ.数量及其分布

舟山潮间带生物种类数量的平面分布与盐度和海岸开敞性有关,垂直分布与潮汐有关;群落数量的水平分布与底质和海岸开敞性有关,垂直分布与潮汐有关。舟山潮间带生物有明显的分带现象,隐蔽的岩岸区分为:滨螺带和藤壶-牡蛎带两个带;开敞性岩岸区分为:滨螺带,藤壶-(虫戚)-藻类带及藻类带3个带。沙滩区分为:沙蟹带和浅蛤-斧蛤带两个带;泥沙滩区分为:盐碱植物-滨螺带和招潮蟹-大眼蟹带;泥滩区分为:蟹守螺-囊螺带和蟹守螺-织纹螺带。     

海底光缆检测技术综述

据统计,我国近岸70%以上海底光缆失效是遭受了渔船拖网作业或抛锚等活动的破坏。维护损坏的海底光缆,首先需要快速准确地定位光缆损坏段,同时获取光缆在海床上的布设状态以及布设区域的海床地形特征、地貌与底质特征等信息。在实际工作中,复杂的海床环境为海底光缆的检修及维护带来巨大的技术困难。围绕海底光缆巡检的技术需求,系统分析了常规海底光缆检测技术的特点,基于国内外水下无人机器人的发展现状,为提高海底光缆的检测效率、识别准确率和智能化水平提供了技术支撑。     

泥河湾盆地磁性地层定年与早期人类演化

主要评述了近年来泥河湾盆地磁性地层学的研究进展,包括建立泥河湾组的磁性地层年代格架、厘定泥河湾动物群的时代和确定华北地区早期人类活动年代序列.研究表明:第一,泥河湾组河湖相沉积序列记录了高斯正极性时末期以来的地磁极性特征(松山和布容极性时),即沉积时代始于约2.6Ma.早期人类至少在1.66～0.78Ma期间的大约90万年的时间内长期持续地占据高纬度的泥河湾盆地.泥河湾动物群(包括广义和狭义)的时代为2.0～0.8 Ma.第二,华北地区早期人类已经能够适应东亚高纬度地区冬季风增强、夏季风减弱和干旱化趋势增强的复杂环境变化,尤其能适应中更新世气候转型前后中国北方多变而且不稳定气候条件和生态环境.因此,气候和生态环境的多变性与不稳定性是促进人类进化的重要因素.第三,早期人类走出非洲以后,可能沿不同的路径并以较快的速度扩散到东亚地区.向南越过印度尼西亚的赤道地区,向北至少扩散到40°N的泥河湾盆地.     

Effects of feeding time on complement component C7 expression in Pelteobagrus vachellii subject to bacterial challenge

Journal of Oceanology and Limnology - Shifting the feeding time for fish from daytime to nighttime could alter their digestive behavior, disturb their metabolism, and may affect immune-related...