Efficient expression of green fluorescent protein （GFP） mediated by a chimeric promoter in Chlamydomonas reinhardtii

To improve the expression efficiency of exogenous genes in Chlamydomonas reinhardtii,a high efficient expression vector was constructed.Green fluorescent protein(GFP) was expressed in C.reinhardtii under the control of promoters:RBCS2 and HSP70A-RBCS2.Efficiency of transformation and expression were compared between two transgenic algae:RBCS2 mediated strain Tran-Ⅰ and HSP70A-RBCS2 mediated strain Tran-Ⅱ.Results show that HSP70A-RBCS2 could improve greatly the transformation efficiency by approximately eightfold of RBCS2,and the expression efficiency of GFP in Tran-Ⅱ was at least double of that in Tran-Ⅰ.In addition,a threefold increase of GFP in Tran-Ⅱwas induced by heat shock at 40°C.All of the results demonstrated that HSP70A-RBCS2 was more efficient than RBCS2 in expressing exogenous gene in C.reinhardtii.     

Impact of the Three Gorges Dam on reproduction of four major Chinese carps species in the middle reaches of the Changjiang River

Silver carp (Hypophthalmichthys molitrix), bighead carp (Aristichthys nobilis), grass carp (Ctenopharyngodon idella), and black carp (Mylopharyngodon piceus) are the four major Chinese carps and are commercially important aquaculture species in China. Reproduction of these carp has declined since the construction of the Three Gorges Dam (TGD) due to an altered water flow and thermal regime in the Changjiang (Yangtze) River. However, details of the changes in reproduction of the four species are not well understood. To assess the impact of the TGD on reproduction of the four carp, we investigated their eggs and larvae at Yidu City, which is 80 km below the TGD, during 2005–2012. We examined diff erences in larval abundance of the four species in the Jianli section (350 km downstream of the TGD) before (1997–2002) and after (2003–2012) construction of the TGD. Based on these observations, the first spawning date of the four species was delayed a mean of about 25 days after the dam was constructed. Mean egg abundance in the Yidu section of the river was 249 million and mean larval abundance was 464 million, which were significant decreases since the 1980s. Moreover, larval abundance in the Jianli section after the dam was constructed was significantly lower than that before construction (ANCOVA, P<0.05). The observed larval abundance accounted for only 24.66% of the predicted value in 2003 when the dam was first inundated. The present spawning grounds between the TGD and Yidu section of the river are very similar to those described in the 1980s, and some spawning grounds exist upstream of the TGD. Large free-flowing stretches upstream of the TGD and the creation of artificially flooded downstream reaches are needed to stimulate spawning and eff ectively conserve these four major Chinese carps species.     

襄渝铁路增建二线--新白岩寨隧道地应力测量及其在岩爆分析中的应用

本文在襄渝增建二线———新白岩寨深埋长隧道(最大埋深近500m)工程区进行了水压致裂地应力测量,叙述了地应力测试方法和结果。测量结果表明:该工程区的原地应力以水平应力为主,最大主应力方向为NNW,与区域地质分析的结果相吻合。根据该工程区应力量值及其方向,分析了隧道区应力作用特征,并结合该工程区地质条件,对隧道的稳定性和地质灾害发生的可能性进行了讨论。     

梧州“6.15”强对流暴雨过程技术分析

利用现有预报业务中使用的各种常规、新型观(探)测资料,对2010年6月13～16日广西梧州市出现的连续暴雨天气过程,特别是15日梧州北部强对流大暴雨天气过程成因及预报技术难点等分析,结果表明:强对流暴雨主要由一个中尺度雨团在梧州北部附近活动而造成,冷空气与低层切变辐合配合使得强回波带在梧州北部近似静止,是造成此次强降水的主要原因;中小尺度系统分析判断为降水落区和预警预报起到关键作用。     

郴州白腊水锡矿矿床地质特征

白腊水矿区为郴州芙蓉锡矿田最重要的一个矿区,已发现锡矿脉25条,估算远景资源量在40万吨以上,其中19号主矿脉远景资源量就达到20万吨。文章简要分析了该矿床的地质特征,以期能为多种手段结合找矿提供参考。     

湖南省桂东-汝城地区钨锡多金属矿床地质特征及找矿前景

桂东-汝城钨锡多金属成矿区是南岭有色、稀有金属成矿带的重要组成部分。近年来,该区找矿工作取得了明显进展,新发现了竹园里、上山、大岭背等一批具大型找矿前景的钨锡多金属矿产地,矿床类型多样。本文通过对区内成矿地质条件及矿床地质特征的研究,探讨了矿床成因,并分析了找矿前景,提出了找矿方向。     

西藏班公湖-怒江结合带木嘎岗日岩群时代上限的新证据——来自恐弄拉地区早白垩世早期孢粉化石的报道

在班公湖-怒江结合带中段的恐弄拉地区木嘎岗日岩群其西弄岩组中发现早白垩世早期Dicheiropollis sp(.双手粉)和Cicatricosisporites sp(.无突肋纹孢)孢粉组合。明确了木嘎岗日岩群的沉积上限至少持续到早白垩世早期,为从生物年代学角度厘定木嘎岗日岩群提供了可靠的资料,也为今后进-步分析班公湖-怒江结合带中生代盆地演化提供了线索。     

赣南晚侏罗世九龙脑钨锡铅锌矿集区不同成矿类型花岗岩年龄、地球化学特征对比及其地质意义

九龙脑花岗岩体位于南岭东部,它周围分布着众多钨、锡和铅锌矿床(点).本文选择岩体北侧淘锡坑石英脉型钨矿、东侧宝山矽卡岩型铅锌矿底部的隐伏花岗岩,对比九龙脑岩体开展了成岩年代学、地球化学、Sr- Nd同位素研究.上述岩体的SHRIMP锆石U-Pb年龄分别是158.7±3.9Ma、157.7±2.7Ma、154.9±2.2...     

湖南茶里岩矿区铅锌多金属矿矿床地质特征及找矿前景浅析

茶里岩铅锌多金属矿床位于著名的香花岭矿田南部,是南岭多金属成矿带的重要组成部分。笔者通过野外地质工作、综合整理和分析研究。总结了区内的成矿地质条件、控矿因素等特征,确定矿床成因类型为中-高温热液裂隙充填型矿床,矿床规模为中型。从研究香花岭矿田内各大中型矿床的矿化类型,结合工作区地质条件,提出了本区的找矿方向及前景。