all 1691基因表达及铁元素对鱼腥藻生长的影响

为实现FurA的表达,探究铁元素对藻生长的影响,首先运用Primer5.0设计引物,克隆出鱼腥藻PCC7120染色体上all1691(furA)基因片段;构建含组氨酸融合表达标签和T7启动子标签的表达载体.IPTG诱导FurA蛋白表达.然后设计不同Fe3+浓度梯度培养基,利用SDS-PAGE检测高、中、低Fe3+浓度培养液的藻细胞总蛋白,考马斯亮蓝g-250法测定蛋白含量,并用Trizol法提取不同Fe3+浓度培养的藻细胞总RNA.结果表明,获得纯化的all 1691克隆片段,大小为456bp,pET-1691重组蛋白在1mmol/L的IPTG诱导下,于37℃下摇床培养15h得到成功表达;低浓度Fe3+促进藻生长,高浓度Fe3+抑制藻生长;Fe3+浓度为2.0mg/L时rRNA位置与亮度清晰可见,而缺铁培养的藻生长几乎停滞,转录和翻译水平都很低.     

Redox condition during Ediacaran–Cambrian transition in the Lower Yangtze deep water basin,South China: constraints from iron speciation and δ~(13) Corg in the Diben section,Zhejiang

Cherts of the Piyuancun Formation and black mudstones of the Hetang Formation in Diben Town, Kaihua County, Zhejiang were deposited in a deep water basin of the Lower Yangtze area during the Ediacaran–Cambrian transition(E–C transition), offering an opportunity to reconstruct the ancient redox condition of the deep water basin. Total 53 samples were collected and analyzed for iron speciation, including pyrite iron(FePy), carbonate associated iron(FeCarb), iron oxide and hydroxide(FeOx),magnetite iron(FeMag) and total iron(FeT) as well as d13 Corgto gain a deeper understanding of specific redox condition during the period. The results show that(1) most samples have pyrite concentration \1 %, with the FePy/FeHR ratio ranging from \0.01 to 0.81(mostly \0.5), and the FeHR/FeT ratio between 0.39 and 0.93(mostly [0.5).(2) The E–C boundary in the Diben section occurred at the maximum negative excursion of organic carbon isotope within the Piyuancun Formation, which can be correlated with other sections by using d13 Corg. We thus concluded that the relatively high content of highly reactive iron and low content of pyrite iron in the Diben section indicate a minor occurrence of H2 S and a predominance of anoxic and ferruginous environment, which is similar to other reported sections such as the Longbizui and Yanwutan sections, western Hunan. In addition, oxygen concentration in sea water showed an increasing trend in the interval corresponding to the bottom and upper layer of the Hetang Formation as indicated by the FeHR/FeT ratio, which decreased from 0.7 to 0.38, however, it was not great enough to oxidize the whole deep water. Therefore, during the E–C transition deep water basin in South China was most likely an anoxic and ferruginous enrironment, which prevented metazoon from the evolution in the deep water basin. Our work offers an important reference to better understanding of the spatiotemporal occurrence and dynamic processes of the ‘‘Cambrian Explosion'.     

基于GCRN的矿岩可爆性分级模型及其应用

为了准确反映岩体可爆性等级,构建了由弹性波阻抗、坚固性系数、平均裂隙距和标准爆破漏斗炸药单耗4个因素组成的评价体系,采用改进的灰色关联分析法对传统的岩体可爆性等级划分标准进行优化。利用灰色关联相对贴近度(GCRN)来反映各可爆性等级之间的差别,确定各可爆性等级对应的灰色关联相对贴近度区间,以此划分新的岩体可爆性等级。采用基于GCRN的矿岩可爆性分级模型对武钢资源集团公司程潮矿业有限公司东、西区矿体的可爆性级别进行评价,评价结果与实际情况基本一致,表明利用灰色关联相对贴近度来划分矿岩可爆性等级的方法是可行的。     

团簇离子FenPm+结构的量子化学研究

对激光等离子体反应生成的原子团簇 Ｆｅｎ Ｐｍ ＋ （ｎ＝ １～３, ｍ ＝ ２～１２）进行了量子化学从头算研究, 对可能的几何结构进行了试探性计算, 并对其中较稳定构型进行结构优化． 结果表明： Ｆｅ Ｐｍ ＋ 中, Ｆｅ 倾向与 Ｐ形成多配位磷化物． 其中 Ｆｅ Ｐ６＋ 较稳定． 同时, 铁与磷易形成多铁磷化物．讨论了 Ｆｅ２ Ｐ５＋ ～ Ｆｅ２ Ｐ８＋ , Ｆｅ３ Ｐ２＋ ～ Ｆｅ３ Ｐ１２＋ 不同构型对其稳定性的影响．     

微波消解-火焰原子吸收法连续测定三氯苯肼中的铬、铁含量

采用微波消解-火焰原子吸收法,利用金属离子混合标液进行标准曲线测定,实现了2,4,6-三氯苯肼中微量铬和铁的快速连续测定.结果表明:混合标准溶液中铬的标准曲线为:A=0.087+0.028C,相关系数r=0.999 4;铁回归方程为A=0.048 8+0.127 6C,相关系数r=0.998 1.用该法测得三氯苯肼试样中的铬、铁含量分别为3.170 mg/L、1.620 mg/L;相对标准偏差分别为1.02%和1.79%;平均加标回收率为101%和99%.     

大关悦乐奥陶-志留统沉积地球化学特征及古环境意义

选取云南昭通大关悦乐矿区一个代表性剖面进行宏观和微观两方面的研究。宏观方面从野外产状态、岩石组合以及沉积环境等方面对大关悦乐矿区的地层做了比较系统的研究;微观方面开展了沉积岩常量元素地球化学研究,试图用系统的地球化学方法来更进一步揭示研究区在地史上这段时期的沉积地球化学特征和古环境的变迁。     

铁基超导体中的玻色模和超导电性的密切关系

铁基超导材料作为一类新的高温超导材料,其超导产生的原因一直备受关注,超导电子配对的机制一直是铁基超导研究中最具有挑战性的重大科学问题。目前有一个争论的焦点是,该类超导体是否仍然可以用BCS理论的延时电子和玻色子之间的相互作用来描述。我们通过扫描隧道谱仪,对两个不同铁基超导体系的样品进行了测量,发现除了超导特征的谱形之外,还有另一个特征峰,即玻色模,在两个样品中波色模的特征能量与中子自旋共振得到的能量数值相同,与超导临界温度之间呈现一个线性关系Ω/kBTc≈4.3±0.5。玻色模的特征峰与超导电性密切相关,并随着超导特征的减弱而减弱。上述研究结果揭示了铁基超导的非常规超导电性。     

基于反应体系的表面增强拉曼光谱快速检测乙基麦芽酚

以铁离子(Fe~(3+))为媒介,鞣酸还原氯金酸制备的金纳米粒子(Au NPs)作为表面增强拉曼散射(SERS)基底,实现比色-散射光谱双响应,快速鉴别食品中的乙基麦芽酚.其中比色法中,对乙基麦芽酚的检测限为0.50 mg·mL~(-1).SERS检测中,利用Fe~(3+)和乙基麦芽酚的络合作用,乙基麦芽酚的最低检测限降低到0.01 mg·mL~(-1),线性范围为0.05～1.00 mg·mL~(-1).该方法使用的仪器简单,操作方便,可对样品中的乙基麦芽酚进行现场直接测定.     

掺铁铌酸锂晶体中三维光子晶格的诱导及结构分析

笔者描述了一种使用振幅掩膜在自散焦光折变晶体掺铁铌酸锂中制作光诱导三维光子晶格的实验方法,并提供平面导波、布里渊区潜、远场衍射图样三种方式对晶格结构进行分析．此外,笔者对光强极弱的会聚光束在晶格中的传播行为进行研究并得到独特的衍射图样．这对二维微结构的制作与光在接中传播特性的研究是非常有意义的．     

Evidence for metasomatic mantle carbonatitic magma extrusion in Mesoproterozoic ore-hosting dolomite rocks in the middle Kunyang rift, central Yunnan, China

The Kunyang rift lying on the western margin of the Yangtze platform is a rare Precambrian Fe-Cu mineralization zone. Wuding- Lufeng basin that is an important part of the zone is located on the west edge in the middle of the rift. The most important ore-hosting rocks are Mesoproterozoic dolomite rocks in the basin controlled by a ring fracture system, which is a fundamental structure of the basin. Plenty of silicate minerals and acicular apatite, feldspar phenocrysts and small vesicular, flown line and flown plane structures, melt inclusion and high temperature fluid inclusion found in most ore-hosting dolomites suggest that this kind of rocks could not be sedimentary dolomite, marble or hydrothermal carbonate rocks. The Zr/Hf and Nb/Ta values of the rocks are identical with those of associated mantle-derived rocks, and vary widely. For the monomineral dolomite, δ^18OSMOW‰=＋5.99 to ＋18.4 and δ^13CPDB‰ = -3.01 to ＋0.94, which fall within the range for all carbonatitic volcanic rocks of the world. As for the accessory minerals, the values of δ^18OSMOW‰ of magnetite （=＋3.47 to ＋5.99‰） are close to that of the mantle （〈5.7%）, and the δ^34S‰ values of sulfides （-5.09 to ＋5.78, averaging ＋1.50） are close to that of meteorite. For all the ore-bearing dolomite rocks, εNd = ＋0.19 to ＋2.27, and the calculated Isr=0.699143, while for the associated mantle-derived rocks, εnd = ＋3.18 to ＋3.72. All the data suggest that the mineral assemblage is not only igneous but also of metasomatic mantle origin. And the presence of acicular apatite indicates that the rocks were formed by magma rapidly cooling. And the phenocryst texture and vesicular, flown and ropy and pyroclastic structures suggest that the igneous rocks were extrusive. Therefore, the ore-bearing dolomite rocks are carbonatitic volcanic rocks. This conclusion implies that most iron and copper ore deposits hosted in the dolomite rocks should be of the carbonatite type.