六价的

The percentage of Cyanide, phenol, mercury and chromium which have little effect on water quality is small and the variation tendency is slow. The percentage of Ammoniac azote, TP, TN, Cd, potassium permanganate index and fluoride which have much effect on water quality is big and the variation tendency is great. The percentage of DO, BOD5, petrochemical compounds and lead lies in the mean place between two guidelines above, which plays a normal role in contributing to the water quality of Yuehai, but the variation tendency is obvious.

选取了15个参数作为评价因素，其中，氰化物、挥发酚、汞、六价铬等指标的权重较小，对水质变化的总体影响不大，并且年度变化趋势较平缓；氨氮、总磷、总氮、镉、高锰酸盐指数以及氟化物等指标在阅海湿地水质总体评价中所占比重较大，直接影响水道水质；DO、BOD5、石油类、铅等指标的权重介于上述指标的中间。

It is feasible to produce yellow chrome by using the leachate of chrome slag.

由铬渣中提取的六价铬的方法和试验的影响条件，通过研究证明了利用铬渣淋滤液制取铬黄颜料的可行性。

The residual Pb2+ can be removed by phosphorite to avoid bringing new pollution.(3) It is feasible to produce yellow chrome by using the leachate of chrome slag.

由铬渣中提取的六价铬的方法和试验的影响条件，通过研究证明了利用铬渣淋滤液制取铬黄颜料的可行性。

The different fishes which are employed in the present studies are wild-type salmon, cultured salmon of freshwater and seawater, sea perch and fat greenling. The complete CT gene sequences of salmons are obtained by PCR amplification. The partial CT sequences of sea perch and fat greenling are obtained by in vitro cloning PCR method. Alignment of obtained CT sequences with other fish CT shows that CT appears to be well conserved among the same family. And the relative in taxonomy is far away, the similarity of different fish CTs is low. On the contrary, the closer the relative in taxonomy is, the higher the similarity of different fish CTs is. The sCT is expressed in pGEX-4T-X by recombinant form . We also succeed in the research of sCT expression alone by expression PCR. In addition, sCT antiserum is obtained using GST-sCT as antigen, and the high titer is tested by double immunodiffusion. In the rat bioassay, administration of 50 μg recombinant protein evoked significant hypocalcemia at 1 h after the data are analyzed by t-test.

本文用PCR方法克隆了野生鲑鱼、养殖鲑鱼的降钙素基因，并应用体外克隆PCR的方法首次克隆出鲈鱼、六线鱼降钙素的部分基因序列，通过对克隆的降钙素序列的比较研究，结果显示同一科的鱼降钙素序列保守性较高，同时，根据降钙素的部分氨基酸序列进行了降钙素相似性的比较研究，结果显示在分类学上，分类地位较远的鱼，其降钙素相似性较低，分类地位越接近的鱼，其降钙素相似性越高；我们利用谷胱甘肽S-转移酶(Glutathions S-transferase，GST)融合表达载体pGEX-4T-X对克隆的鲑鱼降钙素基因进行了融合表达研究，应用表达PCR的方法对降钙素基因的独立表达进行了初步的研究探索，并将纯化的融合蛋白作为抗原，获得了高效价的兔抗鲑鱼降钙素免疫血清；生物活性研究表明，大肠杆菌表达的融合蛋白具有显著的降血钙作用。

Cyclic voltammetry indicated that there were Cr→Cr, Cr →Cr oxidation reaction on anode, while there were Cr→Cr, Cr→Cr, Cr →Cr deoxidization reaction on cathode. The graphite electrodes treated by acid and heating could enhance the reversibility and kinetic of the electrode reaction. The nature graphite electrodes had been eroded during charge/discharge process, while the graphite electrodes by activation could avoide corroding by hexad chromium ion. The reversibility and kinetic of the electrode reaction of chromium ion on activation electrode had been increased, so which indicated that graphite surface augment oxygenous function corps which could increase electrode hydrophile capability.

循环伏安实验表明：铬液流电池的电极反应非常复杂，在阳极存在Cr→Cr，Cr→Cr的氧化反应，在阴极存在Cr→Cr，Cr→Cr，Cr→Cr的还原反应；热处理的石墨电极和重铬酸钾处理的石墨电极能提高电极反应的活性和可逆性；在充放电实验中未处理的石墨电极发生严重腐蚀；分别用这两种方法处理过的石墨电极具有防止六价铬侵蚀的功能；铬离子在活化处理过的石墨电极上的反应活性和可逆性增加，可以认为：重铬酸钾溶液活化处理和加热处理后的石墨表面的含氧官能团增加，电极亲水性增强。

Chromic trioxide and chromium hemitrioxide are determined with iodometry, the coefficient of variation of chromic trioxide is 0.056%, and the recovery of marked compound is 99.82-99.83%; the coefficient of variation of chromium hemitrioxide is 1.45%,and the recovery of marked compound is 98.55-99.26%; iron is determined by complexometric titration, the coefficient of variation of iron is 1.73%, and the recovery of marked compound is 99.12-99.23%;sulfate is determined by complexometric titration, the coefficient of variation of sulphate is 0.16%, and the recovery of marked compound is

Analysis Of The Chromium Electroplating Wastewater By Oxidation-reduction And Complexometric Titration-化学工程与工艺-本文采用氧化还原滴定法与络合滴定法对镀六价铬的废水中铬酸酐，三氧化二铬，铁和硫酸根的含量进行了测定：铬酸酐和三氧化二铬用碘量法测定，铬酸酐的变异系数为0.056%，加标回收率为99.82-99.83%，三氧化二铬的变异系数为1.45%，加标回收率为98.55-99.26%；铁用络合滴定法测定，其变异系数为1.73%，加标回收率为99.12-99.23%；硫酸根用络合返滴定法测定，其变异系数为0.16%，加标回收率为

In the paper, the approach of chromic residue phosphate recycling has been introduced, and the feasible conditions of production technique have also been fixed.

介绍了磷酸铬渣回收再利用的途径，并给出适宜的生产工艺条件，为废渣的处理提供了依据，也为六价铬的回收再利用找出了一种新方法。

From July 1, 2006, the new electronic and electrical products into the EU market, lead, mercury, hexavalent chromium, polymerization bromide biphenyl or polymerization bromide diphenyl ether content must not exceed 0.1% of the weight of the components, the cadmium content of no more than 0.01% of the weight of the host material.

从2006年7月1日起，新投入欧盟市场的电子电器产品中铅、汞、六价铬、聚合溴化联苯或者聚合溴化联苯乙醚含量不得超过该元件的重量的0.1%，镉的含量不得超过所在材料重量的0.01%。

EC 28. Hexavalent chromium in corrosion preventive coatings of unpainted metal sheetings and fasteners used for corrosion protection and Electromagnetic Interference Shielding inequipment falling under category three of Directive 2002/96/EC (IT and telecommunications equipment).

EC 2002/96/EC 指令涉及的第三类设备中用来防止腐蚀和干扰的未喷漆金属薄板及紧固件上防腐涂层中的六价铬。

Hexavalent chromium in corrosion preventive coatings of unpainted metal sheetings and fasteners used for corrosion protection and Electromagnetic Interference Shielding in equipment falling under category three of Directive 2002/96/EC (IT and telecommunications equipment).

用于防腐或屏蔽电磁干扰，用在特定仪器设备中（欧盟指令2002/96/EC第三类规定的IT和通讯设备）的斤属片或斤属扣件上的防腐涂层中的六价铬。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。