关于硫化矿及烧结矿的分析方法（1）

本文介绍了测定硫化铁矿,铜矿,锌矿等作为硫酸原料的矿石和烧结矿中Bi,Cd,Co,Cu,Fe,Ni,Pb,Zn,Al,Cr,TiO_2,V,CaO,MgO,Mn,As,Sb,Se,Te,Sn20种元素的原子吸收分析方法。     

高纯石墨中金属杂质成分的检测研究

本文探讨了快速测定石墨灰分含量中的14种污染物Al,Ca,Cd,Co,Cr,Cu,Fe,Mg,Mn,Mo,Ni,Ti,V,Zn的方法,以满足研究要求,了解石墨精炼效果的要求。     

黑龙江省金龙达经贸有限责任公司

公司成立2002年,公司位于哈尔滨市南岗区中山路258号,企业类型为有限责任公司,经营范围：购销冶金矿产品,冶金炉料,焦炭,生铁,铁合金,金属材料,钢材,有色金属不含稀有金属,化工产品不含危险品,剧毒品,建筑材料,机械设备,炭素材料及石墨制品。     

老挝矿业

老挝位于东南亚地区,北临柬埔寨,南靠中国,西面是越南,东南部是缅甸,东北部是泰国,是一个国土面积仅有237,000平方公里的小国。2005年,人口总数为6,200,000。老挝是亚太地区最贫穷的国家之一,已知的矿产资源有铝土矿,黏土,煤,铜,白云石,黄金,石墨,石膏,石灰岩,石盐,蓝宝石,银,锡,及锌等。老挝2005年的国内生产总值增长率为7.3%,2004年增长率为6.3%。老挝具有得天独厚的地质环境优势,潜在的矿产有:锑,石棉,铋,钴,铁矿,瓷土,铅,褐煤,镁,钼,钾碱,硅沙,及钨等。另外,该国很可能储藏有煤,铜,黄金,铁矿,钾碱,岩盐,及锡等。据老挝工业及手工业部(M…     

基体分离ICP-AES法测定金属铁粉中的杂质元素

研究了在7mol/LHCl体系中,以4 甲基 2 戊酮萃取分离铁,残液用ICP AES法同时测定Mn,Cr,Ni,Cu,Mo,V,Al,Ti,Zn,Cd,Co,Ca,Mg,As,Pb的新方法。方法的检出限为0.002～0.220μg/mL,回收率为93.5%～109%,相对标准偏差小于4.5%。方法简单、快速、准确,应用于金属铁粉中杂质元素的测定,结果令人满意。     

ICP-AES法测定高纯阴极铜中杂质元素

研究了EDTA存在下 ,氯化钠 -二乙基二硫代氨基甲酸钠 -丙醇体系萃取分离铜 ,用ICP AES法同时测定高纯阴极铜样品中Pb ,Fe ,Bi,Sb ,As ,Sn ,Ni,Zn ,P ,S ,Ag ,Se ,Te ,Si,Mn ,Cr的新方法。方法的检出限为 0.0 0 3～ 0.0 2 8μg/mL ,回收率为 94.5 %～ 10 7.2 % ,RSD小于 4.7%。该法准确、快速、简便 ,应用于阴极铜中杂质元素的测定 ,结果满意     

X-射线荧光光谱法测定铝用炭素材料中微量元素

粉末压片法制样,选用预焙阳极、石油焦标准样品,采用X-射线荧光光谱法对样品中的S,V,Si,Fe,Na,Ca,Ni,Ti,Al,P,Pb,K,Mg,Cl,Mn,Cr,Cu,Zn等元素进行测定。讨论了样品研磨时间、粒度对测量强度的影响、光谱背景、元素间谱线重叠干扰和基体效应。在选定实验条件下,重复制样得到各元素的相对标准偏差均小于7.94%,对比试验结果表明,测定结果与认定值或化学法测定值相符,该方法能满足铝用炭素中微量元素分析的需要。     

Barrier Effect of Placenta Membrane of Pregnant Rat on Mixed Rare Earth Changle

MixedrareearthChangleisamixturecomposedofLa ,Ce ,Pr ,andNdnitrates ,inwhichcontentofCeisthemost .Ithasbeenwidelyusedasafeedad ditiveinanimalhusbandryinChina ,Thefactcuesthatalittlerareearthnitratemaygraduallyenterhu manbodywithconsumptionoffood ,furthermorerareearthnitratecannotbeexcretedcompletelywhilecanbeaccumulatedintheliver ,spleenandbone[1] ,theincreasingaccumulationiswithlongertime ,thereforeitisveryimportantthatsafetyofrareearthsnitrateisassessed .Therelationshipbetweenapplieddosean…     

冶金科技英才

龙红明,男,1979年8月生,湖北省嘉鱼县人,中共党员,博士,教授,安徽工业大学冶金工程系主任,炼铁新技术研究所副所长,安徽省学术和技术带头人后备人选,安徽省战略新兴产业领军人才,安徽省科学技术协会第九届委员,美国TMS学会会员,中国金属学会青年委员会委员,全国非高炉炼铁学术委员会委员,全国中小高炉学术委员会委员。     

塑性加工变形物理场研究的发展趋向

发生物理现象的空间部分,称为物理场。根据这个定义塑性加工时的变形区称为塑性加工变形物理场。塑性变形过程中,由开始到终了,矢量参数(位移,变形,应力,速度等),标量参数(温度,密度,体积,硬度,屈服极限,强度极限,位错密度,金属组织的主体相与剩余相的尺寸等)、各种系数(变形系数,晶粒尺寸比值,延伸率,断面减缩率,     

反应条件对钌催化剂和铁催化剂的氨合成性能影响

Activated carbon-supported Ru-based catalyst and A301 iron catalyst were prepared, and the influences of reaction temperature, space velocity, pressure, and H2/N2 ratio on performance of iron catalyst coupled with Ru catalyst in series for ammonia synthesis were investigated. The activity tests were also performed on the single Ru and Fe catalysts as comparison. Results showed that the activity of the Ru catalyst for ammonia synthesis was higher than that of the iron catalyst by 33.5%-37.6% under the reaction conditions: 375-400 ℃, 10 Mpa, 10000 h-1,H2:N2=3,and the Ru catalyst also had better thermal stability when treated at 475℃ for 20 h. The outlet ammonia concentration using Fe-Ru catalyst was increased by 45.6%-63.5% than that of the single-iron catalyst at low temperature (375-400℃),and the outlet ammonia concentration increased with increasing Ru catalyst loading.     

Effect of rare earth on the performance of Ru/MgAl-LDO catalysts for ammonia synthesis

A series of MgAl-layered double oxides (LDO) doped with different rare-earth elements (Y, La, and Ce) were synthesized by the calcination of Mg–Al layered double hydroxides, and Ru, which were used to prepare ammonia synthesis catalysts. The as-obtained oxides and catalysts were characterized by XRD, TEM, TPD, TPR and XPS to understand their catalytic performances in ammonia synthesis. The H₂-TPR and HRTEM studies reveal that Ru/Y-LDO catalyst possesses more active Ru metal and small particle size. The XPS demonstrates that the electronic interaction between Y and Ru metals is stronger, which can be tentatively explained by most of Y inserted into the hydrotalcites structure. CO₂-TPD demonstrates that Ru/Y-LDO catalyst shows stronger basic site densities than catalysts doped with Ce and La. Higher activity of the Ru/Y-LDO catalyst can be attributed to smaller particle size, more active metal (Ru) and strong Ru–support interaction.     

Effect of rare earth elements(La,Y,Pr)in multi-element composite perovskite oxide supports for ammonia synthesis

A series of BaCe0₃modified with different rare earth elements(La,Y,Pr)were synthesized by coprecipitation and calcination and the effect of rare earth elements for catalytic ammonia synthesis under mild conditions was studied.The ammonia synthesis performance tests show that 2.5%Ru/BaCe_0.9La_0.1O_3-δcatalyst(All the percentages of Ru in this article are in mass fraction)exhibits the highest ammonia synthesis rate(34 mmol/(g·h))at 3 MPa,450℃,and no sign of deactivation after 100 h of reaction.H₂-TPR and XPS analyses indicate that the introduction of La increases the amount of oxygen vacancies of the catalyst,which is beneficial to increasing the electron density of Ru surface.HRTEM analysis shows that the Ru particle size is reduced greatly after La is introduced,which facilitates the catalyst generating more Bs-type sites(active sites of Ru species for N=N dissociation).CO₂-TPD analysis indicates that BaCe_0.9La_0.1O_3-δhas stronger basicity,which promotes electrons transfer from support to Ru.This work provides an effective method for design and synthesis of Ru-based multi-element composite perovskite oxide catalysts.     

La_2Ce_2O_7 supported ruthenium as a robust catalyst for ammonia synthesis

La_2Ce_2O_7 nanoparticles were prepared by citric acid complexation method followed by calcination at varied temperatures. Then, supported with 4 wt% Ru, they were evaluated as the catalysts for ammonia synthesis under conditions similar with industry. With La_2Ce_2O_7 being calcinated at 700 or 800℃, the experimental results indicate that the Ru/La_2Ce_2O_7 catalyst exhibits much higher ammonia concentration or ammonia synthesis rate than that of Ru/CeO_2 and Ru/La_2O_3. In addition, Ru/La_2Ce_2O_7 possesses high stability under over-heating test. In the absence of any promotor, ammonia concentration of Ru/La_2Ce_2O_7 catalyst approaches 14% at 450℃, GHSV of 10000 h~(-1) and pressure of 10 MPa. The rate-determining step of ammonia synthesis, dissociation of N_2 is significantly facilitated by the strong metalesupport interaction(SMSI) between Ru and La_2Ce_2O_7. Due to the interaction, La_2Ce_2O_7 tends to donate electrons to Ru,resulting in the high electron density over the surface of Ru active sites which is favorable for the dissociation of N_2. Consequently, high activity is achieved.     

CeO2-x modified Ru/γ-Al2O3 catalysts for ammonia decomposition reaction

Developing high-performance ammonia decomposition catalysts for preparing CO_x-free hydrogen shows great practical significance.Herein,CeO₂ is used as a promoter to modulate the metal-support interaction to enhance the catalytic performance of Ru/Al₂O₃ catalysts.A series of 1Ru/xCe-10AI(x=0.5,1,or 3)catalysts was prepared by a facile colloidal deposition method.We find that the optimized 1 Ru/1Ce-10Al catalyst exhibits excellent activity for the decompo...     

新显色剂羧基三氮唑偶氮氯膦的合成及其与镧(Ⅲ)的显色反应

研究了新显色剂羧基三氮唑偶氮氯膦(简称CTACPA)的合成及其与镧(Ⅲ)的显色反应。在pH 4.0的HAc-NaAc缓冲介质中,CTACPA与镧(Ⅲ)形成稳定的紫红色配合物,其最大吸收波长为645nm,表观摩尔吸光系数为3.79×104 L·mol-1·cm-1,镧(Ⅲ)质量浓度在0.08~0.8μg/mL范围内符合比尔定律,一些镧系稀土离子对测定结果没有干扰。方法可不经分离直接测定Pt-La/CNTs和Pt-La/ZrO2催化剂样品中微量镧,测定值与原子吸收光谱法(AAS)测定值相符。     

纳米TiO2负载钯催化剂的性能研究

采用浸渍法制备了纳米TiO2负载钯催化剂,以乙炔选择催化加氢制备乙烯为反应模型考察了稀土元素La、空速对纳米Pd／TiO2催化剂性能的影响,并与纳米SiO2为载体的Pd—La／SiO2催化剂的性能做了比较。实验结果表明,纳米Pd／TiO2催化剂具有良好的催化活性和性能稳定性,La的加入显著提高了乙烯的选择性、增幅达加％左右。与Pd—La／SiO2催化剂相比,Pd—La／TiO2催化剂具有更高的选择性。     

Investigation on Walking and Pacing Stability of German Shepherd Dog for Different Locomotion Speeds

The motion of three German Shepherd Dogs on a treadmill was recorded using a three-dimensional motion capture system.The locomotion speed of the dog was respectively set at 4 km·h-1, 5.5 km·h-1, 7 km·h-1 and 8.5 km·h-1 By processing the acquired data, the joint trajectories of the dogs' hind limbs were computed and a time series analysis was conducted. Joint angle-angle diagrams were obtained and the Lyapunov exponents were computed. Results show that the stability decreased when speed increased, which can be attributed to the decrease in the stance phase respect to the swing phase when speed is increased. Results also show that the dogs changed gait during the tests, namely walking in the range of 4 km·h-1 to 7 km·h-1 and pacing at 8.5 km·h-1. A significant drop in stability was observed from walking to pacing.     

Partial Oxidation of Methane to Syngas over Monolithic Ni/γ-Al2O3 Catalyst——Effects of Rare Earths and Other Basic Promoters

A series of monolithic Ni/γ-Al2O3 catalysts with and without basic promoters (Na, Sr, La, Ce) were prepared. Partial oxidation of methane (POM) to syngas was carried out in a continuous-flow, fixed-bed reactor. The influences of reaction conditions, including temperature, CH4/O2 ratio and space velocity, on the performance of the catalyst were investigated. The results show that at a high space velocity of 1×105 h-1, optimal CH4 conversion can be obtained. Effects of promoters such as Na, Sr, Ce, La were also investigated, and the catalyst samples were characterized by means of temperature-programmed reduction and XRD techniques. XRD suggests that the addition of promoters has no influence on the crystal structure of Ni/γ-Al2O3 catalyst. The results show that the addition of a small amount of promoters improves the reducibility and activity of the catalyst. The side reaction CH4 2 O2→CO2 H2O, is fully restrained and 100% H2 selectivity is achieved when Ce and La are used as promoters, respectively.     

稀土在甲烷部分氧化制取合成气中的应用研究

稀土（La,Ce,Pr,Nd等）通常可以作为催化剂载体、助剂或与其它元素形成固溶体,成为催化剂的重要组成部分。文中系统地介绍了稀土在甲烷部分氧化（CPOM）制取合成气中的相关应用,重点分析了稀土作为催化剂载体、助剂、固溶体等在催化部分氧化制取合成气中的应用,并对其在CPOM中未来前景做出展望。