Structure of Complexes of Lanthanides with N,N′-Dimethyl-3-Oxa-Glutaramic Acid

With the development of nuclear energy, how todispose of the nuclear wastes especially high level liq uid wastes (HLLW) is the world′s subject. One strat egy for reducing the main long term hazard of radioac tive waste is to separate actinides from high level liq uid waste (HLLW) and transmute them into short lived or stable nuclides by nuclear reactions in nuclearreactors or accelerator driven transmutation systems.For this subject, many countries have brought forwardmany p…     

世界经济复苏加快全球钢铁高速增长中国经济稳健发展钢铁产需持续强劲——2004年钢铁发展的回顾与展望

详细介绍了去年世界钢铁工业高速增长的情况；论述了我国钢铁产需的强劲势头，认为亮点与难点并存，机遇与挑战同在；列举了突现我国钢铁工业结构调整巨大成果的十大亮点。提出了必须应对的新情况和新难点。     

Spectroscopy Study on Crystal Structure of Ce（NO3）3 （phen）2 and Interactions of Ce（NO3）3 （phen）2 with DNA

Inrecentyears ,Komiyaetal.[1] havefoundthatrareearthsionsmaybeoneofthestrongestcutre agentsofnucleicacids .Theexperimentalresults ,thatrareearthsrepresscancersonwholeanimalbodiesandonhumanbodies(invitro) ,indicatedthatrareearthselementsactuallyhavestrongf…     

Lanthanum-Promoted Ru／Sepiolite in Ammonia Synthesis

Theiron basedcatalystsforammoniasynthesishavethecommonproblemsoflowefficiency ,highconsumptionofenergy ,strictrequirementforequip ment,andlowoperationflexibility ,etc .,anditishardtoradicallylowerenergyconsumptionbysimplyimprovingiron basedcatalystsproper…     

Effects of Lanthanum on Bone Resorbing Activity of Rabbit Mature Osteoclasts Co-Cultured with Osteoblasts

The effects of lanthanum (Ⅲ) on the bone resorbing activity of rabbit mature osteoclasts (OCs) in the presence of osteoblasts (OBs) were studied in vitro by measuring the number and area of absorption pits. La(Ⅲ) at concentrations ranging from 1.00×10-5 to 1.00×10-8 mol·L-1 show no effect on mature OC number (P＞0.05). In the OC-OB co-culture systems without La(Ⅲ), osteoblasts alone did not influence the pit number and area whether the two kinds of cells were in contact or not (P＞0.05). Under the OC-OB not-in-contact condition, the effect of La(Ⅲ) on the bone-resorbing activity of OCs was similar to that of La(Ⅲ) in the absence of OBs (P＞0.05). However, while OCs were in direct contact with OBs, the inhibitory effects of La(Ⅲ) on OCs' bone-resorbing activity decreased at the concentrations of 1.00×10-5, 1.00×10-6 and 1.00×10-7 mol·L-1, and the promotion effects increased at 1.00×10-8 mol·L-1 (P＜0.05). The results suggest that direct cell-cell contact between OC and OB be essential for OBs to play their role in regulating the response of OCs to La(Ⅲ).     

电路实验教学模式的改革与探索

理论教学与实践教学是高等工科院校人才培养体系的两个重要组成部分,而实践教学又是应用型人才培养的重要手段.通过实践教学可以提高学生分析问题和解决问题的能力,培养学生的创新意识和创新能力.实践性教学环节主要有实验和实习两种方式.实验是通过学生亲自动手操作而获得知识、技能的一种教学方法,如何发挥学生在实验中的主动性和独立性,是搞好实验教学的关键.传统的实验教学把学生看作是被动接受知识的客体,没有认识到学生既是教学的对象,又是学习的主体,没有充分发挥学生在教学过程中的主观能动性.因此,改革实验教学已成为当务之急.     

The Nature of Struck-by Accidents

Construction accidents are broadly categorized into five basic groups, namely falls (from elevation), shock (electrical), caught in/between, struck-by, and other. “Struck-by” accidents accounted for 22% of all construction-related fatalities recorded by the Occupational Safety and Health Administration between 1985 and 1989. Recent (1997 to 2000) data show that the percentage of struck-by accidents constituted 24.6% of the fatalities and serious construction worker injuries. Struck-by accidents primarily involve workers struck by equipment, private vehicles, falling materials, vertically hoisted materials, horizontally transported materials, and trench cave ins. Determining possible causation factors of these accident types is often difficult, due to the broad categories utilized in the accident coding system. This study resulted in gaining insights about the root causes of the struck-by injuries. By finding the root causes, effective methods for accident prevention can be developed.     

Study on Pb-Bi natural circulation phenomena

For the development of 45w%Pb-55w%Bi cooled direct contact boiling water small fast reactor (PBWFR), experimental study on Pb-Bi-water direct contact boiling two-phase flow has been performed using Pb-Bi-water direct contact boiling two-phase flow loop. For stable start-up of the boiling flow operation, Pb-Bi single-phase natural circulation must be realized in a Pb-Bi flow system of the loop before water injection into Pb-Bi. The Pb-Bi flow system consists of a four-heater-pin bundle, a chimney, an upper plenum, a level meter tank, a cooler, and an electromagnetic flow meter. A stable Pb-Bi single-phase natural circulation was realized in the range of flow rate from 1.5 l/min to 4.8 l/min by heating Pb-Bi in the heater-pin bundle with a power up to 7.7 kW. The inlet and outlet temperatures of the heater bundle were in the ranges from 243°C to 278°C, and from 251°C to 278°C, respectively. The natural circulation flow was simulated analytically using one-dimensional flow model including frictional, form and drag forces. Total hydraulic head through the loop were calculated from Pb-Bi densities at measured Pb-Bi temperatures in the loop. It was found that the calculated flow rate agreed well with the measured ones, which indicated the validity of the analytical models.     

Pressure wave propagation in air-water bubbly and slug flow

Related to nuclear reactor safety problems, such as the loss of coolant accident caused by some small crevasses in nuclear reactor, choked flows after postulated breaks of hot and cold legs of pressurized water reactors and the boiling flow instability in parallel channels, the characteristics of pressure wave propagation were investigated experimentally for the air-water bubbly and slug two-phase flow in a vertical pipe. Pressure wave was generated from the small pressure disturbance by the up-and-down movement of piston in the test section. Air void fraction was up to 0.7 and superficial liquid velocity was up to 1.5 m/s as experimental conditions. The experimental results show that the pressure wave propagation velocity in bubbly flow decreases acutely with the increase of air void fraction from 0 to 0.05. In slug flow, it is constant when the air void fraction is less than 0.5 but increases gradually when the void fraction increases beyond 0.5. The attenuation coefficient of pressure wave increases with the increase of air void fraction in bubbly flow. The dependency of pressure wave propagation velocity on angle frequency ω in air-water flow shows the dispersion characteristic. The propagation velocity and attenuation coefficient increases gradually with the increase of angle frequency. However, the increase vanishes slowly as the angle frequency reaches 250 Hz in bubbly flow. The propagation of pressure wave in bubbly flow is independent of the superficial velocity of fluids in the range of experiment.     

气相色谱法测定茶多酚中的氯仿和乙酸乙酯残留

以正已烷为萃取剂,对茶多酚(TP)水溶液进行萃取,用气相色谱法分析了TP溶液中的残迹物氯仿和乙酸乙酯。色谱柱为2m×3mmi.d.不锈钢填充柱,固定相为10%的PEG20M,载体为ChromosorbW/WA。氯仿和乙酸乙酯的回收率分别为96.7%～104.3%和98.5%～103.6%;相对标准偏差分别为3.5%和1.7%;最低检测限分别为0.50ug/和0.36ug/g。