~（99m）Tc－EC的动物研究及初步临床评价

研究显示了９９ｍＴｃ－ＥＣ的化学量对小鼠肾放射量浓聚有很大的影响，只有当鼠接受１．２５ｍｇ／ｋｇ剂量时肾的放射量最高．肾／肝达３．２。它的小鼠毒性和与血浆蛋白的结合率均低．１４例健康志愿者肾显像表明９９ｍＴｃ－ＥＣ是一种有用的锝标记肾功能显像剂．     

Theoretical consistency test of steam transport properties

The kinetic theory of polyatomic gases is used to test the mutual consistency of the thermal conductivity, viscosity and specific heat of low-pressure steam from 100° to 700°C. No inconsistency exists within the cited tolerances of the skeleton tables recommended by the Sixth International Conference on the Properties of Steam, but there is some basis for suspecting that the high-temperature thermal conductivity values are slightly low. Methods for tightening the consistency bounds are suggested.     

考虑风险因素的两市场购电优化分配问题

不同国家和地区的电力市场通常根据自己的特点采用不同的市场模式,但无论在何种模式下,都存在一个类似于长期市场和短期市场的结构。电力市场中的购电商通常要在长期市场和短期市场进行电力交易,而其中的关键问题之一是如何针对本公司的情况,根据市场信息,寻求一种购电策略,优化两个市场的购电分配,使总的购电费用和风险尽可能得小。文中对这一问题进行了建模和讨论,针对由总费用和风险共同构成的目标函数,研究了两个市场的购电问题,给出了问题的解析解并针对实际市场数据进行了数值仿真,该问题的研究结果不仅有利于购电商分配不同市场的购电量,也为购电商进一步构造竞标曲线奠定了基础。     

计算机搜寻平衡Gold序列方法研究

分析了平衡、不平衡伪随机Gold序列对通信系统通信质量的影响,通过对Gold序列产生方法的研究,提出了平衡Gold序列的2种计算机搜寻方法,并通过这2种搜寻方法的比较,分析了其不同特点及其适用情况.该研究来源于“高动态、高码率、多通道数字解扩接收机”项目对伪随机序列的需求,用文中方法搜寻了长度分别为15位、31位、63位、127位、255位、511位的平衡Gold序列各6组,并在项目中成功应用.     

Protactinium-231: A new radionuclide for AMS

For the first time, an AMS system was used to determine concentrations of the actinide Protactinium-231. ²³¹Pa has widespread applications in the earth sciences. It can be used for U-series disequilibrium dating, and ²³¹Pa is an important tracer in Paleoceanography. The Pa isotopes were measured with the compact ETH/PSI-AMS facility TANDY operating at about 300 kV. The linearity of the AMS is documented with two standard-dilution experiments and first measurements of natural samples from very different climate archives are presented. Our results show that it is possible to determine ²³¹Pa amounts in the lower femtogram (1 fg = 10^{−15} g) range with the TANDY. In natural samples, ²³¹Pa concentrations between 1 and 4 pg/g (1 pg = 10^{−12} g) were measured with an average total error of 3% (one sigma). The average over all reproducibility of these first measurements was better than 2% with clear potential for improvement.     

Scintillation light produced by low-energy beams of highly-charged ions

Measurements have been performed of scintillation light intensities emitted from various inorganic scintillators irradiated with low-energy beams of highly-charged ions from an electron beam ion source (EBIS) and an electron cyclotron resonance ion source (ECRIS). Beams of xenon ions Xe^m>qm>+ with various charge states between m>qm> = 2 and m>qm> = 18 have been used at energies between 5 and 17.5 keV per charge generated by the ECRIS. The intensity of the beam was typically varied between 1 and 100 nA. Beams of highly charged residual gas ions have been produced by the EBIS at 4.5 keV per charge and with low intensities down to 100 pA. The scintillator materials used are flat screens of P46 YAG and P43 phosphor. In all cases, scintillation light emitted from the screen surface was detected by a CCD camera. The scintillation light intensity has been found to depend linearly on the kinetic ion energy per time deposited into the scintillator, while up to m>qm> = 18 no significant contribution from the ions’ potential energy was found. We discuss the results on the background of a possible use as beam diagnostics, e.g. for the new HITRAP facility at GSI, Germany.     

The role of IAEA in coordinating research and transferring technology in radiation chemistry and processing of polymers

The IAEA has been playing a significant role in fostering developments in radiation technology in general and radiation processing of polymers in particular, among its Member States (MS) and facilitate know-how/technology transfer to developing MS. The former is usually achieved through coordinated research projects (CRP) and thematic technical meetings, while the latter is mainly accomplished through technical cooperation (TC) projects. Coordinated research projects encourage research on, and development and practical application of, radiation technology to foster exchange of scientific and technical information. The technical cooperation (TC) programme helps Member States to realize their development priorities through the application of appropriate radiation technology.The IAEA has implemented several coordinated research projects (CRP) recently, including one on-going project, in the field of radiation processing of polymeric materials. The CRPs facilitated the acquisition and dissemination of know-how and technology for controlling of degradation effects in radiation processing of polymers, radiation synthesis of stimuli-responsive membranes, hydrogels and absorbents for separation purposes and the use of radiation processing to prepare biomaterials for applications in medicine.The IAEA extends cooperation to well-known international conferences dealing with radiation technology to facilitate participation of talented scientists from developing MS and building collaborations. The IAEA published technical documents, covering the findings of thematic technical meetings (TM) and coordinated research projects have been an important source of valuable practical information.     

气管滴注99mTc-C60(OH)x大鼠的SPECT显像观察

为了解C60(OH)x经呼吸道进入体内后的分布情况,用放射性标记技术和单光子发射计算机断层(Single photon emission computed tomography,SPECT)成像技术,研究了99mTc-C60(OH)x经气管滴注后在SD大鼠体内分布、吸收和代谢的情况,及其与纳米颗粒粒径的依赖关系.用99mTc标记了富勒烯多羟基衍生物C60(OH)x(x=22,24),标记率为93%.标记物在体外和体内都有良好的稳定性.比较了99mTc-C60(OH)x和Na99mTcO4经气管滴注后在SD大鼠体内的SPECT成像.结果表明,与水溶性的小分子Na99mTcO4不同,纳米尺度的99mTc-C60(OH)x标记物大多滞留于肺中,且清除缓慢;少部分99mTc-C60(OH)x能迅速通过肺泡-毛细管屏障进入血液,主要分布于肝、骨和脾中,并通过肾代谢排泄,显示了纳米颗粒生物分布的主要特征.由此可见,纳米颗粒穿越气血屏障的能力与颗粒物的粒径相关.研究结果为纳米颗粒的呼吸毒性研究提供了重要基础资料.     

Critical cooling rate for the glass formation of ferromagnetic Fe40Ni40P14B6 alloy

Bulk ferromagnetic amorphous Fe-Ni-P-B alloys in rod shape were formed by a rapid solidification technique. The largest amorphous specimen prepared had a diameter of ∼ 2.5 mm and the corresponding cooling rate for the glass formation of this alloy system in our experiment can be estimated to be around 492.4 K/s by the method of finite-difference numerical calculation. This value is on the same order of magnitude as the critical cooling rate m>Rm>_c of Fe₄₀Ni₄₀P₁₄B₆ alloy estimated by the method of constructing the continuous-cooling-transformation (CCT) curve. It is indicated that the heterophase impurities have been eliminated well in our experiment.