131I-epidepride的制备与SD大鼠体内分布特性研究

采用双氧水标记法和氯胺 -T法进行13 1I -epidepride标记 ,考察标记物的纯度及稳定性 ,并进行SD大鼠体内分布特性研究。实验结果表明 ,双氧水法和氯胺 -T法标记率分别为 97.4 %和 5 2 .9%。标记物的生理盐水溶液室温放置 4h ,放化纯大于 90 %。大鼠静脉注射13 1I -epide pride的生理盐水溶液后 ,纹状体与小脑比值在注射后 32 0min时高达 2 37:1。13 1I -epidepride进入血液后很快被组织摄取 ,其中以肺的早期摄取最高 (2 .11± 1.0 5 ) %ID·g- 1,各脏器的清除均较快 (T1/2 <4h) ,甲状腺的摄取率随时间的延长而增加。     

铁谱分析技术在燃油中非金属杂质监测方面应用的研究

通过对制谱时，谱片上磨屑沉积机理的重新分析，发现非金属磨屑在自身重力的作用下，仍可有规律地沉积在谱片上。据此特点成功地将柴油中的沙砾等杂质有规律地沉积到谱片上，并检测出了某型叉车柴油机喷油泵柱塞断裂的原因。     

低能离子束辅照对溅射镀TiN膜生长的影响

用诱导型等离子体辅助磁控溅射装置在Si（100）表面低温沉积TiN膜，研究了高密度低能量（≈20eV）离子束辅照对溅射镀TiN膜生长、结构和性能的影响．结果表明，高密度低能离子束辅照会改变TiN膜的择优生长方向并使薄膜致密化。即使沉积温度低于150℃，当入射基板离子数和Ti原子数的比值Ji／JTi≥4.7时，沉积的TiN膜仍可具有完全的（200）面择优生长，薄膜微观结构致密，硬度达到25GPa，残余压应力小．     

Effect of Cooling Rate on the Microstructure of Laser-Remelted INCONEL 718 Coating

The rapid cooling rate was achieved during laser remelting with high scanning speed. The microstructure and precipitations in the INCONEL 718 remelted layer were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), and solid phase microextraction (SPME). The phase transition temperatures were carried out by differential thermal analysis (DTA). The results showed that columnar-dendritic and equiaxial structures appeared in different regions of the remelted layer. The dendritic spacing of the columnar dendrite and equiaxed grain size decreased with increasing scanning speed. The precipitations in the remelted layer consisted of Laves, granular phase, and a small quantity of quadrangular nitride (Ti, Nb)N. The granular phase Nb(Al, Ti) was precipitated at about 1272 K (999 °C) with the spontaneous decomposition of the supersaturation Laves during the cooling stage, and the small-size granule became coarsened to 0.2 to 0.9 μm during the cooling stage. The noncoherent relationship existed between the granular phase and austenite, and the coarsening of granule was related to the cube root of the diffusion coefficient, interfacial energy, and diffusion time. The microhardness of the remelted layer was increased by increasing the cooling rate due to the Nb atomic solid solution strengthening caused by the distorted elastic stress field and the short-range internal stress.     

Microstructure and Strengthening Mechanism of Fiber Laser-Welded High-Strength Mg-Gd-Y-Zr Alloy

Journal of Materials Engineering and Performance - The microstructure and mechanical properties of laser-welded high-strength Mg-Gd-Y-Zr alloy in T6 condition were investigated. The...     

天然红枣果肉饮料生产研究

本文以红枣、银耳和莲子等天然滋补品为原料，经蒸煮打浆、调配、均质、脱气、灌装、灭菌等过程加工成天然红枣果肉饮料，其色泽枣红、枣香味浓、口感细腻淡雅，营养丰富，总氨基酸含量高达３２３．９８ｍｇ／１００ｇ。     

掺钇(Ba,Sr,Ca)TiO_3纳米粉体及细晶陶瓷的制备与性能

采用sol-gel法制备了Y3+掺杂Ba0.90Sr0.08Ca0.02TiO3(BSCT)纳米粉体及细晶陶瓷。通过TG-DTG、XRD、SEM和TEM对样品结构及形貌进行了表征,并测试了陶瓷的介电性能。研究表明,Y3+掺杂BSCT纳米粉体主要为立方相BaTiO3,烧结后陶瓷晶粒尺寸在0.68~2.24μm可控,Y3+掺杂可以抑制陶瓷晶粒的生长,使陶瓷的tC向低温方向移动。随Y3+掺杂量的增大,陶瓷的介电温谱εr-t趋于平缓,当x(Y3+)为7.0%时,陶瓷的室温εr大幅度提高到9 176。     

Microstructure and Softening of Laser-Welded 960 MPa Grade High Strength Steel Joints

The microstructural evolution of laser-welded 960 MPa grade high strength steel joints and its effect on softening behavior of heat affected zone (HAZ) were investigated in this paper. The results show that microstructure of HAZ and fusion zone (FZ) is composed of lath martensite and bainitic ferrite. The microstructure of mixed grained zone presents strip-like characteristics and small block martensite distributes along the grain boundary. The grain size near the fusion line is about 25 μm, and the grain size in the fine grain zone is less than 5 μm. Microhardness of HAZ and FZ is lower than base metal. The soft zone locates in transitional region between tempering zone and mixed grained zone due to the interaction of the martensite tempering and the recovery and recrystallization of the rolled microstructure. Microhardness of soft zone is 310 HV and drops 18% compared to base material. Welding heat input has a remarkable effect on the width of soft zone and microhardness. The tensile properties of weld joints are closely related to the softening behavior of HAZ.     

线粒体Mn-SOD参与预适应大鼠心肌抗梗死保护作用的实验研究

为定量去甲肾上腺素（NE）诱导的延迟相预适应抗心肌梗死保护强度，研究了预适应机体抗氧化剂量酶活性变化与预适应保护的关系。将50只大鼠分为NE组、I／R组和正常组。3.1μmol/kgNE腹腔内注射诱发预适应，24h后开胸结扎左冠状动脉主干（LGA）、造成LCA支配区缺血30min，再灌注120min复制预适应模型，用伊文斯蓝，TTC色分别显示左室未缺血区，梗死区，危险区，数码相机与实体显微镜结合拍摄左室切面，Metamorph Imaging System软件定量各组左室梗死区／危险区面积，放免法和黄嘌呤氧化法分别测定血清Cu^2 、胞浆Cu^2 ，Zn^2 -SOD含量、活性及线性体Mn-SOD活性。结果显示，1）预适应保护可使心肌梗死面积减少33．4％；2）预适应心肌线粒体Mn-SOD活性增高；3）血清及心肌细胞胞浆Cu^2 ，Zn2＋-SOD含量，活性预适应组与非预适应组差别不显著，实验研究启示，NE可诱导大鼠产生延迟相心肌预适应保护。其机制可能是通过使心肌线粒体Mn-SOD活性增高，减少自由基损伤，产生预适应保护。     

Microstructures and properties of Fe-Co-B-Si-Nb coating prepared by laser cladding and remelting

High power laser cladding of [(Fe0.5Co0.5)0.75B0.2Si0.05] 95.7 Nb4.3 powder mixture afier-remelting was performed to fabricate Fe-based metallic glass coating on the surface of steel of China Classification Society:Grade B (CCS-B).Scanning electron microscopy (SEM),X-ray diffraction (XRD),transmission electron microscopy (TEM)with energy dispersive spectrometer (EDS),Vickers hardness tester and corrosion resistance tester were employed to characterize microstructures and evaluate properties of this coating.According to the results of SEM ,XRD and TEM ,the cladding coating consisted of nanocrystalline embedded in amorphous phase.EDS data indicated that Nb segregated in the amorphous matrix.The results of hardness test revealed that the hardness of the top layer was higher than that of the inner layer of the coating.The coating exhibited excellent corrosion resistance in a 3.5% NaCl solution.