Sm部分取代Tb对TbCo／Cr薄膜磁光性能的影响

利用磁控溅射法制备了SmTbCo/Cr薄膜,分析了Sm含量对SmTbCo/Cr薄膜磁光性能的影响.结果表明:随着Sm含量的增加,(SmxTb1-x)31Co69薄膜的Ms、θk和R增加,而Hc随之减少;Sm含量在0.286～0.343范围内的(Sm0.286Tb0.714)31Co69(120nm)/Cr(240nm)和(Sm0.343Tb0.657)31Co69(120nm)/Cr(180nm)薄膜的磁光性能均满足光磁混合记录对介质的要求.     

14Cr1MoR+410S复合钢板的工艺试验

在分析焦炭塔14Cr1MoR 410S复合钢板焊接性的基础上,制定了合适的焊接工艺,并进行了焊接工艺试验,能有效防止裂纹的产生,获得满意的焊接接头,确保了焦炭塔制造质量。     

Effects of chromium nanoparticle dosage on growth,body composition,serum hormones and tissue chromium in Sprague-Dawley rats

This 6-week study was conducted to evaluate the effects of seven different levels of dietary chromium (Cr) (0, 75, 150,300, 450, 600, and 1200 ppb Cr) in the form of Cr nanoparticle (CrNano) on growth, body composition, serum hormones and tissue Cr in Sprague-Dawley (SD) rats. Seventy male SD rats (average initial body weight of (83.2±4.4) g) were randomly assigned to seven dietary treatments (n=10). At the end of the trial, body composition was assessed via dual energy X-ray absorptiometry (DEXA). All rats were then sacrificed to collect samples of blood, organs and tissues for determination of serum hormones and tissue Cr contents. The results indicated that lean body mass was significantly increased (P＜0.05) due to the addition of 300 and 450 ppb Cr from CrNano. Supplementation of 150, 300, 450, and 600 ppb Cr decreased (P＜0.05) percent body fat significantly. Average daily gain was increased (P＜0.05) by addition of 75, 150, and 300 ppb Cr and feed efficiency was increased (P＜0.05) by supplementation of 75, 300, and 450 ppb Cr. Addition of 300 and 450 ppb Cr decreased (P＜0.05) the insulin level in serum greatly. Cr contents in liver and kidney were greatly increased (P＜0.05) by the addition of Cr as CrNano in the dosage of from 150 ppb to 1200 ppb. In addition, Supplementation of 300, 450, and 600 ppb Cr significantly increased (P＜0.05) Cr content in the hind leg muscle. These results suggest that supplemental CrNano has beneficial effects on growth performance and body composition, and increases tissue Cr concentration in selected muscles.     

Cr~(3+)、Pb~(2+)单一及复合胁迫对小麦种子萌发及幼苗脯氨酸含量的影响

研究在污染条件下小麦对重金属胁迫的反应,为农业生产中早期诊断重金属污染提供一些依据。用Cr3+、Pb2+及Cr3+、Pb2+混合溶液的各种浓度溶液处理小麦,研究Cr3+、Pb2+及Cr3+、Pb2+混合溶液对小麦萌发和脯氨酸含量的影响。结果表明:在Pb2+的培养环境中,各个浓度下的发芽率相差不多;在Cr3+的培养环境中,小麦的发芽率随着浓度的增加呈下降趋势,浓度越大对小麦发芽率的抑制作用越明显;在Cr3+、Pb2+混合的培养环境中,各个浓度下的发芽率随浓度的增加而呈降低的趋势,并且各个浓度下发芽率基本都相对低于相同浓度下的单一Cr3+、Pb2+的发芽率。在低浓度的重金属离子中,游离脯氨酸的含量与重金属离子浓度呈正相关。     

Determination of Diffusion Coefficient and Analysis of Diffusion Factors of Cr（Ⅵ） Ion in Clay Soil

Some laboratory diffusion tests were conducted with diffusion device to determine the diffusion coefficient of Cr(Ⅵ) ion passing through Dalian red clay samples. The concentrations of Cr(Ⅵ) at different places of the samples were then measured spectrophotometrically after a standing time of 1 000 d. A one-dimensional solute transport equation was used to simulate the transport of Cr(Ⅵ) through clay samples. Back-calculation of diffusion coefficient of Cr(Ⅵ) was made with finite difference method. Parametric analysis was conducted to simulate variations in soil dry density, temperature, pH and standing time. The results show that the method used in this paper is simple and effective. The diffusion coefficient of Cr(Ⅵ) in Dalian red clay varies from 1.50×10-7 cm2/s to 2.08×10-7 cm2/s. After 1 000 d diffusion, the concentration of the source solution drops down to 1.27 mg/L from 62.5 mg/L, and the diffusion distance is only 3.5 cm. Under the assumption that diffusion coefficient is constant, the diffusion effect becomes more obvious with lower density, lower temperature, higher pH value, and much more time.     

柚子皮对水中六价铬的吸附性能研究

采用柚子皮制备生物吸附剂用于去除水中的Cr(VI),考察了p H值、柚子皮投加量、柚子皮粒径、溶液离子强度、反应温度等因素对吸附效果的影响。结果表明,当溶液中Cr(VI)离子初始浓度15mg/L、p H 1.5、反应温度25℃、柚子皮投加量1.0g/100 m L、吸附时间7 h时,Cr(VI)离子去除率可达90%以上。柚子皮对Cr(VI)离子的吸附过程可以用Langmuir和Freundlich吸附等温模型来描述,吸附等温线线性相关性均较显著,吸附过程符合准二级动力学方程。柚子皮对水中Cr(VI)离子吸附性能较好,且运行成本低,可推广应用于水中重金属离子的治理。     

Hg2+、Cr3+及复合污染下对苦草的SOD、POD活性变化的实验研究

本文研究了不同浓度Hg2 、Cr3 以及二者共同胁迫对苦草.O-2、MAD含量和SOD、POD的影响,实验结果表明:单离子随浓度的增加,对苦草的毒性效应呈现加重趋势,同浓度情况下Hg2 比Cr3 毒性效应明显;Hg2 、Cr3 共同作用所产生的毒性效应大于单一Hg2 、Cr3 .具体表现为随着Hg2 、Cr3 浓度的增加,.O-2、MAD含量先升后降,MAD峰值较.O-2滞后,SOD、POD活性先升后降;这些都表明抗氧化酶系统在清除活性氧自由基过程中起一定作用和具有抗性机制,但植物抗性能力是有一定范围的.     

槲皮素与铬（Ⅲ）配合物合成及光谱分析

利用槲皮素与铬盐在无水乙醇中回流加热,用三乙醇胺调节PH至中性得到产物.合成配合物用红外光谱、紫外光谱对其结构进行表征,推测出螯合位置发生在槲皮素3-羟基与4-羰基及3＇,4＇-羟基处.并采用TU—1900双光束紫外可见分光光度计研究一系列不同浓度溶液的吸光度,通过摩尔比法确定Cr3＋与槲皮素的配位比为1：1和2：1.     

血清和唾液中尿素氮、肌酐、尿酸测定的相关性研究

本文主要探讨唾液与血清中BUN、Cr、UA的相关性和临床应用价值。住院肾脏病患者73例和健康人42例,检测血清和唾液中的尿素氮、肌酐及尿酸浓度。肾脏病患者唾液和血清BUN、Cr、UA有较好的相关性。肾脏病患者唾液BUN、Cr、UA含量均比健康人高。健康人唾液和血清BUN有较好的相关性,Cr无相关性。唾液UA浓度随血清UA浓度的增加而升高。唾液中BUN、Cr、UA可用于判定肾脏功能障碍病人的疾病损害程度。     

聚乙烯吡咯烷酮-盐液-固体系分离Cu(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)、Cr(Ⅱ)

在一定浓度硫酸铵存在的条件下,聚乙烯吡咯烷酮(PVP)水溶液能形成盐水相与聚合物固相。实验研究了Cu(Ⅱ)、Pb(Ⅱ)、Cd(Ⅱ)、Cr(Ⅱ)与邻苯二酚紫(PV)形成的配合物在聚乙烯吡咯烷酮盐水萃取体系液固两相中的分配行为。探讨萃取酸度、硫酸铵浓度和萃取剂用量等条件对金属离子萃取率的影响,通过控制一定的条件实现Cr(Ⅱ)与Cu(Ⅱ)的定量萃取分离。