浅析粉丝类食品中铝含量的测定方法

粉丝类食品中铝过量会给人体健康带来危害。粉丝中铝含量测定的主要方法有:电感耦合等离子体质谱法、石墨炉原子吸收法、马弗炉灰化铬天青S分光光度法。重点介绍了3种测定粉丝类食品中铝含量的方法,并比较了其特点。     

Hazard and Control of Residual Aluminum in Drinking Water

In drinking water, excessive residual aluminum can harm human health severely, such as retaining foetus neurofibril development, leading to dementia and exhibiting dialysis osteo-dystrophy. In addition, excessive residual aluminum may have certain effect on the water distribution system. The World Health Organization and many developed countries have regulated the residual aluminum as a norm of drinking water quality and limited the respective maximum concentration level. Aluminum is present in all natural water, but the total residual aluminum in drinking water mainly comes from use of aluminum coagulants under improper operational conditions. Thus, optimizing the operational conditions or adopting other measures would reduce the total residual aluminum in drinking water.     

利用基因组简约法开发烟草SNP标记及遗传作图

提出了一种基于基因组简约法开发SNP标记的方法, 即利用特定限制性内切酶酶切降低基因组复杂度, 利用高通量测序平台对酶切位点周围的目标片段进行富集测序, 设计一个生物信息学流程进行序列分析和SNP鉴定。以烤烟DH群体为例, 通过基因组简约法收集烟草基因组代表性片段和高通量测序产生11.4 Gb数据, 经生物信息学分析获得了1015个高质量SNP位点。以SSR标记为骨架, 绘制包括SNP标记在内、标记总数为1307的烤烟遗传连锁图。最后利用该遗传图谱和普通烟草2个祖先种的基因组序列, 分析烟草24个连锁群(染色体)之间的同源关系, 发现了大量染色体之间的重组或交换事件以及部分染色体之间的共线性。     

电解铝厂周边农作物氟污染评价

为了解电解铝厂氟污染对周边农作物的影响,通过采用氟离子选择电极法,对凯里某电解铝厂周边农作物的氟含量及污染程度进行研究。结果表明：铝厂周边农作物中氟含量最高为163.33 mg/kg,最低为16.73 mg/kg,平均含量为51.09 mg/kg,都已超过国家标准规定的农作物中氟污染物最大容许含量,农作物受到了较为严重的氟污染。不同农作物对氟的吸收、积累能力不同;农作物不同器官对氟的积累不同,对氟的吸收主要集中于叶片。铝厂周边不同区域的农作物都受到严重程度的氟污染,主要与铝厂的距离有关,距离铝厂越近,农作物受到氟污染越严重。     

140份甜玉米自交系耐铝性鉴定

以华南农业大学选育的140份甜玉米自交系为材料,利用0.4 mmol·L-1的AlCl3溶液处理玉米幼苗,测定其相对根长、相对叶绿素含量、相对株高、相对鲜重和相对干重等值并汇总排序,进行耐铝性鉴定分析评价.结果表明,系统聚类分析将140份甜玉米自交系分为4个类群,类群Ⅲ中自交系平均耐铝水平较高.分析140个甜玉米自交系...     

沙棘的花芽分化及花器发育进程研究

利用光学显微镜对中国沙棘花芽分化及花器发育进程进行观察研究,结果表明:沙棘花芽分化分为花芽分化开始期、花序分化期、花蕾分化期、花萼分化期、雄蕊分化期、雌蕊分化期。花粉性细胞的发育经过花粉母细胞、二分体、四分休、单核花粉粒、双核花粉粒几个阶段。胚囊发育包括孢原阶段、四分孢子、经减数分裂,形成成熟胚囊等几个阶段。该研究为合理制定沙棘的栽培技术措施和培育新品种提供了科学依据。     

马铃薯化肥农药双减绿色生产技术研究

研究旨在探索最佳的化肥农药双减绿色生产技术,以期提升马铃薯产量及品质,进而指导实际生产。本研究以‘青薯9号’为试验材料,设计了4个肥料处理,每个肥料处理又设A、B两个农药对比试验。结果显示,处理2减施化肥、增施商品有机肥(750 kg/hm²),可改善品质,较对照增产6460.2 kg/hm²;处理3减施化肥、增施有机肥(600 kg/hm²)+菌肥(300 kg/hm²),改善了马铃薯的部分品质;处理4减施化肥,增施有机肥(600 kg/hm²)+腐殖酸肥(45 kg/hm²),可改善品质,增产32.24%;农药处理未对马铃薯块茎产量及品质造成不良影响。试验证明,处理4在减少化肥用量、增施腐殖酸肥后增加马铃薯结薯数量,提高产量,改善品质,可在生产中推广应用。     

利用野生苜蓿资源进行耐酸铝研究的前景

紫花苜蓿是一种优质高产且各类家畜均喜食的豆科牧草,在中国种植历史悠久且种植面积较大,但是,这些仅限于中国北方地区,在中国南方却少有种植。究其原因,与南方大部分地区土壤呈酸性有关,酸性土壤带来了铝的毒害,这些都大大影响了紫花苜蓿在南方的栽培与推广。结合现今国内外对植物耐酸铝性的研究以及云南本地野生资源的状况,阐述苜蓿耐酸铝性研究的进展与意义。     

Analysis of the Effects of Speed and Tension in Aluminum Foil Rolling and Their Modeling

Though speed effect and tension effect are keys to controlling thickness in producing aluminum foil, sort of their mathematical models, which will be widely used, can't be obtained theoretically at present. Based on the study of aluminum foil rolling in some factory, speed effect and tension effect of some 1850 aluminum foil mill are analyzed, and mathematical models which are about the relation between the exit thickness of aluminum foil and the speed change and the tension change, are developed according to the attained trial data. Those models are used to optimize the process of this mill.     

水稻反足细胞发育期间超微结构变化的观察

本文通过透射电镜对水稻反足细胞形成发育过程中超微结构的变化进行观察。结果表明,反足细胞反育过程中细胞壁,细胞核和各种细胞器均出现明显的变化。在发育早期（即胚囊中两个极核移向卵器上方之前的时期）,反足细胞位于胚囊合点端顶部,细胞间的壁很完整。反足细胞与株心细胞相邻的壁（即最顶部的胚囊壁）,反足细胞彼此之间的壁,以及反足细胞与中央细胞相领的壁上均有胞间连丝分布;在发育中后期（即胚囊中两个极核移向卵器上     

边缘细胞对水稻生长和细胞壁组分的影响及其与耐铝性的关系

以水稻II优3027 (耐铝基因型)和红良优166 (铝敏感基因型)为材料,采用悬空培养法,在根尖附着和移除边缘细胞(root border cell, RBCs)条件下,比较研究水稻生长、根尖铝含量和细胞壁组分含量变化及其与耐铝性的关系。结果表明,铝抑制水稻根系伸长,导致根尖和细胞壁铝积累。移除根尖边缘细胞令根伸长抑制率、根尖胼胝质含量、根尖和细胞壁铝含量及细胞壁单核铝含量显著低于保留边缘细胞的根。此外,对比于根尖移除边缘细胞,保留边缘细胞降低了细胞壁中果胶和半纤维素1含量,而对半纤维素2含量无影响。表明铝毒胁迫下水稻根尖由于附着边缘细胞,阻止了根系铝吸收,并维持较低的细胞壁果胶和半纤维素1含量,减少细胞壁吸附铝的位点。同时也减少了根尖毒性形态铝的含量,降低了铝的生物有效性,从而提高了水稻的耐铝性。     

Formation Model of Alumina in the Course of Directed Oxidation of Aluminum Magnesium Alloy

By analyzing the characteristics of magnesium volatilization and linear growth kinetic of Al/ Al_2O_(3 )in directed oxidation of Al-Mg alloy, as the formation process of MgO is considered to be the process of which Al_2O_(3)dissolved in the scale MgO and MgO is partially n-type oxide, formation condition of Al_2O_(3)is established easily in the coure of oxidation. Volatilization of magnesium is to promote the growth of p-type MgO in the surface layer and the formation of Al_2O_(3 )in the inner layer of n-type MgO, and to promote the transformation of MgO toMgAl_2O_(4).MgAl_2O_(4)plays an important role in the formation process of Al_2O_(3), growth stress between MgO and MgAl_2O_(4)cause the formation of cavity in the MgAl_2O_(4 )and aluminum alloy melts is easier to transfer to oxidation front by means of this cavity. The transformation velocity ofMgO to MgAl_2O_(4 )depends on growth kinetic of Al_2O_(3),the faster transformation velocity of MgO to MgAl_2O_(4)is main reason that growth kinetic of Al/Al_2O_(3)transformation exhibits linear relationship.     

Formation of Zinc Oxide in the Course of Directed Nitriding With Aluminum Zinc Alloy

ZnO is formed in the course of directed nitriding with Al-Zn alloy, and that the effect of zinc and magnesium on the directed nitriding process is big different. The long fibers which diameter are far less than one micrometer, short bar-like and tetrapod-like zinc oxide is obtained. The three important stages of initial growth kinetic of ZnO approving ZnO have growth mechanism of VS, they are stage of accelerating, linear and parabola, are discovered. Experimental results show that the volatilization of zinc play a very important role in the growth of ZnO,the growth of ZnO is controlled by the diffusion of zinc in the Al-Zn alloy , and the morphologies of ZnO is depend on the saturation level of the vapour.     

Design Method for Bending Buckling of Web in Aluminum Beam

As for the local buckling of aluminum bending members, a finite element analysis of the stability of aluminum plates under bending was performed. Compared with the results of codes’ method and finite element method, the advantages and disadvantages of existing codes were discussed. Base upon the results of simulation, the relevant design formula in Code for design of steel structures (GB50017) were modified with the reference of existing foreign codes. And the design methods were proposed for buckling strength and post buckling strength of aluminum plates under in plate bending. It was found that the results of proposed methods were in high accuracy and safer condition, and suitable for the stability design of aluminum plates under in plate bending.     

干法灰化—石墨炉原子吸收法测定面制食品中铝含量

建立了面制食品中铝残留量的石墨炉原子吸收测定方法。通过干法灰化样品,筛选最佳石墨炉原子吸收分析条件,并对面制食品中铝进行测定。结果显示,该法在质量浓度20～50μg/L内呈线性关系,相关系数R=0.9998,回收率96.4%～98.5%,RSD为1.46%～3.32%;定量限下限7.35μg/L,最低检出质量浓度3.50μg/L。该方法结果符合要求,操作简便、快速、准确、干扰小、检出限低,适用于面制食品中铝含量的测定。     

Mechanism of Multipeaks Feature forVanadium titanium containing Magnetite in Smelting Reduction

The mechanism of multipeaks of reduction rate for vanadium titanium containing magnetite in the process of smelting reduction has been studied.The structure feature of vanadium titanium containing magnetite and changing character of slag structure as well as the kinetic feature of vanadium titanium containing magnetite in smelting reduction process were also analysed in this paper.     

农产品中真菌毒素γ辐照降解的研究进展

介绍了农产品中真菌毒素的危害性,综述了γ辐照对农产品中真菌毒素降解的研究进展。     

不同硫酸铝施用条件下对苏打盐碱地水稻吸肥规律的研究

通过对苏打盐碱地水稻施用硫酸铝改良剂的研究,阐明了不同硫酸铝施用量对水稻氮、磷、钾素营养吸收及产量的影响。试验结果表明,在重度盐碱化稻田上,施用硫酸铝可使水稻对氮、磷、钾的吸收量增加,水稻吸收养分能力分别提高40%、100%、40%。吸磷量增加最明显。其中吸氮量、吸磷量最大值均出现在成熟期。不同硫酸铝施用量对水稻吸收养分的影响无规律性。但在硫酸铝施用量为300 kg/hm2的情况下,水稻产量可较不施用硫酸铝处理增加近8倍,是盐碱地水稻产量最大时硫酸铝的施用量。盐碱地稻田土壤供肥能力较低,氮肥分次施用是提高其利用率的重要措施,也是提高产量的重要保障。硫酸铝的施用提高了磷肥的利用率,因此,今后在盐碱地水稻种植中一定要注意改良剂硫酸铝的合理投入并不断加强对硫酸铝施用量有效性的研究。     

稻田土壤中添加不同浓度铬对 异化铁还原和铬还原的影响

采用水稻土为供试土壤,通过添加不同浓度铬的模拟试验,在厌氧培养条件下测定了土壤中可浸提态的亚铁和Cr(VI)浓度的变化,探讨了不同Cr(VI)浓度对厌氧条件下水稻土中微生物铁还原的影响及Fe(III)和Cr(VI)还原的竞争关系。结果表明：以一定浓度值为界限,在此浓度之下,铬参与水稻土中铁的微生物还原过程,可显著降低土壤中Cr(VI)浓度;在此浓度之上,铬对于土壤中的铁还原微生物是有毒害作用的,而导致铁的微生物还原不能发生,使土壤中Cr(VI)不被还原。     

以小鼠骨髓间充质干细胞为饲养层分离培养胚胎干细胞的研究

【研究目的】为了探求一种更简单有效地分离培养昆明小鼠胚胎干细胞的饲养层培养体系;【研究方法】将昆明小鼠3.5d的胚胎,接种于昆明小鼠骨髓间充质干细胞的饲养层培养体系,来分离培养昆明小鼠的胚胎干细胞。【结果】发现在骨髓间充质干细胞的饲养层培养体系上,获得了典型的ES细胞样集落,碱性磷酸酶染色呈阳性,且具有分化的潜能。【结论】小鼠骨髓间充质干细胞可以作为饲养层来分离培养ES细胞,并且能保持ES细胞的体外未分化状态。