脉冲激光轰击法连续制备纳米金掺杂YBCO

利用超声法获得钇钡铜氧（YBCO）和乙醇混合溶液,采用聚焦脉冲激光轰击浸于流动无水乙醇中的金靶,连续制备得到纳米金和乙醇混合溶胶.将纳米金和乙醇混合溶胶直接滴入接收器中的YBCO和乙醇混合溶液中,经干燥获得纳米金掺杂的YBCO材料.结果发现,纳米金未明显改变YBCO的吸放热现象,对样品的组成影响不大;掺杂0.01%、0.05%重量比例的纳米金后YBCO的结晶度和超导转变温度Tc均有所提高.     

头孢氨苄免疫层析表面增强拉曼光谱检测方法研究

【目的】 建立一种简便、快速、灵敏度高、特异性强的头孢氨苄免疫层析表面增强拉曼光谱(SERS)检测新方法。【方法】 制备金银复合核壳结构的纳米贵金属,用来标记头孢氨苄抗体和拉曼信号分子5,5’-二硫代双2-硝基苯甲酸 (DTNB),合成拉曼免疫探针,用透射电子显微镜和双光束紫外分光光度计对纳米金和修饰拉曼信号分子的金银复合核壳结构进行表征。将合成的拉曼免疫探针固定在微孔板上,待测样品中的头孢氨苄与包被在硝酸纤维素膜上的头孢氨苄抗原竞争结合拉曼免疫探针,通过免疫层析试纸条结合共聚焦拉曼光谱仪读取DTNB的信号值,建立头孢氨苄定量检测技术,并应用于实际牛奶样品的检测。【结果】 透射电子显微镜和双光束紫外分光光度计表征结果显示,纳米银成功包裹在金颗粒表面。用共聚焦拉曼光谱仪检测免疫层析试纸条上拉曼信号分子的特征峰,拉曼信号分子特征峰为1 062、1 154、1 334和1 558 cm^-1,其中1 334 cm^-1处特征峰信号最强,选取此处峰高定量测定头孢氨苄的含量。头孢氨苄免疫层析表面增强拉曼光谱检测的线性范围为0~1 ng/mL,检测限为0.001 ng/mL,头孢氨苄的半数抑制质量浓度为0.05 ng/mL。与头孢克洛交叉反应率为111.1%,与头孢曲松钠、头孢夫辛酯、头孢噻吩钠交叉反应率均低于0.1%。实际样品加标浓度为1、4和8 ng /mL,回收率分别为94.4%、103.3%和97.5%。【结论】 本研究建立的头孢氨苄免疫层析表面增强拉曼光谱检测方法操作简便、快速、灵敏,耗材成本低廉,可满足奶牛养殖农场和乳品加工企业进行大批量样品初筛检测需求。     

基于复合纳米微粒修饰和磁性分离富集的一次性有机磷农药酶传感器

在Fe3O4/Au微粒上固定乙酰胆碱酯酶(AChE),制得磁性复合粒子Fe3O4/Au/AChE。通过磁力将其吸附于涂覆了碳纳米管(CNTs)/纳米ZrO2/普鲁士蓝(PB)/Nafion(Nf)复合膜的丝网印刷碳电极(SPCEs)表面,制得一次性有机磷农药(OPs)酶传感器。采用扫描电镜(SEM)、X射线荧光光谱(XRFS)表征传感器的制备过程,采用循环伏安法(CV)和示差脉冲伏安法(DPV)研究了传感器的电化学性质。利用OPs对AChE的抑制作用,以硫代乙酰胆碱(ATCh)为底物,对乐果进行了检测。在pH=7.5的0.1 mol/L硝酸钾溶液中,乐果浓度的对数与酶电极的抑制率(A)在1.0×10-6~1.0×10-2 mg/L间呈良好的线性关系,检测限为5.6×10-7 mg/L,用于实际样品白菜检测时的添加回收率在88% ~105%之间,与气相色谱法(GC)所得结果一致。该传感器采用复合纳米粒子修饰电极表面,具有较高的比表面活性,响应迅速,检测限低;ZrO2可特异性地富集样品中的OPs,磁性纳米颗粒包被AChE可实现磁场分离和电极表面更新,且具有高灵敏度、低样品量、一次使用可抛弃、便携式等特点,可用于蔬菜等农产品中痕量OPs的快速、简便、准确检测。     

活性炭富集溶液中Au(Ⅲ)的研究

本文绘出了利用活性炭自溶液中吸附Au（Ⅲ）及改性试验结果。在溶液酸度CH+=2～3mol·L-1时活性炭的吸附能力较强,经NH3·H2O、苯胺等改性后的活性炭增强了对Au（Ⅲ）的吸附作用,回收率可达98．0％。     

Au Elements and Their Evolution in Some AIIopolyploid Genomes of Aegilops

To study the sequences of short interspersed nuclear elements （SINEs） evolution in some allopolyploid genomes of Aegilops, 108 Au element fragments （a novel kind of plant SINE） were amplified and sequenced in 10 species of Aegilops, which were clustered into three different groups （A, B and C） based on their related geuome types. The sequences of these Au element fragments were heterogouous in di-, tetra-, and hexa-ploids, and the deudrograms of Au element obtained from phylogenetic analysis were very complex in each group and could be clustered into 15, 15 and 22 families, respectively. In this study, three rules about Au elements evolution have been drawn from the results： i. Most families were composed of Au element members with different host species in three groups; ii. Family 1-6 in Group A, Family 1-6 in Group B, Family 1-4 and Family 6-13 in Group C contained only one, apparently highly degenerate Au dement member （a single representative elemeut）; iii. Elements generally fell into clades that were species-specific with respect to their host species. The potential mechanisms of Au element evolution in Aegilops were discussed.     

扫描电子显微镜样品常规处理镀膜技术的改进

扫描电子显微镜是观察研究试材表面微观、超微观结构的大型精密仪器。在观察研究试材前,要对试材表面进行镀金膜处理,此处理消耗材料成本十分昂贵,阻碍大数量样品的科学研究。几年来,沈阳农业大学分析测试中心根据生物、农业研究中微观试材的特点,用自主设计的铂合金靶和铜合金靶组合使用,替代国外同类专用产品,成本降低80%,对大数量样品的科学研究、试材处理的结果优于国外同类专用产品处理结果,为科学研究工作创造了有利条件。     

Au Elements and Their Evolution in Some Allopolyploid Genomes of Aegilops

To study the sequences of short interspersed nuclear elements (SINEs) evolution in some allopolyploid genomes of Aegilops, 108 Au element fragments (a novel kind of plant SINE) were amplified and sequenced in 10 species of Aegilops,which were clustered into three different groups (A, B and C) based on their related genome types. The sequences of these Au element fragments were heterogonous in di-, tetra-, and hexa-ploids, and the dendrograms of Au element obtained from phylogenetic analysis were very complex in each group and could be clustered into 15, 15 and 22 families,respectively. In this study, three rules about Au elements evolution have been drawn from the results: i. Most families were composed of Au element members with different host species in three groups; ii. Family 1-6 in Group A, Family 1-6 in Group B, Family 1-4 and Family 6-13 in Group C contained only one, apparently highly degenerate Au element member (a single representative element); iii. Elements generally fell into clades that were species-specific with respect to their host species. The potential mechanisms of Au element evolution in Aegilops were discussed.     

A new method of searching for concealed Au deposits by using the spectrum of arid desert plant species

With the increase of exploration depth, it is more and more difficult to find Au deposits. Due to the limitation of time and cost, traditional geological exploration methods are becoming increasingly difficult to be effectively applied. Thus, new methods and ideas are urgently needed. This study assessed the feasibility and effectiveness of using hyperspectral technology to prospect for hidden Au deposits. For this purpose, 48 plant (Seriphidium terrae-albae) and soil (aeolian gravel desert soil) samples were first collected along a sampling line that traverses an Au mineralization alteration zone (Aketasi mining region in an arid region of China) and were used to obtain soil Au contents by a chemical analysis method and the reflectance spectra of plants obtained with an Analytical Spectral Device (ASD) FieldSpec3 spectrometer. Then, the corresponding relationship between the soil Au content anomaly and concealed Au deposits was investigated. Additionally, the characteristic bands were selected from plant spectra using four different methods, namely, genetic algorithm (GA), stepwise regression analysis (STE), competitive adaptive reweighted sampling (CARS), and correlation coefficient method (CC), and were then input into the partial least squares (PLS) method to construct a model for estimating the soil Au content. Finally, the quantitative relationship between the soil Au content and the 15 different plant transformation spectra was established using the PLS method. The results were compared with those of a model based on the full spectrum. The results obtained in this study indicate that the location of concealed Au deposits can be predicted based on soil geochemical anomaly information, and it is feasible and effective to use the full plant spectrum and PLS method to estimate the Au content in the soil. The cross-validated coefficient of determination (R²) and the ratio of the performance to deviation (RPD) between the predicted value and the measured value reached the maximum of 0.8218 and 2.37, respectively, with a minimum value of 6.56 μg/kg for the root-mean-squared error (RMSE) in the full spectrum model. However, in the process of modeling, it is crucial to select the appropriate transformation spectrum as the input parameter for the PLS method. Compared with the GA, STE, and CC methods, CARS was the superior characteristic band screening method based on the accuracy and complexity of the model. When modeling with characteristic bands, the highest accuracy, R² of 0.8016, RMSE of 7.07 μg/kg, and RPD of 2.20 were obtained when 56 characteristic bands were selected from the transformed spectra (1/lnR)' (where it represents the first derivative of the reciprocal of the logarithmic spectrum) of sampled plants using the CARS method and were input into the PLS method to construct an inversion model of the Au content in the soil. Thus, characteristic bands can replace the full spectrum when constructing a model for estimating the soil Au content. Finally, this study proposes a method of using plant spectra to find concealed Au deposits, which may have promising application prospects because of its simplicity and rapidity.     

落叶松单宁原位固化及其对AU(Ⅲ)吸附性能的研究

以富含单宁的落叶松树皮为原料制备吸附材料,研究了该吸附材料对水溶液中Au(Ⅲ)的吸附特性.结果表明:以甲醛作为交联剂可以实现落叶松树皮中单宁的原位固化;当温度为303 K,pH=4.0,Au(Ⅲ)的初始浓度为5223 mg/L时, 该吸附材料对Au (Ⅲ)的平衡吸附量达到Au(Ⅲ)1 821.9 mg/g,而且平衡吸附量随温度的升高进一步增大.pH对吸附容量的影响较大,最佳pH 为4.0.该吸附材料对Au(Ⅲ)的吸附平衡符合Langmuir方程,吸附动力学可以用拟二级速度方程来描述.固定床吸附实验表明,当原料液的浓度为Au(Ⅲ)239.2 mg/L,流出液的体积约为117个床层体积时才达到穿透点.分析表明,原位固化落叶松单宁对Au(Ⅲ)的吸附为氧化-还原吸附.      

基于金纳米团簇的比率型pH荧光探针制备及表征

在合成牛血清白蛋白(BSA)修饰的金纳米团簇(金簇)的基础上,将荧光素异硫氰酸酯(FITC)与金簇偶联,构建一种新型比率型p H荧光探针。当体系p H值在4.0~10.0之间变化时,FITC的荧光强度逐渐增加,而金簇的荧光强度基本保持不变。在p H为5.5~8.0之间,该探针对于p H具有良好的线性关系,线性方程为Y=1.72X-8.8,相对标准偏差为0.994,同时该探针在p H为6.0~9.0之间还具有良好的可逆性。此外,将此p H荧光探针与PK15细胞共培养,通过MTT实验证明该比率型p H荧光探针对细胞几乎没有毒性。