Construction and Identification of Yeast Surface Display Libraries of Ovis aries DRA Gene Exon 2

The specific primers were designed according to Ovis aries DRA gene sequence deposited in GenBank and the multiple cloning site of the plasmid pYD1,which was a vector used for protein surface display on Saccharomyces cerevisiae.The gene encoding DRA was amplified by PCR using the genomic RNA of Ovis aries.The 762 bp fragment was cloned and released in GenBank and registration number was KR422362.The PCR product was inserted into the yeast surface display plasmid vector pYD1 by double enzyme digestion.It was indicated that DRA gene was successfully integrated into the genome.Dot mutation was made at both ends of exon 2 in DRA gene for making restriction enzyme cutting site and design the exon 2 specific primers according to mutated Ovis aries DRA gene sequence.Sequenced exon 2 amplification products based on DNA pooling of sheep large sample template was analyzed the polymorphic loci.The polymorphic exon 2 246 bp fragment was obtained by double enzyme digestion and connected to surface display restructuring mutation carriers pYD1-DRA by the same double enzyme digestion,and then we successfully constructed yeast surface display libraries.We transformed it into Saccharomyces cerevisiae EBY100 cell.Yeast monoclone was identified by PCR amplification and sequencing,and we confirmed that DRA gene had been integrated into Saccharomyces cerevisiae genome.After galactose induced,it was detected that DRA gene library had been successfully demonstrated on the yeast cell surface under the fluorescence microscope by immunofluorescence method.     

响应面法优化杜仲叶提取物的制备工艺

优化杜仲叶提取物制备的工艺条件,在单因素试验基础上,以杜仲叶提取物浸膏得率和绿原酸转移率为评价指标,采用Box-Behnken中心组合设计法优化杜仲叶提取物制备的工艺条件。杜仲叶提取物制备的最佳工艺条件为乙醇浓度500mL/L,液料比10∶1(mL/g),提取温度97℃,提取4次,每次30min;在此最佳工艺条件下,杜仲叶提取物浸膏得率和绿原酸转移率综合评分均值为99.08,与预测值基本一致。响应面法(RSM)优化的杜仲叶提取物制备工艺稳定可靠。     

膜孔灌溉田面综合糙率系数的确定

根据膜孔灌溉田面水流运动特性 ,建立了膜孔灌溉田面水流运动零惯性量数学模型 ,并将其与优化理论相结合 ,提出了确定膜孔灌溉田面综合糙率系数的优化模型。实例计算与方法验证表明 ,该方法能够简单而有效地确定膜孔灌溉田面综合糙率系数。该研究成果为膜孔灌溉理论与技术的进一步研究奠定了基础     

Hydrolysis and Condensation of Silane Agent for Metallic Surface Treatment

Novel surface treatment technique by silane film is developing for metallic anti corrosion and coat improvement. The key points, hydrolysis and condensation, for the stability of the Silane agent(SA) solution is investigated, and the effective factors of stability for silane agent solution and the relative rule are discussed. It is found that stability of SA solution is related to the temperature, pH, solvents, SA concentration and additive by studying the state of the solution and the conductivity-time curve of SA solution. Meanwhile, controlling factors and improving methods for SA stability are proposed to guide the practical application of metallic surface anti-corrosion treatment by SA.     

Calculating the Hollowing-center Grounding Device Resistance Based on the Surface Charge Simulation Method

An equivalent model for hollowing-center grounding device is proposed, the hollowing-center grounding device resistance is calculated with the surface charge simulation method and the computer programme is programmed based on this model. The accuracy of the model and method is validated by experimentation.