Al2O3/Ti(C，N)-Ni-Ti陶瓷刀具的切削性能

研究了Al2O3/Ti(C,N)-Ni-Ti陶瓷复合刀具对淬硬35CrMo合金钢进行连续干切削时各切削参数对切削力的影响.结果表明:切削深度对切削力的影响最显著,切削速度的影响最小.对比研究了Al2O3/Ti(C,N)和Al2O3/Ti(C,N)-Ni-Ti陶瓷刀具的耐磨性能和磨损形态:后者的耐磨性能明显优于前者,其中Al2O3/Ti(C,N)-5%(Ni,Ti)的耐磨性能最高.Al2O3/Ti(C,N)-Ni-Ti刀具的磨损形态主要表现为后刀面的磨粒磨损和疲劳磨损,由于这种材料具有较高的弯曲强度和断裂韧性,能有效防止前刀面出现崩刃破损现象,因此具有较高的可靠性,适用于高速切削.在高速切削条件(ap=006mm,vc=2549m/min,vf=009mm/r)下,Al2O3/Ti(C,N)-5%(Ni,Ti)刀具的切削耐用度为150min.     

H3 PW12 O40/ZrO2-WO3催化合成己酸正丁酯

采用浸渍法制备了H3 PW12 O40/ZrO2-WO3催化剂,并通过FT-IR、XRD对其进行了表征.探讨了该催化剂对合成己酸正丁酯的催化活性,研究了不同因素对产品收率的影响.在n(正丁醇)∶n(己酸)=1.5∶1,催化剂用量为反应物总质量的1.0%,带水剂环己烷4mL,反应时间75min的条件下,己酸正丁酯的收率为84.1%.     

β相V2O5纳米棒的生长及其光电性能

为研究退火温度对生长β相V2O5纳米棒的晶体结构、光学和电学性质的影响规律,采用直流磁控溅射法在玻璃衬底上生长了非晶态V2O5薄膜,样品经一定温度区间的O2氛围退火后,开始生成β相V2O5纳米棒。实验表明,在一个狭窄温度范围内,V2O5纳米棒光电性能呈现温度敏感特性;室温下,所制样品在紫外及近紫外线波长范围具有很高的吸收率,在近红外线波长范围具有较高的透射率;其中,经500 ℃热处理的样品,高低温电阻变化了2个数量级,相变温度出现在350 ℃左右。     

H6P2W9Mo9O62·24H2O催化清洁氧化环己酮合成己二酸

通过水热法合成新型Dawson结构磷钨钼杂多酸催化剂,对催化剂进行FT-IR、TG-DTA表征,并用于催化30%H2O2氧化环己酮制备己二酸.通过正交实验确定了优化工艺条件,并探讨了反应机理.结果表明,当n(环己酮)∶n(过氧化氢)∶n(草酸)∶n(催化剂)=100∶400∶1.00∶0.15,反应温度100℃,反应时间5h,进行3次平行实验,己二酸平均收率为71.6%,纯度为99.7%.经蒸发浓缩,催化体系可重复使用5次,收率为50.3%.     

一种新型T1-T2双模磁共振造影剂的制备及性能研究

研究了Fe_3O_4@SiO_2@Gd_2O(CO_3)_2核/壳/壳磁性纳米粒子,作为一种新型的T1-T2双模磁共振成像造影剂.并对这种纳米粒子的细胞活性进行了体外细胞毒性试验(MTT).结果显示其具有良好的生物相容性,有望成为一种新型双模磁共振造影剂.     

三峡库区消落带土壤N2O排放和反硝化影响因子分析

应用乙炔抑制培养法研究了水分、温度、氮源和碳源等影响因子对三峡库区腹地消落带土壤N2O排放和反硝化作用的影响,并与原位试验结果进行了比较。结果表明,土壤含水量是影响土壤N2O排放和反硝化作用的重要因素,反硝化速率随着土壤充水孔隙度（WFPS）的增加而增大,土壤反硝化速率最大值出现在土壤WFPS为100%时,N2O排放速率最大值出现在土壤WFPS为60%时。温度在10～40 ℃范围内,土壤N2O排放速率和反硝化速率随着温度的升高而增大,相关性分析表明,土壤N2O排放速率和反硝化速率均与温度呈显著正相关。外加氮源为NO -3-N时,反硝化速率随氮源量的增加有减小的趋势,过多的硝态氮抑制反硝化作用;而添加易被微生物利用的葡萄糖作为碳源则会明显提高土壤反硝化速率,当每千克土加入碳源量为240 mg时反硝化速率最大。     

1,4-二(2′,6′-二异丙基苯基)-2,2,5,5-四甲基-1,4-二氮杂-2,5-二硅杂环己烷的合成、表征及其晶体结构

用2,6-二异丙基苯胺2,6i-Pr2C6H3NH2与1当量的n-BuLi在乙醚溶液中-78℃条件下反应,以98%的产率得到2,6i-Pr2C6H3NHLi(1).用化合物1以当量比1:1与ClSiMe2CH2Cl冰水浴条件下反应,得到1,4-二(2′,6′-二异丙基苯基)-2,2,5,5-四甲基-1,4-二氮杂-2,5-二硅杂环己烷.产物经1H NMR,IR,其晶体结构经X-射线单晶衍射分析确证.晶体属单斜晶系,空间群P21/n,晶胞参数:a=8.4917(2),b=11.2259(2),c=16.2409(2);α=90°,β=98.4080°,γ=90°;V=1531.56(4)3,T=293K,Z=2,Dc=1.073mg/m3,μ=0.135mm-1,λ=0.71073,F(000)=544,结构偏离因子R=0.0402,wR=0.1197,共收集到7610个独立衍射点,其中I>2σ(I)的可观测点为3462个.     

The Escherichia coli O157:H7 DNA detection on a gold nanoparticle-enhanced piezoelectric biosensor

This paper presents development of a quartz crystal microbalance (QCM) biosensor for real-time de- tection of E. coli O157:H7 DNA based on nanogold particles amplification. Many inner Au nanoparticles were immobilized onto the thioled surface of the Au electrode, then more specific thiolated sin- gle-stranded DNA (ssDNA) probes could be fixed through Au-SH bonding. The hybridization was in- duced by exposing the ssDNA probe to the complementary target DNA of E. coli O157:H7 gene eaeA, then resulted in a mass change and corresponding frequency shifts ( △f ) of the QCM. The outer avidin-coated Au nanoparticles could combine with the target DNA to increase the mass. The electro- chemical techniques, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were adopted to manifest and character each step. The target DNA corresponding to 2.0×103 colony forming unit (CFU)/mL E. coli O157:H7 cells can be detected by this biosensor, so it is practical to develop a sensitive and effective QCM biosensor for pathogenic bacteria detection based on specific DNA analy- sis. The piezoelectric biosensing system has potential for further applications, such as food safety and environment monitoring, and this approach lays the groundwork for incorporating the method into an integrated system for in-field bacteria detection.     

Stepwise prediction and statistical screening: B-cell epitopes on neuraminidase of human avian H5N1 virus

The B-cell epitopes of virus are associated with the antiviral drug and the vaccine screening. As the nucleotide sequences of neuraminidase （NA） of stain GD-01-06 were sequenced, we predicted the a-helix and β-fold structure and the indexes of the flexible regions of secondary structure of NA with methods of the Hydrophilicity plot by Kyte-Doolittle, the Surface probability plot by Emini and the An- tigenic index by Jameson-Wolf, and then screened statistically the parameters to predict B-cell epi- topes by the Hierarchical cluster and the Bivariate correlation and the quartiles with SPSS 13.0. The impact of variation of amino acids in NA on its epitopes was analyzed. The predictive results were evaluated by Wu＇s Antigenic Index and SWISS-MODEL. We found that the most possible epitopes on NA were located within or nearby its N-terminal Nos. 120--137, 81--84, 408--415, 273--282, 429--432, 356--368, 46--55, 146--155, 341 --350 and 198--209, which were the dominant regions of NA epitopes. Peptide 120--137 including the glycoprotein domain （NGT126 128） was first chosen as the B-cell epitopes on NA. NA in H5N1 strain isolated after 2003 lacked in No. 53 amino acid （I）, resulting in an increase in the surface flexible region of NA in GD-01-06 and an enlargement to their epitope regions （VEP48-48→ VEPISNTNFL46-55）. Conclusively, prediction of the B-cell epitopes on the NA based on multiple pa- rameters is useful for researches on the molecular immunology and drug screening and immuno-prophylaxis. A deletion of No. 53 amino acid （I） in NA in strain GD-01-06 might increase its anti- genicity.     

Preparation and luminescence characteristics of Sr3SiO5：Eu^2＋ phosphor for white LED

The Sr3SiO5：Eu^2＋ phosphor was synthesized by high temperature solid-state reaction. The emission spectrum of Sr3SiO5：Eu^2＋ shows two bands centered at 487 and 575 nm, which well agree with the theoretic values of emission spectrum. The excitation spectrum for 575 nm emission center has several excitation bands at 365, 418, 458 and 473 nm. And the results show that the emission spectrum of Sr3SiO5：Eu^2＋ is influenced by the Eu^2＋ concentration. The relative emission spectra of the white-emitting InGaN-based YAG：Ce^3＋ LED and Sr3SiO5：Eu^2＋ LED were investigated. The results show that the color development of InGaN-based Sr3SiO5：Eu^2＋ is better than that of InGaN-based YAG：Ce^3＋, and the CIE chromaticity of InGaN-based Sr3SiO5：Eu^2＋ is （x=0.348, y=0.326）.