A Lattice Hydrodynamic Model for Traffic Flow Accounting for Driver Anticipation Effect of the Next-Nearest-Neighbor Site

In this paper, a new lattice hydrodynamic model is proposed by incorporating the driver anticipation effect of next-nearest-neighbor site. The linear stability analysis and nonlinear analysis show that the driver anticipation effect of next-nearest-neighbor site can enlarge the stable area of traffic flow. The space can be divided into three regions: stable, metastable, and unstable. Numerical simulation further illuminates that the driver anticipation effect of the next-nearest-neighbor site can stabilize traffic flow in our modified lattice model, which is consistent with the analytical results.     

不同排布方向性椭圆孔液体润滑机械密封性能的研究

为提高液体润滑多孔端面密封的动压性能,提出了方向性多孔端面机械密封.考虑端面间润滑液膜的空化现象,基于质量守恒的JFO空化边界条件建立了理论模型,采用有限差分法求解Reynolds控制方程,获得了端面膜压分布,从而对比分析了方向性椭圆孔的排布方式对多孔端面机械密封性能的影响规律.结果表明:椭圆孔的方向性排布对端面密封的密封性能影响较大,高压侧下游泵送孔可有效提升密封端面的流体动压特性,上游泵送孔不论在高压侧还是在低压侧均可有效降低密封泄漏率;当形状因子γ为3~5,内外孔倾斜角α为35°~45°和β为125°~135°时,可获得最佳的动压性能,当形状因子γ为3~5,倾斜角α为30°~50°和β为30°~50°时,可以获得最低泄漏率.     

Design, Syntheses and Biological Activities of Novel Anthranilic Diamide Insecticides Containing N-Pyridylpyrazole

In search of environmentally benign insecticides with high activity, low toxicity and low residue, a series of novel anthranilic diamide derivatives containing N-pyridylpyrazole was designed and synthesized. All the compounds were characterized by ¹H NMR spectroscopy and elemental analysis. The single crystal structure of compound 8j was determined by X-ray diffraction. The insecticidal activities of the new compounds were evaluated. The results show that some compounds exhibited moderate insecticidal activities against Lepidoptera pests. Among this series of compounds, compounds 8o and 8p showed 100% larvicidal activity against Mythimna separate Walker, Plutella xylostella Linnaeus and Laphygma exigua Hubner at a test concentration of 200 mg/kg, which is equal to the commercial chlorantraniliprole.     

氢气对AlN薄膜择优取向的作用机制

采用脉冲反应磁控溅射方法在Si衬底上沉积了(100)和(002)择优取向的AlN薄膜,随着溅射功率的降低或氢气浓度的增加,放电电压下降,沉积粒子能量降低,薄膜由(002)取向逐渐向(100)取向转变.在溅射气氛中加入氢气后,薄膜中的氧含量降低,表面形貌与表面粗糙度均随着择优取向的改变发生变化.溅射功率及氢气浓度对AlN薄膜择优取向的影响规律表明,氢气主要是通过降低沉积粒子的能量和在衬底表面产生吸附两种作用方式来影响AlN薄膜的择优取向.     

超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱鉴别纺织品中禁用芳香胺及其异构体

针对目前纺织品中禁用偶氮染料检测中的假阳性问题,建立了一套应用超高效液相色谱-线性离子阱/静电场轨道阱高分辨质谱（UPLC-LTQ/Orbitrap）同时筛选24种禁用芳香胺及其常见的14种异构体的方法。样品经连二亚硫酸钠还原,叔丁基甲醚提取后,以水/甲醇（9/1,v/v）稀释定容,用ZORBAX SB-C₁₈色谱柱（150 mm×2.1 mm,5 μm）分离,以0.1%甲酸水溶液和甲醇为流动相,电喷雾正离子（ESI⁺）模式电离。以准分子离子峰的精确质量数和保留时间定性,以提取的色谱图峰面积定量。38种芳香胺的线性相关系数大于0.99,方法检出限为0.5~5 μg/kg。该方法可通过一次实验同时对24种禁用芳香胺及其常见的14种异构体准确定性定量,大大缩短检测周期,实际样品检测也进一步验证了其灵敏性和准确性。     

Ratiometric Fluorescent Probe Based on Novel Red-emission BODIPY for Determination of Bovine Serum Albumin

A novel red-emission boron-dipyrromethene（BODIPY） dye with a pyrrole ring was synthesized simply via one-pot reaction. The spectral properties of it were investigated under the conditions of different solvents. The results show that the as-prepared BODIPY dye is extremely sensitive to solvent polarity, and the fluorescent emission enhances with the decrease of solvent polarity. In aqueous buffer, the addition of bovine serum albumin leads to a ratiometric change in absorption spectra with an association constant of 1.16×10^6 L/mol. Meanwhile, the fluorescence emission increases greatly at 622 nm but changes slightly at 575 nm. The response time is very short（less than 3 min）, and the changes of color can be noticed by naked eyes. Bovine serum albumin can be detected by this ratiometric fluorescence probe, but other proteins or enzymes cannot be detected by this method, which indicates that this novel dye has high selectivity towards bovine serum albumin. The reason is that bovine serum albumin has suitable hydro- phobic cavities for binding with the dye. In addition, the dye molecule can penetrate cell membrane easily and make a fast fluorescent stain, which makes it a potential probe for living-cell fluorescence imaging.     

Synthesis and Antitumor Activity of 4-tert-Butyl-5-benzyl-2-benzyliminothiazoles

A series of novel Schiff bases including 4-tert-butyl-5-benzyl-2-benzyliminothiazoles was synthesized by reacting the aromatic aldehydes with the corresponding 2-aminothiazoles.The antitumor bioassay revealed that compounds 2n and 2m exhibited potent cytotoxicity against human cervix cancer（HeLa） cell line with IC50 values of 0.001 and 0.007 mmol/L,respectively.The preliminary structure-activity relationship（SAR） investigations and the apoptosis evaluation suggest that 4-tert-butyl-5-benzyl-2-benzyliminothiazoles may be a satisfactory backbone for antitumor activity,and compound 2n can serve as an attractive candidate for the development of novel apoptosis in anticancer treatment.     

Synthesis,Structure and Characterization of Three Metal Molybdate Hydrates: Fe(H2O)2(MoO4)2·H3O,NaCo2(MoO4)2(H3O2)and Mn2(MoO4)3·2H3O

Three metal molybdate hydrates,Fe(H2O)2(MoO4)2·H3O(FeMo),NaCo2(MoO4)2(H3O2)(CoMo)and Mn2(MoO4)3·2H3O(MnMo),were synthesized by the mixed-solvent-thermal methods and characterized by singlecrystal X-ray...     

Influence of Steric Hindrance Between Hydrogen Atoms of Linkage Groups and Adjacent Phenyls on Properties of Polyimide

A diamine monomer 4,4′-methylenedianiline(MDA) was introduced to modify the polyimide of pyromellitic dianhydride(PMDA) and 4,4′-oxydianiline(ODA) by polycondensation. A series of polyamic acids was synthesized from MDA and ODA of different molar ratios with PMDA of sum mole of moles of MDA and ODA, and polyimide films were obtained by thermal imidization. Polyimide(PI) films were characterized by tensile testing, dynamic mechanical analysis(DMA), thermal gravimetry analysis(TGA), Fourier transform infrared spectroscopy (FTIR), wide X-ray diffraction(WAXD) and molecular simulation. With the increase of MDA content, the tensile strength and thermal decomposition temperature remained generally stable compared with those of PMDA/ODA polyimide. Unexpectedly, the glass transition temperature(T_g) and Young’s modulus increased from 388.7 ℃ and 2.37 GPa to 408.3 ℃ and 5.74 GPa, respectively. The results of WAXD and molecular simulation indicate the steric hindrance among hydrogen atoms of the linkage groups and adjacent phenyls enhanced the properties of the polyimide modified with MDA.     

老鼠血清中苯扎贝特的HPLC-MS法测定

建立一种简便、快速、灵敏的高效液相色谱-质谱联用测定老鼠血清中苯扎贝特的方法。 采用Gemini C18色谱柱;流动相：V(乙腈)∶V(甲醇)∶V(水)=60∶15∶25(0.03%甲酸水溶液);柱温35 ℃,流速0.3 mL/min;紫外吸收波长为235 nm;进样量5 μL。 质谱采用电喷雾电离负离子模式,用于定量分析的离子分别为[M-H]- m/z 359.65→273.70(苯扎贝特)和[M-H]- m/z 212.95→127.08(氯贝酸)。 对苯扎贝特检测的线性范围为0.073~7.884 mg/L,r=0.9995。 得到苯扎贝特的平均回收率为94.3%~103.1%;方法的日内和日间的相对标准偏差(RSD)均小于6%;最低检测限(LOD)与定量限(LOQ)分别为9.0和30 μg/L;为临床上人体血清中苯扎贝特的浓度检测提供了一种重现性好、灵敏度高的分析方法。