张籍诗重出补辨二则

张籍现存450余首诗中有30多首重出于他人诗集,对于这些"重出"诗,佟培基《张籍诗重出甄辨》已作比较深入地考辨,本文就佟文未考定的、证据不足的两首重出诗作补充甄辨。认为《送李评事游越》确为张籍之作;《赠项斯》为王建之作,题应为"寄贾岛"。     

RRM1 gene expression in peripheral blood is predictive of shorter survival in Chinese patients with advanced non-small-cell lung cancer treated by gemcitabine and platinum

Objective  

To evaluate the predictive values of gene expressions of ribonucleotide reductase M1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) in peripheral blood from Chinese patients with non-small-cell lung cancer (NSCLC) treated with gemcitabine plus platinum.     

Evaluation of the antioxidant effects of four main theaflavin derivatives through chemiluminescence and DNA damage analyses

Theaflavins (TFs) are the dimers of a couple of epimerized catechins, which are specially formed during black tea fermentation. To explore the differences among four main TF derivatives (theaflavin (TF₁), theaflavin-3-gallate (TF₂A), theaflavin-3′-gallate (TF₂B), and theaflavin-3,3′-digallate (TF₃)) in scavenging reactive oxygen species (ROS) in vitro, their properties of inhibiting superoxide, singlet oxygen, hydrogen peroxide, and the hydroxyl radical, and their effects on hydroxyl radical-induced DNA oxidative damage were systematically analyzed in the present study. The results show that, compared with (−)-epigallocatechin gallate (EGCG), TF derivatives were good antioxidants for scavenging ROS and preventing the hydroxyl radical-induced DNA damage in vitro. TF₃ was the most positive in scavenging hydrogen peroxide and hydroxyl radical, and TF₁ suppressed superoxide. Positive antioxidant capacities of TF₂B on singlet oxygen, hydrogen peroxide, hydroxyl radical, and the hydroxyl radical-induced DNA damage in vitro were found. The differences between the antioxidant capacities of four main TF derivatives in relation to their chemical structures were also discussed. We suggest that these activity differences among TF derivatives would be beneficial to scavenge different ROS with therapeutic potential.     

黄山风景区浮溪河水域淡水藻类种群结构调查

通过对黄山风景区浮溪河水域藻类植物的采集、室内显微镜检分类方法对该水域的淡水藻类资源进行调查研究。镜检过程中在所有样品中共记录到藻类植物112种(其中包括变种和变型),隶属5门42属。根据该水域藻类植物种群结构分析,知该水域中藻类植物群落属硅藻-蓝藻-绿藻-黄藻型。其中,硅藻在种类及数量上均占优势,有20属68种,占60.7%;蓝藻门,有11属21种,占18.7%;绿藻门,有9属16种,占14.3%;黄藻门1属4种,占3.6%;裸藻门,有2属3种,占2.7%。通过调查得知在沿河流自上而下采集的四个样品中,藻类的种类数以及植物体数量呈递增趋势。     

食品中亚硫酸盐使用及检测方法的研究进展

亚硫酸盐是一类在食品中广泛使用却常被忽视的添加剂,不恰当的使用会对人体造成一定的损伤.笔者综述了食品中亚硫酸盐的使用及检验方法,并讨论了各种检测方法的优缺点.旨在对食品生产过程中亚硫酸盐的使用及检测起到一定的指导作用.     

苯二酚在PTh/NTiO2/GCE上的电化学行为的研究

该文利用循环伏安法(CV)和线性扫描溶出伏安法(LSSV)研究了对苯二酚(HQ)和间苯二酚(RS)在聚噻吩/纳米二氧化钛修饰玻碳电极(PTh/NTiO2/GCE)上的电化学行为。该修饰电极作为两种苯二酚传感器表现出极好的灵敏度和选择性。在0.2mol/L柠檬酸-磷酸氢二钠缓冲溶液(pH 4.6),RS和HQ的氧化峰电位相距508 mV,且在PTh/NTiO2/GCE上的峰比在裸GCE上的高出6.5倍。在最佳条件下,PTh/NTiO2/GCE对HQ和RS在1.0×10-7～8.0×10-6范围内都有较好的线性关系,混合物中的检出限(S/N=3)分别为3.3×10-8 mol/L和3.7×10-8 mol/L。通过计算得出了一些动力学参数如电子转移数(n),质子转移数(m)。该法被用来同时测定废水中的RS和HQ结果满意。     

基于古诺模型的斯密悖论探究——兼评心理主义与反心理主义

＂斯密悖论＂指斯密在《国富论》中以利己心为核心的经济人和《道德情操论》中以同情心为核心的道德人之间的矛盾。一个半世纪以来,国内外学界围绕着这一＂悖论＂的研究持续不断。借助古诺模型的方法对＂斯密悖论＂中的经济人与道德人进行博弈分析,试图提出利己与利他的有机统一体——经济道德人。     

滨海新区现代物流基础岗位人才需求与教育衔接的研究

近年来,滨海新区经济一直保持稳步上涨趋势。通过调查研究发现企业人才需求,与现在高职教育不能实现完全对接。通过分析企业对人才的能力要求,找出目前高职教学计划、教学方法的不当之处,建议构建"一体两翼"式的课程体系、推进"2+1"教学模式等措施,强化高职生能力素质,进而培养出适应滨海新区经济发展需要的实用型人才。     

Comparison of different techniques for time-frequency analysis of internal combustion engine vibration signals

In this study, we report an analysis of cylinder head vibration signals at a steady engine speed using short-time Fourier transform (STFT). Three popular time-frequency analysis techniques, i.e., STFT, analytic wavelet transform (AWT) and S transform (ST), have been examined. AWT and ST are often applied in engine signal analyses. In particular, an AWT expression in terms of the quality factor Q and an analytical relationship between ST and AWT have been derived. The time-frequency resolution of a Gaussian function windowed STFT was studied via numerical simulation. Based on the simulation, the empirical limits for the lowest distinguishable frequency as well as the time and frequency resolutions were determined. These can provide insights for window width selection, spectrogram interpretation and artifact identification. Gaussian function windowed STFTs were applied to some cylinder head vibration signals. The spectrograms of the same signals from ST and AWT were also determined for comparison. The results indicate that the uniform resolution feature of STFT is not necessarily a disadvantage for time-frequency analysis of vibration signals when the engine is in stationary state because it can more accurately localize the frequency components excited by transient excitations without much loss of time resolution.     

Dynamic responses of cable-stayed bridges to vehicular loading including the effects of the local vibration of cables

Stay cables, the primary load carrying components of cable-stayed bridges (CSBs), are characterised by high flexibility which increases with the span of the bridge. This makes stay cables vulnerable to local vibrations which may have significant effects on the dynamic responses of long-span CSBs. Hence, it is essential to account for these effects in the assessment of the dynamics CSBs. In this paper, the dynamic responses of CSBs under vehicular loads are studied using the finite element method (FEM), while the local vibration of stay cables is analyzed using the substructure method. A case study of a cable-stayed steel bridge with a center span of 448 m demonstrates that stay cables undergo large displacements in the primary mode of the whole bridge although, in general, a cable’s local vibrations are not obvious. The road surface roughness has significant effects on the interaction force between the deck and vehicle but little effect on the global response of the bridge. Load impact factors of the main girder and tower are small, and the impact factors of the tension of cables are larger than those of the displacements of girders and towers.