浙产山胡椒根挥发油化学成分的研究

采用水蒸汽蒸馏法提取挥发油,气相色谱-质谱联用法结合计算机检索对浙产山胡椒根挥发油的化学成分进行分析和鉴定,用气相色谱面积归一法计算各组分的相对百分含量。从山胡椒根的挥发油中,分析并鉴定出17种化合物。主要含1,2,3,3a,4,5,6,7-八氢-1,4-二甲基-7-(1-甲基乙烯基)-奥艹、4,6,6-三甲基-2-(3-甲基-1,3-丁二烯基)-3-氧杂环-辛烷、愈创木醇、1,2,3,5,6,7,8,8a-八氢-1,4-二甲基-7-(1-甲基乙烯基)-奥艹,它们占挥发油总量的84.75%。     

Development of a sequential injection anodic stripping voltammetry (SI-ASV) method for determination of Cd(II), Pb(II) and Cu(II) in wastewater samples from coatings industry

This paper describes the development and validation of a sequential injection (SI) anodic stripping voltammetry (ASV) method using the hanging mercury drop electrode for accumulation of the heavy metal cations Cu(II), Pb(II) and Cd(II). The method was applied to wastewater samples after proper acid digestion in open vessels to eliminate matrix effects. For a deposition time of 90 s at the flow rate of 10 μl s⁻¹, the detection limits of the method were 0.06, 0.09 and 0.16 μmol L⁻¹ for Cd, Pb and Cu, respectively. Under these conditions the linear dynamic range was between 0.20 and 9.0 μmol L⁻¹ and the sampling frequency was 30 analyses per hour. The relative standard deviation of the method was 3%(n=7) at the concentration level of 2.0 μmol L⁻¹. The accuracy of the method was evaluated by spiking the samples with known amounts of the metal cations, and by comparison with an independent analytical technique, the inductively coupled plasma atomic emission spectroscopy (ICP-AES). Average recoveries were around of 84%, and the results showed no evidence of systematic errors in comparison to the ICP-AES.     

Sliding behavior of oil droplets on nanosphere stacking layers with different surface textures

Two facile coating techniques, gravitational sediment and spin coating, were applied for the creation of silica sphere stacking layers with different textures onto glass substrates that display various sliding abilities toward liquid drops with different surface tensions, ranged from 25.6 to 72.3 mN/m. The resulting silica surface exhibits oil repellency, long-period durability > 30 days, and oil sliding capability. The two-tier texture offers a better roll-off ability toward liquid drops with a wide range of γ_L, ranged from 30.2 to 72.3 mN/m, i.e., when the sliding angle (SA) < 15°, the oil droplet start to roll off the surface. This improvement of sliding ability can be ascribed to the fact that the two-tier texture allows for air pockets (i.e., referred to as the Cassie state), thus favoring the self-cleaning ability. Taking Young-Duprè equation into account, a linearity relationship between sine SA and work of adhesion (W_ad) appears to describe the sliding behavior within the W_ad region: 2.20-3.03 mN/m. The smaller W_ad, the easier drop sliding (i.e., the smaller SA value) takes place on the surfaces. The W_ad value ∼3.03 mN/m shows a critical kinetic barrier for drop sliding on the silica surfaces from stationary to movement states. This work proposes a mathematical model to simulate the sliding behavior of oil drops on a nanosphere stacking layer, confirming the anti-oil contamination capability.     

产业转移下的海上丝绸之路沿线集装箱港口的投资决策研究

在产业转移背景下,考虑港口服务货运需求与刺激货运需求的双重功效,研究海上丝绸之路沿线产业承接地的港口投资建设问题。首先,在现实交通运输网络中加入虚拟链接构建超级网络,用以刻画制造业的转移、生产和运输过程。其次,建立制造业承接地港口投资决策优化模型,用运输阻抗、地价和工资三个内生变量描述港口投资、产业转移与区域经济之间均衡关系。模型以产业承接地港口收益最大为目标,确定承接地港口的投资规模及费率水平。最后,以斯里兰卡的科伦坡口为例进行数值分析,计算海上丝绸之路沿线港口需求与供给间正向反馈的数量关系及上确界,为优化沿线港口投资实现投资利益最大化提供依据。     

现代物流业与其相关产业灰色关联度研究——基于山西省的实证分析

结合山西省2002～2006年的相关行业生产总值增加值,运用灰色系统理论方法,得到山西省现代物流业与相关产业的灰色关联系数,按照关联度的不同排序,对山西省发展现代物流业提出了切实可行的政策建议.     

几种食用植物油发热量的测定

利用WZR-1A型精密微电脑量热计系统地测量了10种食用植物油的恒容燃烧热.准确称取一定量的基准物质,放入氧弹中充人高压纯氧,将测试样品在氧弹中完全燃烧,并记录燃烧前后时间与量热计温度变化数据,运用仪器所带的数据处理软件计算出仪器热容量,然后再准确称取一定量的食用植物油,装入已准确测定热值的燃烧胶囊中后,将测试数据用自编的计算机处理程序对测试数据处理,从而得到食用植物油的燃烧热值.此法准确、简便、实用,可用于日常检测工作.     

Untersuchung der Schwefelbilanz bei metallurgischen Prozessen unter Verwendung von 35S

Es werden Methoden und Ergebnisse der Untersuchung der Schwefelbilanz beim Krupp-Rennverfahren und beim Siemens- Martin-Prozeβ unter Verwendung von ³⁵S beschrieben. Die Markierungsverfahren für die Ausgangsstoffe werden angegeben.     

Anwendung nuklearer Verfahren in der ungarischen Tonerdeindustrie

Der Beitrag gibt einen zusammenfassenden Überblick über die in der ungarischen Tonerdeindustric verwendeten nuklearen Versuchsmethoden.

Anhand von Beispielen werden die an Betriebsapparaturen durchgeführten Durchlauf- und Verteiungsmessungen sowie die unter Laborbedingungen vorgenommenen reaktionskinetischen Untersuchungen, die auf die Klärung verschiedener Prozesse der Tonerdeherstellung gerichlet waren, veranschaulicht.

Weiterhin werden analytische Anwendungen der Neutronenaktivierungs- und Röntgenfluoreszenzmethode sowie Meß- und Regelungseinrichtungen, die auf der Strahlenabsorption beruhen, bekanntgemacht.     

Analysis of emitter-coupled multivibrators by singularly perturbed systems

Emitter-coupled multivibrators play a decisive role in electrical engineering, especially for phase locked loops which are key-building blocks of analogue RF front-ends. Since multivibrators correspond to relaxation oscillators, in the following the modelling and analysis by the theory of singularly perturbed systems is presented. Models for fast and slow phenomena are derived, and the fast transients of emitter-coupled multivibrators are analysed for the first time. The results of our analysis lead to significant advantages for the design of electrical multivibrators.     

中国股市行业板块的动态相关性建模——基于DCC—MVGARCH模型

相关性的讨论是现代金融分析的重要内容,行业板块的相关分析是组合投资的关键步骤。基于能刻画动态相关的DCC-MVGARCH模型对我国波动剧烈的六个股市行业板块进行了相关性研究,结果表明：十个板块相关性序列可看成常量,Pearson相关系数仍能刻画其相对大小,这为机构投资者按Pearson相关系数进行组合构建提供了实证依据;五个动态相关性序列是宽平稳而非严平稳的,适合采用随机过程建模以实现预测,另外动态相关性与时变波动率存在一定的关系,当波动率增强时,相关性有随之增大的趋势。