Comparative analysis of volatile constituents between herbal pair flos lonicerae-caulis lonicerae and its single herbs

Gas chromatography-mass spectrometry (GC-MS) and the chemometric resolution method (alternative moving window factor analysis, AMWFA) were used for comparative analysis of volatile constituents in herbal pair (HP) flos lonicerae-caulis lonicerae (FL-CL) and its single herbs. The temperature-programmed retention index (PTRI) was also employed for the identification of compounds. In total, 44, 39, and 50 volatile chemical components in volatile oil of FL, CL and HP FL-CL were separately determined qualitatively and quantitatively, accounting for 87.22%, 94.54% and 90.08% total contents of volatile oil of FL, CL and HP FL-CL, respectively. The results show that there are 32 common volatile constituents between HP FL-CL and single herb FL, 33 common volatile constituents between HP FL-CL and single herb CL, and 10 new constituents in the volatile oil of HP FL-CL.     

基于GC-MS结合HELP法的药对金银花—连翘及其单味药挥发性化学成分分析

采用气相色谱—质谱(GC-MS)技术和化学计量学新方法——直观推导式演进特征投影法分析药对金银花—连翘及单味药的挥发性化学成分。从药对金银花—连翘及其单味药金银花、连翘的挥发油中分别鉴定了46、12和28种化合物,分别占总挥发油相对含量的96.84%、91.51%和96.94%。三者共有挥发油成分5种。从化合物数目上看,药对金银花—连翘的挥发性化学成分主要来自连翘,但各物质的含量发生了改变。结果表明,中药配伍对挥发性化学成分及含量均存在一定影响。     

Analysis of volatile components in herbal pair herba schizonepetae-ramulus cinnamomi

Analysis of volatile components in herbal pair (HP) herba schizonepetae-ramulus cinnamomi (HS-RC),single herb HS and RC was carried out by gas chromatography-mass spectrometry (GC-MS) data and chemometric resolution method (CRM).The two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound by CRM.In total,47,61 and 51 chemical components in volatile oil of HS,RC,and HP HS-RC were respectively determined qualitatively and quantitatively,accounting for 90.52%,88.37%,and 88.72% total contents of volatile oil of HS,RC,and HP HS-RC,respectively.The number of the volatile components of HP HS-RC is almost the addition of that of two single herbs,but their relative contents are changed.     

Analysis of volatile components in herbal pair herba schizonepetae-ramulus cinnamomi

Analysis of volatile components in herbal pair （HP） herba schizonepetae-ramulus cinnamomi （HS-RC）, single herb HS and RC was carried out by gas chromatography-mass spectrometry （GC-MS） data and chemometric resolution method （CRM）. The two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound by CRM. In total, 47, 61 and 51 chemical components in volatile oil of HS, RC, and HP HS-RC were respectively determined qualitatively and quantitatively, accounting for 90.52%, 88.37%, and 88.72% total contents of volatile oil of HS, RC, and HP HS-RC, respectively. The number of the volatile components of HP HS-RC is almost the addition of that of two single herbs, but their relative contents are changed.     

局部双层柱面网壳与单层网壳的对比分析

合理的局部双层网壳结构能够较好的解决单层网壳承载力低、整体稳定性较差以及双层网壳由于杆件、节点较多造成结构繁杂的缺点,近年来得到了较多的应用.以正交正放局部双层柱面空腹网壳为例,通过与相同跨度及截面下单层网壳的对比,详细阐述了局部双层网壳在承载力、稳定性及经济指标上的优越性,得出了一些对工程设计具有指导意义的结论.     

HS-SPME-GC/MS法分析金银花-连翘药对挥发性成分

采用顶空固相微萃取-气相色谱/质谱法(HS-SPME-GC/MS)分析金银花、连翘及其药对粉末中的挥发性成分,鉴定出的化合物种类分别为57,68和88种;金银花、连翘药对配伍对挥发性成分和含量有一定的影响.并采用该法分析了药对混合粉末样品和水煎液样品中挥发性成分,并与SD法所得结果进行了比较.SPME法较SD法所得挥发性成分更多,组成分布有一定差异;粉末样品与水煎液样品的SPME法所得的组成分布大致相同,且重现性良好.结果表明:HS-SPME-GC/MS是一种简单、方便、有效的中草药挥发性成分的分析方法,粉末样品可以替代水煎液样品用于金银花、连翘药对配伍研究.     

Chemical component analysis of volatile oil in drug pair Herba Ephedrae-Ramulus Cinnamomi by GC-MS and CRM

Active volatile components in drug pair(DP)Herba Ephedrae-Ramulus Cinnamomi(HE-RC),single drug HE and RC were analyzed by gas chromatography/mass spectrometry(GC/MS),chemometric resolution method(CRM)and overall volume integration.By means of CRM,the two-dimensional data obtained from GC-MS instruments were resolved into a pure chromatogram and a mass spectrum of each chemical compound.In total,97,62,and 78 volatile chemical components in volatile oil of HE,RC,and DP HE-RC,were respectively determined qualitatively and quantitatively,accounting for 90.08%,91.62%,and 89.76% total contents of volatile oil of HE,RC,and DP HE-RC respectively.It is further demonstrated that the numbers of volatile components of DP HE-RC are almost the sum of those of two single drugs,but some relative contents of them are changed.Some new components,such as 1,6-dimethylhepta-1,3,5-triene,tetracyclo[4.2.1.1(2,5).0(9,10)]deca-3,7-diene,globulol and(E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one are found in DP HE-RC because of chemical reactions and physical changes during decoction.     

蜜柚果皮挥发油成分的GC—MS分析

本文用气相色谱／质谱／计算机联用法分析了蜜柚果皮挥发油的化学成分,分离出53个组分,鉴定了奴卡酮,柠檬烯,芳醇,α－萜品醇,α－荜澄茄油烯睾36化合物。     

蜜柚果皮挥发油成分的GCMS分析

本文用气相色谱/质谱/计算机联用法分析了蜜柚果皮挥发油的化学成分,分离出53个组分,鉴定了奴卡酮、柠檬烯、芳醇、α萜品醇、α荜澄茄油烯等36个化合物.     

基于SPA安全综合评价方法及其应用

为了克服传统安全评价方法不能同时考虑信息的确定性和未确定性特征的不足,提高复杂系统工程安全评价方法的计算效率,通过将集对分析法(SPA)引入安全系统评价领域,提出了一种全新的基于集对分析的同异反系统安全综合评价模型.该模型能够结合层次分析法(AHP)确定指标权重,对评价所得联系度中的不确定性开展分析,从而实现对工程系统中信息的确定性和不确定性进行同异反系统研究.以油库安全管理为例给出了该模型的操作步骤,计算结果表明,由于该模型体现了同异反系统的辨证思想,所得评价结果更为合理;同时该模型具有运算简明、快捷的特点,在安全工程中有良好的实用价值.     

基于令牌的单点登录协议及其形式化分析

提出一种新的适用于分布式网络的单点登录协议，利用令牌将身份认证和服务授权结合起来由一个验证服务器实现，授权校验的同时进行密钥分配，实现了用户和应用服务器的双向认证，令牌使用户只需在登录网络时进行一次身份认证即可接入各应用服务器。从而提高了网络认证效率，同时使验证服务器不需要保存用户的状态，有效提高验证服务器的性能，采用BAN逻辑对该协议进行形式化分析表明，协议达到了认证和密钥分配的目标，具有较强的安全性。     

板蓝根挥发性成分的GC-MS分析及抗菌抗氧化活性研究

通过气相色谱–质谱 (GC-MS) 对板蓝根挥发性成分的化学组成进行分析,并通过 Kirby-Bauer 药敏纸片法、普鲁士蓝法、铁还原抗氧化能力 (FRAP) 和 1,1-二苯基-2-三硝基苯肼自由基 (DPPH·) 清除法研究其体外抗菌和抗氧化活性. 结果表明,板蓝根挥发性成分的质量分数较低 (0.038%),通过NIST数据库分析从中鉴定出60种化学成分,主要包括异硫氰酸酯、芳香烃类、羧酸类等. 板蓝根挥发性成分对大肠杆菌、金黄色葡萄球菌有一定抑菌作用,平均抑菌圈直径分别为8.1和6.5 mm;板蓝根挥发性成分具有较好的还原能力,对DPPH自由基清除效果明显, IC₅₀值为7.169 mg/mL.     

湖北长阳绿茶挥发油成分的GC／MS分析

用气相色谱／质谱联用法分析了湖北长阳绿茶挥发油的化学成分，分离出93个组分，鉴定了84个化合物，挥发油中含芳樟醇、香叶醇、香茅醇等多种香气成分。     

湖北长阳绿茶挥发油成分的GC/MS分析

用气相色谱/质谱联用法分析了湖北长阳绿茶挥发油的化学成分,分离出93个组分,鉴定了84个化合物, 挥发油中含芳樟醇、香叶醇、香茅醇等多种香气成分.     

互叶白千层挥发性成分的提取和分析

采用水蒸气蒸馏法从互叶白千层叶及嫩枝中提取挥发油中的油相成分,用乙醚作为溶剂从蒸馏残液中萃取挥发油的水溶性物质,利用气相色谱-质谱（GC-MS）联用分析二者的化学成分并进行比较。互叶白千层挥发性成分的油相部分经鉴定确认了27种成分,占油相部分总量的98.60%,主要成分为松油烯-4-醇（52.15%）、γ-松油烯（19.60%）、α-松油烯（5.86%）、α-松油醇（3.93%）、对伞花烃（3.52%）、1,8-桉叶油素（2.67%）;水溶性部分经鉴定确认了61种成分,占水溶性部分总量的79.15%,主要成分为松油烯-4-醇（27.42%）、α-松油醇（6.55%）、香芹酚（5.00%）、1,8-桉叶油素（4.10%）。     

中小板与创业板首次公开募股首日溢价的比较分析

对中小板与创业板IPO首日溢价进行了比较,对影响溢价的因素分别进行检验,得出共同因素为换手率,表明二级市场上投机气氛依然较浓.中签率、发行成本、股权集中度和国有股背景对中小板新股溢价的影响较为显著,而创业板则为发行价格和市场气氛.此外,是否有国有股背景对新股发行状况也有一定影响.     

单螺母滚珠丝杠副静刚度可靠性及灵敏度分析

为提高数控机床整机可靠度,基于赫兹接触理论,对单螺母滚珠丝杠副静刚度可靠性及灵敏度进行研究,利用单螺母滚珠丝杠副的导程、接触角、丝杠公称直径、滚道曲率比、工作载荷等技术参数建立了轴向接触变形的理论模型.根据滚珠丝杠副的轴向接触变形小于加工精度的原则,建立滚珠丝杠副可靠性模型.利用改进一次二阶矩法分析和计算单螺母滚珠丝杠副的可靠度和灵敏度。结果表明:适当增大滚珠丝杠副的导程以及减小滚道曲率比可提高滚珠丝杠副的刚度,减小工作载荷可以降低滚珠丝杠副的轴向接触变形,提高滚珠丝杠副的可靠度.     

喷油单螺杆压缩机试验研究

为了深入研究水润滑单螺杆空气压缩机性能的影响因素,设计制造了一台水润滑单螺杆空气压缩机,并搭建了测试试验台,通过试验研究了不同转速、排气压力和喷水流量对水润滑单螺杆压缩机性能的影响. 结果表明,增加转速可以减小泄漏量,提高压缩机的性能. 其余工况不变,只增大喷水流量时,可以提高压缩机的水气比,增强水气之间的换热和压缩机的密封效果,进而提高水润滑单螺杆空气压缩机的各项性能. 如转速为3000r/min、排气压力为0.50MPa时,喷水流量由50L/min提高至80L/min,压缩机的容积效率提高5.15%,绝热效率提高2%,比功率降低0.26kW/(m³·min^-1). 由于水的黏度远小于润滑油,因此为了保证压缩机的性能,水气比要高于同工况下的油气比. 在额定转速3000r/min下,排气压力为0.50~0.65MPa时,建议的水气比范围为2.94%~3.48%.

     

侧风作用下货车和小汽车行驶稳定性对比分析

为对比侧风作用下货车和小汽车的行驶稳定性,基于8自由度驾驶模拟器,构建了侧风作用下山区高速公路桥隧连接段驾驶模拟平台.招募30名驾驶员进行6种侧风工况下的驾驶模拟实验,采集侧风作用下的侧向位移、横摆角速度、侧向加速度等车辆动态响应和驾驶员反应数据,探讨厢式货车和小汽车的侧滑稳定性、横摆稳定性以及侧翻稳定性.并基于静态稳...     

Comparison of simultaneous distillation extraction and solid-phase micro-extraction for determination of volatile constituents in tobacco flavor

1INTRODUCTION Manyresearchershavestudiedcigarettesmokeforspecificcompoundssuchaspolynucleararomatichydrocarbons(PAHs)andtobaccoflavoradditives[15].Tobaccoflavoradditivesarethees sentialmaterialsincigaretteproduction,andtheuseofvarioustobaccoflavoradditivesisoneofthecoretechniquesintobaccoindustry.Overthepasttwodecades,therehasbeenanincreasedinterestinandusageoftobaccoflavoradditives.Tobaccoflavorsareaddedtoimprovethephysicochemicalcharacterofthecigarette,modifythebaseflavorofthesmokeande…