气相色谱法测定蔬菜中残留的甲氰菊酯农药

文章对蔬菜中甲氰菊酯农药残留测定的样品预处理方法和检测条件进行了优化研究。采用乙腈振荡提取、Strata FL-PR Florisil(1000mg/6mL)固相萃取柱净化、浓缩以及电子捕获/气相色谱法检测。蔬菜样品中的添加浓度为0.1~1.0μg/mL时,添加回收率为97.3%~100.1%,相对标准偏差为1.59%~2.36%。     

GC-NCI-MS分析粮谷中多类农药残留

 建立了粮谷中14种农药残留（9种有机氯、3种拟除虫菊酯和2种含氯有机氮）气相色谱-负化学源-质谱（GC-NCI-MS）的分析方法,试样样品用V(正己烷)∶V(丙酮)=1∶1超声波提取,硅镁吸附剂净化,采用GC-NCI-MS选择离子扫描方式检测.结果表明,该方法准确、快速、选择性好、抗干扰能力强,14种农药的方法最低检出限：0.01～0.18?μg/kg,平均添加回收率在75.2%～109.7%之间,变异系数都小于10%,并成功应用于大米、面粉试样中痕量农药残留分析.     

凝胶渗透色谱-气相色谱串联质谱法测定禽蛋中16种有机氯类农药残留

建立了凝胶渗透色谱(GPC)净化、气相色谱-串联质谱(GC-MS/MS)同时测定禽蛋中16种有机氯类农药残留的方法.样品中的待测农药组分经丙酮、正己烷提取、GPC净化去除油脂等杂质,GC-MS/MS采用多反应监测模式(MRM)采集数据后进行定性/定量分析.待测农药的标准加入回收率在70％～110％之间,方法的相对标准偏...     

固相萃取净化分析牡蛎中有机氯农药

文中针对牡蛎中的有机氯农药,采用固相萃取小柱Florisil柱净化,达到了较好的净化效果。对固相萃取净化条件进行讨论的结果表明,体积比为95∶5的正己烷-丙酮作为洗脱溶剂,洗脱速率为1.5mL/min时,16种有机氯农药回收率较高,为95%～106%。该方法 简单、快速、溶剂无毒且用量少,是一种环境友好的样品净化方法。     

基质固相分散-气相色谱-质谱法检测蔬菜中的农药多残留

建立了蔬菜中多种农药残留的基质固相分散(MSPD)前处理以及气相色谱-质谱的检测方法。蔬菜样品经粉碎、与佛罗里硅土混匀研磨、装柱、乙酸乙酯淋洗、浓缩后,利用气相色谱-质谱在选择离子监测模式下进行快速定性定量分析。研究结果表明,在上述优化条件下,61种农药回收率在73.1%~114.9%,相对标准偏差小于15.3%,最低检出限保持在0.002~0.01mg/kg之间,方法具有快速、经济、省时、省力等优点。     

中草药中农药残留检测技术新进展

综述了近年来中草药中农药残留常用的检测技术,如气相色谱、高效液相色谱、气相色谱-质谱联用技术、毛细管电泳、免疫分析技术、生物传感器技术等.着重介绍了农药残留分析常用的前处理技术以及新技术,如超声提取、微波辅助提取、固相萃取、固相微萃取、超临界流体萃取、基质固相分散技术、加速溶剂萃取、免疫亲和色谱、分子印迹技术等,并展望了中草药中农药残留测定技术的发展.     

微波萃取-气相色谱质谱法测定土壤中的多环芳烃

本文通过微波萃取的方法提取土壤中的15种多环芳烃(PAHs),萃取液经硅酸镁(Florisil)固相萃取柱净化,采用DB-5MSUI毛细管柱(30 m×0.25 mm×0.25μm)进行分离,使用气相色谱-质谱进行测定分析.方法的加标回收率为70.85%～117.90%,相对标准偏差(RSD)为2.1%～6.7%.微波萃取比其他萃取方法回收率高,重复性好,方法简单快速,具有良好的精密度,可以满足土壤中多环芳烃的提取,建立的方法可以满足土壤中多环芳烃测定的技术要求.     

固相萃取-气相色谱法检测三七中有机磷农药残留

文章采用固相萃取—气相色谱的方法检测三七样品中的有机磷类农药残留。采用超声法提取,并用弗罗里硅土固相萃取柱净化,用氮磷检测器进行检测,最后用外标法定量。5种有机磷杀虫剂的回收率范围为73.66%～112.22%,相对标准偏差（RSD）范围为2.94%～4.31%,在5个三七样品中检出了乐果和敌敌畏,没有检测到甲胺磷、对硫磷、辛硫磷。该方法快速、准确,可用于三七中有机磷农药残留的分析。     

水果和蔬菜中苯醚甲环唑残留量的气相色谱-串联质谱测定方法研究

目的建立气相色谱-串联质谱法测定水果和蔬菜中苯醚甲环唑残留的分析方法.方法试样用乙腈提取,经Sep-Pak Carbon NH2固相萃取柱净化,气相色谱分离,串联质谱多反应监测模式下测定,外标法定量.结果苯醚甲环唑质量浓度在0.01mg/L~2.5mg/L范围内线性关系良好,相关系数R0.996.苯醚甲环唑在不同基质中平均回收率为73.40%~115.1%,相对标准偏差为4.86%~13.24%,检出限为0.005mg/kg.结论该方法灵敏度高,选择性好,抗干扰能力强,适合苯醚甲环唑残留量的定性确证分析和定量分析.     

气相色谱-质谱联用法测定广西传统用药苦玄参中有机磷农药残留

采收广西梧州大坡苦玄参种植基地、广西龙州县种植的苦玄参为样品,经干燥、粉碎,加入石油醚-丙酮(2:1)超声提取,提取物通过活性炭,Florisil硅土柱净化后,用气相色谱-质谱联用法(GC-MS法)测定苦玄参药材中甲胺磷、敌敌畏、乙酰甲胺磷、甲拌磷、乐果、杀螟硫磷、马拉硫磷、毒死蜱8种常用有机磷农药的残留.结果显示未检出有机磷农药残留,标准工作曲线r在0.990～0.997,线性良好,样品加样回收率为92.22%～108.9%.本实验说明采收的苦玄参作为原料药材,在存放一段时间后,未检出有机磷农药残留量,该药材可以放心使用.本次试验为快速、方便地检测苦玄参中有机磷农药残留提供了可行的方法.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.