分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃

建立了分散固相萃取-超低温液液微萃取-气相色谱质谱法测定烟熏及烧烤肉制品中16种欧盟优控多环芳烃的分析方法。样品用乙腈提取、上清液经分散固相萃取净化后在-80℃条件下采用甲苯液液微萃取浓缩,选用DB-EUPAH色谱柱(20m×0.18mm×0.14μm)分离,最后经质谱检测定量。结果表明,16种欧盟多环芳烃在5~500μg/L浓度范围内线性关系良好,相关系数均大于0.999,对烟熏和烧烤的肉制品进行3个不同浓度的加标实验,平均回收率为75.2%~114.2%,RSD为1.84%~7.57% (n=6),检出限(S/N=3)为0.1~0.5μg/kg。 应用该方法对40批次市售腊肉制品和烤肉制品中多环芳烃进行了检测,发现部分腊肉制品和烤肉制品中多环芳烃含量超过相关标准和法规的限量要求。 该检测方法成本低,灵敏可靠,同时符合国家标准和欧盟法规对烟熏及烧烤肉制品中多环芳烃的限量检测要求。     

分散液-液微萃取与气相色谱-质谱联用检测白菜汁和橙子汁中11种农药残留

建立了基于分散液-液微萃取的气相色谱-质谱（GC-MS）联用对白菜汁、橙汁中11种痕量农药的富集和检测方法. 实验优化了各种分散液-液微萃取的影响因素,最终选择萃取剂为20μL 四氯化碳,分散剂为1.5mL 乙腈. 在最佳条件下各农药检出限低于0.25μg·L^-1,富集因子最高为636倍. 除氟硅唑和稻丰散回收率偏低外,大部分农药在白菜汁中的中、高浓度平均加标回收率在62.8%~119.7%,RSD在 2.66%~15.62%(n=3);在橙汁样品中的中、高浓度平均加标回收率在67.6%~112.8%,RSD在6.64%~15.98% (n=3). 实验结果表明,分散液-液微萃取技术具有操作简单、快捷、富集因子高、精密度高等特点,与GC-MS联用是检测蔬菜及水果汁中痕量农药残留的一种方便、高效的方法.     

离子液体分散液液微萃取-高效液相色谱分析苹果中有机磷农药残留

建立了苹果中有机磷农药残留多组分同时定量分析的离子液体分散液液微萃取-高效液相色谱分析(IL-DLLME-HPLC)方法.以[C_6MIM][PF_6]离子液体为萃取剂,甲醇为分散剂,对样品体积、萃取温度和萃取时间等萃取条件进行优化.结果显示,苹果样品中哒嗪硫磷、对硫磷、倍硫磷和伏杀硫磷4种有机磷在20～2 000μg/kg范围内线性关系良好,检出限为5.7～8.4μg/kg,加标回收率在85.3%～101.1%范围内,富集倍数为246～273.该方法回收率和富集倍数高,适用于苹果中有机磷农药残留的多组分同时分析.     

盐析液液萃取-超高效液相色谱-串联质谱法测定奶粉中四环素类抗生素

建立了盐析液液萃取-超高效液相色谱-串联质谱法检测婴儿配方奶粉中四环素、土霉素、金霉素和强力霉素4种四环素类抗生素的方法。奶粉样品经Na₂EDTA-Mcllvaine缓冲液提取,在硫酸铵辅助下采用少量乙腈萃取浓缩后,以体积分数0.1%甲酸水溶液和乙腈为流动相梯度洗脱,经BEH C18柱分离,ESI+电喷雾模式扫描,MRM多反应模式检测,外标法进行定量。结果显示,在硫酸铵作用下,乙腈对目标化合物的提取净化效果较好;该方法下4种四环素类抗生素的最低检出限为0.36μg/kg,远远低于国标固相萃取法的50μg/kg;质量浓度为1～100ng/mL时,4种化合物的线性相关性好,相关系数都在0.9990以上;加标浓度为1、5、50μg/kg时的回收率为71.88%~107.13%,相对标准偏差都小于8%。研究结果可为婴儿配方奶粉中四环素类抗生素的定性定量分析提供参考。     

化妆品塑料包装中16种增塑剂的迁移规律

将超声辅助-分散液液微萃取(UA-DLLME)与气相色谱-质谱联用技术(GC-MS)相结合,建立了化妆品和化妆品模拟液中痕量增塑剂的检测方法.优化了前处理条件,并系统研究了模拟液种类、温度、时间对16种增塑剂迁移行为的影响.结果表明,化妆品属性对增塑剂的迁移行为有显著影响,脂溶性化妆品与塑料包装材料间的迁移情况较为严重;迁移量与温度、时间均呈正相关.在最佳萃取和检测条件下,该方法对16种增塑剂具有较高的富集倍数(88~106),在10~400 μg/L内呈良好的线性关系,相关系数R²为0.998 3~0.999 8,在3个加标质量浓度水平下的平均回收率为70.66%~99.65%,相对标准偏差为4.48%~14.56%,检出限为0.09~11.66 μg/L.该方法简捷、环保,可满足国际市场对增塑剂日趋严格的检测低限需求,为化妆品包装材料的选择提供实验依据.     

基于轻质萃取剂的涡旋辅助分散液液微萃取-气相色谱法测定瓶装水中塑化剂

以密度比水小的溶剂为萃取剂,建立了涡旋辅助分散液液微萃取-气相色谱检测瓶装水中塑化剂的方法.传统分散液液微萃取技术一般采用密度大于水的有机溶剂为萃取剂.本方法以密度比水小的轻质溶剂正己烷-甲苯(1∶1,体积比)为萃取剂,乙腈为分散剂,涡旋辅助分散,离心后获得富集相,进行气相色谱检测,富集倍数高达171倍,具有良好的线性关系(相关系数为0.998 2~0.999 2)和精密度(3.1%~11.8%),以及较低的方法检出限(1.43~12.05μg/L),加标回收率为81.2%~107.8%.该方法简便,快速,环保,可以用于测定实际水样中塑化剂.     

气相色谱-串联质谱检测烟草中10种酰胺类除草剂残留

采用固相萃取-气相色谱-串联质谱来测定烟草中10种酰胺类除草剂的残留量。烟草样品通过含1%乙酸的乙腈混合液提取,固相萃取净化,采用气相色谱分离,串联质谱多反应监测模式分析。10种酰胺类除草剂在0.01~1.0 mg/L线性范围内均呈良好线性关系,相关系数大于0.997,方法的检出限在0.2~4.7μg/kg之间。在10μg/kg,50μg/kg,100μg/kg等3个浓度水平下进行加标实验,其加标回收率在79.6%~101.4%之间,测定值的相对标准偏差(n=6)在1.6%~6.7%之间。建立的方法简便、快速、灵敏,为常见烟草中酰胺类除草剂残留的准确判断提供了可靠依据,适用于烟草中10种酰胺类除草剂的同时检测。     

DSPE-GC/MS快速检测葡萄酒中52种农药残留

利用分散固相萃取GC-MS分析,建立了葡萄酒中52种不同极性农药残留的快速检测方法.葡萄酒样品用酸化乙腈经振荡提取和超声辅助提取后,上清液用混合吸附填料进行分散固相萃取净化,高速离心后,再通过氮吹方式浓缩,复溶,过滤膜,用GC/MS检测.与传统前处理方法相比,分散固相萃取技术在检测成本和处理速度上有很大优势.52种农药在3个浓度添加水平上的加标回收率范围是60%~110%,RSD15%(n=5),定量限是0.000 7~0.032 3 mg/kg.     

高效液相色谱法测定水中α-萘酚和β-萘酚

建立了液液萃取—高效液相色谱法测定水样中α-萘酚和β-萘酚的分析方法。对流动相组成及流速、柱温、萃取剂种类、色谱柱类型等条件进行了优化。选用三氯甲烷为萃取剂,乙腈:水(0.1%乙酸)=50:50为流动相,流速1m L/min,柱温40℃,作为色谱条件。在1L空白水样中添加低浓度水平的萘酚标准溶液(加标量为0.2μg),测定平行样品7份,α-萘酚加标回收率为92%~117%,标准偏差为5.5%;β-萘酚加标回收率为96%~121%,标准偏差为5.1%。当萃取体积为1L,浓缩至1m L,进样量为10μL时,α-萘酚和β-萘酚的方法检出限分别为0.15μg/L和0.17μg/L。     

分散液液微萃取-高效液相色谱法测定蔬菜中氟喹诺酮类药物残留

建立了分散液液微萃取与高效液相色谱测定蔬菜中的左氧氟沙星、诺氟沙星和环丙沙星3种氟喹诺酮类药物残留的方法.实验对影响分散液液微萃取的影响因素如分散剂的选择、分散剂体积、萃取剂、萃取剂体积和pH值等进行了优化.在最佳萃取条件下,3种药物的线性范围在10~1 000μg/kg之间(R2≥0.994 09),检测限在5~30μg/kg之间,样品回收率在73.7%~118.2%之间,用于实验样品中的左氧氟沙星、诺氟沙星和环丙沙星3种氟喹诺酮类药物残留分析,结果满意.     

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.