快速检测试纸检测肉类食品安全

目的建立检测肉类食品安全的快速检测方法。方法使用快速检测试纸检测肉类掺假,以及肉类中残留的盐酸克伦特罗、莱克多巴胺与沙丁胺醇。结果使用猪肉检测快速检测试纸,检测羊肉中掺加的猪肉,掺加猪肉的比例为0.75%~25%,可以检出。使用胶体金检测仪结合快速检测试纸,检测肉类中添加的盐酸克伦特罗、莱克多巴胺与沙丁胺醇,盐酸克伦特罗的平均添加回收率在110%左右,莱克多巴胺的平均添加回收率为90%~120%,沙丁胺醇的平均添加回收率在110%左右。结论快速检测试纸适合对肉类食品安全进行现场快速筛查。     

蜂产品中硝基咪唑类药物残留高效液相色谱法研究

样品经盐酸稀释(蜂王浆另加氯化钠和正己烷去脂),磷酸二氢钾调节pH值后用二氯甲烷提取,盐酸反萃,过SCX SPE柱,磷酸氢二钾溶液(pH 8.8)洗脱,洗脱液用二氯甲烷萃取.紫外320 nm处检测,建立了检测蜂蜜和蜂王浆中甲硝唑、洛硝唑、地美硝唑、替硝唑、奥硝唑残留的高效液相色谱法.该方法检测蜂蜜和蜂王浆中5种硝基咪唑药物的检测限为0.01μg·g -1,定量限为0.001 μg·g-1,平均回收率范围各自为59.2%-70.6%和54.9%-69.1%,变异系数分别小于18%和16%,结果表明该方法符合残留检测的要求.     

用火焰原子吸收光谱法测中草药中的金属元素

在微波消解罐内用硝酸消化样品,采用火焰原子吸收光谱法对9种中草药中的K、Na、Mg、Mn、Fe、Zn、Cu七种金属元素进行分析测定,并研究了最佳实验条件。在选定条件下,钾的检测限为0.0019μg/mL,钠的检测限为0.0077μg/mL,镁的检测限为0.0024μg/mL,铁检出限为0.0047μg/mL,锌检出限为0.0032μg/mL,铜检出限为0.0052μg/mL,锰检出限为0.0028μg/mL,相对标准偏差为0.54%～3.2%,回收率为94.8%～101.7%。用于中草药中金属元素的测定,简便、省时、准确,结果满意。     

气相色谱法检测饮料中的盐酸氯胺酮

文中考察了液液提取-气相色谱法检测饮料中盐酸氯胺酮的条件.饮料检材中添加pH值为9.2的缓冲溶液,再用三氯甲烷提取,提取液浓缩后加内标烯丙异丙巴比妥,进行气相色谱法分析.以盐酸氯胺酮与烯丙异丙巴比妥色谱峰面积比Y对橙汁中盐酸氯胺酮浓度X(g/mL)进行线性回归,在0.02-25.0 g/mL浓度范围内,线性回归方程为Y=0.0055 0.4785X(r=0.9999),检测限为0.005μg/mL,平均提取率91.5%.该方法可用于饮料中的盐酸氯胺酮的提取检验.     

盐酸克伦特罗的电化学发光检测器的研究

基于2 [(叔丁氨基)甲基] 4 氨基 3,5 二氯苯甲醇酸盐(盐酸克伦特罗)对联吡啶钌(Ru(bpy)2 3)电化学发光信号有较强的增敏作用,建立了一种检测盐酸克伦特罗的电化学发光新方法.结果表明,在0.1mol/L的Na2HPO4介质中,以循环伏安为电解方式,联吡啶钌的浓度为1 0×10-6g/mL时,盐酸克伦特罗对联吡啶钌电化学发光信号的增敏效果最好,在此条件下,该方法对盐酸克伦特罗的线性范围为6.0×10-7～9.0×10-6g/mL,检出限为7.3×10-8g/mL,相对标准偏差RSD为3 9%(n=7,c=1 0×10-6g/mL).     

高效液相色谱法检测单基发射药中的二苯胺

采用不同的萃取条件对发射药进行处理,检测对二苯胺的萃取情况。考察不同试验条件下单基发射药中二苯胺的液相色谱行为,建立了二苯胺的HPLC测定方法。选用VenusilMP-C18色谱柱(250mm×4.6mm,5μm),用甲醇和水为流动相(80:20),流速为1mL/min,检测波长280nm。该方法的线性范围为(0.05—100)μg/mL,线性回归方程为:Y=708956X,相关系数r=0.9998。该方法最低检测浓度为0.05μg/mL。回收率在98%-102%之间,相对标准偏差均小于2%。说明方法简单,操作简便,结果准确可靠,可用于单基发射药中二苯胺的含量测定和控制。     

虚拟模板分子印迹固相萃取 高效液相色谱法检测果蔬中三唑类杀菌剂

采用本体聚合法自制了联苯三唑醇分子印迹聚合物(MIP),以此聚合物为固相萃取剂,制备固相萃取柱,对果蔬中烯唑醇、戊唑醇进行分离富集,并采用高效液相色谱法测定其在果蔬中的残留。烯唑醇平均回收率在74.6%⁸8.6%之间,检测限为0.5μg/mL。戊唑醇平均回收率在66.9%88.6%之间,检测限为0.5μg/mL。戊唑醇平均回收率在66.9%⁷3.3%之间,检测限为0.25μg/mL。     

猪内脏中盐酸克伦特罗的毛细管电泳电导检测

建立了可用于检测猪内脏中盐酸克伦特罗含量的毛细管电泳电导检测方法 ,考察了实验参数对分离、检测的影响。采用醋酸 /醋酸氨缓冲体系为运行电泳介质 ,在最佳实验条件下 ,盐酸克伦特罗的线性范围为 1 2～ 2 0mg/L ,检测限为 0 6mg/L ,是一种较好的检测盐酸克伦特罗的方法。     

气相色谱法检测饮料中的盐酸氯胺酮

文中考察了液液提取-气相色谱法检测饮料中盐酸氯胺酮的条件。饮料检材中添加pH值为9.2的缓冲溶液,再用三氯甲烷提取,提取液浓缩后加内标烯丙异丙巴比妥,进行气相色谱法分析。以盐酸氯胺酮与烯丙异丙巴比妥色谱峰面积比Y对橙汁中盐酸氯胺酮浓度X(g/mL)进行线性回归,在0.02-25.0g/mL浓度范围内,线性回归方程为Y=0.0055 0.4785X(r=0.9999),检测限为0.005μg/mL,平均提取率91.5%。该方法可用于饮料中的盐酸氯胺酮的提取检验。     

KMnO_4-HCHO化学发光反应体系测定白藜芦醇

在酸性介质中,高锰酸钾氧化白藜芦醇产生微弱的化学发光,甲醛对此体系有增敏作用,据此建立了一种化学发光测定白藜芦醇的新体系.在优化的实验条件下,白藜芦醇的浓度在0.005~1.000μg/mL范围内与发光强度呈良好的线性关系,方法的检测限为1.0 ng/mL.对浓度为0.1μg/mL的白藜芦醇连续进样11次,其RSD=0.76%.将本方法用于红葡萄酒中白藜芦醇的测定并做回收率实验,回收率为81%~116%.同时,在基于化学发光和紫外的基础上,对可能的机理进行了探讨.     

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.     

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.     

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

A computer generator for randomly layered structures

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

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the