A Rapid Test Procedure for Estimating the Amylose Content of Pea Starch *)

Rapid estimation of the amylose content of pea starch is of particular importance in breeding for pea starches high in amylose. An amylose test for starch in fresh potato tubers was adapted for use with high-amylose pea flour. Wavelengths for photometric detection were slightly changed, and the iodine concentration could be reduced. Defatting of the flour was not necessary. Reproducibility of the analyses was good (s% <3; n = 95). Variability of amylose content was investigated for different potato, barley and pea varieties. An analysis of the F4-generation of a crossing experiment with peas underlined the specific suitability of this rapid test method for supporting breeders' activities.     

数控加工工艺过程分析与处理探索

通过研究和分析数控编程中要确定的各种加工参数和工艺内容，讨论了在控加工时进行工艺分析和确定工艺参数的方法，并以相应的实例解释了具体完成各项工作的正确方向。     

山西省蔬菜地有害生物药防现状及残留控制对策研究

采用速测法对山西省2003年至2004年10个地级市不同时期的生产蔬菜和市场销售蔬菜共22 846个样品进行了农药残留阳性率的测定调查,研究分析表明,山西省蔬菜上的农药残留阳性率呈下降趋势,说明各级政府和植保部门对蔬菜农药残留超标问题的重视及采取的治理措施已取得了初步成效。但在蔬菜生产高峰季节和蔬菜病虫危害高峰期生产的蔬菜农药残留阳性率仍然较高,表明了实施蔬菜病虫无害化生态控制的任务任道重远,施用化学农药防治病虫的科学水平仍需进一步提高。为此作者提出进一步降低山西省蔬菜农药残留的6项对策。     

Study on the Factors Influencing the Efficiency of Wheat Transformation

Wheat transformation efficiency is closely related to several factors such as receptor genotype, constructed plasmid and selection procedure after bombardment or co-cultivation. In our study, several kinds of antibiotics, which were normally used in plant transformation to the selection genes of nptⅡ, bar and hpt,were tested for the optimal concentrations for wheat transformation. The results showed that 25 - 50mg/L of geneticin (G418) was suitable for the selection of nptⅡ, kanamycin or neomycin was not suitable for use. 3 5mg/L of phosphinothricin (PPT) or biolaphos could be used for the selection of bar, 100 - 150mg/L of hygromycin for the selection of hpt. Yangmai 158 and Yangmai 10 with high tissue culture response and good agronomic characteristics were screened from 25 potential Chinese wheat cultivars. The concentration changing of selectable agent in selection medium was helpful to obtain enough regeneration plantlets with strong root system.     

S形内锁针张力带内固定治疗肩锁关节脱位

目的 :比较肩锁关节全脱位用S形内锁针张力带内固定法与传统克氏针固定法的效果。方法 :根据肩锁关节解剖学和生物力学特点 ,本文设计了S形内锁克氏针结合张力带内固定系统治疗肩锁关节全脱位 2 6例 (S形针组 ) ,并用传统克氏针张力带内固定 2 2例作为对照组 (传统组 )。结果 :S形针组优 2 2例 ,良 4例 ,差 0例。传统组优 13例 ,良 5例 ,差 4例 (P <0 .0 5 )。结论 :S形内锁针张力带内固定 ,为肩锁关节脱位的复位固定提供一种有效的方法     

预期式时距估计干扰效应的实验研究

采用时间和非时间双重作业的实验范式,以11 s和23 s为目标时距,探讨了干扰项数（1,3或5个无意义音节）和延迟时间（0 s,9 s或27 s）对预期式时距估计的干扰效应.结果表明：在双重作业中,干扰项数没有显著的影响时距估计,延迟时间表现出显著的主效应.干扰项数和延迟时间的交互作用显著,实验结果说明了单一的注意模型、变化/分割模型不能对时距估计的干扰效应做出全面的解释,时间分段综合模型促进了时间认知研究向综合的方向发展.     

痕量分析实验室内质量保证的系统分析

本文用系统分析研究痕量分析的室内质量保证。1.给出系统的结构设计,提出 QA 系统由质量传递、QA 措施、QC 措施和室间性能研究4个子系统所组成。系统设计的理论依据是痕量分析的误差分布论,目标是分析数据的五性,即准确性、精密性、代表性、可比性和完整性;任务是把分析误差控制在给定的不确定度水平;手段是五性的表征指标;约束条件是QA 措施。2.误差分析;质量传递是非连续的随机过程,是个灰色系统。而各类误差又具有模糊性,恰能证明系统的灰色性质。3.建立灰色模型:总误差 R=△a+bx,△a是加和性误差,b 是乘积性误差。△a0,b=常数1是灰色模型的分级优化解。4.给出评价 QA 系统标准:±不确定度。     

铺地竹叶中除草活性物质的提取工艺研究

采用正交试验设计,研究了提取溶剂、料液比、提取温度和提取次数等因素对铺地竹竹叶中除草活性成分提取的影响,并通过生物测定评价了提取物对杂草抑制效果。结果表明,提取溶剂为50%乙醇,料液比为1∶7,提取温度为60℃,提取次数为3次时,提取率最高,达14.50%;以75%乙醇为提取溶剂,料液比为1∶6,提取温度为80℃,提取3次时,所得提取物在0.4 g.L-1浓度时对结球生菜根和匍匐翦股颖根的抑制效果均达到最高水平,抑制率分别为67.83%和36.82%。     

Use of the BCR three-step sequential extraction procedure for the study of the partitioning of Cd, Pb and Zn in various soil samples

A slightly modified three-step sequential extraction procedure proposed by the Community Bureau of Reference (BCR) for analysis of sediments was successfully applied to soil samples. Contaminated soil samples from the lead and zinc mining area in the Mezica valley (Slovenia) and natural soils from a non-industrial area were analysed. The total concentrations of Cd, Pb and Zn and their concentrations in fractions after extraction were determined by flame or electrothermal atomic absorption spectrometry (FAAS, ETAAS). Total metal concentrations in natural soils ranged from 0.3 to 2.6 mg kg^-1 for Cd, from 20 to 45 mg kg^-1 for Pb and from 70 to 140 mg kg^-1 for Zn, while these concentrations ranged from 0.5 to 35 mg kg^-1 for Cd, from 200 to 10000 mg kg^-1 for Pb and from 140 to 1500 mg kg^-1 for Zn in soils from contaminated areas. The results of the partitioning study applying the slightly modified BCR three-step extraction procedure indicate that Cd, Pb and Zn in natural soils prevails mostly in sparingly soluble fractions. Cd in natural soils is bound mainly to Fe and Mn oxides and hydroxides, Pb to organic matter, sulphides and silicates, while Zn is predominantly bound to silicates. In contaminated soils, Cd, Pb and Zn are distributed between the easily and sparingly soluble fractions. Due to the high total Cd, Pb and Zn concentrations in contaminated soil close to the smelter, ! and their high proportions in the easily soluble fraction (80% of Cd, 50% of Pb and 70% of Zn), the soil around smelters represents an environmental hazard.     

提取、纯化沉积物中有机磷农药和菊酯类农药的两种程序的比较

Two procedures were compared for extraction and clean-up of 20 organophosphorus and 19 pyrethroid pesticides in sediment to identify the more effective procedure for groups of pesticides or individual compounds. In Procedure Ⅰ, methanol/water and n-hexane were used for extraction, and 1:10 (v/v) dichloromethane in n-hexane and acetone were used as eluents for eluting the analyte through the cartridge, with one evaporating steps on a rotary evaporator and two eluting steps on the cartridge, n-hexane/acetone (2:1, v/v) was used for extraction and elution in Procedure Ⅱ with one evaporating step on a rotary evaporator and one eluting step on the cartridge. All extractions were performed under an ultrasonic bath and gas chromatography and mass spectrometry were utilized for measurements. Procedure Ⅱ was developed as a rapid, timesaving, less costly and safer substitute for Procedure Ⅰ which was an old method. Procedure Ⅱ was more effective for almost all the organophosphorus pesticides tested and 11 of the 19 pyrethroid pesticides, while Procedure I was more appropriate for analysis of 5 pyrethroid pesticides. However, recoveries of most pyrethroid pesticides were fairly low. Thus, further studies should focus on adjustment and formulation of solvents for more efficient extraction and clean-up of pyrethroid pesticides from sediment samples.