水胺硫磷在白菜上的残留动态

本文报道了水胺硫磷农药在白菜上的残留动态，根据田间试验数据推导出该农药消解过程中的数学模式，该模式表明水胺硫磷在白菜上存在两个速率不同的消解阶段，白菜中水胺硫磷残留量与喷药量和喷后间隔期有密切关系，本研究采用气相色谱法测定水胺硫磷农药残留，方法灵敏度为0．015ppm，添加回收率大于90％。     

新杀菌剂杀枯肽和叶枯宁防治水稻细菌性条斑病的效果

通过室内离体测定和盆栽稻株上的防病效果试验结果表明,新杀菌剂枯肽和叶枯宁两种药剂是防治水稻细菌性条斑颊的安全,高效药剂,在喷药接菌后１３天,５００ｐｐｍ浓度的防病效果为１００％,到２０天时杀枯肽还有４５．６５％的防病效果,喷药后观察对水稻安全无药害。同时指出离体测定的抑菌效果和稻株上的防病效果不一致,因此,筛选防治水稻细菌性条斑病的药效测定方法应以盆栽稻株测定为主。     

喹硫磷防治菜青虫的试验研究

1985～1987年,我们开展了用喹硫磷(供试药剂为嘉兴农药厂生产的25％喹硫磷乳油)防治菜青虫的试验研究,并在大田防治中广泛应用,取得了良好效果,现将结果简要报告如下。一、室内试验 1.杀卵效果用不同浓度药液浸卵、蘸药点卵、喷雾三种方法处理,效果都很好,浓度为1000～2000倍的,杀卵效果都达100％,3000～5000倍的效果各重复平均都在93.1～98.2％之间。为明确残留杀卵效果,分期喷药,同日接成虫产卵。结果表明:喷药第3天接卵,效果即明显下降。喷药当天接卵,效果为83.3％,第二天接卵为75.5％,第3天为32.8％,     

恒温热分离称重法测定火药包覆材料有机玻璃中的硝化甘油

提出了一种试样无需分离，测定简便快速，称为恒温热分离称重法的测定火药包覆材料中硝化甘油含量的新方法，并应用于有机玻璃中硝化甘油浓度分布的测定。对于５ｍｇ的试样，当硝化甘油浓度为４０％－１％时，５次测定的标准偏差约为０．４％。不仅可用无ＤＴＧ的热天平，而且也可用其它常用热分析仪进行热分离，在与十万分之一的天平配合后，即能直接测定包覆材料中硝化甘油的含量。     

降解菌对菠菜和土壤中氯氰菊酯残留动态的影响

通过盆栽实验,测定降解菌对菠菜体内和土壤中氯氰菊酯残留动态的影响.结果表明:在菠菜和土壤中,氯氰菊酯的残留呈现先上升后下降的过程,在喷药后3～6 h菠菜和土壤中氯氰菊酯含量达到最大值,3 h后开始逐渐减少,到24 h以后,菠菜中氯氰菊酯的含量低于1 mg/kg,达到叶菜类蔬菜氯氰葡酯农药残留的最大残留量标准;其中,具有内生性的菌株Y3对菠菜中的氯氰菊酯降解作用非常明显,而不具有内生性的菌株T1对菠菜中的氯氰菊酯降解作用就很少.     

克螨特药效试验初报

为了解克螨特防治害螨的有效浓度和剂量,我们进行了不同浓度的防效试验。现将试验结果整理如下。一、对柑桔红蜘蛛的试验 1.室内试验:在未喷药的柑桔园选取健康雌成螨,移植于培养皿的温州蜜桔叶片上,按处理用手持喷雾器喷药,并用20％三氯杀螨醇1000倍液和不喷药作对照。喷药24小时后用手提扩大镜检查死、活螨数,计算死亡率,并用Abbott公式计算杀螨效果。喷药24小时后的杀螨效果:73％克螨特乳油2000、3000、4000倍液均达100％,而20％三氯杀螨醇1000倍液为98.82％。     

苦豆子总碱对菜青虫的防效及对青菜品质的影响

为了探讨苦豆子总碱对菜青虫的防效及其对蔬菜品质的影响,2004年通过田间试验进行了初步研究。结果表明：喷施苦豆子总碱200mg/L后对菜青虫的防效达81．1％;喷药各处理均未检出苦豆子总碱的残留;叶绿素含量平均提高到对照的1．6倍;植株内亚硝酸盐含量明显下降;维生素C含量呈现先下降后提升的变化趋势。     

毛细管气相色谱法分析中药半夏中有机氯农药的残留

采用毛细管气相色谱法测定半夏中8种有机氯农药的残留量。经HP-5石英柱程序升温技术分离，电子捕获检测器检测，外标法计算含量。该方法对8种有机氯农药的平均回收率为85．5％～97．3％RSD为3.38％～4．56％；本方法快速、简便、准确，具有良好的通用性，可用于半夏中8种有机氯农药残留量的测定。     

气相色谱法测定推进剂药浆中的残留丙酮含量

采用气相色谱外标法对推进剂药浆中的残留丙酮含量进行了定量测定。结果表明,该方法能够准确地测定推进剂药浆中的残留丙酮含量,方法的平均回收率为93．5％-97．0％,相对标准偏差RSD不大于4％,适合于推进剂药浆中残留丙酮含量的测定和监测。     

顶空气相色谱测定草酸酯溶液中甲苯的残留含量

采用静态顶空气相色谱法对草酸酯溶液中甲苯残留含量的测定进行了研究。用气相色谱仪法，HP-5毛细管柱，自制顶空取样瓶，确定平衡时间30分钟，平衡温度110℃，测定了草酸酯溶液中甲苯的残留含量，方法的加标回收率为91．0％。     

Physico-chemical and microbiological evaluation of UHT milk commercialized in three Mercosul countries (Brazil, Argentina and Paraguay)

With the aim to evaluate the physico-chemical and microbiological quality of UHT milk commercialized in three countries of Mercosul, samples of four different brands were acquired in each city (Foz do Igua?u-Brazil, Puerto Iguazú-Argentina and Ciudad del Este-Paraguay) and submitted to the following analysis: fat content, titratable acidity, milk ethanol stability (with the following ethanol concentrations: 68, 72, 76 and 80%), total dry extract and no fat dry extract, pH, density and freezing point. Counts of mesophilic and psychrotrophic microorganisms were already done. In the physico-chemical evaluation of UHT milk, a significant number of samples were in disagree with the established patterns for fat content, no fat dry extract, density and freezing point. Except one brand from Brazil, milk samples showed stability to 68% ethanol. pH averages of Brazilian milk were in agree with the patterns and highest values were observed in samples acquired on Paraguay. Observing the microbiological analysis, 37.5%, 62.5% and 12.5% of samples acquired from Brazil, Argentina and Paraguay, respectively, showed counts above the established patterns for mesophilic microorganisms. Counts of psychrotrophic microorganisms were in disagree with the established patterns in 50%, 50% and 100% of samples from Brazil, Argentina and Paraguay, respectively.     

利用泥鳅红细胞微核及核异常测定法对四种除草剂遗传毒性的研究

采用红细胞微核和核异常测试法,研究了除草剂精禾草克、氟乐灵、扫特、2甲4氯钠盐水剂对泥鳅红细胞的遗传毒性。泥鳅在各除草剂试验液中染毒24h,采血制片。结果表明,四种除草剂均不同程度地引起微核细胞率和核异常细胞率等遗传指标的上升,其中部分浓度组较对照组差异显著(P<0.05)或极显著(P<0.01)。除草剂浓度与微核率或核异常率无显著相关,不表现剂量效应关系。四种除草剂对泥鳅红细胞具有明显的诱变效应,其中扫特的诱变效应大于其它三种除草剂。     

Synthesis and magnetic properties of nano-sized Cu0.5Ni0.5Fe2O4 via citrate and aloe vera: A comparative study

In this report, Cu_0.5Ni_0.5Fe₂O₄ nanoparticles were synthesized by solgel using eco-friendly aloe vera extract and citric acid separately and their properties were discussed. Structural, Functional, morphological, magnetic properties of the samples were characterized using X-ray diffraction (XRD), Fourier transform infrared (FT-IR), Transmission electron microscopy (TEM), Vibrating sample magnetometer (VSM). XRD exhibited the samples have single phase cubic spinel with average size of 46.4?nm and 35.45?nm. Two characteristics bands of ferrite were confirmed by FTIR. TEM indicated different morphology of the samples with some regularity. VSM data showed that higher coercivity for the sample prepared by aloe vera extract.     

Application of ZnO–NiO greenly synthesized nanocomposite adsorbent on the elimination of organic dye from aqueous solutions: Kinetics and equilibrium

Organic dyes are discharged into aquatic systems from several industries causing severe environmental problems and toxicity to aquatic life. Therefore, it should be removed from water with a suitable process. Among several treatment processes, adsorption is one of the most attractive because of its simplicity, efficiency, and low operating cost. Moreover, adsorption supports environmental sustainability if a suitable adsorbent is used. In this work, a green route was followed to prepare ZnO: NiO nanocomposites using the Neem leaf extract as a stabilizing agent instead of harmful chemicals. Four different samples with three different ZnO:NiO ratios were prepared, namely: 3Z:1 N, 1Z:1 N, 1Z:3 N and 1Z:1 N without extract. The samples were characterized by XRD, TEM, SEM, IR, and UV, which all confirmed the successful synthesis of the nanocomposites. The nanocomposites were used for the adsorption of methyl orange (MO) from aqueous solutions. The four nanocomposites prepared with the aid of the extract showed a high sensitivity with 100% removal of MO from 6.25 ppm solutions. Furthermore, all the samples have a relatively fast kinetic with an equilibrium time less than 1 h. Also, the three samples maintained 100% removal efficiency after 5 adsorption-desorption cycles. The difference in particle size distribution obtained for the 1Z:1 N prepared with and without the extract confirms the important rule of the extract as a capping agent with an average size of 18 nm for the sample with the extract and 88 nm for the sample prepared without the extract. This difference in the particle sizes has been reflected on the adsorption performance of the two samples with a maximum adsorption capacity of 33 mg/g for the sample prepared with the extract compared to 6 mg/g for the sample without the extract.     

3-Pentanol: A New Attractant Present in Volatile Emissions from the Ambrosia Beetle, Megaplatypus mutatus

Megaplatypus mutatus (=Platypus mutatus) (Coleoptera: Platypodidae) is an ambrosia beetle that is native to South America. It attacks only standing live trees and causes severe stem breakage and death in commercial poplar (Populus) plantations. Previous work showed that male M. mutatus emits a sex pheromone composed mainly of (+)-sulcatol and sulcatone. We collected male volatile emissions during the hours of maximum emergence by using a specific polar microextraction phase; analyzed the extract by GC-MS; and tested the biological activity of selected compounds in the extract with a walking behavioral assay. Female M. mutatus emerged primarily between 7 and 11 h. In the chemical analyses of volatiles, a third compound, 3-pentanol, was identified in a small percentage of samples. Walking behavioral bioassays with video image analysis showed that at the doses tested, 3-pentanol elicited an attractive response from females.     

Physical and chemical properties of powder produced from spray drying of inulin component extracted from Jerusalem artichoke tuber powder

In this study, inulin was extracted from Jerusalem artichoke tuber (JAT) powder and then concentrated before spray drying. The aims of this study were to (1) determine the drying condition that provided high powder yield together with superior qualities of JAT inulin powder and (2) investigate the chemical and physical properties of inulin powder. The inulin extracts at different concentrations of 10, 20, and 30 °Brix were spray-dried and then compared. The spray drying experiments were conducted at the inlet/outlet air temperatures of 150/90, 170/90, and 190/90?°C for the chosen concentration of inulin extract. It appeared that spray drying of the 30 °Brix extract at the inlet/outlet drying air temperatures of 190/90?°C resulted in the highest value of powder recovery, bulk density, water solubility and the lowest moisture content and hygroscopicity in comparison with its counterparts. SEM micrographs showed that the powder produced by this condition was more stable and less sticky than others. The sugars, total fructo-oligosaccharides (1-kestose, nystose, and 1^F-β-fructofuranosyl nystose) and inulin-type fructans contents of powder were 12.88, 11.12, and 64.36?g/100?g of powder, respectively. The moisture sorption data and models developed in this work could be used for determining the suitable condition of surrounding air for inulin powder storage.     

Antioxidant activity of tea extracts in lipids and correlation with polyphenol content

The present study examined the antioxidative activity of water and ethanol extracts of green and black tea leaves against the oxidation of heated sunflower oil and lard. Oxidation was conducted at 110 °C in the Rancimat test. Total polyphenols and catechin contents in tea extracts were measured. The research showed that the total polyphenol content in green and black tea leaves was 205.2 and 148.7 mg/g, respectively. In tea leaves extracts, it ranged between 245.9 mg/g and 837.7 mg/g and depended on the extraction solvent and the kind of tea used (p <0.001). The highest polyphenol content was observed in samples extracted with 95% ethanol, lower contents were found with the use of water. Results showed that the highest antioxidant activity, measured as an induction period, with 1000 ppm green tea ethanol extract, was comparable to á‐tocopherol activity in sunflower oil. In lard, the longest induction period was measured with 500 and 1000 ppm of green tea ethanol extract. Other tea extract concentrations were significantly less active. Statistical analysis of the tea extract antioxidant activity in lipids in the Rancimat test showed an essential influence of the catechin contents. Further statistical analysis also showed an influence of (?)‐epicatechin gallate (ECG), (?)‐epicatechin (EC), and (+)‐catechin (C) contents in the tea extracts on the antioxidant activity in lipids. It was stated that the antioxidant activity was higher in tea extracts containing high levels of ECG, EC, and C.     

不锈钢缩放管中典型致垢微生物致垢能力

以电厂循环冷却塔塔底黏泥中分离纯化出的3种致垢微生物铁细菌（IB）、硫酸盐还原菌（SRB）、黏液形成菌（HB）为实验菌种,利用污垢热阻动态模拟实验台,在恒定工况下（水温30 ℃,流速0.4 m/s）,动态模拟了3种致垢菌及其混合菌的微生物污垢形成过程。实验测得了3种致垢菌和混合菌的污垢热阻,并对垢样成分进行了ICP-MS和阴离子分析。结果表明：污垢诱导期分别为28 h、45 h、70 h和18 h;污垢热阻渐近值为2 10?4 m2?K/W、1.75 10?4 m2?K/W、1.45 10?4 m2?K/W和4.9 10?4 m2?K/W。由此表明致垢菌的致垢能力大小为：混合菌＞IB＞SRB＞HB。垢样成分分析结果表明：IB垢样成分分析中Fe、C和NO3?含量较多,而重金属离子及Cl?含量较少,说明其具有较强的致垢能力而腐蚀能力较弱;SRB垢样分析显示,S、Fe及Cl?相对较高,且重金属Ni、Cr含量较多,说明其致垢的同时具有较强的腐蚀特性;HB形成的污垢主要以C、N及NO3?为主,且含有一定量的Cl?,表明此菌也具有一定的腐蚀性质。     

Na2CO3处理制备复合孔ZSM-5分子筛及其丙烷脱氢制丙烯的催化性能

通过不同浓度的Na₂CO₃溶液处理合成的HZSM-5分子筛,并采用X射线衍射、N₂低温物理吸附和X射线荧光光谱分析仪对溶液处理前后的样品进行了表征。表征结果显示,适量浓度的Na₂CO₃溶液处理HZSM-5,能够形成介孔-微孔复合孔道,增加了分子筛介孔容积和外比表面积;同时不会明显破坏HZSM-5的MFI结构,从而保持较好的高温热稳定性。在上述碱处理后的载体上制备了Pt-Sn-K/HZSM-5分子筛催化剂,并在固定床反应器上考察了丙烷脱氢制丙烯的催化活性。结果表明,随着Na₂CO₃溶液浓度的增加,催化剂的初始活性增加,而稳定性先增加后减少。当采用Pt-Sn-K/HZSM-5（1.8）分子筛催化剂用于丙烷脱氢反应,其呈现了良好的脱氢活性和稳定性：反应100h后,其丙烷化率为35.53%,相比初始活性仅下降了2.8个百分点,丙烯选择为98.4%,基本保持不变。