2,4-D/CMC接枝物纳米粒子的制备与缓释性能研究

以羧甲基纤维素钠（CMC）为基材，甲基丙烯酸甲酯（MMA）和二甲基二烯丙基氯化铵（DMDAAC）为改性单体，通过乳液聚合制备了CMC-g-P(MMA-DMDAAC)共聚物，采用自组装方法负载2,4-二氯苯氧乙酸（2,4-D）得到2,4-D/CMC-g-P(MMA-DMDAAC)纳米药物缓释体系。利用傅里叶红外光谱（FTIR）、差示扫描量热法（DSC）、热重分析（TGA）、扫描电镜（SEM）、粒度分析仪对其结构和形貌进行表征，并探究其载药性能和缓释性能。结果表明，2,4-D/CMC-g-P(MMA-DMDAAC)载药粒子呈笼状结构，粒度分布为160～425 nm；其载药率随着CMC∶MMA∶DMDAAC的摩尔比增大而提高，最高可达40.8%；其药物累计释放率随CMC∶MMA∶DMDAAC的摩尔比增大而降低，其释放行为符合Weibull模型，遵循Fick扩散机理。     

多孔淀粉在内墙涂料中的应用

本用多孔淀粉和淀粉吸附天然除虫菊酯后加入内墙涂料，通过对两解吸附量、释放时间的比较，说明在内墙涂料中加入杀虫剂的可行性，同时也表明多孔淀粉作为一种新型的吸附和缓释剂，有着广泛的用途。     

Insect sex pheromones

The half-lives (t _1/2) for evaporative loss ofn-alkyl andn-alkenyl acetates from rubber septa were determined at temperatures varying from 15 to 35 °C. The changes int _1/2 with temperature gave high correlations with the equation, Int _1/2 = H/RT+y _o where H is the heat of vaporization,R is the gas constant,T is the absolute temperature, andy _o is a constant. Half-lives changed dramatically with temperature and the degree of change with temperature increased with increasing molecular weight. For mixtures, component ratios changed with temperature, but the degree was modest. At 20 °C there was a 7.5-fold ratio oft _1/2 between members of the homologousn-alkyl orn-alkenyl acetates differing by two carbon atoms. The large change int _1/2 with temperature and with number of carbon atoms is a consequence of the thermodynamic relationships and the temperature range of pheromone usage. Therefore, a similar degree of change inf _1/2 with temperature and number of carbon atoms will apply to other formulations of the same type (those in which the rate of evaporation is first order). The values oft _1/2 at 20 °C mainly agreed very well with those reported previously at room temperature. However, our previously reported values for pentadecyl and hexadecyl acetate were revised. Half-lives were shown to depend on the vapor pressure of a compound in the formulation substrate, but not on the vapor pressure of the pure compound.Mention of a commercial or proprietary product does not constitute an endorsement by the USDA.     

Uric Acid: The Sperm-Release Pheromone of the Marine Polychaete Platynereis dumerilii

In the marine polychaete, Platynereis dumerilii, reproductive behavior in the two sexes is synchronized by the consecutive discharge of male and female sex-specific pheromones. After the female releases the eggs into the free water column, immediate fertilization is achieved by several males circling around the eggs emitting sperm clouds. We report the isolation and identification of the sperm-release pheromone present in the coelomic fluid of sexually mature females. Each step in isolation was guided by bioassay. Isolation methods included extraction and solvent partitioning and separation methods included ultrafiltration and high-performance liquid chromatography. Uric acid was identified as the sperm-release pheromone that is discharged by the female with release of the eggs. The threshold concentration for sperm release by males was determined as 0.6 M.     

Effect of alkali and alkaline earth metals on nitrogen release during temperature programmed pyrolysis of coal

Formation of HCN, NH₃, and N₂ during fixed-bed pyrolysis at 10K min⁻¹ has been studied using coal samples after partial demineralization followed by addition of metal hydroxides from aqueous systems. Without additives, NH₃ is the predominant product at ≤ 700°C, showing the two peaks in the formation rate profile, whereas N₂ is the only product at ≥ 800°C. The presence of NaOH, KOH and Ca(OH)₂ promotes considerable NH₃ formation between 450 and 600°C, but in contrast suppresses HCN formation in this region. The Ca shows the largest effect on both the promotion and suppression. It is likely that the NH₃ increased by Ca addition arises partly from HCN, but mainly from secondary reactions of tar-N. These hydroxides affect N₂ formation in quite different manners: the Na decreases the rate between 700 and 950°C, and the K changes it less significantly than the Na, but the Ca remarkably increases the rate in a low temperature region of 550–700°C. These different features are discussed in terms of solid-phase reactions of alkali metal carbonates with char-N and secondary decomposition reactions of tar-N on CaO particles. As a result, total conversion of coal-N to HCN, NH₃ and N₂ up to 1000°C increases in the sequence of Na < none < K < Ca.     

日用陶瓷铅溶出量与儿童多动症关系的探讨

根据目前日用陶瓷铅溶出量状况和铅中毒儿童多动症的研究结果，论证了日用陶瓷铅溶出量与儿童多动症存在相互关系，介绍了日用陶瓷铅溶出量与铅中毒检测方法，对铅中毒儿童多动症的预防和治疗提出了建议。     

Failure load prediction of structural adhesive joints : Part 2: Experimental study

The objective of this study was to determine how the fracture of adhesive joints depends on elastic beam parameters describing the adherends and the applied loads. The basic specimen geometry was the cracked lap shear joint constructed of aluminium alloy with various adherend and bondline thicknesses. Loads were applied in different combinations of bending, tension and shear to generate a failure envelope for each adhesive and specimen geometry. It was found that crack propagation for precracked specimens occured at a critical strain energy release rate but was also a function of the G_I/G_II ratio and the bondline thickness. The experiments also showed that the loads required to propagate a crack in a precracked specimen were always lower than the loads required to break the fillet. Hence, by treating uncracked joints as being cracked, where the fictitious crack tip is assumed to coincide with the location of the fillet, a conservative estimate of the failure load is obtained.     

Compositional analysis of biodegradable polyphosphoester copolymers using nmr spectroscopic methods

The chemical composition and quantitative molar ratios among all components of biodegradable polyphosphoester copolymers of DL ‐lactide and ethylphosphate were determined by a comprehensive set of NMR spectroscopic methods. The polyphosphoester copolymers studied were synthesized using condensation polymerization of oligomeric DL ‐lactide prepolymers and ethyl dichlorophosphate. Conclusive identification of the chemical shift patterns of all functional groups in the copolymers required additional NMR methods such as ³¹P‐NMR and two‐dimensional ¹H–¹H COSY NMR, in addition to the synthesis and comparative NMR analysis of model compounds possessing identical phosphoester linkages in the polyphosphoester copolymers. For the polymers synthesized using the bulk polycondensation process, ¹H–¹H COSY NMR analysis revealed the presence of a small amount of side products that were undetected by ¹H‐NMR alone. These side reactions most likely occurred between the pendant ethoxy group of the phosphoesters and the hydrogen chloride gas generated in the bulk polycondensation process. ³¹P‐NMR spectra of the copolymers revealed a consistent triple‐peak pattern characteristic of phosphoesters linked to a racemic mixture of D,L ‐lactides. These results offered new insight into the side reactions occurring in bulk polymerization of polyphosphoesters and provided a powerful tool of characterizing complex biodegradable polymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 4021–4031, 2003     

包膜控释肥料研究与产业化开发

从控释和缓释肥料提高肥料利用率的基本原理出发，对国际肥料工业协会(IFA)提出的和国际上公认的肥料养分释放、缓释、控释、控释肥、缓释肥和稳定性肥料的概念和定义进行了讨论和认定。介绍了山东农业大学主持承担的国家“948”项目、农业部跨越计划项目和山东省优秀中青年科学家科研奖励基金项目——包膜控释肥研究与开发的进展情况，包括包膜控释肥的包膜材料与工艺流程的选择、研制的包膜控释肥生产设备、开发出的控释肥系列品种、控释肥的质量检测标准、控释肥在多种作物上的应用效果，并分析了控释肥的经济、社会、生态效益及推广应用前景。     

国内外缓释／控释肥料标准概况

为提高化肥利用率,国内外都致力于缓释/控释肥料的研究、产业化,为规范产业化行为,急需制定符合中国国情的缓释/控释肥料标准,为此,将国内外缓释/控释肥料标准的情况作一介绍。