农药残留薄层色谱分析中的显色技术

农药残留特别是剧毒有机磷农药残留一直是国内外农药科技工作者比较关注的一个课题。显色技术是农药残留薄层分析技术发展迅速的关键 ,对显色技术作了较为系统全面的介绍     

Physical properties of polycaproamide/cationic dyeable poly(ethylene terephthalate) polyblended fibers

Polycaproamide (PCA) and cationic dyeable poly(ethylene terephthalate) (CDP) polymers were blended mechanically (in ratios of 75/25, 50/50, and 25/75) in a melt twin‐screw extruder to prepare three PCA/CDP polyblended materials. The blends of PCA and CDP were spun into fibers. The molar ratio of dimethyl 5‐sulfoisophthalate sodium salt for CDP was 2%. This study investigated the physical properties of PCA/CDP polyblended fibers with nuclear magnetic resonance, gel permeation chromatography, gas chromatography, potentiometer, differential scanning calorimetry (DSC), thermogravimetric analysis, scanning electron microscopy (SEM), extension stress–strain measurements, density gradient analysis, and rheometry. The experimental results of DSC proved that PCA and CDP formed an immiscible system. In an SEM image of a 50/50 PCA/CDP blend, the morphological aggregation of a larger size, from 3 to 5 μm in diameter, was observed. The rheological behavior of the PCA/CDP polyblended materials exhibited negative‐deviation blends, and the 50/50 blend of the PCA/CDP polyblended fibers showed a minimum tenacity value. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1710–1715, 2004     

A203型低温氨合成催化剂使用小结

对Ａ２０３型低温氨合成催化剂的使用进行总结，介绍了该催化剂的装填，升温还原情况及使用效果。     

固体三元稳态ClO2急性经口、遗传及蓄积毒性研究

固体三元稳态二氧化氯是为了解决二元产品活动化率低、活化酸度高、活化损失大的缺点而研制出的新型固体ClO2产品。通过对其急性经口毒性、遗传毒性及蓄积毒性的试验研究，发现雌雄小鼠的急性经口LD50值均大于21．5g/kg，该产品属于实际无毒级；剂量达5．00g/kg，未检出对雌雄小鼠骨髓嗜多染红细胞的诱变活性；给药20d后，动物死亡仍未足半数，K＞5，该产品为弱蓄积性。     

Synthesis and characterization of a new water-soluble endohedral metallofullerene for MRI contrast agents

Water-soluble amino acid derivatives of gadolinium (Gd) endohedral metallofullerenes (AAD-EMFs), Gd@C₈₂O_m(OH)_n(NHCH₂CH₂COOH)_l (m ≈ 6, n ≈ 16 and l ≈ 8) are synthesized by a direct reaction of the pure endohedral metallofullerene Gd@C₈₂ with an excess of alkaline solution of β-alanine. The structure of the AAD-EMFs is characterized by FTIR, XPS and laser-desorption time-of-flight (LD-TOF) mass spectrometries. Water proton relaxivity analysis indicates that the longitudinal relaxivity R₁ (the effect on 1/T₁, 9.1 mM⁻¹ s⁻¹) of AAD-EMFs is higher than that of the commercial MRI contrast agent, Magnevist (gadolinium-diethylenetriaminepentaacetic acid, Gd-DTPA, 5.6 mM⁻¹ s⁻¹). The MRI phantom studies are performed to confirm the high efficiency of this sample as MRI contrast agents.     

硫酸氢钠催化合成苯甲酸正丁酯的研究

以硫酸氢钠为催化剂，催化合成了苯甲酸正丁酯，并用正交实验法确定了反应的最佳条件：催化剂用量为0．6g／0．1mol苯甲酸，醇酸物质的量比为2：1，回流时间为3．5-4．0h。苯甲酸的酯化率可达98％。该催化剂催化效果好，用量少，酯化率高，污染小，价廉易得，具有工业应用价值。     

热塑性淀粉／聚己内酯共混物的制备和性能的初步研究

利用热塑性淀粉（TPS）与聚己内酯（PCL）熔融共混并挤出可用来制备完全可生物降解的塑料，研究表明，组分PCL以及增塑剂水和甘油的含量对体系的力学性能和耐水性有显著的影响。     

肥皂霜的成分分析及成因研讨

采用红外光谱、气相色谱 ,X-射线能谱、原子吸收光谱、紫外分光光度法及化学法分析了肥皂霜中脂肪酸盐、硅、磷、碳酸盐等成分。其结果如下 :RCOONa:94.82 %;Si O2 :2 .43%;PO3-4:0 .40 %;Na2 CO3:1 .0 8%、水份及挥发物余量。依据测试结果 ,对肥皂冒霜的原因进行了探讨     

40%乙·二·扑乳油的气相色谱分析

4 0 %乙·二·扑乳油是以乙草胺、2 ,4 -滴丁酯和扑草净为有效成分复配加工而成的新型除草制剂。本文提出了测定其有效成分的气相色谱分析方法。此法快速、准确 ,为控制乙·二·扑乳油的产品质量提供了准确的分析数据     

State space approximation for general fractional order dynamic systems

Approximations for general fractional order dynamic systems are of much theoretical and practical interest. In this paper, a new approximate method for fractional order integrator is proposed. The poles of the approximate model are unrelated to the order of integrator. This feature shows benefits on extending the algorithm to the systems containing various fractional orders. Then a unified approximate method is derived for general fractional order linear or nonlinear dynamic systems via combining the proposed new method with the distributed frequency model approach. Numerical examples are given to show the wide applicability of our method and to illustrate the acceptable accuracy for approximations as well.