Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions

The hydrolysis/precipitation behaviors of Al3+, Al-13 and Al-30 under conditions typical for flocculation in water treatment were investigated by studying the particulates' size development, charge characteristics, chemical species and speciation transformation of coagulant hydrolysis precipitates. The optimal pH conditions for hydrolysis precipitates formation for AlCl3, PAC(A113) and PAC(A130) were 6.5-7.5, 8.5-9.5, and 7.5-9.5, respectively. The precipitates' formation rate increased with the increase in dosage, and the relative rates were AlCl3 >> PAC(A130) > PACA113. The precipitates' size increased when the dosage increased from 50 mu M to 200 mu M, but it decreased when the dosage increased to 800 AM. The Zeta potential of coagulant hydrolysis precipitates decreased with the increase in pH for the three coagulants. The isoelectric points of the freshly formed precipitates for AlCl3, PAC(A113) and PAC(A130) were 7.3, 9.6 and 9.2, respectively. The Zeta potentials of AlCl3 hydrolysis precipitates were lower than those of PAC(A113) and PAC(A130) when pH > 5.0. The Zeta potential of PAC(A130) hydrolysis precipitates was higher than that of PACA113 at the acidic side, but lower at the alkaline side. The dosage had no obvious effect on the Zeta potential of hydrolysis precipitates under fixed pH conditions. The increase in Zeta potential with the increase in dosage under uncontrolled pH conditions was due to the pH depression caused by coagulant addition. Al-Ferron research indicated that the hydrolysis precipitates of AlCl3 were composed of amorphous AI(OH)3 precipitates, but those of PACA113 and PACA130 were composed of aggregates of Al-13 and Al-30, respectively. Al3+ was the most un-stable species in coagulants, and its hydrolysis was remarkably influenced by solution pH. Al-13 and Al-30 species were very stable, and solution pH and aging had little effect on the chemical species of their hydrolysis products. The research method involving coagulant hydrolysis precipitates based on Al-Ferron reaction kinetics was studied in detail. The Al species classification based on complex reaction kinetic of hydrolysis precipitates and Ferron reagent was different from that measured in a conventional coagulant assay using the Al--Ferron method. The chemical composition of Al-a, Al-b and Al-c depended on coagulant and solution pH. The Al-b measured in the current case was different from Keggin Al-13, and the high Alb content in the AlCl3 hydrolysis precipitates could not used as testimony that most of the Al3+ Was converted to highly charged Al-13 species during AlCl3 coagulation.

On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants

The acid-base stabilities of Al-13 and Al-30 in polyaluminum coagulants during aging and after dosing into water were studied systematically using batch and flow-through acid-base titration experiments. The acid decomposition rates of both Al-13 and Al-30 increase rapidly with the decrease in solution pH. The acid decompositions of Al-13 and Al-30 with respect to H+ concentration are composed of two parallel first-order and second-order reactions, and the reaction orders are 1.169 and 1.005, respectively. The acid decomposition rates of Al-13 and Al-30 increase slightly when the temperature increases from 20 to ca. 35 A degrees C, but decrease when the temperature increases further. Al-30 is more stable than Al-13 in acidic solution, and the stability difference increases as the pH decreases. Al-30 is more possible to become the dominant species in polyaluminum coagulants than Al-13. The acid catalyzed decomposition and followed by recrystallization to form bayerite is one of the main processes that are responsible for the decrease of Al-13 and Al-30 in polyaluminum coagulants during storage. The deprotonation and polymerization of Al-13 and Al-30 depend on solution pH. The hydrolysis products are positively charged, and consist mainly of repeated Al-13 and Al-30 units rather than amorphous Al(OH)(3) precipitates. Al-30 is less stable than Al-13 upon alkaline hydrolysis. Al-13 is stable at pH < 5.9, while Al-30 lose one proton at the pH 4.6-5.75. Al-13 and Al-30 lose respective 5 and 10 protons and form [Al-13] (n) and [Al-30] (n) clusters within the pH region of 5.9-6.25 and 5.75-6.65, respectively. This indicates that Al-30 is easier to aggregate than Al-13 at the acidic side, but [Al-13] (n) is much easier to convert to Alsol-gel than [Al-30] (n) . Al-30 possesses better characteristics than Al-13 when used as coagulant because the hydrolysis products of Al-30 possess higher charges than that of Al-13, and [Al-30] (n) clusters exist within a wider pH range.

5-氨基乙酰丙酸对日光温室番茄生长发育和产量品质的影响

为外源5-氨基乙酰丙酸(ALA)在日光温室蔬菜上的应用提供科学依据。【方法】研究了不同浓度ALA处理对日光温室番茄生产的影响。【结果】ALA以及ALA+N叶面施用均明显提高了番茄植株株高、叶绿素相对含量和果实产量,并改善了番茄果实品质;与对照相比,外源ALA各处理植株株高、叶绿素相对含量和单株生物产量均有明显提高,其中D处理(ALA1号肥料第1次2 kg/hm2,第2~4次1 kg/hm2)效果最佳,植株株高、叶绿素相对含量及单株生物产量分别提高27.18%,17.75%和13.93%;外源ALA对番茄果实产量和品质也有明显的提高和改善作用,其中处理B(ALA1号肥料第1次0.5 kg/hm2,第2~4次0.3 kg/hm2)对果实产量效果最明显,处理E(ALA3号肥料第1次2.5 kg/hm2,第2~4次1.5 kg/hm2)对果实品质效果最佳。【结论】处理E(ALA3号肥料第1次2.5 kg/hm2,第2~4次1.5 kg/hm2)既有利于番茄生长发育,又能增加产量并改善品质,为最佳的ALA施用量及方法。

含硒抗体酶及酶法合成~（13）C尿苷二磷酸葡萄糖

胞质谷胱甘肽过氧化物酶（cGPX）是生物体内重要的抗氧化含硒酶，在保护机体免受活性氧损伤方面起着重要作用，因此利用抗体酶技术进行cGPX的人工模拟具有重要意义。本文在疏水腔修饰法指导下，设计合成了两种新的具有GSH特征的半抗原Hp4和Hp5。通过单克隆抗体及化学诱变技术制备得到三种针对半抗原Hp4的含硒抗体酶和两种针对Hp5 特异的含硒抗体酶。其中SeHB5(1867 U/μmol)和SeIA7（3567U/μmol）活力达到和天然酶同一数量级，进一步验证了疏水腔修饰法。本文还对含硒抗体酶SeHB5和SeIA7的酶学性质进行了系统的研究。生物活性实验表明含硒抗体酶对不同浓度H_2O_2损伤的小鼠心肌细胞均有一定程度的保护作用。本文同时报道了三种硒代β-环糊精作为cGPX模拟物的活力，其中6,6'-(O-亚苯基）二硒基桥联-β-环糊精二聚体的活力超过目前被认为最理想的补硒试剂Ebselen。~（13）C标记UDPG在利用核磁手段发现新的UDPG依赖糖基转移酶和检测新的糖基化合物，确定糖基间连接方式，合成同位素标记寡糖和多糖等方面具有广阔的应用前景。本文首次从植物培养细胞Rauvolfia serpentina经四步纯化得到具有一定纯度的UDPG焦磷酸化酶，并应用该酶建立了经济，简便，高产率的从葡萄糖出发，酶法大量合成UDPG的方法。利用该方法首次合成得到0.5克级的UDP-[4-~（13）C]-glucose，产率高达～70%。在NMR谱学方面确定了UDPG中葡萄糖基上4位C的归属，从而纠正了文献中关于UDPG核磁谱归属中的部分错误。

聚丁二烯的序列结构Ⅰ. ~(13)C-NMR研究聚丁二烯的序列结构 Ⅱ. 1,2-聚丁二烯的构象分析

本文详细分析了聚丁二烯分子链的序列结构，以聚丁二烯的(13)C-NMR波谱测试为依据，划分聚丁二烯分子链为三种序列、十七类脂碳碳核。在此基础上发现并论证了T_4碳核的存在，同时在聚丁二烯的~(13)C-NMR谱图上确认了与之对应的共振吸收峰－T_4峰。通过处理谱峰化学位移数据，得到一组计算聚丁二烯~(13)C-NMR谱图脂碳部分各谱峰化学位移的经验参数。应用这一组参数于聚丁二烯的~(13)C-NMR谱图（脂碳部分），各谱峰化学位移的计算值和实验值有良好的一致性。但是，与聚丁二烯分子链的1,2－序列两端的四类碳核：C_4、T_4、V_2和V_8相对应之谱峰的化学位移，其实验值一致地大于计算值而趋向低场方面，为深入研究聚丁二烯的链结构提供了有价值的情报。本文还讨论了对于4'峰和8'峰的归属，并对定量表征聚丁二烯分子链的序列结构进行了初步尝试。

全同1，2－聚丁二烯的合成及用~(13)C-NMR方法研究1，2－聚丁二烯的序列结构

采用Cr／Al催化体系，成功地合成了全同1，2－聚丁二烯（PBD），并用DSC方法、X－射线衍射、红外光谱及~(13)C－NMR的方法进行结构与物性测定，得如下结果：全同1，2－PBD的熔点为124.3℃；三角晶系中，分子链成了螺旋，晶胞参数为a＝17.3A，c＝ 6.5A；在红外光谱中，其特征谱带出现在694.4 cm~(-1)处；在~(13)C－NMR谱中仅出现四条谱峰，其化学位移分别为142.51、111.56、39.26、37.43 ppm。全同1，2－PBD的~(13)C－NMR谱提供的实验数据表明，在~(13)C－NMR谱中1，2－PBD－CH二碳十个五元组谱峰的归属是有别于Elgert、Kumar已有的归属。它属于一种新的归属，与半经验方法所推演的结果相符。它恰巧同聚丙烯侧甲基五元组谱峰的归属一致。采用半经验方法研究了1，2－PBD的~(13)C－NMR增中CH二碳五元组、CH_2－碳四元组及六元组共振谱峰，同时讨论了模型链的链长、温度以及立构序列的排列对各立构序列键概率的影响，求得了相应的r值。同时采用经验方法对1，2－PBD的~(13)C－NMR谱中CH_2=碳、CH－碳五元组及CH_2－碳四元组谱峰做了归属。两种方法对CH_2－碳谱峰的归属得到了一致的结果。

EV共聚物序列结构的~(13)C NMR研究

本工作以EV共聚物为研究对象，明确地提出了共聚物的序列结构与其~(13)C NMR谱，包括符号表示在内的一致性问题。通过对EVAc共聚物~(13)C NMR谱的分析认为，共聚物的序列结构与其~(13)C NMR谱之间存在着某种内在的联系。我们从EV共聚物序列结构的符号表示和Bovey关系出发，阐述了它们之间的一致性，即一一对应关系，并发现了EV共聚物~(13)C NMR谱的两种类型，提出了利用取代基参数进行EV共聚物~(13)C NMR谱分类的判别标准及其衍生出的两种判别方法，阐述了关于EV共聚物~(13)C NMR谱峰分布的预见性。

南沙群岛海区NS97-13柱样沉积物磁化率各向异性研究

二类水体光学活性成分的复杂性导致了水体光学特性的复杂性。通过对太湖区域

光子晶体波导定向耦合型1×3光分束器

将五光子晶体单模波导平行、邻近放置构成定向耦合器,依据自映像原理,数值分析了输入光场对称入射时,该系统中光的传播行为.基于此结构,设计了1×3光分束器,其器件长度可短至14.26μm.仅仅通过对称地改变耦合区中两个介质柱的有效折射率,使光场在横向发生重新分布,便可实现输出能量的均分或自由分配.通过非对称地改变耦合区中的一个介质柱,可实现3个输出端的输出能量的自由分配.该光分束器具有微小尺寸和各输出端输出能量的比例可自由调制的特点,在未来集成光回路中具有广泛的应用价值.