A method for studying the effect of some organic compounds, which are neither soluble in water nor to be made into soluble salts in water, on DNA has been investigated by a series of experiments. The solubility experiments have shown that dimethyl sulphoxide (DMSO) and its aqueous solution are excellent solvents for the hydrophobic multicycles compounds with nitrogen atoms. The data of UV (298 K), CD (298 K), ~(31)P-NMR (323 K) spectra and molar enthalpy changes (298 K) for the effect of DMSO on DNA have not shown that DMSO has an effect on DNA when the pH of solution is equal to 7.0 and its concentration is less than 0.15 mol·L~(-1). This has further proved it is safe when DMSO is used as a carrier of medicinal compounds and enters into human bodies. Under the fixed experimental conditions, no differences were found out from the results of viscous tests (298 K) and UV spectra (298 K) for the effect of harmine hydrochloride on DNA in the presence and absence of DMSO even if the concentration of DMSO reached 0.5 mol·L~(-1). It has indicated that the existence of DMSO in aqueous solutions doesn't disturb the effect of compounds on DNA. The data of UV (298 K), CD(298 K), ~(31)P-NMR (323 K) spectra and molar enthalpy changes (298 K) for the effect of some multicycles compounds with nitrogen atoms on DNA in aqueous solutions of DMSO have also given a clear explanation to the intercalation bindings of these organic compounds to DNA, and a method to study the effect of these compounds on DNA can be developed from these experiments. By analying all the data for the effect of the above compounds on DNA, both the mechanism of interaction between the compounds and DNA and the relationship between the rule of intercalation binding of a series of compounds with same multicycles structures to DNA and their microstructures have been discussed. Since the two multicycles compounds with nitrogen atoms including harmine have high bioactivity, the further experiments inside animal bodies and clinical trial on patients as anticancer drugs should be carried out.

This note reports a successful preparation of a new catalyst particles through the reaction between Ni~(2+) and H_2PO_2~- in aqueoud solution at room temperature. X-ray diffraction pattern indicates that the particles are in amorphous and alloying state. Transmission electron micrograph shows that the particles are spherical and the size distribution is very narrow. The average diameter of the particles is determined to be about 100 nm which is in“ultrafine”scale.

In this paper, a new way to increase the specific surface areas of supported catalysts has been suggested. The results for MoO_3/ZrO_2, WO_3/ZrO_2, CuO/ZrO_2, SO_4~(2-)/ZrO_2, NiO/ZrO_2, Fe_2O_3/ZrO_2, Fe_2(SO_4)_3/ZrO_2, MoO_3/TiO_2, WO_3/TiO_2, SO_4~(2-)/TiO_2, NiSO_4/TiO_2, NiO/TiO_2, V_2O_5/TiO_2 etc. systems show that the specific surface areas of the samples, prepared by impregnating some hydroxides then calcinating at high temperature, are much larger than those of the samples prepared with a traditional method——impregnating their oxides calcinated at the same temperature. Using this way, the specific surface areas of some supported catalysts can increase by several times. The surface areas of some supports such as zirconia and titania are not large enough, and they are easy to sinter at high temperature. In these cases, the advantage of of this preparation method is fully displayed, and the specific surface areas of the resulting zirconia-or titania-supported catalysts can compare favourably with those of the catalysts prepared from some classical supports (such ar γ-Al_2O_3, SiO_2).
In addition, it has been proved by means of XPS, XRD, LRS, and DTA that as an active component disperse on a support as a monolayer and its content comes up to its monolayer dispersion capacity, the specific surface area of the obtained catalyst would be the largest. We suggest a mechanism that an active component covered on a support can not only segregate its particles, but also hinder the surface diffusion of support, and as a result, its crystalline growth, an accompanying phase transformation and inter-crystalline sintering are all retarded.

WO_3/钛铝胶系列样品通过浸渍法制备. XRD 和XPS 测定结果表明WO_3单层分散在钛铝胶表面, 分散阈值为0.22 g WO_3/(100 m~2). 假定WO_3在钛铝胶表面按照密置单层模型分散, 其计算值为0.198 g WO_3/(100 m~2). 表明测定值与理论模型的计算值相接近. LRS测定表明: 当WO_3的载量低于0.082 g WO_3/(100 m~2钛铝胶)时, 只有四而体配位的钨存在; 当WO_3的载量超过0.082 g WO_3/(100 m~2钛铝胶)时, 钨主要以八面体配位存在. 同时, LRS的实验结果也表明, 550 ℃焙烧的WO_3/钛铝胶样品没有Al_2(WO_4)_3生成. 对高温焙烧条件下, Al_2(WO_4)_3的生成也进行了研究.

用平衡渗析法研究了阳离子聚电解质PAm·MG 和P(St-Am·MG)与甲基橙(MO)及P(St-Am·MG)与MO的同系物乙基橙(EO)、橙武Ⅳ(O-Ⅳ)在25、35、45和55 ℃下相互作用的热力学. 由K1otz方程, 求得键合常数K_1和热力学参数ΔG、ΔH及ΔS. 含疏水基的P(St-Am·MG)与MO的键合能力比不含疏水基的PAm·MG 强. P(St-Am·MG)与不同染料作用时, 键合程度为O-Ⅳ>EO>MO, 即染料的疏水性越强, 与高聚物的作用程度越大.键合体系加入脲或甲醇, 疏水相互作用受到破坏, 导致高聚物与染料之间的键合受到削弱.

在电极表面反应物浓度均匀的近似假设下, 得到了微圆盘电极上暂态可逆反应的一般解. 然后利用该一般解得到了微圆盘电极上耦合一级均相反应的可逆电极反应CE、EC、EC′和ECE 的稳态电流计算公式.

在考虑电极电位、浓度极化等影响因素的情况下, 提出了介体型酶电极响应的数学表达式, 并对吸附法制备的修饰酶电极进行了初步的实验验证和模拟计算, 其实验结果与理论推导是一致的.

在分子结构-生物活性关系(SAR)研究中, 最困难的问题之一是结构特征的计算机化表达和提取. 一种有机小分子二维结构信息数值化的方法——结构框架模型法(SFM)被提出. 该方法根据所研究体系结构变化的范围来定义其分子结构框架模型, 进而对体系中化合物分子结构变化的全部信息进行处理, 得到结构因子矩阵. 介绍了SFM 的概念和方法, 以及SFM 与模式识别相结合用于高效磺酰脲类除草剂生物活性分类和预报研究的初步结果.

制备了NH_4Y、USY、PrHY、USPrHY、F8Y及FSPrHY催化剂, 测定其组成和物性. 于红外光谱装置上比较了上述催化剂羟基峰的异同, 通过对吡啶的吸脱附测定了诸催化剂的酸强度. B 酸强度顺序为: FSPrHY>FSY>USPrHY>USY>PrHY>NH_4Y. ~(29)Sit MAS NMR谱表明, 在USPrHY 及FSPrHY 的Si(0Al)%甚多于PrHY 和NH_4Y中的Si(0Al)%. IR、~(29)Si MAS NMR及活性测试等结果说明: 沸石中0NNN铝位的存在, 是达到强酸性的必要条件. 高价稀土阳离子形成(?)及Pr(OH)~(2+)抵消了方钠石笼中AlO_4~-上的电荷, 增强了剩余铝位上羟基酸强度; 且从骨架羟基上吸引电子, 因而使质子酸性更强, 从而提高了裂解、岐化、脱烷基活性.

进行了在SiO_2担载的Ru-Co双金属原子簇催化剂上合成气(CO+H_2)反应和模型化合物吸附的红外、质谱研究. 结果表明, 在原子簇制备的Ru-Co/SiO_2催化剂上, 在453 K下合成气(CO+H_2)反应在红外谱图产生了1584 cm~(-1)谱带, 它与CO加氢反应中含氧化台物的生成速率成线性关系. 因此提出了此谱峰对应着在CO加氢反应中生成古氧化合物的一个十分重要的中间体. 以CO+D_2、~(13)CO+H_2和~(13)CO+D_2代替CO+H_2, 在Ru-Co/SiO_2催化剂中, 1584 cm~(-1)谱带分别位移至1575、1542和1539 cm~(-1)处. 还观察到, 1584 cm~(-1)物种与H_2反应, 产物给出了CH_4和CH_3OH; 如果1584 cm~(-1)物种和D_2反应则生成CHD_3和CHD_2OD. 这些结果提出了1584 cm~(-1)谱带归属于表面甲酰基的羰基振动, 这同Ru-Co/SiO_2催化剂吸附甲醛的结果基本一致.

应用程序升温还原和化学吸附考察了硫化态Mo/Al_2O_3, Co-Mo/Al_2O_3, Ru-Mo/Al_2O_3, Ru-Co-Mo/Al_2O_3系列催化剂中的钴与钌的助剂作用. 实验结果发现, TPR谱图中Co-Mo/Al_2O_3上的Co 中心的还原峰强度比Co/Al_2O_3上的大大降低, 并且氧在Co-Mo/Al_2O_3上化学吸附量少于分别在Co/Al_2O_3和Mo/Al_2O_3上的吸附量之和, 说明钴和钼发生了相互作用, 可能生成了所滑的CoMoS相, 减少了独立的钴或钼中心. 与Co不同, 在Ru-Mo/Al_2O_3催化剂上助剂钌使得部分高温还原的Mo中心位移到中温区还原, 并且还增加了H_2和O_2在Mo中心上的吸附量, 这表明在硫化和还原过程中Ru促进了Mo中心的还原, 生成了更多的配位不饱和铝中心, 在Ru-Co-Mo/Al_2O_3催化剂上也发现了类似的钌助还原现象, 钉的这种助还原功能可以用氢溢流机理来解释.

用停止流动分光光度法在pH=9.89-10.70范围内, 研究了商铁酸钾氧化乙醇胺反应的动力学及其机理. 研究结果表明: 反应对高铁酸钾和乙醇胺均为一级; 对OH~-为负分数级; 离子强度对速率没有影响. 提出了一个包含有离子与分子间通过氢桥进行双电子转移的反应机理, 由此导出了能圆满解释所有实验事实的速率方程, 并求得了有关的速率常数.

研究了三种摩尔质量大体相同而脱乙酰度分别为93%、78%和62%的甲壳素-壳聚糖在pH=3～6范围内对皂土悬浮液的絮凝性质, 并与非离子型絮凝剂聚丙烯酰胺作了比较, 证明含自由氨基的甲壳素-壳聚糖在酸性溶液中形成阳离子聚电解质后. 对带负电的皂土悬浮颗粒有很好的絮凝能力. 通过对上述三种聚合物的絮凝能力、在皂土颗粒表面的吸附量等测定, 认为絮凝中桥连机制起了主导作用, 但聚合物所带正电荷则有利于被皂土颗粒所吸附, 电中和还降低了颗粒间的静电排斥, 这都对桥连絮凝起了促进作用. 聚丙烯酰胺分子在水中不带电, 故当介质pH升高使皂土颗粒双电层变厚时, 絮凝能力迅速下降.

We have prepared polyamine capsules with ethylenediamine and diethylenetri-amine or their mixtures as aqueous phase monomer, and sebacoyl chloride as oil phase monomer. By using cell-tensiometer, their critical tensile pressures were measured, which could contrast the tensile strength of all kinds of capsules quantitatively. We have also compare the porous properties of the capsules qualitatively by the permeable efficiencies of KCI through the capsule wall. The results showed that the tensile strength and porous properties could be related to the proportion of ethylenediamine to diethylenetriamine monomeres.

The electrochemical roduction of methylene blue has been studied by long path-length thin-layer spectroelectrochemical method. It was found that the reduction of methylene blue at SnO_2 electrode is a two electron transfer reversible process. The standard potential E(?) determined was 0.286 V(vs. SCE). The acid dissociation constants for the leuco methylene blue were obtained as pK_(α1)=5.18, pK_(α1)=6.03. The mechanism of electrode reaction has been proposed.

Procedures have been developed which may yield spherical type bismuth oxych-loride particles with narrow size distribution by forced hydrolysis of bismuth nitrate solutions at elevated temperature. The particle size and shape characteristics in each precipitation region were investigated by electron microscopy. The presence of sur-factants during the precipitation and aging processes has a marked effect on the properties of the sols resulted.

The photocurrent-potential relationship for copper and brass electrodes under periodic illumination was obtained during slow (6 mV·s~(-1)) cyclic potential scans with lock-in amplifier in 0.1 molo·L~(-1) Na_2B_4O_7 contianing variable concentration of NaCl. Only cathodic photocurrent was exhibited on photocurrent vs. potential curves in absence of or in the presence of low concentrations of chloride ion in the solution. The minimum concentration of NaCl at which an anodic photocurrent peak appeared is 7.5×10~(-4) g·g~(-1) for copper and 3.8×10~(-3) g·g~(-1) for brass. With the continuous increase of NaCl concentraton the peak area of anodic photocurrent increases and that of cathodic decreases. The appearance of anodic photocurrent peak and its magnitude on photocurrent vs. potential curve may be served as a criterion for the characterization of the corrosion extent of copper material by Cl~-.

Five kinds of thioether p-CH_3C_6H_4SR (R=n-C_4H_9, C_6H_(13), C_8H_(17), C_(10)H_(21), and C_(12)H_(25)) and their palladium complexes Pd(p-CH_3C_6H_4SR)_2Cl_2 were synthesized. The thermal decomposition of these complexes have been studied by using TG and DTG methods. It was found that the former two of the complexes firstly decompos into organic ligands and PdCl_2, then PdCl_2 to chlorine atoms and palladium; The latter three of complexes decompose into organic ligands chorine atoms and palladium almost simultaneously. Kinetic parameters such as activation energy E, frequency factor A and reaction order n were obtained using the Coats-Redfern and Freeman-Carroll methods. In addition, entropy of activation ΔS has also been calculated.

The monodisperse sol of Cu_2O was prepared by reduction of sulfate copper or acetate copper with glucose, hydroxychloride amine and hydrazine hydrate. The dis-tribution of particle radius is very narrow. Different types of Cu_2O sol can be obtained under different conditions.

The experimental retention time obtained for a series of the different injection concentration are compared to formula related the retention time to injection con-centration, which is derived from the nonlinear chromatography equation. The results show that the theoretical formula is a appropriate approximation to the practical nonliear chromatography.

The isomer conversion of formanilide was investigated by ~(13)C 2D-EXSY NMR, and the conversion rate was obtained by approximation method proposed by ourselves~[5]. Cis-and Trans-isomer coexist at ambient temperature. It was due to amide bond restricted rotation and intermolecular association.

The aggregation structure of monolayer was discussed by the observations of electron diffraction patterns and bright field images. When 2C_(14)SNa was spread on pure water surface, a homogeneous monolayer was formed before compressing as the result of electrostatic repulsion among hydrophilic anionic groups, the crystallization was occurred in the process of compressing, i.e., it was a compressing crystallized monolayer. When 2C_(14)SNa was spread on PEI solution surface, a crystalline monolayer with an un-oriented domain structure was formed before compressing as the results of anchoring effect of ion complex and the weakened electrostatic repulsion, the orientation was occurred in the process of compressing, i.e., it was a compressing oriented crystalline monolayer. The formation of polyion complex at the air/water interface greatly affected the aggregation state of monolayer.

~1H NMR spectra of acetoxime have been measured as a function of the mole fraction of certain aromatic hydrocarbons in mixed solvent of CCl_4 and benzene or toluene. It has been found that the chemical shifts of the two methyl groups in acetoxime and of benzene or toluene move upfield gradually in the mixed solvent as the mole fraction of aromatic component increases. The moving rate of the resonance absorption line of the two methyl groups in acetoxime are different. The △δ of β-CH_3 is larger than that of α-CH_3. The absorption line of the two methyl groups is a singlet in CCl_4 and splits to a doublet when the concentration of benzene or toluene in the solvent is higher than 30% (mole/mole). The experimental results also show that the extent of upfield shifts of either the methyl groups in acetoxime or the aromatic hydrogens are reduced when a hydrogen of benzene is substituted by methyl group. All of the chemical shifts can be correlated with a linear equation as δ=A+Bx, Where, x is the mole fraction of benzene or toluene in the mixed solvent. The correlation coefficients R are approximately equal to -1.

The cathodic reduction of Co~(2+) ions in solutions of pH 4—6 has been inves-tigated by using polarization measurements and ac impedance technique. The reduction behaviour depends to a great extent on the acidity of solution. Based on the mechanism proposed, which is characterized by a stepwise reduction and the inter-mediate formation of an adsorbed monovalent cobalt, (CoOH)_(ads), and with the reaction sequence as a model, an impedance analysis is made of the electrode process. The consistency of the conclution derived from the analysis with experimental electrochemical impedance spectroscopy (EIS) further confirms the reasonableness of the proposed mechanism. The present impedance study also gives evidence that there exists no one-to-one correspondence between a given reaction path (mechanism) and a certain mode of EIS, as ascertained by Cao~[12], and the method of equivalent circuit is limited in studying reaction mechanism.

Conformational studies of antitumor drug phenyl-tri-azenes were carried out using MINDO/3 MO method. The conformational energy has been calculated as a function of torsion angles θ_1 and θ_2. The rotation barrier of θ_2 is about ten times as high as θ_1. The original conformation may be play an important role in the antitumor procedure.

This paper reports the establishment of the set-up of ion-neutral reaction and the measurement of the rate constant of the reaction O~+ ions with N_2 at 298 K. O~+ ions were generated by microwave and electrode in this discharge flow system, and the O~+ concentriation was detected by quadrapole mass spectrometer.
The specific rate constant obtained is
k=(2.50±0.52)×10~(-12) cm~3·molec~(-1)·s~(-1) (T=298 K)

Two series of luminescent rare-earth chelates have been studied spectroscopically, one is(TOPO)_2Eu(β-dik)_3(TOPO=tri-n-octyl-phosphine oxide; β-dik=trifluoroace-tylacetone(TFA), hexafluoroacetylacetone(HFA), thenoyltrifluoroacetone(TTA)), the other is (Phen)_2RE(NO_3)_3 (Phen=1,10-phenanthroline; RE=Eu,Tb,Sm). By using British NIMA LB system 2000 round trough, the pressure area (π-A) isotherms for (TOPO)_2Eu(β-dik)_3, (Phen)_2RE(NO_3)_3 monolayers at the air-water interface were investigated, then the monolayers were transfered on hydrophobic glass slides. The alternate-layer LB films were deposited by arachidic acid (AA, odd layers) and (TOPO)_2Eu (β-dik)_3 (even layers). The mixed LB films were deposited by (Phen)_2Eu(NO_3)_3 and AA (in molar ratio 1:4). Low angle X-ray diffraction results showed that the LB films mentioned above all have a periodic structure. The lattice spacing, for alternate-layer LB films are 5.32—5.52 nm, for mixed LB films are 5.23—5.32 nm. FTIR results indicated that hydrogen bond established between —CF_3 of (TOPO)_2Eu(β-dik)_3 and —COOH of AA in alternate-layer LB films. It was found that the fluorescent emission from the LB films mentioned above is strong and the fluorescent emission strength increases with the increasing of the number of layers. that the fluorescent emission from the LB films mentioned above is strong and the fluorescent emission strength increases with the increasing of the number of layers. Especially, even with only two alternate layers of AA and (TOPO)_2Eu(β-dik)_3, the characteristic fluorescent emission of Eu(III)(~5D_0→F_1 and ~5D_0→~7F_2) could be detected also. The fluorescent emission spectra of these rare-earth chelates in multilayers are much similar to those in solution, but the fluorescent excitation spectra are a little different. The characteristic fluorescent emission for each rare-earth chelate appeared in the spectra provided that the mixed LB film of (Phen)_2Eu(NO_3)_3, (Phen)_2Tb(NO_3)_3, (Phen)_2Sm(NO_3)_2 and arachidic acid (in molar ratio 1:1:1:12) was excited by optimum excitation wavelength corresponding to each rare-earth.

Tbe reaction path (IRC or MEP) of the reaction CH(~4∑~-)+H_2→CH_2(~3B_1)+H has been traced by Fukui's theory and ab initio calculation. Furthermore, the dynamic properties along the reaction path and CVT rate constants have been investi-gated by reaction path Hamiltonian theory and variational transition state theory. On this basis, the adiabatic and diabatic vibrational-state-selected rate constants were calculated. The results show that the effects of CVT method are notable, and the rate enhancement is also notable while H_2 stretch mode is vibrationally excited.

The electronic states of a C_(60) molecule have been calculated by using the SSH model. The electronic energy spectrum and dimerization on molecular structure are in good agreement with that obtained from the method of molecular orbit and local density function theory. With the SSH model, there is string polaron for both neutral excited and charged C_(60) molecule, and this is consistent with the experimental results. Besides, a comparison has been made between C_(60) and polacetylene.

用量子化学EHMO方法对碳六十C_(60)及含卤原子碳六十C_(60)X(F,Cl,Br,I)的电子结构进行了计算. 据此, 对C_(60)、C_(60)X及C_(60)X_y(y=1-10)的导电性进行了讨论.

通过在谱仪真空中对碱土金属氧化物作原位加热, 使其表面碳酸盐分解, 然后记录其晶格氧的O_(1s)电子结合能. 结果表明测得的MgO, CaO, SrO和BaO 的O_(1s)结合能明显地低于大部分文献报导的数值. 本文测得的碱土金属氧化物的O_(1s)电子结合能与氧原子上的Sanderson电荷分数有合理的相关性. 本文测得的BaO_2的O_(1s)结合能是530.9 eV, 它比文献报导的数值要低.

研究了桑色素在pH=1～14的水溶液中的极谱行为. 于不同pH范翻内得列了四个还原波. 研究证实在pH<4条件下获得的P_1波为表面催化氢波. 其余三个波为不同形态桑色素的单电子吸附还原波, 并伴有随后化学反应过程. 测得在单分子层饱和吸附条件下, 每一个桑色素分子所占汞电极面积为1.36 nm.

研究使用白金-SPE 复合电极, 以二价锰离子为催化剂进行肉桂醇的电化学氧化实验. 电解结果的分析表明, 在电化学氧化中肉桂醇中的双键不被破坏. 该反应为后续化学反应(即EC 反应), 对电解生成物的选择性较高, 肉桂醛生成的电流效率高于80%, 肉桂酸生成的电流效率仪在5%左右.

用原位XRD方法证明V_2O_5能在硅胶表面自发分散, 但所需温度较高. 水汽对V_2O_5的分散有一定的阻碍作用. K_2SO_4可显著加快V_2O_5在SiO_2表面的分散速度, 并能降低V_2O_5/SiO_2的表面酸性. 被中和的主要是强酸位. 这可能是K_2SO_4能够改善V_2O_5/SiO_2催化剂在选择氧化反应中选择性的重要原因之一.

用两种方法合成了一系列不同Fe/Al比的铁铝复合柱撑牯土(FeAl-PlLC). 用~(27)Al-NMR、UV、ESR等手段考察了柱溶液的结构和状态, 用XRD、DTA、UV-DRS 等技术对其结构、稳定性进行了研究. 结果表明, 铁铝柱撑粘土的底面间距为1.98～1.55 nm, Fe/Al比对其柱结构、比表面积、热稳定性均有较大影响. Fe/Al<0.5时, 层间柱主要呈现Keggin结构, Fe/Al≥0.5时, 可能为三聚结构. 随Fc/Al比的增加, d(001)值, 比表面面、热稳定性逐渐下降.

对二阶和四阶Legondre多项式构造的取向分布函数进行了仔细研究, 发现该函数适于描述二维凝聚体系中单轴取向分子的四种分布模式, 给出了这四种分布模式对应的序参数〈P_2〉,〈P_4〉的取值区域, 具体讨论了序参数〈P_2〉,〈P_4〉改变时, 分布图形的相应变化.

用粉末XRD法、EXAFS法,激光喇曼散射法、热重法和高真空质谱TPD法研究了超导体型氧化还原催化剂Ba_(2-x)Sr_xYCu_3O_(7-α)(x=0,0.25, 0.50, 0.75, 1.00)的物理化学性质, 并用常压连续流动法测定了它们的CO催化氧化活性, 得到了催化剂氧化反应活性大小与催化剂的可失氧量(即晶胞中O_I 位置上的氧量)之间存在着线性关系的结论.

从俄歇电子激发过程讨论了化学位移和元素化合价以及电负性的关系, 提供了常用元素在不同化合物中的俄歇电子动能及化学位移数据, 运用俄歇化学位移研究了氧在锌表面的吸附和初始氧化反应, Ti/SiO_2的界面固相反应机理以及摩擦过程中润滑膜的组成和结构.

用电位法研究了间苯二酚-KBrO_3-H_2SO_4(体系A)及间苯二酚-KBrO_3-H_2SO_4-MnSO_4(体系B)的化学振荡现象. 得出了两振荡体系的诱导期及振荡周期与反应物起始浓度及温度关系的经验方程.间苯二酚在诱导期结束时全被氧化, 它不是参与振荡的物质.
体系B在低Mn~(2+)浓度下可呈现双振荡现象, 即第一类振荡结束后, 经一段非振荡时间再产生第二类振荡. 两类振荡的特征不同. 第一类振荡与体系A的振荡行为基本相似. 第二类振荡的各个周期随c_M 减小而缩短,最后趋于相同; 随c_K、c_H增大而减小, 最后各自趋于一致. 但周期与c_R基本无关. 第二类振荡出现周期双单调变化现象, 它补充与支持了文献[1]中的提法. 当Mn~(2+)浓度增高到一定程度后, 双振荡现象消失, 仅产生一种振荡. 体系B是产生双振荡现象的典型事例之一.