土壤干湿处理与储存时间对土壤溶液组分离子活度及离子活度…

采用真空置换法提取土壤溶液。研究了土壤湿度及储存时间两种处理对离子化学形态电脑模型计算结果的影响。研究不同处理效应的电脑输出数据以负对数表示，计有：（１）Ｈ＾＋，Ｃａ＾２＋，Ａｌ＾３＋及ＳＯ４＾２－的离子活度，（２）（Ａｌ＾３＋）（ＯＨ＾－）＾３，（Ａｌ＾３＋）＾２（ＯＨ＾－）＾６（Ｈ４ＳｉＯ４）＾２及（Ａｌ＾３＋）＾３．７７（Ｈ４ＳｉＯ４）＾３．２４（Ｋ＾＋）＾０．２４（Ｃａ＾２＋）＾０．０８（     

辽东半岛滨海盐土脱盐过程中pH上升及碱化问题探讨

对鸭绿江口和辽河口滨海盐土脱盐过程的分析研究结果表明：不同母质的盐土脱盐,随着含盐量的下降,Ｎａ＾＋、Ｃｌ＾－、ＳＯ４＾（２－）、Ｍｇ＾（２＋）、Ｃａ＾（２＋）、Ｋ＾＋的绝对含量都逐渐减少,ＨＣＯ３＾－逐渐增加;ＣＬ＾－ＮＡ＾＋的相对含量逐渐下降,而ＳＯ４＾（２－）、Ｍｇ＾（２＋）、Ｋ＾＋特别是Ｃａ＾（２＋）、ＨＣＯ３＾－的相对含量增加。由于各离子的迁移能力不同,导致土壤的盐分化学类型由Ｃｌ－Ｎａ     

NO^—2与水稻幼苗N素化合物代谢的关系

以水稻幼苗为材料，在水培条件下研究了ＮＯ＾－２水与稻Ｎ素化合物代谢的关系。结果表明，随ＮＯ＾－２浓度增加，地上部和根中的ＮＯ＾－２浓度增加，地上部和根中的ＮＯ＾－２含量上升，随着时间延长，ＮＨ＾４－Ｎ含量增加；Ｆｅ＾＋＋可降低ＮＯ＾－２－Ｎ含量，促进ＮＨ＾４－Ｎ积累。施ＮＯ＾－２Ｎ时秧苗中的天门冬氨酸，谷氨酸，内氨酸含量高，而根中天门冬氨酸，谷氨酸含量较低；结构性蛋白，叶绿体蛋白，细胞质白含量...     

模拟酸沉降下南方两种森林土壤对SO^2—4及NO^—3的吸附

通过３种模拟酸沉降溶液对福建和贵阳两种森林土壤样品的连续浸泡试验,研究了土壤对酸沉降中ＳＯ＾２－４和ＮＯ＾－３的吸附,以及盐基离子输入对这种吸附的影响,结果表明,２种土壤对ＳＯ＾２－４均有一定的吸附能力,但福建土壤的吸附量比贵阳土壤大,土壤对ＳＯ＾２－４的吸附与酸沉降中ＳＯ＾２－４浓度及土壤水溶性ＳＯ＾２－４含量有关,但高沈度的盐基离子输入会降低ＳＯ＾２－４的吸附量,土壤对ＮＯ＾－３的吸附主要发生     

新型抗癌配合物的研究 IV：[Pd（二齿胺）（NO3）2]配合物的合成,表…

合成了二齿胺配体内消旋－１，２－二苯基乙二胺（Ｓｔｅｉｎ）内消旋－１，２－二对氯苯基乙二胺（４－Ｃｌ－ｓｔ）和钯配合物［Ｐｄ（ｓｔｅｉｎ）（ＮＯ３）２，［Ｐｄ（４－Ｃｌ－ｓｔ）（ＮＯ３）２，［Ｐｄ（ｔｍｃｐｄａ）（ＮＯ３）２］，［Ｐｄ（Ｏ－ｐｈｅｎ）（ＮＯ３）２］，用元素分析红外光谱进行了表征，并用ＭＴＴ染色法测定了配合物的抗癌活性，结果表明［Ｐｄ（４－Ｃｌ－ｓｔ）（ＮＯ３０２］对人体宫颈癌和鼻咽     

微量元素对银杏愈伤组织细胞生长和黄酮醇粮苷含量的影响

研究证实了在银杏愈伤组织培养过程中,７种微量元素对细胞生长率和黄酮醇糖苷含量有明显的影响。ＭｎＳＯ４,ＺｎＳＯ４,Ｈ３ＢＯ３三组试验中,当浓度分别为ＭＳ培养基原浓度时,细胞生长率最高,黄酮醇糖苷含量随ＭｎＳＯ４浓度增加而下降;在分别Ｃｏ＾６＋,Ｃｕ＾２＋,Ｃｏ＾２＋的三个处理中,其细胞生长率和黄酮醇糖苷含量均低于对照。     

新型抗癌配合物的研究Ⅳ［Pd（二齿胺）（NO＿3）＿2］配合物的合成、表征和抗癌活性的研究

合成了二齿胺配体内消旋－１．２－二苯基乙二胺（Ｓｔｅｉｎ）内消旋－１．２－二对氯苯基乙二胺（４－Ｃｌ－ｓｔ）和钯配合物［Ｐｄ（ｓｔｅｉｎ）（ＮＯ＿３）＿２，［Ｐｄ（４－Ｃｌ－ｓｔ）（ＮＯ＿３）＿２］，［Ｐｄ（ｔｍｃｐｄａ）（ＮＯ＿３）＿２］，［Ｐｄ（Ｏ－ｐｈｅｎ）（ＮＯ＿３）＿２］，用元素分析红外光谱进行了表征，并用ＭＴＴ染色法测定了配合物的抗癌活性，结果表明［Ｐｄ（４－Ｃｌ－ｓｔ）（ＮＯ＿３）＿２］对人体宫颈癌和鼻咽癌细胞的杀伤力优于顺铂，配合物［Ｐｄ（ｔｍｃｐｄａ）（ＮＯ＿３）＿２］水溶性好，对荷瘤Ｓ—１８０（Ａ）小鼠进行实验，其延命率１７５％（Ｐ＜０．００１）表明有肯定的抗癌活性．     

双核锰配合物的合成和表征

合成了对称的六齿（Ｎ６型）双核配体Ｎ,Ｎ,Ｎ’,Ｎ’－四（２－甲基苯并咪唑）乙二胺（ＥＤＴＢ）及两种含锰（Ⅱ）双核配合物：［Ｍｎ２ＥＤＴＢ（ＣＨ３ＣＯＯ）２］（ＣＨ３ＣＯＯ）（ＣｌＯ４）·２ＣＨ３ＣＨ２ＯＨ·４Ｈ２Ｏ（Ⅰ）,［Ｍｎ２ＥＤＴＢ（ＣＨ３ＣＯＯ）２］（ＣＨ３ＣＯＯ）（ＮＯ３）·４ＣＨ３ＣＨ２ＯＨ（Ⅱ）,并对配体ＥＤＴＢ,配合物（Ⅰ）,（Ⅱ）进行了核磁共振氢谱（＾１ＨＮＭＲ）、紫外一可见光     

氢氧化铝表面硼吸附络合物结构状况的解析

对Ａｌ（ＯＨ）３＋Ｈ３ＢＯ３,Ａｌ（ＯＨ）３,Ｈ３ＢＯ３等样品进行了红外光谱,红外差分谱以及Ａｌ（ＯＨ０３＋Ｈ３ＢＯ３的二次离子质谱分析。结果表明,Ａｌ（ＯＨ）３＋Ｈ３ＢＯ３样品在１４２３和１２７９ｃｍ＾－１处有２个特征吸收峰,这些峰与Ｈ３ＢＯ３表现出的吸收峰相比,峰带更宽,说明在Ａｌ（ＯＨ）３＋Ｈ３ＢＯ３处理中,Ａｌ（ＯＨ）３表面形成了一种新物质即硼的吸附络合物。     

氯离子对水稻根营养吸收动力学的影响

本文以水稻为试材,研究了氯离子对根吸收ＮＯ３＾－、Ｈ２ＰＯ４＾－和Ｋ＾＋吸收动力学参数的影响,结果表明,Ｃｌ＾－对ＮＯ３＾－,Ｈ２ＯＰ４＾－吸收均存在抑制作用,对ＮＯ３＾－的抑制属竞争性抑制;对Ｈ２ＰＯ４＾－的抑制属混合性抑制。低浓度氯离子促进Ｋ＾＋的吸收,高浓度氯离子抑制Ｋ＾＋的吸收。     

X-ray diffraction study of the ultrathin Al2O3 layer on NiAl110

Ultrathin Al2O3 layers on alloys are used as templates for model catalysts, tunneling barriers in electronic devices, or corrosion-resistant layers. The complex atomic structure of well-ordered alumina overlayers on NiAl110 was solved by surface x-ray diffraction. The oxide layer is composed of a double layer of strongly distorted hexagonal oxygen ions that hosts aluminum ions on both octahedral and tetrahedral sites with equal probability. The alumina overlayer exhibits a domain structure that can be related to characteristic growth defects and is generated during the growth of a hexagonally ordered overlayer (Al2O3) on a body-centered cubic (110) substrate (NiAl).     

O_3与O_3/H_2O_2两个体系降解除草剂2,4-D反应特性研究

分别采用O3、O3/H2O2体系降解苯氧羧酸类除草剂2,4-D,探讨了降解过程中反应温度、pH值、O3混合气流量、有机物初始浓度等操作条件的变化对降解动力学的影响。结果发现,温度和pH值的影响较大,O3流量影响最小,温度升高、pH值增大、臭氧流量增加、2,4-D初始浓度降低均有助于降解速率的提高。O3/H2O2体系中,H2O2能促进O3分解产生大量自由基,导致2,4-D反应活化能降低。和O3相比,O3/H2O2体系降解效果好,降解时间短,反应条件温和,操作费用低,是很有发展前景的高级氧化技术。     

The "Ozone Deficit" Problem: O2(X, v ge 26) + O(3P) from 226-nm Ozone Photodissociation

Highly vibrationally excited O(2)(X(3)sigmag(-), v >/= 26) has been observed from the photodissociation of ozone (O(3)), and the quantum yield for this reaction has been determined for excitation at 226 nanometers. This observation may help to address the "ozone deficit" problem, or why the previously predicted stratospheric O(3) concentration is less than that observed. Recent kinetic studies have suggested that O(2)(X(3)sigmag(-), v >/= 26) can react rapidly with O(2) to form O(3) + O and have led to speculation that, if produced in the photodissociation of O(3), this species might be involved in resolving the discrepancy. The sequence O(3) + hv --> O(2)(X(3)sigmag(-), v >/= 26) + O; O(2)(X(3)sigmag(-), v >/= 26) + O(2) --> O(3) + O (where hv is a photon) would be an autocatalytic mechanism for production of odd oxygen. A two-dimensional atmospheric model has been used to evaluate the importance of this new mechanism. The new mechanism can completely account for the tropical O(3) deficit at an altitude of 43 kilometers, but it does not completely account for the deficit at higher altitudes. The mechanism also provides for isotopic fractionation and may contribute to an explanation for the anomalously high concentration of heavy O(3) in the stratosphere.     

超声辅助磁性纳米四氧化三铁催化过氧化氢降解亚甲蓝染料的研

建立了一种基于超声辅助磁性四氧化三铁纳米微粒催化过氧化氢降解亚甲蓝染料的方法,研究了四氧化三铁纳米微粒浓度、过氧化氢浓度、pH值、反应时间、超声时间和温度等对催化降解反应的影响.结果表明,当四氧化三铁纳米粒子浓度为600mg/L,过氧化氢浓度为0.32mol/L,pH值为5,超声时间为3min,温度为30℃,反应时间为2h时,模拟染料废水中亚甲蓝的去除率最高可达到95%.     

Colossal Magnetoresistance Without Mn3+/Mn4+ Double Exchange in the Stoichiometric Pyrochlore Tl2Mn2O7

Structural analysis from powder neutron and single-crystal x-ray diffraction data for a sample of the Tl2Mn2O7 pyrochlore, which exhibits colossal magnetoresistance (CMR), shows no deviations from ideal stoichiometry. This analysis gives an Mn-O distance of 1.90 angstroms, which is significantly shorter than the Mn-O distances (1.94 to 2.00 angstroms) observed in phases based on LaMnO3 perovskites that exhibit CMR. Both results in Tl2Mn2O7 indicate oxidation states very close to Tl23+Mn24+O7. Thus, Tl2Mn2O7 has neither mixed valence for a double-exchange magnetic interaction nor a Jahn-Teller cation such as Mn3+, both of which were thought to have an important function in CMR materials. An alternate mechanism for CMR in Tl2Mn2O7 based on magnetic ordering driven by superexchange and strong spin-fluctuation scattering above the Curie temperature is proposed here.     

A New High-Temperature Superconductor: Bi2Sr3-x Cax Cu2O8+y

A new superconductor that displays onset behavior near 120 K has been identified as Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y), with x ranging from about 0.4 to 0.9. Single crystal x-ray diffraction data were used to determine a pseudo-tetragonal structure based on an A-centered orthorhombic subcell with a = 5.399 A, b= 5.414A, and c = 30.904 A. The structure contains copper-oxygen sheets as in La(2)CuO(4) and YBa(2)Cu(3)O(7), but the copper-oxygen chains present in YBa(2)Cu(3)O(7) do not occur in Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y). The structure is made up of alternating double copper-oxygen sheets and double bismuth-oxygen sheets. There are Ca(2+) and Sr(2+) cations between the adjacent Cu-O sheets; Sr(2+) cations are also found between the Cu-O and Bi-O sheets. Electron microscopy studies show an incommensurate superstructure along the a axis that can be approximated by an increase of a factor of 5 over the subcell dimension. This superstructure is also observed by x-ray diffraction on single crystals, but twinning can make it appear that the superstructure is along both a and b axes. Flux exclusion begins in our samples at about 116 K and is very strong by 95 K. Electrical measurements on a single crystal of Bi(2)Sr(3-x)Ca(x)Cu(2)O(8+y) show a resistivity drop at about 116 K and apparent zero resistivity at 91 K.     

Crystal Structure of Kernite, Na2B4O6(OH)2 {middle dot} 3H2

Kernite, Na(2)B(4)O(6)(OH)(2). .3H(2)0, contains parallel infinite chains of the borate polyanion[B(4)O(6)(OH)(2)](n)(2n-). The chains are composed of six-membered rings containing one boron-oxygen triangle and two boron-oxygen tetrahedra. The rings are linked through commonly shared boron-oxygen tetrahedra.     

A-Axis--Oriented YBa2Cu3O7/PrBa2Cu3O7 Superlattices

A modulated structure has been fabricated from high transition temperature superconductors where the individual CuO(2) planes are composed of alternating superconducting and insulating strips. This structure is made by growing a-axis-oriented YBa(2)Cu(3)O(7)/PrBa(2)Cu(3)O(7) superlattices by 90 degrees off-axis sputtering on (100)SrTiO(3) and (100)LaAlO(3) substrates. Superlattice modulation is observed to a modulation wavelength of 24 angstroms (12 angstroms-YBa(2)Cu(3)O(7)/12 angstroms-PrBa(2)Cu(3)O(7)), both by x-ray diffraction and by cross-sectional transmission electron microscopy. Rutherford backscattering spectroscopy indicates a high degree of crystalline perfection with a channeling minimum yield of 3 percent. Quasi-one-dimensional conductivity should be obtainable in these structures.     

脱氮微生物脱氮性能及N_2O逸出量研究

[目的]研究具有好氧反硝化特性的异养硝化细菌NYMO和NYTE同时进行硝化和反硝化作用的能力及好氧反硝化菌HWTT的产物N2O逸出量情况。[方法]通过NH4＋-N和NO3--N的质量浓度的变化情况来分析细菌硝化作用和反硝化作用的能力,采用空气密封摇瓶培养和额外补充O2保证好氧条件的2种方式培养菌株HWTT。[结果]菌株NYMO和NYTE 2 d内NH4＋-N去除率为34.60%和35.08%,NO3--N去除率为33.40%和99.92%[结论]NYMO和NYTE具有异养硝化好氧反硝化能力。缺氧条件下,N2O逸出量最高值为0.15μmol,N2O/（N2O＋N2）低于0.15%;好氧条件下,N2O逸出量为35.71μmol,N2O/（N2O＋N2）为70%以上。     

超声/紫外/O3/H2O2处理去除水中DDT的研究

[目的]研究超声/紫外/O3/H2O2处理去除水中DDT的效果,为建立新的去除水中DDTs的AOPs技术提供参考。[方法]配制一定浓度的DDT水溶液,分别采用超声、紫外、O3/H2O2、超声/紫外和超声/紫外/O3/H2O2组合处理,并用超声/紫外/O3/H2O2组合处理北江佛山段水样,用GC-EDC方法检测DDT含量变化,比较各处理方法的DDT去除率。[结果]水中DDT去除率分别为:超声波处理为45%～56%、紫外光处理近70%、超声/紫外联合处理超过80%、O3/H2 O2处理为28%～32%、超声/紫外/O3/H2 O2处理为91%,而北江水样DDT去除率达到85%。[结论]超声/紫外/O3/H2O2联合处理可有效去除水中DDT。