Effect of Zn and Ti mole ratio on microstructure and photocatalytic properties of magnetron sputtered TiO_2-ZnO heterogeneous composite film

Series of TiO 2-ZnO heterojunction composite films with different n（Zn）/n（Ti） ratios were prepared by UDP450 magnetron sputter ion plating equipment, and the mole ratio of Zn to Ti was controlled by adjusting the current values of sputtering target. The effects of n（Zn）/n（Ti） on the microstructures of TiO2-ZnO films were investigated by SEM, AFM, Raman and XPS, and their photocatalytic decomposition of methyl orange solutions was evaluated. The results show that an increase in n（Zn）/n（Ti） typically results in a decrease in the grain size of composite films firstly and then an increase of grain size, while an increase in n（Zn）/n（Ti） leads to an increase in film roughness firstly and then a decrease in film roughness. Both grain size and roughness of TiO2-ZnO films reach the maximum and minimum at n（Zn）/n（Ti） of 1/9.3, respectively. The n（Zn）/n（Ti） shows little effect on the valences of Zn and Ti elements, which mainly exist in the form of TiO2 and ZnO phases. The n（Zn）/n（Ti） has influence on the amount of anatase/rutile TiO2 heterojunction in the film. With increase of the n（Zn）/n（Ti）, the absorption intensity of the composite film increases and the absorption region extends to 450 nm, which is redshifted as much as 150 nm in comparison with the pure TiO2 films. However, the photocatalytic abilities of heterogeneous composite films do not depend on the n（Zn）/n（Ti） but rather on the microstructures of the TiO2-ZnO composite films. Degradation rate of the film reaches the maximum and the photocatalytic decomposition of pollutants works best when n（Zn）/n（Ti）=1：9.3.

多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结的制备及紫外探测性能研究

本文首先采用紫外光辅助电化学刻蚀(UV-EC)方法制备出了孔隙密度为1.51×10^(10)cm^(-2)、平均孔径为38 nm的多孔n-GaN薄膜;随后在其上通过水浴法沉积了一系列Zn_(x)Cu_(1-x)S复合薄膜,x为0.0、0.2、0.4、0.6、0.8、1.0,形成的多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结带隙在2.34~3.51 eV调控;最后基于这些异质结构建出p-n结型紫外探测器。I-V曲线结果表明这些探测器均具有良好的整流特性,特别是n-GaN/p-Zn_(0.4)Cu_(0.6)S探测器性能最优。在暗态下,I_(+3 V)/I_(-3 V)约为1.78×10^(5);在偏压为-3 V、光功率密度为432μW/cm^(2)(365 nm)的条件下,光暗电流比超过10^(3),上升/下降时间为0.09/39.8 ms,响应度(R)为0.352 A/W,外量子效率(EQE)为119.6%,探测率(D^(*))为3.21×10^(12)Jones。I-t曲线结果表明,多孔n-GaN/p-Zn_(x)Cu_(1-x)S异质结紫外探测器在连续开-关光循环过程中拥有稳定的光电流响应。该研究为制备异质结紫外探测器提供了一定的理论指导和实验数据。

不同硅铝比电镀污泥烧制陶粒过程中Zn和Pb的挥发特性

为研究电镀污泥陶粒烧制过程中不同工况条件及固体基质组分下Zn和Pb迁移转化规律,以电镀污泥和页岩为原料开展了不同硅铝比生料的烧制陶粒实验,选取烧结温度为700、800、900、1 000、1 150℃,停留时间为8、16、24、32、40 min。结果表明,Zn和Pb的挥发率随着温度升高和反应时间延长而逐渐增大。当烧结温度为1 150℃、停留时间为40 min时,Zn和Pb的挥发率达最大值,挥发率为Pb>Zn。当陶粒原料中硅铝比增大,重金属挥发率减小。动力学分析结果表明,陶粒原料中硅铝比增大,Zn的反应级数和反应活化能均下降,Pb的反应级数和反应活化能均上升。XRD分析结果表明,1 150℃下陶粒中Pb分布较少,可能与Pb氧化物的熔沸点较低有关,而Zn主要以性质较稳定的ZnCr_2O_4和ZnGa_2O_4结构存在于陶粒中,分布量较大。SEM分析进一步表明,陶粒原料中硅铝比增大,导致了高温下陶粒熔融产生的玻璃相物质增多,对重金属挥发的抑制作用增强。

Efficient removal of Al(Ⅲ)and P507 from high concentration MgCl_(2)solution based on in-situ reaction strategy

For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_(x)(OH)_y^(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_(2)(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%.

Effect of compression ratio on microstructure evolution of Mg−10%Al−1%Zn−1%Si alloy prepared by SIMA process

A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experimental alloy was investigated.The results indicate that the average size ofα-Mg grains decreases and spheroidizing tendency becomes more obvious with the compression ratios increasing from 0 to 40%.In addition,the eutectic Mg2Si phase in the Mg−10%Al−1%Zn−1%Si alloy transforms completely from the initial fishbone shape to globular shape by SIMA process.With the increasing of compression ratio,the morphology and average size of Mg2Si phases do not change obviously.The morphology modification mechanism of Mg2Si phase in Mg−10%Al−1%Zn−1%Si alloy by SIMA process was also studied.

Concentrative phenomenon of relative content ratios of Cu, Pb and Zn in soils

It is discovered that there is the concentrative phenomenon of relative content ratios of Cu, Pb and Zn in soil by studying their parageneous association in soil, meteorites and rocks with the relative content ratios. This not only is helpful to understand the trends of Cu, Cd and Zn enriched and dispersed in the evolution course of earth matter, but also provides evidence for geochemical self-organization that there may be in the process of Cu, Pb and Zn translation and distribution.

Zn/O ratio and oxygen chemical state ofnanocrystalline ZnO films grown atdifferent temperatures

ZnO nanocrystalline films are prepared on Si substrates at different temperatures by using metal-organic chemical vapour deposition （MOCVD）. It is observed that when the growth temperature is low, the stoichiometric ratio between Zn and 0 atoms has a large deviation from the ideal ratio of 1：1. The ZnO grains in the film have small sizes and are not well crystallized, resulting in a poor photoluminescence （PL） property. When the temperature is increased to an appropriate value, the Zn/O ratio becomes optimized, and most of Zn and 0 atoms are combined into Zn-O bonds. Then the film has good crystal quality and good PL property. If the temperature is fairly high, the interracial mutual diffusion of atoms between the substrate and the epitaxial film appears, and the desorption process of the oxygen atoms is enhanced. However, it has no effect on the film property. The film still has the best crystal quality and PL property.

Preparation and Characterization of Nano-ZnO Precursor for the Antibacterial Activity against Thielaviopsis paradoxa

[Objectives]The paper was to explore a new method for preparing nano ZnO particles.[Methods]A mixture of 2,6-di(2′,4′-dicarboxylphenyl)pyridine(0.05 mM),Zn(NO_(3))2·6H_(2)O(0.1 mM)were added to the solution of DMA(3 mL)and H_(2)O(3 mL),and heated at 90℃for 12 h.The PXRD,TGA and fluorescence properties were characterized.[Results]Transparent block crystals of the[Zn_(2)(2,6-ddpp)(DMA)_(3)(H_(2)O)·H_(2)O]n were obtained(yield 85.4%,based on Zn).The Zn-MOF framework would collapse to form ZnO particles when the temperature exceeded 350℃.[Conclusions]A new Zn(II)-MOF is successfully constructed,and the compound exhibits monoclinic P21/c space group.The results will provide a theoretical basis for the preparation of nano ZnO.

PREPARATION AND ANALYSIS OF Ni-P-Zn ELECTROLESS DEPOSITION FROM ALKALI BATH

Electroless Ni-P-Zn alloys deposited from alkali bath were investigated in this paper. The deposition bath contained nickel sulfate, zinc chloride and hypophosp hate. The process parameters, such as temperature, pH and zinc salt concentratio n were presented and discussed. The microstructure of the coatings was studied b y XRD and SEM. The cathode glowing discharge characters of Ni-P-Zn depositions w ere studied with luminous Neon lamps. Electrodes deposited by electroless Ni-P a lloys were apt to sputter during luminous working hours. Electroless Ni-P-Zn dep ositions improved the discharge characters of the electrodes. With the concentra tion of zinc in the deposition rising to 4wt%, electrode sputter was largely res trained. The thickness of the deposition also influenced the discharge character s of the electrode. To avoid electrode sputter, the concentration of zinc has to rise with the thickness of the depositions.

FCC汽油不同馏分在P-Zn/HZSM-5上的芳构化研究

在连续固定床反应器上考察了P-Zn/HZSM-5催化剂对FCC汽油不同馏分芳构化的反应性能,探讨了原料对芳构化反应的影响。结果表明,在一定的反应条件下,P-Zn/HZSM-5催化剂对50～100℃馏分芳构化反应具有很高的活性和稳定性。在反应16 h后,液相产品中烯烃及芳烃的质量分数分别为5.23%和79.9%,得到了低烯烃、高芳烃的汽油调合产品。在50～100℃馏分芳构化反应中,液相产品中苯、甲苯和二甲苯的含量分布会发生变化。反应进行4 h后,苯、甲苯和二甲苯的含量以甲苯、二甲苯、苯的顺序递减,而反应进行20 h后,由于催化剂积炭,改变为以二甲苯、甲苯、苯的顺序递减;C9+芳烃的含量则先增加后降低。

P·Cd·Zn交互作用对沉水植物吸收积累P·Cd·Zn的影响

[目的]研究P、Cd、Zn交互作用对沉水植物吸收积累P、Cd、Zn的影响。[方法]采用溶液培养的方法,模拟Cd、Zn重金属污染和P富营养化污染环境,研究P、Cd、Zn交互作用对沉水植物吸收积累P、Cd、Zn的影响。[结果]对于黑藻施加P浓度为1 mg/L范围内,P与低浓度Cd、Zn之间为协同关系,施加P促进植物体对Cd、Zn的吸收积累。对于伊乐藻在P浓度为5~50 mg/L时,P与高浓度Cd、Zn之间为拮抗关系,随着P浓度的增加,植物体内Cd、Zn含量呈下降趋势。黑藻与伊乐藻对P的吸收积累有一个平衡态,约为20~23mg/g。[结论]湖泊环境中当重金属及富营养化污染同时存在时,重金属对植物的胁迫是污染的主要因素,而富营养化元素在一定程度上还可以缓解这种重金属对植物的毒害作用。

不同土壤性质和P水平下土壤-植物系统中的Zn-Cd交互作用研究

采用Zn背景值和P含量都较高的肥沃的农田粘质土和缺Zn缺P的贫瘠的沙质土进行盆栽试验,研究了不同土壤性质和P水平对土壤-植物系统中Zn-Cd交互作用的影响。结果表明,在试验1非缺Zn的土壤条件下,施Zn(0～100mg·kg-1)对小麦幼苗体内Cd的浓度无明显影响,只有在Zn浓度高至污染水平(1000mg·kg-1土)时,才显著降低小麦幼苗体内Cd浓度;而在试验2缺Zn缺P的土壤条件下,施加低浓度的Zn(0～10mg·kg-1土)即显著影响了小麦幼苗对Cd的吸收(P<0.001)。施加试剂纯的P(CaHPO4)也显著影响了小麦幼苗根和地上部的Cd浓度,过去多认为P肥促进植物对Cd的吸收是由于P肥中含有一定量的Cd所致,试验结果提示了P肥促进植物对Cd的吸收与P元素本身也有关系。

Mg-Zn系合金G.P.区和时效强化的研究进展

评述了国内外Mg-Zn系合金的研究进展。总结了Mg-Zn系合金中时效析出行为和各析出强化相的特征,通过分析铝合金G.P.区的形成规律,探讨了Mg-Zn系合金G.P.区的存在可能性。指出Mg-Zn系合金G.P.区的研究对Mg-Zn合金析出相变理论和发展高强度镁合金具有重要意义。

Zn_(1-x)Mg_xO薄膜p型导电和光学性能

采用超声喷雾热分解(U ltrason ic Spray Pyrolysis,USP)方法,以醋酸锌、醋酸镁、醋酸铵、氯化铝的混合水溶液为前驱溶液,在单晶S i(100)衬底上制备了ZnO,Zn0.81Mg0.19O,N-A l共掺杂ZnO和N-A l共掺杂Zn0.81Mg0.19O薄膜。以X射线衍射(XRD)、场发射-扫描电镜(FE-SEM)、霍尔效应(Hall-effect)、光致发光(Photolum inescence,PL)谱等手段研究了薄膜的晶体结构、表面形貌、电学性能、光学性能和带隙变化。电学测试结果表明,未掺杂ZnO及Zn0.81Mg0.19O薄膜为n型导电;而N-A l共掺杂ZnO和N-A l共掺杂Zn0.81Mg0.19O薄膜呈p型导电。Zn0.81Mg0.19O和N-A l共掺杂Zn0.81Mg0.19O(p型)薄膜在维持ZnO纤锌矿结构的前提下,光学带隙随Mg掺杂量增加而增大。初步结果显示,优化工艺参数下通过Mg掺杂制备光学带隙可调的p型Zn0.81Mg0.19O薄膜,对于试制Zn1-xMgxO基同质p-n结、短波长(紫外、深紫外)器件等方面有重要意义。

Effects of Regulation of C/N Ratio Wheat Straw Application on Nitrogen,Phosphorus and Potassium Uptake in Tobacco

[Objective]The aim was to study the effects of regulation of C/N ratio wheat straw application on tobacco nitrogen,phosphorus and potassium uptake. [Method]Effects of regulation C/N ratio wheat straw application on the flue-cured tobacco yield,output value,nitrogen,phosphorus and potassium content and cumulative uptake of the upper,middle and bottom leaf were studied by using the field plot experiments at Banqiao town,Qujing city,Yunnan Province during the 2008-2009 summer growing seasons. [Result]The results showed that the application of wheat straw alone or after C/N regulation,could significantly increase tobacco production,potassium content,the potassium and nitrogen accumulation amount of leaf,and was more conducive to the potassium uptake of tobacco leaf with wheat straw application after C/N regulation. Compared with non-straw application,the yield of tobacco increased by 6.59%,3.58%,5.98%,8.80% with application of wheat straw alone,wheat straw and vetch,wheat straw and oilseed cake,wheat straw and urea nitrogen,the potassium content in tobacco leaf increased by 3.85%,7.76%,8.82%,11.21%,respectively,the total potassium cumulative amount of leaf increased by 10.71%,11.62%,15.32% ,21.01% and the total nitrogen cumulative amount increased by 9.76%,1.22%,8.14%,14.00%. However,the differences of tobacco leaf nitrogen content among the different treatments were not significant,the phosphorus uptake of tobacco leaf decreased. [Conclusion]application of high C/N ratio wheat straw in flue-cured tobacco production,which should be concerned not only to adjust C/N ratio by adding nitrogen,but also considering additional phosphorus application.

Concentrations of foliar and surface soil in nutrients Pinus spp. plantations in relation to species and stand age in Zhanggutai sandy land, northeast China

The concentrations of the foliar and surface soil nutrients and the variation with species and stand age were studied inPinus spp. plantations in Zhanggutai area, northeast China. The results showed that the total N, total P and C: N ratio of the soil inP. sylvestris var.mongolica stands were significantly higher in comparison with those inP. tabulaeformis andP. densiflora stands. ForP. sylvestris var.mongolica, the foliar P concentration appeared to decrease with age, and the foliar N and K concentrations did not show a consistent change with age. As for the different tree species of the similar age, the foliar N and P concentrations were significantly different (p<0.05), being withP. sylvestris var.mongolica>P. densiflora>P. tabulaeformis. The foliar N: P ratio ofP. densiflora significantly was higher thanP. sylvestris var.mongolica andP. tabulaeformis, while the foliar K was no obvious difference between the three tree species. There were significant correlation (p<0.05) between soil total N and P, soil organic matter and total P, foliar N and P, but it did not show significant correlations between soil and foliar nutrient concentrations, which might attribute to the excessive litter raking, overgrazing and low soil moisture in this area. Based on the foliar N: P ratio, we introduced a combination threshold index of N: P ratio with their absolute foliar nutrient concentrations to determine the possible limiting nutrient. According to the critical N: P ratio and their absolute foliar N, P concentrations, theP. sylvestris var.mongolica stands showed a decreased N limitation degree with age, theP. densiflora stands showed unlimited by N and P in the whole, and theP. tabulaeformis stands showed co-limited by N and P. No significant difference in soil nutrient concentrations of the surface soils was found between 45, 29, 20-yr-oldPinus sylvestris var.mongolica plantation stands. Keywords coniferous trees - foliar nutrient concentration - limiting nutrients - N - P ratio - Zhanggutai sandy land CLC number S718.55 Document code A Article ID 1007-662X(2004)01-0011-08 Foundation item: This research was supported by Key Knowledge Innovation Project (KZCX3-SW-418) of Chinese Academy of Sciences.Biography: CHEN Guang-sheng (1978-), male, master candidate in Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, P. R. ChinaResponsible editor: Song Funan

化学沉积Ni-Zn-P合金制备和腐蚀性能研究

采用柠檬酸钠为络合剂 ,在氨性缓冲介质中化学镀Ni Zn P合金 .考察了工艺参数 (pH、ZnSO4·7H2 O浓度和温度 )对沉积速度和镀层组成的影响 .发现Zn离子在沉积过程中起阻碍作用 ,致使镀层中Zn含量不高 (最多含16 .0mass% ) .采用差示扫描量热 (DSC)和X射线衍射 (XRD)技术研究所得化学镀Ni Zn P合金 (Ni=78.7mass % ,Zn =11.7mass % )的晶化行为和结构 .结果表明 ,镀态Ni Zn P合金主要由非晶相和少量立方镍两相构成 .热处理至 384 .8℃时出现四方Ni3 P相 ,至 5 80 .7℃时出现Ni5Zn2 1相 .镀态及热处理后的Ni Zn P合金 (Ni=78.7mass% ,Zn =11.7mass% .)在 3.5 %NaCl中 (pH =7.0 )的腐蚀失重及阳极极化测量 .结果表明 ,该合金的耐腐蚀性能优良 ,特别是镀态Ni Zn P合金 .

P、Zn在小麦细胞内的积累、分布及交互作用的研究

报道了小麦无性系细胞在含有３ 个Ｐ 水平（０５ 、１５ 、３５ ｍ ｍ ｏｌ·Ｌ－１） 和２ 个Ｚｎ 水平（０ 、６０μｍ ｏｌ·Ｌ－１） 的ＭＳ 培养液中，细胞对Ｐ、Ｚｎ 的积累、分布特性及交互作用的研究．Ｐ 和Ｚｎ 在细胞内的积累分别随外施Ｐ、Ｚｎ 浓度的提高而提高．与缺Ｚｎ 比较，加Ｚｎ 处理能抑制培养７ｄ 细胞中Ｐ 的含量．营养液中０５ ～１５ ｍ ｍｏｌ·Ｌ－１ Ｐ 能促进细胞的含Ｚｎ 量，但高Ｐ 处理即抑制细胞的含Ｚｎ 量．小麦细胞壁固定了细胞８３９ ％ ～８８３ ％ 的Ｐ，而外施Ｐ浓度越高，则细胞壁中Ｐ 分配的比例越大． 在供Ｚｎ 条件下，细胞壁截留了细胞中一半以上的Ｚｎ（５２０ ～６０５ ％ ） ．小麦液泡中Ｐ 和Ｚｎ 的含量较少，分别为２２ ％ ～３８ ％ 和１０６ ％ ～３０ ％

化学沉积Ni-Zn-P合金及其冲蚀特性

研究了镀液中硫酸锌、次亚磷酸钠、pH值及镀液温度对化学沉积Ni-Zn-P合金沉积速度、镀层成分和镀层表面形貌的影响。用SEM、EDS和XRD对沉积层进行表征。确定最佳工艺条件为:硫酸镍25g/L,次亚磷酸钠30g/L,硫酸锌8g/L,柠檬酸钠60g/L,硫酸铵25g/L,乳酸30ml/L,镀液温度为(85±1)℃,镀液pH值为9.0。X射线衍射分析表明,镀态下化学沉积Ni-Zn-P合金由非晶态的相和镍的固溶体存在。研究了沉积层在0.05mol/L盐酸流动介质中的冲蚀行为,化学沉积Ni-Zn-P合金层质量损失随介质流动速度提高,冲击角度的减小而增加。

Zn-Fe-P合金镀层中磷、铁含量影响因素的研究

采用自制的析磷助剂EA P作为Zn Fe P合金镀层中的磷源 ,研究了Zn Fe P合金镀液组成及工艺条件对镀层中磷、铁含量的影响。在最佳工艺条件下 ,可得到磷、铁含量分别为 0 .6 %左右和 0 .4%Zn Fe P合金镀层。腐蚀试验证明 ,经银白色钝化后的Zn Fe P合金镀层的耐蚀性能是Zn Fe合金镀层的 2倍以上。