High power red-light GaInP/AlGaInP laser diodes with nonabsorbing windows based on Zn diffusion-induced quantum well intermixing

The layer structure of GaInP/AlGaInP quantum well laser diodes (LDs) was grown on GaAs substrate using low-pressure metalorganic chemical vapor deposition (LP-MOCVD) technique. In order to improve the catastrophic optical damage (COD) level of devices, a nonabsorbing window (NAW), which was based on Zn diffusion-induced quantum well intermixing, was fabricated near the both ends of the cavities. Zn diffusions were respectively carried out at 480, 500, 520, 540, and 580 Celsius degree for 20 minutes. The largest energy blue shift of 189.1 meV was observed in the window regions at 580 Celsius degree. When the blue shift was 24.7 meV at 480 Celsius degree, the COD power for the window LD was 86.7% higher than the conventional LD.

Investigation on Fe, Mn, Zn, Cu, Pb and Cd fractions in the natural surface coatings sampled and surficial sediments collected in the Songhua River, China

Natural surface coatings sampled (NSCSs) from the surface of shingles and surficial sediments (SSs) in the Songhua River, China were employed to investigate the similarities and difference in fractions of heavy metals (Fe, Mn, Zn, Cu, Pb, and Cd) between NSCSs and SSs using the modified sequential extraction procedure (MSEP). The results show that the differences between NSCSs and SSs in Fe fractions were insignificant and Fe was dominantly present as residual phase (76.22% for NSCSs and 80.88% for SSs) and Fe-oxides phase (20.33% for NSCSs and 16.15% for SSs). Significant variation of Mn distribution patterns between NSCSs and SSs was observed with Mn in NSCSs mainly present in Mn-oxides phase (48.27%) and that in SSs present as residual phase (45.44%). Zn, Cu, Pb and Cd were found dominantly in residual fractions (>48%), and next in solid oxides/hydroxides for Zn, Pb and Cd and in easily oxidizable solids/compounds form for Cu, respectively. The heavy metal distribution pattern implied that Fe/Mn oxides both in NSCSs and SSs were more important sinks for binding and adsorption of Zn, Pb and Cd than organic matter (OM), and inversely, higher affinity of Cu to OM than Fe/Mn oxides in NSCSs and SSs was obtained. Meanwhile, it was found that the distributions of heavy metals in NSCSs and SSs were similar to each other and the pseudo-total concentrations of Zn, Cu, Pb and Cd in NSCSs were greater than those in SSs, highlighting the more importance for NSCSs than SSs in controlling behaviours of heavy metals in aquatic environments.

掺P、B对纳米Zn-O薄膜电学特性的影响

现在普遍采用ITO薄膜(In_2O_3:Sn)作为太阳电池的窗口材料，但由于In资源的稀缺，使太阳能电池的成本增加。Zn-O是一种低成本材料，具有良好的电学、光学特性，因此可代替ITO薄膜作为窗口材料。由于ZnO/n-Si异质结太阳电池的转化效率为6.9%～8.5%，而ITO光电转换效率为12%～15%，采用液态源掺杂方法，取得较好效果，证实了掺P、B对纳米ZnO薄膜提高导电性是有效的。本文利用扫描俄歇探针等手段研究分析了掺P、B随热处理温度的变化对纳米Zn-O薄膜电学特性的影响。在研制过程中，对掺入P、B的纳米Zn薄膜，曾采用X射线衍射议进行分析，其结果未见P、B。

Zn扩散工艺在降低VCSEL p型DBR串联电阻中的应用

于2010-11-23批量导入

MOVPE生长Al（0.35）Ga（0.65）As/GaAs量子阱结构的光致发光

于2010-11-23批量导入

Determination of the interdiffusion coefficients of liquid Zn and Sn using Ta/Zn-Sn/Si trilayers

In this paper we present a new method for measuring diffusion coefficients in liquid metals under convection-less conditions with solid/liquid-liquid/solid trilayer. The advantage of this kind of trilayer is that effects from gravity-induced convection and Marangoni-convection can be omitted, so that the diffusion coefficient is determined more accurately. The Ta/Zn-Sn/Si trilayer were prepared with a multi-target ion-beam sputtering deposition technique and annealed in an electric furnace under an argon atmosphere. The interdiffusion of liquid zinc and tin at 500 degrees degree C was investigated. The diffusion concentration profiles were determined by energy dispersive spectroscopy. The interdiffusion coefficients range from 1.0x10(-6)cm(2)/s to 2.8x10(-6)cm(2)/s, which is less than previous values measured by capillary reservoir technique under 1g-environment where various convection exist. The precise interdiffusion coefficients of liquid zinc and tin result from the removing of disturbances of various kinds of convection.

重金属对矮小拟丽突线虫的毒性效应研究

为了探讨重金属对矮小拟丽突线虫（Acrobeloides nanus）的毒性作用，本文采用室内培养的方法，研究了不同浓度Cu、Zn、Pb、Cd对矮小拟丽突线虫死亡率、生长发育和繁殖的影响，并对线虫世代间的毒性效应进行了比较。结果表明：1）Cu、Zn、Pb、Cd对矮小拟丽突线虫24 h的半致死浓度LC50值分别为 0.80、71.20、12.94 和 1.42 mg • L-1，48 h 的半致死浓度LC50值分别为 0.71、35.08、2.65 和 0.32 mg • L-1。不同重金属离子对矮小拟丽突线虫产生的毒性具有一定的差异，24 h四种重金属离子对矮小拟丽突线虫的毒性大小依次为Cu > Cd > Pb > Zn，48 h毒性大小依次为Cd > Cu > Pb > Zn；2）与对照组相比，各暴露组当代（P0）和后代（F1）线虫平均体长均显著降低（P<0.05, P<0.01）；随着暴露浓度的增加，当代（P0）和后代（F1）线虫平均体长呈逐渐降低的趋势。生物量比体长更能敏感地反应重金属对矮小拟丽突线虫生长发育的影响，可作为重金属污染的敏感检测指标；3）供试线虫的产卵数随着Cu、Zn、Pb、Cd暴露浓度的增加而降低；其中Cu对线虫产卵数的72h-EC50、EC20和EC10值分别为1.35、0.49 和 0.2mg • L-1，Zn的72h-EC20和EC10值分别为330.29 和 163.9 mg • L-1，Pb的72h-EC20、EC10分别为17.41、4.36 mg•L-1，而Cd对线虫产卵数的72h-EC50、EC20和EC10分别为4.47、0.91 和 0.53 mg • L-1。研究结果表明，重金属Cu、Zn、Pb、Cd暴露可显著抑制矮小拟丽突线虫的生长发育和繁殖；线虫体长、产卵数表现出明显的重金属浓度依赖性。

Cd、Pb、Cu、Zn和As在草甸棕壤中垂直迁移规律的研究

本文运用土柱淋溶试验，研究了不同条件下Cd、Pb、Cu、Zn和As等五种重金属元素在草甸棕壤中垂直迁移的规律。试验表明，一般情况下各重金属元素向下迁移的深度不超过10cm，绝大部分还是滞留在表层污染土中，因此在本试验条件下不会因淋溶迁移而导致地下水的污染。从不同重金属元素的迁移情况来看，Cd和Zn的迁移能力较强，Cu、Pb和As的迁移能力较弱。随着土壤pH值降低，Cd、Pb、Cu和Zn的迁移加强，As的迁移减弱。加大淋溶水量，能促进各种重金属离子随土壤水溶液的迁移。在供试浓度下，各重金属元素对水稻的生长没有危害，但对紫花苜蓿的生长却有影响，水稻籽实（或糙米）和紫花苜蓿茎叶中各重金属元素的含量都有增加，甚至超标。土壤施用石灰，能抑制各重金属元素在草甸棕壤中的迁移及被作物的吸收，是降低土壤重金属污染危害的一个有效措施。但是利用施加腐殖酸来防治土壤重金属污染往往会因造成土壤pH值下降、增加某些重金属的可溶性而遭失败。试验还表明，Cd、Pb、Cu和Zn的迁移在酸雨条件下会加剧，但As的迁移仅在弱酸性酸雨条件下增加，强酸性酸雨反而抑制As的迁移。