大口黑鲈Micropterus salmoides仔、稚鱼窒息点与耗氧率的初步测定

在多种水温条件下，对平均体长１０．５ｍｍ和３０．０ｍｍ的大口黑鲈仔、稚鱼进行了窒息点与耗氧率的测定。结果表明：仔、稚鱼的平均窒息点分别为２．１５ｍｇ／ｌ和０．５４ｍｇ／ｌ，而平均耗氧率各为０．７６１６ｍｇ／ｇ·ｈ和０．２２２４ｍｇ／ｇ·ｈ。鱼体规格和水温对窒息点及耗氧率均有较大影响。在水温相同的条件下，仔、稚鱼的耗氧率呈现明显的昼夜变化。     

碱土金属氟化物／三氧化二钆催化剂的甲烷氧化偶联性能

考察碱土金属氟化物／三氧化二钆在甲烷氧化偶联反应中的催化性能．发现在Ｇｄ＿２Ｏ＿３中添加碱土金属氟化物，Ｃ＿２选择性和收率都有明显提高。当Ｇｄ＿２Ｏ＿３摩尔含量相同时，催化性能按Ｃａ－Ｓｒ－Ｂａ顺序递增，在８０％ＢａＦ＿２／Ｇｄ＿２Ｏ＿３催化剂上Ｃ＿２选择性和收率分别达５９．５％和１８．７％．ＸＲＤ分析结果表明，在含氟催化剂中出现了四方Ｇｄ＿４Ｏ＿３Ｆ＿６新相，其结构与立方ＣａＦ＿２，ＳｒＦ＿２和ＢａＦ＿２相似．可能有利于物相之间的匹配及载流子传递．ＸＰＳ测试发现，催化剂表面上存在着（或Ｏ￣－）物种．与Ｇｄ＿２Ｏ＿３相比，在含氟的催化剂中，Ｏ＿１ｓ结合能较高，表明该吸附氧物种所带电荷较少，对提高Ｃ＿２选择性有利。     

温度对荒漠沙蜥能量代谢、呼吸和水分蒸发的影响

本文研究了温度对荒漠沙蜥(Phrynocephalus przewalskii)能量代谢、呼吸和水分蒸发的影响.荒漠沙蜥的耗氧量(mg/g·h)log(?)和实验温度 X 之间呈正相关,回归方程为 log(?)=-1.037+0.028x,r=0.9980.相关非常显著(P<0.01),即随实验温度的升高,其耗氧量也随之增加.荒漠沙蜥的呼吸为非连续性呼吸,即通气期和非通气期相交替.在通气期,每分钟的呼吸率随实验温度的升高而增加,呈现一定的规律性.实验温度升高时,荒漠沙蜥的水分蒸发量也明显增加.22℃时的水分蒸发量为0.48mg/g·h,当实验温度升为45℃时,水分蒸发量则增至4.36mg/g·h.     

广东省血红蛋白研究Ⅵ 一例HbG—Coushatta(α_2β_2~(22)Glu→Ata)的结构与功能测定

1984年我校血红蛋白普查中检出一例电泳慢速血红蛋白,绎肽链裂解、指纹分析、氨基酸组份分析和氨基酸顺序测定确定为β链变异。即在β链22位上的GIu被Ala所取代,这是一例HbG—Coushatta(α_2β_2(~(22)Glu→Ala))。按Benesch法测定其氧亲合力,发现它的氧亲合力比HbA的高。穆斯堡尔谱测定表明这一异常Hb的S值比HbA的大,而其△E_Q值却比HbA的小,说明它所含Fe原子的电子结构有变化。本文对这一异常Hb结构与功能的关系以及穆斯堡尔参数变化的可能机理作了简单的讨论。     

几种常用阻燃剂在酸酐固化的环氧树脂中的阻燃性研究

本文用氧指数测定法研究了阻燃剂磷酸三苯酯(TPP),氯化石蜡—50(氯烃50),十溴联苯醚(FR—10),三氧化锑(Sb_2O_3)及其混合物在酸酐固化的E型环氧树脂中的阻燃规律,并对其阻燃机理进行了讨论.     

苏州河污染底泥处理的合理措施

根据底泥耗氧物质的释放和河槽稳定性的分析，认为河槽断面上不同位置的底泥污染特性不同，宜采用不同的工程措施，开挖、覆盖和曝气充氧三管齐下，可以较低的代价使底泥对水质的不良影响降低到最低，并长期维持．此外，为了满足苏州河变清的整治规划要求，下水排放和支流排放对河水污染的影响也应降到最低．     

多媒体技术综述

本文就多媒体技术应用系统的特点，多媒体技术的主要应用领域和典型应用系统以及多媒体技术的未来发展进行了综述。     

Unveiling the role of Zn dopants in NiFe phosphide nanosheet for oxygen evolution reaction

Transition metal phosphides have been recognized as promising electrocatalysts for oxygen evolution reaction(OER) due to their low cost and high activity. However, the insufficient exposed active region limited the OER performance. Recently, the introduction of sacrificial dopants has been considered an effective strategy to enlarge the surface area. Herein, the Zn dopants are introduced in NiFe phosphide(NiFeZnP) nanosheet, which work as the sacrificial dopants to generate more exposed active N...     

Effect of solvent on Se-modified ruthenium/carbon catalyst for oxygen reduction

Se-modified ruthenium supporting on carbon(Sex–Ru/C) electrocatalyst was prepared by solvothermal one-step synthesis method. The reaction mechanism was revealed after discussing impact of different solvents(i-propanol and EG) in solvotermal reaction. The result showed that the grain size of Se-modified ruthenium electrocatalyst was as small as 1 to 3 nm and highly dispersed on carbon surface. X-ray photoelectron spectroscopy(XPS) presented that selenium mainly existed in the catalyst in the form of elemental selenium and selenium oxides when the solvent was EG and i-propanol, respectively. The oxygen reduction reaction(ORR) performance was improved by appearance of selenium oxides.     

Spatially defined oxygen gradients and vascular endothelial growth factor expression in an engineered 3D cell model

Tissue hypoxia results in rapid angiogenesis in vivo, triggered by angiogenic proteins, including vascular endothelial growth factor (VEGF). Current views of tissue viability are founded on whether ‘deeper-lying’ cells receive sufficient nutrients and oxygen for normal activity and ultimately survival. For intact tissues, levels of such essential nutrients are governed by micro-vascular perfusion. However, there have been few effective quantitatively defined 3D models, which enable testing of the interplay or interdependence of matrix and cell density, and path diffusion on oxygen consumption in vitro. As a result, concepts on cell vulnerability to low oxygen levels, together with the nature of cellular responses are ill defined. The present study has adapted a novel, optical fibre-based system for in situ, real-time oxygen monitoring within three-dimensionally-spiralled cellular collagen constructs, which were then unfurled to enable quantitative, spatial measurements of VEGF production in different parts of the same construct exposed to different oxygen levels. A VEGF response was elicited by cells exposed to low oxygen levels (20 mmHg), primarily within the construct core. Received 3 August 2007; received after revision 24 October 2007; accepted 29 October 2007 An erratum to this article is available at .