Study on variation of smoke component concentration with water mist applying

Interaction between water mist and fire smoke is studied by experiments in an ISO 9705 room, The variation of 02, CO and CO2 concentration is disclosed, and the mathematical models of smoke component con- centration with water mist pressure and ventilation speed are established according to the experimental results. It is found in the experiment that the smoke component concentration will break when ventilation speed exceeds 1.5 kg/s. This paper provides necessary theory for water mist technology using in smoke restraining.     

衢江流域地表水与地下水的转化关系

地表水和地下水之间的转换关系是流域水循环和水环境问题研究的关键.以水化学和氢氧同位素作为示踪剂可以在一定程度上反映流域内地表水和地下水之间的关系.以衢江流域为研究区,分析了流域内地表水、地下水的水化学和氢氧稳定同位素的空间分布规律和演化趋势,定性和定量地揭示了流域内地表水与地下水的转化关系,结果表明:①溶解性总固体(TDS)、pH指标显示研究区地表水与地下水水化学指标空间变化特征相似,两者转化频繁;流域上游主要是地下水补给地表水,中下游则主要是地表水补给地下水;②阴阳离子组分显示:研究区水化学类型主要是HCO3-Ca、HCO3·Cl-Ca类型水,流域内水的最终来源为大气降水;水中离子主要受岩石风化和降水因素影响;③δD-18δO关系显示氢氧同位素含量沿河水流向不断富集;依据氢氧同位素与大气降水线之间的关系,显示出研究区地下水和地表水均受大气降水补给;④地表水与地下水的定量关系显示:研究区上游主要是地下水补给地表水,地下水对地表水的平均贡献率为19.67％,日均补给量为2.73×106 m3/d;中下游主要是地表水补给地下水,地表水对地下水的平均贡献率为22.77％,日均补给量为3.49×106 m3/d.     

Nickel-introduced structurally ordered PtCuNi/C as high performance electrocatalyst for oxygen reduction reaction

Designing highly active and durable oxygen reduction reaction (ORR) electrocatalysts is essential for developing efficient proton-exchange membrane fuel cells (PEMFCs). In this work, ordered PtCuNi/C nanoparticles (NPs) were synthesized using an impregnation reduction method. This study shows that the incorporation of Ni in ordered PtCu/C can effectively adjust the electronic structure of Pt, thereby optimizing oxygen binding energy for the ORR. The obtained intermetallic ordered PtCuNi/C NPs significantly improved ORR activity and durability compared to ordered PtCu/C. Specifically, PtCu_0·5Ni_0·5/C-700 shows a mass activity of 1.29 ​A ​mg _Pt⁻¹ ​at 0.9 ​V vs. reversible hydrogen electrode (RHE), which is about 9.2 times higher than that of commercial Pt/C. PtCu_0.5Ni_0.5/C-700 is also shown to be competent cathode catalyst for a single-cell system exhibiting high power density (461 ​mW ​cm⁻²). This work demonstrates that ordered PtCu_0·5Ni_0·5/C-700 can be used as a highly active and durable ORR catalyst in PEMFCs.     

蚯蚓过氧化氨酶的纯化及性质

赤子爱胜蚓（Ｅｉｓｅｎｉａｆｏｅｌｉｄｅ）组织匀浆抽提液经硫酸铵盐析、透析浓缩后，用大柱制备电泳纯化得到两个过氧化氢酶，均为糖蛋白，Ｍｒ分别为３９００００、４０００００。用氧电极法测得后者的表观Ｋｍ值为１４３ｍＭ，最适ｐＨ值８．０左右。ＮａＮ３、ＫＣＮ及某些金属离子如Ｃｕ（Ⅱ）、Ｃｄ（Ⅱ）、Ｚｎ（Ⅱ）、Ｎｉ（Ⅱ）等抑制酶活性；Ｐｂ（Ⅱ）、Ｆｅ（Ⅲ）有激活作用。在直隶环毛蚓（Ｐｈｅｒｅｔｉｍａｔｓｃｈｉｌｉｅｎｓｉｓ）体内实验中，Ｚｎ（Ⅱ）显著提高过氧化氢酶的总活力；Ｃｄ（Ⅱ）、Ｎｉ（Ⅱ）先是降低、随后提高酶总活力。     

菲律宾蛤仔耗氧率的研究

室内条件下研究了菲律宾蛤仔耗氧率与体重、温度之间的关系．结果表明：在１６．５～３２±１℃条件下，耗氧率随个体重量的增加而降低，呈负指数相关关系．相同条件下耗氧率随温度的升高而增加，为正指数相关系．耗氧率的高低与水中的ＤＯ水平有关，在低氧环境（ＤＯ＝１．３～３．３ｍｇＯ２／Ｌ）中的耐受时间为３５～４０ｈ，窒息点的ＤＯ值为０．７～１．１ｍｇＯ２／Ｌ．     

Dual elemental modulation in cationic and anionic sites of the multi-metal Prussian blue analogue pre-catalysts for promoted oxygen evolution reaction

Designing advanced electrocatalysts for the oxygen evolution reaction (OER) is of great significance owing to its crucial role in facilitating the production of clean hydrogen energy via water splitting. To date, it has been widely accepted that a pre-oxidation process with the in-situ generation of the catalytically active high-valence metal sites is essential for promoting the OER behavior of most transition-metal-based OER catalysts, or more felicitously speaking, pre-catalysts. Hence, exploring such pre-catalysts with high pre-oxidation reactivity is of high promise. Herein, we proposed the dual elemental modulation in the cationic and anionic sites of the multi-metal Prussian blue analogue (PBA) pre-catalysts, resulting in promoted OER behavior benefitted from the efficient pre-oxidation ability as well as the multi-metal synergy. Detailed investigations indicate that the Co-containing multi-metallic cations and mixed Fe^IIICo^III cyanide anions in NiCuCo^II–Fe^IIICo^III PBA (denoted as NiCuCo^II–Fe^IIICo^III) are beneficial to OER catalysis owing to the high intrinsic activity guaranteed by the local Co³⁺ active sites as well as the optimal multi-metal synergy. After the facile pre-oxidation process, additional high-valence Ni, Cu and Fe ions can be in-situ formed and serve as the active sites, thereby resulting in significantly improved OER behavior. For example, the OER current density of NiCuCo^II–Fe^IIICo^III exhibits 1.81 times enhancement even after 72 ?h continuous OER catalysis, and the required overpotential for 10 ?mA ?cm^?2 reduces from 288 ?mV for the fresh pre-catalyst to a remarkable record of 251 ?mV after the pre-oxidation-induced activation, making the optimal PBA-based catalyst a promising candidate for efficient and durable water electrolysis.     

Cu2O-templated fabrication of Ni(OH)2·0.75H2O hollow tubes for electrocatalytic oxygen evolution reaction

Cu₂O is an ideal template material for the preparation of transition metal hydroxide/oxyhydroxides with oxygen evolution reaction (OER) enhanced catalytic performance. Here, inspired by Pearson's principle, Cu₂O wires were prepared and used as a sacrificial template to prepare Ni(OH)₂·0.75H₂O hollow tubes (Ni(OH)₂ HTs) with highly improved surface roughness. Benefiting from unique structural advantages, the Ni(OH)₂ HTs showed excellent catalytic activity, rapid kinetics and a long-term stability as the OER catalyst, where an overpotential of only 207 ?mV was required to drive a current density of 10 ?mA ?cm^?2, an ideal kinetics with a Tafel slope as 79.8 ?mV dec^?1 was calculated, and no obvious attenuation in chronoamperometry was discovered after operation for 24 ?h. This paper provides a novel template-assisted strategy to prepare high-performance transition metal-based OER catalysts possessing hollow and tubular structures.     

Multiple metallic dopants in nickel nanoparticles for electrocatalytic oxygen evolution

Developing efficient oxygen evolution reaction(OER) electrocatalysts is of great importance for sustainable energy conversion and storage. Ni-based catalysts have shown great potential as OER electrocatalysts, but their performance still needs to be improved. Herein, we report the multiple metal doped nickel nanoparticles synthesized via a simple oil phase strategy as efficient OER catalysts. The FeMnMoV–Ni exhibits superior OER performance with an overpotential of 220 mV at 10 mA cm^-2