高纯NF3气体管路系统的预处理

高纯三氟化氮气体在电子工业中有着广阔的应用前景,在生产过程中常存在微粒子的污染问题,本文介绍了目前工业化生产三氟化氮(NF3)过程中微粒子产生的原因及几种不锈钢管路和阀门、附件的处理方法。     

氮对奥氏体不锈钢氢脆敏感性的影响

本文研究了气相充氢条件下,氮对２１—６—９奥氏体不锈钢力学性能的影响,以及不同牌号的Ｃｒ─Ｎｉ—Ｍｎ系奥氏体不锈钢充氢后力学性能的变化。结果表明,不同牌号奥氏体不锈钢的抗氢脆能力随其层错能的增加而提高,氮含量的增加则使２１—６—９钢的抗氢脆能力下降。由此推论氮可能具有降低奥氏体钢层错能的作用。     

液氮远洋渔业综合体--浅谈液氮在远洋渔业中的应用

本文从国内远洋渔业现状出发,大胆地提出一个不同于国内外现有远洋渔业捕捞的技术体系想法---液氮远洋渔业综合体,详细介绍了其构成、存在问题及解决方案等技术要点,为国内远洋渔业的发展提供了重要的价值取向。     

Modelling of high speed gas quenching

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Nitrogenous discharges to the eastern Gulf of Finland, the Baltic Sea: Elemental flows, stable isotope signatures, and their estuarine modification

We studied the nutrient input to the Gulf of Finland via River Neva, the largest river discharging freshwater to the Baltic Sea, and characterised the isotopic signatures (¹⁵N, ¹⁸O, ¹³C) in dissolved and particulate substances (NO₃⁻, PON, POC, DIC) in the River Neva over two seasonal cycles, as well as in samples from St. Petersburg wastewater treatment plants (NO₃⁻, NH₄⁺, PON, POC). These riverine and municipal discharges account for 40% of terrestrial inorganic N loading to the Gulf of Finland, representing annually 7% of the total nitrogen pool in the water mass of the whole Gulf. To describe and evaluate the modification of these isotopic signals along a Gulf of Finland transect towards the Baltic Proper, two cruises were arranged, one in late spring after the annual maximum in River Neva runoff, and one in autumn, in the late phase of the annual growth season.River Neva nitrate signatures of ¹⁵N and ¹⁸O indicated major agricultural fertilizer origin of nitrogen, and the isotopic composition was clearly lighter (δ¹⁵N-NO₃⁻ mean of 2.4‰ air) than previously measured from more southern rivers discharging into the Baltic Sea. Because of the light composition of the River Neva N source, close to the ¹⁵N signatures of the open Gulf, as well as of the efficient depletion of the inorganic load already in the innermost estuary, straightforward end-member tracer analysis of the transport of N in the basin is problematic. St. Petersburg wastewater ammonium showed, however, high δ¹⁵N values (ca. 13‰), which gives a first estimate of 5.8‰ for δ¹⁵N of the easternmost estuarine total inorganic N source. The available sediment data from the basin (δ¹⁵N 6 to 8‰) somewhat exceeds the average source signature. This emphasizes the significance of biological transformation processes, most importantly assimilation of inorganic nitrogen, food web interactions and denitrification, which all involve isotopic fractionation, for the mass balance models describing the dynamics of the sources and sinks of the N cycle of the basin.     

二氧化氮芯片式检定管胶体的研制

选用淀粉-碘化钾法研制二氧化氮芯片式检定管胶体,研究了载体和胶体配比等对胶体性能的影响,并绘制了定量曲线。二氧化氮芯片式检定管的检测下限是0.27mg/m3。芯片式检定管无需手工切割,采用光电识别,读数误差小,可在光线昏暗的环境中使用。     

The nitrogen cycle in tidal flats and eelgrass beds of Ise Bay

A tidal flat-sea grass bed ecosystem model was formulated and applied to Ise Bay to evaluate the purification capability of the shallow-water region where a new airport is expected to be built. The model results were in the range of the observed biomass for each state variable in the model. The purification capability of this shallow-water region is estimated from the model results. The inorganic nitrogen removal is estimated at 56 kg N day⁻¹; the organic particulate nitrogen removal by suspension feeders is 95 kg N day⁻¹; the organic nitrogen removal by harvest and fish predation is 25 kg N day⁻¹, and the purification capability of this site is 51 kg N day⁻¹. Potential loss of the sea grass bed by reclamation will reduce the removal ability of inorganic nitrogen as well as food sources for juvenile fishes.     

膜空分制氮系统在某补给船上的应用

本文详细介绍膜空分制氮系统在某补给船上的应用,主要包括惰性气体保护、液位测量、扫线功能的设计思路和设计方法.     

Investigation on the flow and heat transfer characteristics of diesel engine EGR coolers

An important goal in diesel engine research is the development of a means to reduce the emissions of nitrogen oxides (NOx). The use of a cooled exhaust gas recirculation (EGR) system is one of the most effective techniques currently available for reducing nitrogen oxides. Since PM (Particulate Matter) fouling reduces the efficiency of an EGR cooler, a tradeoff exists between the amount of NOx and PM emissions, especially at high engine loads. In the present study, we performed engine dynamometer experiments and numerical analyses to investigate how the internal shape of an EGR cooler affects the heat exchanger efficiency. Heat exchanger efficiencies were examined for plain and spiral EGR coolers. The temperature and pressure distributions inside these EGR coolers were obtained in three dimensions using the numerical package program FLUENT.