燃煤电厂PM_(2.5)捕集增效技术的研究及应用

介绍了一种燃煤电厂PM2.5捕集增效技术—烟尘预荷电微颗粒捕集增效装置的结构组成和工作原理,研究了双极荷电对粉尘凝并的影响及扰流柱的产涡效果,在中试平台上测试了热态模拟烟气条件下该装置的增效结果。该技术在300MW机组工程上应用的测试结果为:电除尘器出口PM2.5下降30%,烟尘总质量浓度下降20%。     

高耗水工业用水量控制和水价调整政策效果研究:基于水资源动态CGE的分析

论文应用水资源动态CGE模型,研究和分析了高耗水工业不同水资源管理政策对经济、社会和水资源利用的影响。文章首先构建了将水资源作为生产要素的CGE模型,并建立了动态机制,然后以2010年为基准年模拟和分析了2010—2020年间高耗水工业用水量控制和水价上涨不同情景下的影响。分析表明:高耗水工业的水量控制比水价调整对宏观经济的影响大,表现为GDP和居民福利的显著下降以及投资的大幅度上升;而高耗水工业水价上升对宏观经济的影响较小,表现为GDP的小幅度上升以及居民福利的小幅度下降和投资的上升;对部门的影响比较复杂,但高耗水工业水量下降和水价上升,都将导致其产出降低。对水资源利用的影响显示,水量控制和水价上升对用水总量的影响较小,但对提高工业用水效率都十分显著。     

A CFD based explosion risk analysis methodology using time varying release rates in dispersion simulations

A full probabilistic Explosion Risk Analysis (ERA) is commonly used to establish overpressure exceedance curves for offshore facilities. This involves modelling a large number of gas dispersion and explosion scenarios. Capturing the time dependant build up and decay of a flammable gas cloud size along with its shape and location are important parameters that can govern the results of an ERA. Dispersion simulations using Computational Fluid Dynamics (CFD) are generally carried out in detailed ERA studies to obtain these pieces of information. However, these dispersion simulations are typically modelled with constant release rates leading to steady state results. The basic assumption used here is that the flammable gas cloud build up rate from these constant release rate dispersion simulations would mimic the actual transient cloud build up rate from a time varying release rate. This assumption does not correctly capture the physical phenomena of transient gas releases and their subsequent dispersion and may lead to very conservative results. This in turn results in potential over design of facilities with implications on time, materials and cost of a project.In the current work, an ERA methodology is proposed that uses time varying release rates as an input in the CFD dispersion simulations to obtain the fully transient flammable gas cloud build-up and decay, while ensuring the total time required to perform the ERA study is also reduced. It was found that the proposed ERA methodology leads to improved accuracy in dispersion results, steeper overpressure exceedance curves and a significant reduction in the Design Accidental Load (DAL) values whilst still maintaining some conservatism and also reducing the total time required to perform an ERA study.     

旱作小麦─玉米垅种沟盖地膜带田集水调水与增产效应研究

旱作垅种（小麦）沟盖（玉米）地膜带田优于目前推广的沟种（小麦）垅盖（玉米）带田种植形式。在作物共生期相互调水作用更趋合理，平衡了小麦、玉米不同生育阶段对水分的供需矛盾，作物的生态条件更加适宜，群体结构更加协调，提高了作物的生产量，前者比后者增产９０％～１２５％。     

黄土高原水土流失区粮食现状与增产潜力研究

以黄土高原10个试区的攻关资料为基础,从区域旱作产量潜势、试区攻关水平和试区所在县的产量现状三个层次,详细剖析了黄土高原水土流失区粮食现状和增产潜力。结果指出,该区粮食增产潜力很大,目前整体产量水平仅达到试区攻关水平的74.7%,达到旱作粮食产量潜势水平的54.2%。在黄土台塬区和丘陵区中,丘陵区的粮食增产潜力较台塬区大,前者尚有117.6%增产能力,后者仅56.6%。但考虑到人口增长和坡耕地的退垦等因素,未来30年内黄土高原水土流失区的粮食供需仍处于负平衡。     

清初“摊丁入亩”政策对环境的影响

清初“摊丁入亩”政策对清社会经济的恢复发展确实起到了促进作用,但同时对环境也构成了巨大威胁,引发了地表植被遭严重玻坏、自然灾害频繁、珍稀野生动植物大量灭绝等一系列环境问题。剖璞见玉,对今有史鉴作用。     

Selective phonotaxis by male wood frogs (<Emphasis Type="Italic">Rana sylvatica</Emphasis>) to the sound of a chorus

Frogs and toads commonly form large choruses around suitable breeding habitat during the mating season. Although often regarded as a constraint on the acoustic behavior of signalers and receivers, the sounds of a chorus could also serve as an acoustic beacon that allows some frogs to locate the breeding aggregation. Attraction to chorus sounds might be particularly important for explosively breeding frogs. In these species, which often mate just one or a few days during the year, the timing and location of breeding aggregations can be unpredictable because their formation often depends on local climatic factors, such as rainfall or a change in temperature. I used laboratory playback experiments to test the hypothesis that male wood frogs (Rana sylvatica), an explosively breeding frog, exhibit positive phonotaxis toward the sound of a conspecific chorus. Males were released at the center of a rectangular arena with a speaker positioned in each corner facing toward the release point. In a single-stimulus experiment, more males approached a speaker broadcasting a conspecific chorus than the three silent speakers in the arena. In a two-stimulus experiment, more males approached a speaker broadcasting a conspecific chorus compared to the two silent speakers or a fourth speaker simultaneously broadcasting the spectrally overlapping sound of a heterospecific (R. septentrionalis) chorus. These results are consistent with the hypothesis that male wood frogs could use the sound of a chorus as a beacon to locate a short-lived breeding aggregation.     

Development of a method for predicting the ignition of explosive atmospheres by mechanical friction and impacts (MECHEX)

Mechanical friction and impacts is still today a main cause of ignition of explosive atmospheres (ATEX) in the industry and this trend seems to be stable in time. This situation certainly results from a significant gap of knowledge in the underlying mechanisms so that the parameters to play on are not precisely identified. In this programme of European dimensions, the process of degradation of the mechanical energy into heat during friction and impacts have been studied.

An extensive experimental programme is presented to this end. The mechanisms of dissipation of the mechanical energy into heat during friction has been studied with rubbing machines in which a slider equipped with temperature sensors rubs against a rotating wheel. For impacts, a new device has been developed using a special “air driven cannon” to propel a projectile accurately up to 50 m/s onto an inclined target. A very significant effort has been reserved to the investigation of the ignition mechanisms, not only for ATEX but also for dust accumulations.

Some “simple” modelling is proposed on purpose of practical applications. For frictional situations, a critical rubbing power is calculated without any limitations about any lower boundary concerning the rubbing velocity. For “impacts”, the relevant parameter for ignition is not the kinetic energy of the projectile but its velocity and the nature of the materials.     

实施注采一体管柱技术 节能降耗减污增效

超稠油蒸汽吞吐注采一体管柱技术,是对多项稠油开采工艺技术进行实践、总结、分析而来。该项技术,解决了作业频繁的问题,实现了不动管柱直接转抽,并可以多次注汽、转抽;由此而改变传统的蒸汽吞吐注采工艺技术,做到注、采、焖、放一体管柱,减少作业工序和降低井筒热损失,降低环境污染及电能消耗,实现超稠油不动管柱开采,有效降低超稠油开采成本,提高了油井的生产实效,并取得可观的经济效益和环境效益,实现节能、降耗、减污、增效的清洁生产目标。     

Surface solar ultraviolet radiation: A theoretical approach of the SUVR reaching the ground in Athens, Greece

Daily total ozone observations made during 1985–1993 by both the Total Ozone Mapping Spectrometer (TOMS) flown on the Satellite Nimbus-7 and the Dobson Spectrophotometer have been used in order to investigate the fluctuations of the daily broad-band and spectral solar ultraviolet radiation reaching the ground. This investigation has been performed by employing a recently developed parametric algorithm for the estimation of the spectral and broad-band solar ultraviolet radiation which takes the total ozone variations into consideration. Total ozone reductions during the summertime from 1985 to 1993 over Athens, Greece (37.6° N, 23.4° E), cause an increase in the ultraviolet irradiance which reaches the ground of 0.54 %, 0.98 %, 2.60 % and 0.79 % per decade for the months of July at 300 nm, 312 nm, 320 nm and UVB (280-320 nm), respectively.