蒸汽锅炉出力负荷在锅炉烟尘测试中的意义及计算方法

阐明了锅炉出力负荷在锅炉烟尘测试中的意义,同时,提出了锅炉出力负荷的五种计算方法,并特别推荐了"折算烟气流量法".     

正本清源,系统开发整治长江各支流网系的山丘土地

长江流域泥沙问题仍值得重视。长江不同于黄河．黄河年输沙量１６亿ｔ，主要为悬移质；长江多年测得输沙量５．４亿ｔ，这仅是长江的部分泥沙量－悬移质，还有数据不详的推移质随急流滚动位移。防治泥沙的良策是上游绿化造林，但还有很大面积的陡玻耕地，以及紫色土丘陵坡耕地与石灰岩区坡耕地等，仍应重点防护；至于广大的荒山、荒坡，更应多途径合理经营，从各大、小流域；溯江而上到源头径流发生处，采取工程与生物相结合的方法，节节设防，将泥沙来源减少到最低限度。最好利用大坝兴建的空隙期间，有计划有步骤地节节设防，以延长大坝寿命，当地居民亦可获利。     

A SIMPLIFIED STREAM MODEL OF ACID MINE DRAINAGE EFFECTS1

ABSTRACT: Three methods of modeling acid mine drainage effects are discussed. A net alkalinity routing model is the simplest of these, but can be potentially misleading. It typically overestimates the effect of acid sources on pH by neglecting carbon dioxide transfer to the atmosphere. Inclusion of a simple carbon dioxide transfer function can substantially reduce errors in stream quality prediction. A plug flow reaeration equation, coupled with mass balancing at mixing points in a stream network provides modeling results comparable to those of more complex computerized solutions of chemical equilibrium equations. None of the models accounts for carbonate dissolution or oxidation and hydrolysis of ferrous iron.     

我国农村耕地利用及保护对策

论述了当前我国土地资源利用中存在的耕地数量减少、耕地质量下降、土地利用结构和布局不合理、土地资源未能得到有效配置等问题，分析了这些问题产生的原因，并在此基础上提出了相应的耕地保护对策。     

Time-lapse carbon dioxide monitoring with pulsed neutron logging

Elevated levels of CO₂ in the atmosphere have been linked to the rise in land and sea temperature [Climate Change, 2001. In: Houghton, J.T., Ding, Y., Griggs, D.J., Noguer, M., van der Linden, P.J., Xiaosu, D. (Eds.), The Scientific Basis Contribution of Working Group I to the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). Cambridge University Press, UK, p. 944]. To demonstrate geological carbon sequestration as a mitigation technique, a carbon dioxide injection experiment was conducted in East Texas. The target – Frio formation – is a highly porous, permeable and unconsolidated sandstone. The specific interval is the Frio C sand, which originally was saturated with saline formation water. At the injection location, the Frio C sand dips 18° to the south. To monitor the injected CO₂ spreading in the formation, an old well from 1956 drilled into the deeper Yegua formation was selected as the observation well. The injection well was drilled at a distance of 100 ft downdip from the monitoring well. Several borehole measurement methods were available to monitor the CO₂ injection, but the most suitable technology was thought to be the pulsed neutron logging. This logging is used widely in cased hole, and the measured macroscopic thermal absorption cross-section (Σ) is sensitive to CO₂ saturation in high porosity saline water environments. Several log examples are given demonstrating successful the monitoring of the CO₂ plume moving through the two boreholes and the resulting saturation changes.     

Approaches to Evaluate Water Quality Model Parameter Uncertainty for Adaptive TMDL Implementation1

Abstract: The National Research Council recommended Adaptive Total Maximum Daily Load implementation with the recognition that the predictive uncertainty of water quality models can be high. Quantifying predictive uncertainty provides important information for model selection and decision‐making. We review five methods that have been used with water quality models to evaluate model parameter and predictive uncertainty. These methods (1) Regionalized Sensitivity Analysis, (2) Generalized Likelihood Uncertainty Estimation, (3) Bayesian Monte Carlo, (4) Importance Sampling, and (5) Markov Chain Monte Carlo (MCMC) are based on similar concepts; their development over time was facilitated by the increasing availability of fast, cheap computers. Using a Streeter‐Phelps model as an example we show that, applied consistently, these methods give compatible results. Thus, all of these methods can, in principle, provide useful sets of parameter values that can be used to evaluate model predictive uncertainty, though, in practice, some are quickly limited by the “curse of dimensionality” or may have difficulty evaluating irregularly shaped parameter spaces. Adaptive implementation invites model updating, as new data become available reflecting water‐body responses to pollutant load reductions, and a Bayesian approach using MCMC is particularly handy for that task.     

Predictors for people's response to a tornado warning: Arkansas, 1 March 1997

On 1 March 1997, powerful tornadoes touched down in Arkansas (USA) on a Saturday afternoon. Twenty-six fatalities and 400 non-fatal injuries were reported. We performed a population-based cross-sectional study to determine factors associated with appropriate responses to tornado warnings. Of 146 survey participants, 140 (96 per cent) knew the difference between 'tornado watch' and 'tornado warning' and were aware of when the warning was announced. Of those 140 participants, 64 (45.7 per cent) responded to the warning by seeking shelter, and 58 (90.6 per cent) of those 64 acted within five minutes of hearing the warning. Four factors were positively associated with those seeking shelter: having graduated from high school (OR = 4.2, 95 per cent CI = 1.1-15.5); having a basement in one's house (OR = 3.8, 95 per cent exact CI = 1.1-17.1); hearing a siren (OR = 4.4, 95 per cent CI = 1.3-18.9); and having prepared a household plan of response when tornadoes occur (OR = 2.6, 95 per cent CI = 1.1-6.3). On the basis of these findings, we recommend: first, that people who live in tornadoprone areas have a personal plan of action to help them respond immediately to warnings; second, public-health education officials in areas with frequent tornadic activity should do more to educate the public about what they can do to protect themselves from a tornado; and third, that emergency-management officials planning protection measures for vulnerable communities should consider that most people have limited time (our study documented five minutes) in which to respond to a tornado warning. Thus, shelters in tornado-prone areas should be quickly accessible by residents.     

城镇污水处理厂工艺改造及运行调控技术的探讨

为满足《城镇污水处理厂污染物排放标准》（GB18918-2002）的一级A标准水质要求,城镇污水处理厂技术升级与改造已进入实质性阶段。以某高新区污水处理厂升级改造为例,从进水水质、工艺特点、节能降耗、安全运行、技术维护等方面,提出可行措施与技术方法,保证污水处理厂升级改造后稳定运行。     

高速公路两侧大气环境保护初探

随着我国机动车数量与日俱增以及越来越多的企业依托便利的交通条件建设在高速公路沿线,严重影响了高速公路周围的大气环境。围绕辽宁省环境保护局近期制定并发布的《沈大沈丹无烟路工程实施方案》的内容,探讨了高速公路环境保护工作中的问题和解决方法,为今后高速公路的环境保护工作提供参考。     

地下洞室松动圈的研究方法与现状

地下空间的开发和利用是当前岩土工程发展的重要趋势之一.地下洞室是开挖在岩土体中作为各种用途的构筑物,地下开挖后,破坏了岩土体天然应力的相对平衡状态,引起围岩应力的重新分布,因此,地下洞室稳定性分析的重要内容之一是确定围岩应力的大小.围岩应力受诸多因素的影响,松动圈是重要的影响因素之一.文中比较详细地介绍并分析多种松动圈的确定方法,并对各种方法的优缺点进行简要评述,同时介绍了未来研究的方向.