生态清洁小流域中“河湖水系生态防护”治理措施的探索与实践

生态清洁小流域建设是小流域综合治理的深化与发展,对保护涵养水源、复苏河湖生态环境、科学开展大规模国土绿化行动、建设宜居宜业和美乡村具有重要作用。自2021年上海全面启动生态清洁小流域建设以来,到2025年建设50个生态清洁小流域,覆盖约3,200km^(2)的土地,约占全市总面积的51%;到2035年,覆盖全市的151个生态清洁小流域全部建成。文中结合设计工作实践经验,从上海市生态清洁小流域建设评价指标中的“水系治理评价”指标之一——“河湖水系生态防护比例”展开讨论,通过对上海地区河湖水系生态防护现状情况、存在的主要问题进行分析研究,提出提高“河湖水系生态防护比例”的治理措施。

道路农田防护林系统水分关系研究

道路农田防护林系统水分关系研究任勇，王佑民（北京林业大学，１０００８３）（西北林学院，陕西杨陵７１２１００）ＷａｔｃｒＲｅｌａｔｉｏｎｓｉｎＦａｒｍｌａｎｄＳｈｅｌｔｅｒｂｅｌｔＳｙｓｔｅｍｂｙｔｈｅＲｏａｄｓ．ＲｅｎＹｏｎｇ￥（ＢｅｉｊｉｎｉｇＦｏｒｅｓｌｒｙＵｚｉｕｅｒｓｉｔｙ，１０００８３），ＷａｎｇＹｏｕｍｉｎ（ＮｏｒｔｈｗｅｓｔｅｒｎＣｏｌｌｅｇｅｏｆＦｏｒｅｓｔｒｙ，Ｙａｎｇｌｉｎｇ，Ｓｈａａｎｘｉ，７１２１００）．ＣｈｉｎｅｓｅＪｏｕｒｎａｌｏｆＥｃｏｌｏｇｙ，１９９３，１２（４）：ｌ－６．ＩｎｔｈｅｒｅｇｉｏｎｆｒｏｍｌｏｅｓｓｐｌａｔｅａｕｔｏＮｏｒｔｈＷｅｉＲｉｖｅｒ，２０－１００ｃｍｓｏｉｌｌａｖｅｒｉｓｔｈｅｍａｉｎｌａｖｅｒｆｒｏｍｗｈｉｃｈｔｈｅｒｏｏｔｓｙｓｔｅｍｏｆＰ．×ｄａｋｕａｎｅｎｓｉｓＨｓｕａｂｓｏｒｂｓｗａｔｅｒ，ａｎｄ０－０．１ＨｉｓｔｈｅｒａｎｇｅｉｎｗｈｉｃｈＰ．×ｄａｋｕａ－ｎｅｎｓｉｓｂｙｔｈｅｒｏａｄｓｓｔｒｏｎｇｌｙａｆｆｄｃｔｓｂｙｔｈｅｒｏａｄｓｓｔｒｏｎｇｌｙａｆｆｅｃｔｓｍｏｉｓｔｕｒｅｃｏｎｄｉｔｉｏｎｏｆｆａｒｍｌａｎｄ．

空气中常见5种苯系物测定及防护

随着人们环保意识的提高,空气中苯系物的环保数据越来越引起人们的关注。虽然苯系物中的5种苯、甲苯、二甲苯等有害成分制订了职业卫生接触限值,石化行业作为环境中多环芳烃的一个重要的潜在污染源,与周边环境尤其是环境空气中多环芳烃污染的关系。但是目前尚缺少空气体中现场快速定性的定性分析方法,遇到情况不能及时采取有针对性的措施。因此,基于对环境空气中苯系物的监测分析,对进一步探究其相应的治理方法有重大意义。

汽车制动系防护液的研制

在对意大利菲亚特公司原装ＰＲＦ－１防护液剖析的基础上，克服了ＰＲＦ－１防护液防锈性、制动液相容性差的缺点，选用合适的基础液，加入适当添加剂，研制成功ＮＪ－５７８防护液，通过标准规定的各项试验及模拟实际使用试验，并通过批量装车（装泵）试验。

坝系成龙配套经济效益显著

东石羊流域位于石楼县城东面,距县城10km,属黄土丘陵沟壑区,总土地面积110km^2,包括东石羊,西卫两个乡的10个行政村,1500户,6000余人,折合男劳力2000余个,流域内丘陵起伏,沟壑纵横,山高坡陡,地形支离破碎,水土流失十分严重,沟壑密度4.5km/km^2,沟壑面积占总面积的45.1％,为打坝拦泥提供了有利的条件,发展沟坝地,建立高效农田的潜力很大。

STEADY HEAT TRANSFER ANALYSIS AND PARAMETER OPTIMIZATION FOR MULTILAYER THERMAL INSULATIONS

The energy equilibrium equation and discrete ordinate methods are combined to establish the one-dimensional steady heat transfer mathematical model of multi-layer thermal insulations （MTIs） in metallic thermal protection systems. The inverse problem of heat transfer is solved by the genetic algorithm and data from the steady heat transfer experiment of fibrous thermal insulations. The density radiation attenuation coefficient, the albedo of fibrous thermal insulations and the surface emissivity of reflective screens are optimized. Finally, the one-dimensional steady heat transfer model of MTIs with optimized thermal physical parameters is verified by experimental data of the effective MTI conductivity.

A Method for Spatial Heterogeneity Evaluation on Landscape Pattern of Farmland Shelterbelt Networks:A Case Study in Midwest of Jilin Province,China

On the basis of landscape ecology, combining the Spot 5 high resolution satellite imagery with GIS, a method evaluating the spatial heterogeneity of shelterbelts distribution at landscape scale is put forward in this paper. The distance coefficients of reasonable and existing landscape indexes of farmland shelterbelt networks were com-puted, and then through the classification of the distance coefficients, and the establishment of evaluation rules, the spatial heterogeneity of farmland shelterbelts was evaluated. The method can improve the evaluating system of previ-ous studies on shelterbelts distribution, resolve the disadvantages of lacking spatiality of overall evaluation, and make the evaluation results have more directive significance for shelterbelt management. Based on this method, spatial het-erogeneity of shelterbelt networks was evaluated in the midwest of Jilin Province, China. The results show that the re-gions with fewer shelterbelts and no closed network account for 34.7% of the total area, but only 4.9% of the area has relative reasonable pattern of shelterbelt networks. Many problems exist in the distribution pattern of shelterbelts, therefore, much attention should be paid to construct farmland shelterbelts in the study area.

Bio-control of Some Food-Borne Pathogenic Bacteria by Bacteriophage

In recent years, researchers tended to bring new alternative to biological protective systems used in conservation of food and production of safe food. Use of bacteriophage against to pathogen bacteria in food was the most hopeful system in these methods about bio-control. Controls of bacteriophage for each pathogen species and subspecies and determination of phage-host originality are important because efficient bio-control was achieved. Researches concentrated on some food-borne pathogen bacteria such as E. coli O157：H7, Campylobacter, Salmonella and Listeria. In a consequence of these studies made as in vitro and in vivo, first commercial production of phage which will be used in foods was made in Netherlands. Also, it has been informed that use of phage is cost-efficient alternative as compared with other preservatives. This review, discussed application of bacteriophages as bio-control agents in food and advantages and disadvantages about uses of bacteriophages by taking into account antimicrobial characteristics of them.

Climate Characteristics of Thunder and Lightning in Anyang City

The research explored frequencies of different weathers caused by con-vection, characters of thunder and lightning, spatial and temporal changes, move-ment routes, geographical distribution, daily, monthly and annual changes of thunder or lightning, based on 30 years information. Furthermore, a search system of thun-derstorm in history was established, laying foundation for prevention and prepared-ness of thunderstorm in Anyang.

Maintenance decision-making method for manufacturing system based on cost and arithmetic reduction of intensity model

A cost-based selective maintenance decision-making method was presented.The purpose of this method was to find an optimal choice of maintenance actions to be performed on a selected group of machines for manufacturing systems.The arithmetic reduction of intensity model was introduced to describe the influence on machine failure intensity by different maintenance actions (preventive maintenance,minimal repair and overhaul).In the meantime,a resolution algorithm combining the greedy heuristic rules with genetic algorithm was provided.Finally,a case study of the maintenance decision-making problem of automobile workshop was given.Furthermore,the case study demonstrates the practicability of this method.

Effects of flow velocity on electrochemical behavior of seachest 5083-H116 Al alloy for ship

Electrochemical behavior of 5083-H116 Al alloy with flow velocity of seachest material for Al ship was evaluated.To examine the electrochemical characteristics of flow velocity and its effects on the performance of the alloy,experiments were conducted at four flow velocity variables using static state with an agitator.An ultrasonic vibration generator using piezoelectric effect was used in cavitation test according to the requirements of in ASTM-G32.The results show that the corrosion current density and damage were increased by applying the flow velocity compared to static state.Therefore,it is determined that the case of applying flow velocity is weaker to the corrosion.

Preliminary Experimental Analysis of a CHP Hydromethane System

The aim of this paper is to present the preliminary experimental analysis results carried out on the commercial internal combustion engine set in a CHP （combined heat and power） mode, fueled by renewable hydrogen and methane mixtures. The hydrogen is produced by an alkaline electrolyser fed by a 5.8 kWp grid connected PV （photovoltaic） plant. The acceptance test conducted with hydrogen percentages ranging from 0%-10% has been carried out at partial load： 45 kW^l instead of the full power of 60 kWe~. In order to evaluate the CHP energy consumption and environmental performance （NOx and CO）, the analysis was conducted for 240 h, using a portable flue gas analyser and two mass flow meters for hydrogen and methane. Without engine parameters optimization--relative equivalence ratio （2） and spark advance--increasing hydrogen addition rate, a slight enhancement in electrical efficiency occurs. Furthermore, due to the engine control system and lower blends LHV （lower heating value）, the methane consumption decreases disproportionately to the hydrogen amount in the mixture. Finally, referring to standard operating condition, the environmental results show that using enrichment of 10%, running the engine with 18 degrees spark advance and 2 of 1.4, CO and NOx emissions are reduced by 6.3% and 27% respectively.

DYNAMIC GUARD CHANNEL ASSIGNMENT FOR BIDIRECTIONAL CALL-OVERFLOW SCHEME IN HIERARCHICAL CELLULAR SYSTEM

In this paper, a Hierarchical Cellular System (HCS) supporting two classes of users with high and low velocity is considered. Based on the analytical model of the bidirectional calloverflow scheme, a new dynamic guard channel assignment method is proposed In this method, the number of guard channels in both macrocells and microcells varies in realtime according to the different call traffic load in the HCS, and as a result, the lowest dissatisfaction grade of users is achieved.

Evaluation of the Maintenance Management Associated with the Performance of a Public Building

The lack of proper maintenance in buildings is responsible for various anomalies, which can cause property and personal damage. The objective of this study is to analyze the maintenance management of the administration building at the Technological Park UFRJ/Brazil, trying to emphasize the relation between maintenance and good performance of the building and to demonstrate the need to develop a consistent maintenance system to achieve an efficient maintenance management. The study allowed to present strategies and possibilities of interventions, in addition to proposing the essential aspects for the development of a structured maintenance system. After reviewing the issue of building maintenance under the various perspectives presented, the importance of planning a preventive building maintenance, according to standards, to achieve the level of performance expected for the building, besides being essential the search for tools and methods that can increase the efficiency of management can be concluded. It is also pertinent to conclude that prevention is the most effective solution against the depreciation factors that affect a building, being the most economical viable, and ensuring other benefits for the building and its users, such as security, property valuation and attendance to the warranty period.

Evaluation of long-term corrosion durability and self-healing ability of scratched coating systems on carbon steel in a marine environment

Defects in protective-coating systems on steel surfaces are inevitable in practical engineering applications. A composite coating system, including a primer, middle coat and topcoat, were used to protect carbon steel from corrosion in a marine environment. Two environmental additives, glass fibers and thiourea, were applied in the middle coat to modify the coating system. The long-term corrosion durability and self-healing ability of the scratched coating system were evaluated by multiple methods. Results of the electrochemical technologies indicated that the coating system that contained 0.5 wt.% fibers and 0.5 wt.% thiourea presented good corrosion protection and self-healing for carbon steel when immersed in 3.5% NaCl for 120 d. Evolution of localized corrosion factors with time, as obtained from the current distribution showed that fibers combined with thiourea could inhibit the occurrence of local corrosion in scratched coating systems and retarded the corrosion development significantly. Surface characterization suggested that adequate thiourea could be absorbed tmiformly on fibers for a long time to play an important role in protecting the carbon steel. Finally, schematic models were established to demonstrate the action of fibers and thiourea on the exposed surface of the carbon steel and the scratched coating system in the entire deterioration process.

Root Effect of Three Vegetation Types on Shoreline Stabilization of Chongming Island,Shanghai

Coastal erosion is currently a major problem along the southern coast of Chongming Island, Shanghai. To enhance the erosion protection ability of coastal shelterbelts, two woody tree species, Taxodium ascendens and Salix babylonica, were planted separately into Phragmites australis ＋ Scirpus mariqueter communities in 2006. Two years later, we investigated whether either of these experiments reduced erosion and increased stability in the native herbaceous plant community. We also examined soil stability and root length density under T. aseendens added, S. babylonica added and native herbaceous vegetation conditions along an intertidal gradient from the soil surface to a depth of 40 cm in each experiment, thus to determine the capacity of T. ascendens and S. babylonica to contribute to shoreline stabilization. Topsoil under the native vegetation had greater stability at the middle and higher intertidal zones because its soil stability index and root length density were significantly higher than in the T. ascendens or S. babylonica planted communities. The effect of T. ascendens on soil stability was not generally better than that of the native vegetation. Only at the 20-30 cm soil depth of the middle intertidal zone and in the 10-20 cm layer of the higher intertidal zone the soil stability index and root length densities under the T. ascendens added condition were significantly higher （P 〈 0.05） than those of the native vegetation. The S. babylonica planted soil had greater stability in the deeper soil layer than the soil under either the native vegetation or the T. ascendens added condition, and its soil stability index and root length density were significant higher （P 〈 0.05） than those of other vegetation conditions at the 30 40 cm soil depth for the lower intertidal zone and at the 20-40 cm layer for middle and higher intertidal zones.

Energy conversion in woodpecker on successive peckings and its role on anti-shock protection of brain

To investigate the mechanism of brain protection of woodpecker,we built a finite element model of a whole woodpecker using computed topography scanning technique and geometry modeling.Dynamic analyses reveal:(i)99.7%of the impact energy is converted into strain energy in the bulk of body and 0.3%is converted into strain energy in the head after three successive peckings,indicating the majority of the impact energy is stored in the bulk of body;(ii)the strain energy in brain is mainly converted into the dissipated energy,alleviating the mechanical injury to brain;(iii)the deformation and the effective energy dissipation of the beaks facilitate the decrease of the stress and impact energy transferred to the brain;(iv)the skull and dura mater not only provide the physical protection for the brain,but also diminish the strain energy in the brain by energy dissipation;(v)the binding of skull with the hyoid bone enhances the anti-shock ability of head.The whole body of the woodpecker gets involved in the energy conversion and forms an efficient anti-shock protection system for brain.

Numerical Analysis for Heat Shield Ablation Law in Transpiration Cooling System

The transpiration cooling control system of the thermal protective shield with surface ablation is a nonlinear control system of distributed parameter with moving boundary.As far as the boundary conditions the third kind and a one-dimensional incompressible coolant flow under constant transpiration mass flux are concerned,this paper transforms the definite solution problem into the second-type Volterra integral equations,and applies them directly to compute the shield ablation law.Investigation of the system's control by transpiration mass flux,ablation amount and ablation velocity varying with time,time of the ablation's beginning and ending,etc.,are presented.