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1.
诗意湿地     
大凡河湖名川,都有其独特的风姿和神韵,或广袤,或静谧,或清秀,或磅礴,或激荡,或委婉,林林总总,形形色色,各自彰显着与众不同的个性.如果说地球上生物进化经历了一个由水域向陆地的变迁,那么湿地则见证生命发生的全部过程.不仅如此,湿地作为水陆在时空坐标上的交替界面的特别区域、唯一的"四圈交汇"之地(水圈,生物圈,岩石圈,大气圈),湿地独特的自然禀赋所赋予的使命更为深远,在目睹了自然生命变迁的同时,也目睹了人类文明盛衰、社会兴亡演替的历历往事.  相似文献   

2.
清洁生产是控制环境污染的有效途径   总被引:1,自引:0,他引:1  
末端治理在防治污染过程中起一定作用,取得了一定的成绩,但实践证明,末端治理模式在不同方面存在明显不足,不能有效防治污染,清洁生产的引入,使环保史上发生一场革命,清洁生产是一种全程的污染防治,即经济又有效,要全面推广还存在一定的困难,需各部门共同努力.  相似文献   

3.
王国华 《环境》2004,(10):44-45
到长白山一定要看天池。但能否看到天池要凭缘分。导游说,不知道有多少游客兴致勃勃而来,最后却扫兴而归。天池就在那里静静地躺着,已经有千万年,上山的路途虽然艰险,但还不至于难于上青天,怎么还见不到天池呢?原来,长白山上真正是一岭分四季,十里不同天,忽云忽阴,睛雨不定;游客乘车、步行,翻山越岭,好不容易到达山顶,极有可能遇上云雾缭绕或者大雨倾盆,将天池的本来面目遮掩住。或者,干脆就被大雨挡在半路,连上山的机会都丧失掉。  相似文献   

4.
每天的17:30分,我们乘坐的班车在下班号响后会准时驶出厂门,出了厂门的右侧有个站,这儿是机关干部的上车点. 由于班车从我们车间始发,近水楼台先得月,我便有了固定的座位,一个位于车尾,靠窗的单座.而每天经过厂门口停站时,总会上来一个人,站在我边上,伸出一只毛茸茸的手抓住扶手.从那一身将校呢的制服上,我了解到他是厂武装部长,姓王,今年初刚转业到我们厂工作.  相似文献   

5.
打破僵局     
"我们拔了18吨,仍不见动静,请领导拿意见."4月13日,当河南油田井下作业二部副经理靳水生和工艺人员赶到L1256井场时,201修井队技术员范红禅立即向他们汇报拔钻解卡情况. "好,再拔拔看!"听到指令,司机汪佳柱启动30吨斜井作业机,一手扶离合器手柄,一手握刹把,脚踩油门,两眼紧盯指挥手势.作业机吼叫着,掐着油管的"脖子"使劲往上拽,那架势如同一场拔河比赛.压力器指针指向了18吨,油管还是一动不动.  相似文献   

6.
TiO2 nanomaterial is promising with its high potential and outstanding performance in photocatalytic environmental applications, such as CO2 conversion, water treatment, and air quality control. For many of these applications, the particle size, crystal structure and phase,porosity, and surface area influence the activity of TiO2 dramatically. TiO2 nanomaterials with special structures and morphologies, such as nanospheres, nanowires, nanotubes, nanorods,and nanoflowers are thus synthesized due to their desired characteristics. With an emphasis on the different morphologies of TiO2 and the influence factors in the synthesis, this review summarizes fourteen TiO2 preparation methods, such as the sol–gel method, solvothermal method, and reverse micelle method. The TiO2 formation mechanisms, the advantages and disadvantages of the preparation methods, and the photocatalytic environmental application examples are proposed as well.  相似文献   

7.
为了进一步提高HSE管理水平,切实加强采油队在施工中的风险管理,我们在采油队推行了HSE作业指导书,实施以来,增强了职工的HSE意识,规范了HSE管理,有效地防范了作业风险,取得了良好效果.  相似文献   

8.
近年来,北京市经济社会快速发展,城市人口、建设规模以及机动车保有量快速增长,与此同时,北京市围绕"新北京,新奥运"战略构想,将环境保护工作放在突出位置,在环境污染防治和生态保护建设等方面,采取了一系列重大的环境保护行动,环境质量不断好转.  相似文献   

9.
1事故经过 2004年11月30日,某热电厂5#汽轮发电机组来汽电动门下部突然着火,瞬间火势增大,值班人员立即通过控制室内停机按钮紧急停机.但由于停机操作不当,没有及时切断油源,使得火势继续蔓延,将机组前轴承箱、热工就地仪表盘引燃,大火将控制室门口封死,值班人员打碎控制室玻璃逃生.约5 min后,消防队及时赶到,在相关技术人员配合下,消防队员全力扑救,在10 min后将大火扑灭.  相似文献   

10.
郑秀亮 《环境》2012,(7):25-27
鸡乸朗村,一个海滨小渔村,地处织贡河出海口南岸,距阳西县城10公里.站立渔村之中,举目四望,入眼处绿树成片,水草繁茂;村中一栋栋精致的小别墅隐身于绿树繁花之间,美不胜收;三两水牛置身于水田之中,安详地啃着水草,野鸟隐身于灌木丛中,叫的欢快.此时此地,江南水乡特有的田园风光令人如痴如醉.  相似文献   

11.
喀喇昆仑山—西昆仑山地区属于青藏高原西北部寒冷干旱的荒漠、半荒漠地带,是连结高山荒漠和山地荒漠的关键区域。根据垂直自然带谱的基带及各分带的组合配置形式,可区分出干旱、极干旱、高寒干旱及高寒半干旱四种结构类型组。垂直自然带的区域变化明显,喀喇昆仑山与西昆仑山育显著不同,不仅南北翼有别,东西方向的递变也很突出,反映出大尺度的地域分异规律。全新世以来,干旱化的趋势十分明显,人类活动引起的环境问题突出,建议对雪岭云杉和昆仑圆柏等采取保护措施,并在羌塘高原腹地建立高原自然景观及野生动植物自然保护区。  相似文献   

12.
为提高全民综合素质,高校思想政治教育提出创新发展.与此同时,环境污染问题亟待解决,为从根本上改善和保护环境,对全民环境保护意识进行培养至关重要.首先分析高校思想政治教育创新发展历程,说明高校思想政治教育创新发展势在必行的原因,依据其发展准则,制定其创新内容.再对目前全民环保意识现状进行评估,差异性环境教育及较低的国民素质急需对全民环保意识进行培养.分析高校思想政治教育的环保价值,结合环境保护意识培养实现的效果,得出高校思想政治教育创新发展对环境保护意识培养有极大的促进作用.  相似文献   

13.
军工材料环境适应性工程化验证和研究发展战略探讨   总被引:1,自引:1,他引:0  
通过对国内外发展现状分析,讨论了环境适应性工程化验证和研究在军工材料开发、应用及其在武器装备发展中的地位和作用。提出了军工材料环境适应性工程化验证的技术内涵、试验与研究的模式和军工材料开发到武器装备应用各个阶段的任务和目标。在此基础上。探讨了发展军工关键材料环境适应性工程化验证试验与研究的总体战略和目标。结合国情。提出了军工关键材料环境适应性工程化验证与研究和关键材料体系环境适应性数据完善.军工关键材料环境适应性工程化验证自主保障能力建设.军工关键材料环境适应性工程化验证技术的提升等3方面重点发展和研究内容的构想与建议。  相似文献   

14.
辽宁太子河流域非点源氮磷负荷模拟分析   总被引:5,自引:0,他引:5       下载免费PDF全文
以辽宁太子河流域为研究区,为定量估算该区非点源氮磷污染负荷,经过实地调研和资料收集后,利用单位负荷法和SWAT模型相结合的方法对流域进行1997~2008年径流、泥沙和营养盐输出的模拟研究,进行了多参数、多目标和多站点详细的参数率定和模拟验证,最后分析了非点源氮磷负荷的时空分布规律.结果表明:径流模拟效果较好,泥沙和营养盐模拟结果符合要求,模型在太子河流域适用性较好,可以模拟分析该地区的非点源污染负荷问题;1997~2008年年均总氮和总磷负荷为17357.43t和7110.91t,氮磷负荷的时空分布受降雨径流过程的影响,汛期(6~9月)负荷总量占全年的77.76%和80%;负荷强度的空间差异较大,全流域多年平均值为13.20,5.41kg/hm2,流域内污染负荷关键源区是灯塔市和辽阳县.  相似文献   

15.
蒋昊  赵亮  张晶 《中国环境科学》2020,40(9):3981-3991
为了解黄海氮营养盐的循环规律与收支情况,利用一个高分辨率物理-生物地球化学耦合模型(ECSECOM),模拟了黄海溶解无机氮(DIN)、颗粒有机氮(PON)的循环收支情况,分析了各源汇项的空间分布特征及季节变化规律及不同形态之间转化规律.结果表明:黄海DIN浓度在春、夏季较低,秋、冬季恢复至高水平.PON浓度在冬、春季较低,在夏、秋季有升高的趋势.浮游植物光合作用和呼吸作用是DIN最主要的汇和源,初级生产消耗的DIN中29.47%由水体内碎屑物质矿化分解提供,外源输入的DIN占总浮游植物生长需求的14.60%.浮游植物死亡是PON最大的源,沉积物为PON的净汇.大气氮沉降对黄海的影响范围全面,底沉积物释放和河流输入的DIN对黄海的影响是局地的.从PON与DIN之间的循环转化来看,PON中有48.50%转化为DIN,其余大部分都沉积到海底界面,而DIN向PON的转化率为38.85%.  相似文献   

16.
陈晓华  姚林 《自然资源学报》2020,35(8):1958-1971
乡村稀释化是指城乡关系失衡下乡村人口持续减少、社会活力凋敝、人居空间不断被稀释的过程,是我国快速城镇化进程中乡村空间问题的动态化呈现,是新时代乡村地理学亟待深化研究的课题。基于城乡关系视角,从人口活力、土地利用和社会活动三个维度对皖北地区乡村稀释化进行测度,综合运用空间自相关、地理加权回归、地理探测器等方法,揭示皖北地区乡村稀释化时空特征、影响因素及形成机制。结果表明:(1)近10年皖北地区乡村稀释化呈现出阶段性加速化过程、多维度差异化状态、集聚性分异化空间格局等特征;(2)人均水资源量、农业从业人口密度、贫困发生率、城乡居民收入差异系数、单位乡村小学在校生人数、每万农村居民村卫生室医生数等要素对皖北地区乡村稀释化影响显著;(3)在特定城乡关系背景下,基于区域本底条件,城市系统的控制引导与乡村系统的被动响应共同推动了乡村稀释化的形成和蔓延。科学认知乡村稀释化,可为乡村振兴与城乡融合发展精准施策提供理论指导。  相似文献   

17.
某离心机模型辨识与仿真   总被引:1,自引:1,他引:0  
目的辨识某离心机的加速度控制模型,并开展控制系统仿真和优化。方法实测某离心机运行时的转速、电压、电流等,对保载和加速状态的电流进行拟合,进而分析保载阻力、等效转动惯量等模型参数。建立离心机加速度控制系统Simulink仿真模型,进行仿真试验。结果基于辨识的模型参数进行仿真的结果与真实系统试验的结果很接近,为控制系统优化、各种试验能力和误差预估提供了可信的模型。结论采用的辨识方法可行,辨识的参数正确,离心机仿真模型运行快速正确,可供相关离心机辨识和仿真参考。  相似文献   

18.
上海市郊中小河流氮磷污染特征   总被引:18,自引:2,他引:16  
:①上海市郊中小河流有很高的氮磷和有机负荷,其表层水凯氏氮、总磷和CODCr指标均数倍于V类水的最大允许值.②由于受纳污染物类型和总量上的差异,中小河流氮磷污染存在明显的空间分异:居民区附近的小河流氨氮和磷的污染很重;主要受农田径流影响的小河流,氨氮和磷的污染较轻,但受硝氮污染的风险加大;养殖场附近的小河流,氨氮和磷有突发性暴增的现象.③中小河流氮磷污染,还受河流季节性生态环境演变的影响.随着气温升高和河流表层生物量的增大,表层水NH4+、NO3-因大量消耗而降低;有机N和颗粒态P含量因生物量的增加而上升;NO2-也会因硝化细菌活动的加剧而增加.水溶态磷和总磷也有随着气温和生物活动的增加而增高的趋势,但还要受到水体pH、DO等条件的影响.④在盛夏高温季节,水流滞缓的小河流表层水和底层水的氮磷指标存在明显分异:底层水NH4+、水溶态磷和总反应态磷含量高于表层水;而表层水NO3-和NO2含量高于底层水.这种富营养化水质分层现象的产生是夏季河流表层生物量暴增和底泥氮磷释放加剧的必然结果.至秋季,随着气温的回落,水质分层现象逐渐减弱.  相似文献   

19.
工业资源是能为工业所利用的包括自然资源与人文资源在内的一切资源,是资源的产业范畴。工业资源开发学以工业资源为研究对象,以经济开发为主线,是研究工业资源系统开发、利用、保护与管理及其发展变化的规律,并应用这些规律进行不同时、空系统下工业资源经济开发实证研究的学科。其以系统性、应用性为主要特点,以工业资源的基础理论、工业资源开发理论、开发的战略与策略、工业资源组合类型与区域开发实证、资源开发与保护的管理与政策以及工业资源开发研究方法与手段等为主要研究内容。作为学科建设的起点,近期应以工业资源国情及开发战略、工业资源开发基本经验总结、工业资源开发模式、工业资源动态信息网络和开发决策系统的建立等课题为研究重点。  相似文献   

20.
This review surveys the present state of knowledge of the nitrate (NO3 radical. Laboratory data on the physics and chemistry of the radical and atmospheric determination of the concentrations of the radical are both considered. One aim of the review is to highlight the relationship between the laboratory and the atmospheric studies. Although the emphasis of the review is on gas-phase processes, relevant studies conducted in condensed phases are mentioned because of their potential importance in the interpretation of cloud and aerosol chemistry.The spectroscopy, structure, and photochemistry of the radical are examined. Here, the object is to establich the spectroscopic basis for detection of the radical and measurement of its concentration in the laboratory and in the atmosphere. Infrared, visible, and paramagnetic resonance spectra are considered. An important quantity discussed is the absorption cross section in the visible region, which is required for quantitative measurements. Interpretation of the spectroscopic features requires an understanding of the geometrical and electronic structure of the radical in its ground and excited states; there is still some controversy about the groundstate geometry, but the most recent experimental evidence 9eg from laser induced fluorescence) and theoretical calculations suggest that the radical has D3h symmetry. Photodissociation of the radical is important in the atmosphere, and the product channels, quantum yields, and dissociation dynamics are discussed. A short examination of the thermodynamics (heat and entropy of formation) of the radical is presented.The main exposition of laboratory studies of the chemistry of the nitrate radical is preceded by a consideration of the techniques used for kinetic and mechanistic studies. Methods for the generation and detection of the radical and the kinetic tools employed are all presented. The exact nature of the technique used in individual studies has some relevance to the way in which data must be analysed, and to the type of mechanistic information that can be extracted. Continuous and stopped flow, flash photolysis and pulse radiolysis, molecular modulation, and static reactor techniques can all provide absolute kinetic data, while relative rate measurements have been a further rich source of information.The treatment of the chemical reactions of the nitrate radical is formally divided into the interactions with non-radical inorganic (deemed to include NO and NO2) and organic species, and with atoms and free radicals. In general, the reactions with open-shell species are much more rapid than those with closed-shell reactants. With the closed-shell partners, addition reactions are faster than abstraction reactions. An attempt is made to consider critically the published data on most reactions of importance, and to tabulate rate constants and temperature dependences where possible. However, it is not the objective of this review to provide recommendations for rate parameters. Evidence for the products of the reactions is sought, and for the branching ratios into the various channels where more than one exists. One theme of this part of the review is the elucidation of correlations of reactivity with structure and with the reactions of other radical species such as OH.The review turns next to a consideration of the role of NO3 in the atmosphere, of its atmospheric sources and sinks, and of field measurements of concentrations of the radical. Long-path visible-absorption spectroscopy and matrix-isolation ESR have both been used successfully in field measurements in the troposphere as well as the stratosphere. Balloon-borne instruments and ground-based remote sensing have been used to obtain stratospheric concentrations. Two of the most important implications of the measurements are that the stratospheric profiles are consistent with accepted chemistry (and, in particular, do not require the postulation of an unidentified scavenging mechanism that had, at one stage, been proposed), and that the highly variable night-time tropospheric concentrations imply that NO3 is a reactive tropospheric constituent. The inter-relation between laboratory studies and atmospheric observations, and the problems in extrapolating laboratory data to atmospheric conditions, are both explored. Initiation of night-time chemical transformations by NO3 and the possible production of OH are considered. The available information is then brought together to see how far NO3 is a sensitive indicator of the state of the atmosphere, and some speculations are presented about the involvement of NO3 (or N2O5) in damage to trees and plants.The final section of the review suggests some issues that remain unresolved concerning the NO3 radical which is directly or indirectly relevant to a better knowledge of the part played by the radical in the atmosphere. Amongst the requirements noted are improved data for the heat of formation of the radical, its absorption cross section in the visible region (and, especially, the temperature dependence of the cross section), and the details of its photochemistry. There is also still a need for a definitive determination of the equilibrium constant and its temperature dependence for the association with NO2 and the reverse dissociation of N2O5. A series of chemical reactions deserves further investigation, especially with regard to elucidation of product channels, and overall oxidation mechanisms also need to be defined better. Future atmospheric studies that are desirable include study of basic NO3 chemistry in the field to understand the influence of humidity on the conversion (probably on surfaces) of N2O5 to HNO3, and thus on NO3 concentrations. In addition, a study of the chemistry of NO3 in the presence of volatile organic compounds and at elevated concentrations of the oxides of nitrogen should help in the understanding of, for example, polluted marine coasts, forests, and urban areas.  相似文献   

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