大连周边近岸典型海域海洋环境噪声的测量分析

于2013年5月利用带宽为20 Hz¹00 k Hz的水听器测量系统对大连市周边近岸海域的大黑石、付家庄、星海湾、塔河湾、海之韵5个典型站位的水下噪声进行了测量,获取各站点海洋环境噪声数据以及风速、海况等环境要素,然后进行噪声平均声压级(Sound pressure level,SPL)的计算和20 Hz100 k Hz的水听器测量系统对大连市周边近岸海域的大黑石、付家庄、星海湾、塔河湾、海之韵5个典型站位的水下噪声进行了测量,获取各站点海洋环境噪声数据以及风速、海况等环境要素,然后进行噪声平均声压级(Sound pressure level,SPL)的计算和20 Hz¹00 k Hz带宽的噪声频谱分析。结果表明:付家庄、星海湾海区噪声平均声压级分别为126.58、123.39 d B(以1μPa为参考声压,下同),船舶航行、近岸工程建设等人为噪声是该海区的主要噪声源;大黑石、塔河湾海域的海洋噪声较低,平均声压级分别为115.66、122.17 d B,潮汐和风浪等自然噪声是该海域的主要海洋噪声源;货运港口及航道附近的海之韵海域平均声压级最高,为132.53 d B,船舶航行等为主要噪声源。总体上,大连周边近岸海域海洋噪声受人类活动因素影响较大,在港口航道、海洋工程等区域显示了较高的噪声水平,而地处渤海的养殖海域噪声最低。本次测量的平均声压级处于鱼类和海洋哺乳动物的听力范围之内,但因声压级相对较低,对当地海水养殖业和海洋哺乳动物应该不会产生显著影响。     

特定温湿度条件下空调器噪声测试室声学设计

介绍了温湿度可控的空调机噪声测试到的声学设计，该试验室四壁及顶部采用平面吸声层处理，空调送回风管道中采用迷宫式结构，其隔板表面做成尖劈状，低频吸声效果效果好；试验室隔声内门外门采用复合型壁板，内充玻璃棉，吸声层内再夹一层ＮＦＣ板，试验室声学效果达到了预期的要求。     

功率场效应晶体管的低频噪声检测方法

针对目前国内功率VDMOS器件成品率低、可靠性差等问题,采用低频噪声无损检测方法,通过分析功率VDMOS器件低频噪声的产生机理及特性,设计了低频噪声测试的偏置电路并建立了一套低频噪声测试系统。提出了一种基于小波熵的低频噪声检测方法,解决了所测低频噪声容易被测试系统白噪声淹没而造成低频噪声检测准确性低的弊端。通过仿真,验证了小波熵检测方法可以有效检测低频噪声。     

弃置平台与管线对海洋环境的影响

海洋平台及海底管线会随着海上油气田的开采完成而结束其使命,并置于废弃状态。文章论述了废弃平台管线结构由于废弃失效、清洗及拆除对海洋环境所造成的不良影响及其对海洋环境的持续性影响,并从完善规章制度、严格执行环评管理程序、加强海洋环境监测、合理选择弃置方案、再利用等五方面,对海洋环境的可持续发展,有针对性地提出了科学、可行的建议。     

基于750kV变电站低频噪声的人体感受模型研究

低频噪声是环境噪声污染的重要组成部分,对人体会产生包括噪声烦恼在内的诸多不利影响。特高压变电站噪声低频特性显著,其引起的噪声烦恼不容忽视。对750kV变电站噪声进行采样,并用等级评分法进行主观评价试验,得到适合于变电站低频噪声的5个评价指标,确定了最适合于评价变电站低频噪声主观烦恼的预测模型。     

10 kV变电所选址的低频噪声问题探讨

阐述10 kV变电所低频噪声的产生原因及传播方式,综述国家规范针对噪声限制的相关要求.结合噪声治理案例,分析10 kV变电所的低频噪声影响范围,建议重视10 kV变电所建筑投影范围内的低频噪声问题.     

低频噪声舒适度研究现状

论文针对低频噪声舒适度问题,讨论了低频噪声的危害,低频噪声及其与低频振动耦舍环境下的舒适度问题,以及目前低频噪声计权网络的不足等。论文的研究工作可为低频环境下的舒适度评价提供参考。     

海面波浪谱对深海低频环境噪声的影响

提出了一种适用于深海低频环境噪声的波浪谱,通过声压谱和波浪谱的理论关系,分析了深海低频噪声在百赫兹以下的谱特征,解释了不同频段噪声谱的主要产生机理。将深海传播条件下海面波浪谱与海面风速相结合,利用波浪发声理论得到一种低频海洋环境噪声理论表示方法。仿真结果表明,波浪谱决定着辐射噪声谱的强度和斜率,本模型得到的理论噪声谱可以对低频海洋环境噪声进行预报。2016年的深海实验观测数据分析显示,统计的环境噪声谱级在1 Hz至100 Hz频段范围内大于70 dB,并且噪声谱在低频段呈倒"N"型,在3~4 Hz处为噪声谱的谷值,噪声级为70 dB,在50 Hz处为噪声谱的峰值,噪声级为92 dB,通过理论计算和实验对比,相关系数为0.95,理论结果和实验测量对比结果符合较好。     

基于传感器网络的海洋水质监测及赤潮预报系统的设计

针对海洋环境变化快、水质检测难度大的问题,通过建立传感器网络,得到更为准确的水质模型,研发了基于传感器网络的海洋环境监测与预报系统,该系统可实现对海洋水质的在线和离线分析以及对未来水质的预测和预报。系统包含数据采集子系统和数据处理子系统,分别实现海水水质要素的采集、水质监测浮标的位置定位和水质分析分类等功能,两者通过GPRS进行通信。实验结果显示,该系统运行良好,具有较高的可靠性,在赤潮等影响海洋水质的事件发生时,该系统可对相关事件的发展变化进行实时跟踪监测和预报,对预防海洋水质灾害的发生具有积极作用。     

海洋石油工程清洁生产及管理对策

海洋石油工程清洁生产着眼于污染预防，全面考虑开发生产周期过程对海洋环境的影响，最大限度地减少原料和能源消耗，提高能源利用率，使开发过程对海洋环境的影响降到最低。从水资源利用、钻屑泥浆处置、伴生气回收、新能源新试剂和新技术利用、污染物末端处理、作业者管理水平等6个方面介绍了海洋石油工程清洁生产措施，并提出了清洁生产管理对策，为今后的海洋石油工程清洁生产工作提供参考。     

Partitioning of marine antifoulants in the marine environment

The partitioning behaviour of the organic biocides, Irgarol 1051 and diuron and two inorganic biocides (copper and zinc) was investigated using six sediments of differing physico-chemical properties collected from unimpacted sites along the south coast of England. The kinetics of sorption and equilibrium partitioning between the sediments and seawater were investigated over a period of 20 days. Resulting organic carbon/water partition coefficients (log Koc) were related to suspended sediment concentration and ranged from 2.28 to 5.20 for diuron; and from 2.41 to 4.89 for Irgarol 1051. Sediment/water partition coefficients (log Kp) for copper and zinc varied from 2.46 to 5.08 l/kg and from 2.49 to 4.97 l/kg, respectively. Kinetic data indicated that there were significant interactions between the dissolved and particulate phases at the start of the experiments, just after mixing. This is thought to be a result of redistribution of organic carbon between the two phases.     

海岸工程对海洋环境的影响

总结分析了海岸工程对海洋环境的具体影响,包括改变海洋水文动力环境,影响海水水质,破坏近岸海域生态环境等,对环境保护部门进行海洋环境影响因子识别有着重要的意义和参考价值。     

Phosphorus in marine zooplankton

In the euphotic zone, phosphorus compounds dissolved in sea water are utilized by growing plants, many of which are subsequently eaten by herbivorous zooplankton and the dietary phosphorus invested partly in growth and egg production, partly released in insoluble form as faecal pellets and partly metabolized. The fraction metabolized is excreted back into the sea water mainly as inorganic phosphate, which is again available as a nutrient for the plants.Quantitative aspects of this cyclic process are discussed with particular reference to the Calanoid copepods, animals of central importance to the marine food web in several sea areas. Topics include: (1) laboratory and field investigations of the assimilation of dietary phosphorus and the efficiency of this process; (2) the rates at which zooplankton release soluble forms of phosphorus in relation to species, body size, food availability and season; (3) the importance of zooplankton in regenerating phosphorus compounds that may be used by the plant population; (4) the daily rations of phosphorus captured by zooplankton; (5) the total amounts and chemical forms of phosphorus in the animals; (6) growth of zooplankton and the use of N:P ratios in animals, diets and excretion products in estimations of gross growth efficiency interms of phosphorus; (7) future studies.     

Arctic marine ecosystem contamination.

The current state of knowledge of levels, spatial and temporal trends of contaminants in the Arctic marine ecosystem varies greatly among pollutants and among environmental compartments. Levels of polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and some heavy metals such as mercury and lead, in Arctic marine mammals and fish are relatively well documented because of the need for comparisons with biota in more polluted environments and interest in the contamination of native diets. Levels of heavy metals, alkanes, polyaromatic hydrocarbons (PAH) and OCs in the Arctic Ocean are comparable to uncontaminated ocean waters in the mid-latitudes. But concentrations of alpha- and gamma-hexachlorocyclohexane (HCHs) are higher in northern waters far removed from local sources, possibly because lower water temperature reduces transfer to the atmosphere. Bioaccumulation of OCs and heavy metals in Arctic marine food chains begins with epontic ice algae or phytoplankton in surface waters. Polychlorinated camphenes (PCC), PCBs, DDT- and chlordane-related compounds are the major OCs in marine fish, mammals and seabirds. Mean concentrations of most PCBs and OC pesticides in ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic are quite similar indicating a uniform geographic distribution of contamination, although alpha-HCH showed a distinct latitudinal gradient in bears due to higher levels in zones influenced by continental runoff. Ringed seals from Spitzbergen have higher levels of PCBs, total DDT and polychlorinated dioxins/furans (PCDD/PCDFs). In contrast to other OCs, PCDD/PCDFs in Canadian Arctic ringed seals and polar bears were higher in the east/central Arctic than at more southerly locations. Remarkably high cadmium levels are found in kidney and liver of narwhal (Monodons monoceros) from western Baffin Bay (mean of 63.5 micrograms g-1) and western Greenland waters (median of 39.5 micrograms g-1). Mercury concentrations in muscle of ringed seal and cetaceans frequently exceed 0.5 microgram g-1 especially in older animals. Cadmium concentrations in polar bear liver increased from west to east, while mercury levels were higher in ringed seals from the western Canadian Arctic, which suggests that natural sources of these metals predominate. Studies of temporal trends in OCs in ringed seals and seabirds in the Canadian Arctic indicate PCB and DDT levels declined significantly from the early 1970s to the 1980s. There is a lack of temporal trend data for other OC pesticides as well as for heavy metals and hydrocarbons.(ABSTRACT TRUNCATED AT 400 WORDS)     

Yielding of cement-treated marine clay

This paper presents the findings of an experimental study on the primary yielding and post-yield behavior of cement-treated Singapore marine clay. The study was conducted using unconfined compression tests and triaxial tests. The results show that all the primary yield loci for the cement-treated marine clay have a consistent shape regardless of the mix ratio, curing stress or curing period. Three relationships are proposed for determining the size of the primary yield locus. The first two involve the direct determination of the isotropic primary yield stress, whereas the third makes use of the unconfined compressive strength. The first two relations are valid only for 7-day specimens. The third appears to have slightly larger scatter, but it is also applicable over a wider range of curing period and curing stress. Post-yield, over-consolidated samples were obtained by compressing specimens isotropically under effective stress levels higher than their isotropic primary yield stress and then allowing them to swell back to a lower effective confining stress prior to shearing. The normalized yield loci of these pre-yielded samples show a “collapse” from steep arches to more-rounded ellipses, while the yield loci expand with isotropic pre-compression pressure.     

Heptachlor epoxide in marine mammals

The presence of heptachlor epoxide in harbour seals (Phoca vitulina) and white-beaked dolphins (Lagenorhynchus albirostris) has been confirmed by chemical derivatization and mass spectrometric analyses. An unknown compound at a retention time close to that of heptachlor epoxide interfered in the determination by electron capture detector—gas chromatography. On a WCOT CP-Sil 7 column programmed from 85 to 175°C two poorly separated peaks could be detected. Heptachlor epoxide contents up to 1.7 mg/kg (on a fat basis) were obtained, which were about 200 times lower than the PCB levels. The same ratio was also observed in fish from the same area.     

Steel corrosion in concrete marine structures

Considering this problem in relation to work in developing countries, the authors review an extensive literature and report on their own tests. The results highlight the aggressive effects of magnesium sulphate, but the experiments also show that a small quantity of bentonite added to the mixing water can effectively improve resistance.     

Finite-element analysis of the marine riser

A two-dimensional finite-element computational method is presented for determining marine riser displacements and stresses due to self-weight, buoyancy, internal and external pressures, surface vessel motions and environmental forces arising from currents and waves. A dynamic analysis is performed in the frequency domain for regular waves by linearizing the hydrodynamic damping term. A fully nonlinear time step integration of the equations of motion using the Newmark constant acceleration method is also presented.Extensive use is made of a substructuring technique in the dynamicv analysis to reduce the number of degrees of freedom and, therefore, achieve a substantial reduction in computer time and storage without a discernible performance penalty. A number of test cases are presented to compare the linearized and nonlinear dynamic analyses and to highlight the performance of this method in relation to other marine riser analysis techniques. The application of this finite-element method to multitube production risers with complex cross-sections is discussed.     

Mercury in dated Greenland marine sediments

Twenty marine sediment cores from Greenland were analyzed for mercury, and dated by the lead-210 method. In general the cores exhibit a mercury profile with higher mercury concentrations in the upper centimetres of the core. The cores were studied by linear regression of in Hg vs. age of the sediment for the youngest 100 years. As a rule the mercury decreased with depth in the sediment with various degrees of significance. The increase of the mercury flux during the last 100 years is roughly a doubling. The increase may be of anthropogenic origin as it is restricted to the last 100 years. In four cores the concentration of manganese was found also to increase in the top layers indicating diagenesis. In the other cases the higher concentrations were not accompanied by higher manganese concentrations. The mercury flux to the sediment surface was generally proportional to the Pb-210 flux indicating that the mercury mainly originates from atmospheric washout. But the large variability indicates that other processes also influence the mercury flux to Arctic marine sediments.     

海洋既有建筑再生骨料及海洋再生混凝土的性能研究

为促进海洋环境中既有建筑混凝土的循环利用,推进建筑行业可持续化进程,在浙江省宁波市与舟山市采集废弃混凝土构件,测试其抗压强度及游离氯离子含量,利用压汞仪分析其孔隙结构。将海洋既有建筑混凝土破碎成再生骨料,测试其物理力学性能及颗粒形态。采用海水与再生骨料制备海洋再生混凝土,测试其抗压强度及劈裂抗拉强度,利用扫描电镜与X射线衍射仪分析其微观形貌及组成。研究结果表明：受局部环境的影响,海洋既有建筑混凝土的宏微观性能具有较大离散性,性能较差的海洋既有建筑混凝土,破碎成的再生骨料品质也较差,主要表现为表观密度较低,吸水率及压碎指标较高。即使再生粗骨料与再生细骨料取代率达到100%,海洋再生混凝土强度等级也可达到C40~C45,由于原材料就地取用率较高,海洋再生混凝土具有潜在的环境效益和经济效益。