Surface Sediment Density and Moisture Content in North slope of South China Sea

Marine engineering geology is mainly based on the actual project to study the seabed.This provides a variety of engineering geological parameters for the development of marine engineering(Zhu et al.,2016).This is an early

Phytoremediation of PAH-Contaminated Sediments by Potamogeton Crispus L. with Four Plant Densities

In order to investigate the effect of plant density ofPotamogeton crispus L. on the remediation of sedi- ments contaminated by polycyclic aromatic hydrocarbons, a 54-day experiment with four plant densities （642, 1 604, 2 567 and 3 530 plants/m^2） was conducted. The results showed higher plant density with slower plant growth rate. Surface area per plant was the most sensitive root parameter to plant density. At the end of the 54-day experi- ment, planting P. crispus enhanced the dissipation ratios of phenanthrene and pyrene in sediments by 6.5%-26,2% and 0.95%-13.6%, respectively. The dissipation increment increased with increasing plant density. Plant uptake accounted for only a small portion of the dissipation increments. Furthermore, P. crispus could evidently improve sediment redox potentials, and strong positive correlations between root surface area and the redox potential as well as between the redox potentials and the dissipation ratios of phenanthrene and pyrene were obtained, indicating that the oxygen released by the roots ofP. crispus might be the main mechanism by which P. crispus enhanced the dis- sipation of PAHs in sediments.

Cycles of fine-grained sedimentation and their influences on organic matter distribution in the second member of Paleogene Kongdian Formation in Cangdong Sag,Bohai Bay Basin,East China

According to the theory of sequence stratigraphy based on continental transgressive-regressive(T-R)cycles,a 500 m continuous core taken from the second member of Kongdian Formation(Kong 2 Member)of Paleogene in Well G108-8 in the Cangdong Sag,Bohai Bay Basin,was tested and analyzed to clarify the high-frequency cycles of deep-water fine-grained sedimentary rocks in lacustrine basins.A logging vectorgraph in red pattern was plotted,and then a sequence stratigraphic framework with five-order high-frequency cycles was formed for the fine-grained sedimentary rocks in the Kong 2 Member.The high-frequency cycles of fine-grained sedimentary rocks were characterized by using different methods and at different scales.It is found that the fifth-order T cycles record a high content of terrigenous clastic minerals,a low paleosalinity,a relatively humid paleoclimate and a high density of laminae,while the fifth-order R cycles display a high content of carbonate minerals,a high paleosalinity,a dry paleoclimate and a low density of laminae.The changes in high-frequency cycles controlled the abundance and type of organic matter.The T cycles exhibit relatively high TOC and abundant endogenous organic matters in water in addition to terrigenous organic matters,implying a high primary productivity of lake for the generation and enrichment of shale oil.

两坝间河道高含沙水流驱动的下游船闸阀门井水位异常特征分析

葛洲坝船闸充水阀门井与输水廊道进水口水体相连,1993年洪季期间曾发生过阀门井水位异常升高,影响船闸设备设施安全等问题。为分析葛洲坝一号船闸充水阀门井水位异常升高的根本原因,基于Mike三维水沙数值模型,模拟分析了不同流量和含沙量级别下的河道水流和含沙量垂向分布结构特征,进而计算阀门井水位异常升高值与河道水流和含沙量的关系,反演1993年洪季葛洲坝一号船闸两个阀门井出现的水位异常现象。研究结果表明,葛洲坝一号船闸阀门井水位异常超过阈值0.5 m的流量和含沙量条件分别约为(30 000 m^(3)/s, 2.85 kg/m^(3)),(40 000 m^(3)/s, 1.42 kg/m^(3)),(50 000 m^(3)/s, 1.23 kg/m^(3))。受三峡水库及上游梯级水库蓄水拦沙、退耕还林政策等因素的影响,未来葛洲坝船闸出现高含沙水流导致阀门井水位异常升高>0.5 m的可能性极小,但在三峡水库排沙泄洪期间仍应引起重视。研究成果可为葛洲坝一号船闸安全营运和科学管理提供参考依据。

克孜尔水库低水位水力排沙清淤技术应用与实践

泥沙淤积占据水库的库容,使有效库容减少,进而影响水库的灌溉、防洪、发电等功能的发挥。本文根据克孜尔水库2023年低水位水力排沙清淤实际情况,系统分析了低水位水力排沙方案的确定和实施效果,对低水位水力排沙的能力做出客观评价,论证了其可行性,可为新疆类似水库清淤工作提供有益经验和技术参考。

基于泥沙异重流稳定性与衰减过程的床面淤积特性研究

泥沙异重流在稳定分层和不断衰减的过程中,伴随着床面淤积特征的变化。通过水槽试验观测异重流“稳定-衰减”过程,结合异重分层流运动理论模型,探究该过程对床面淤积特征的影响。研究结果表明,增加异重流层密度或厚度,形成稳定分层形态的时间明显缩短,同时延长了分层形态的维持时间;计算得到的临界雷诺数与扰动波数虚部相应增加,分层形态稳定性得以增强。异重流的稳定行进对于减小床面淤积具有重要作用,试验中临界雷诺数增加568~820,平均淤积厚度降低了42%~46%。因此,提高异重流稳定性并延缓衰减速率,有助于提高输沙率,可以达到减淤的目的。

澜沧江中下游泥沙微表面电荷特性与磷吸附关系研究

河流泥沙是水生态系统生源要素的重要附着载体,其微形貌及电荷特性直接关系着泥沙对溶解态营养盐或污染物的吸附能力。本研究选取澜沧江中下游干流及主要支流为考察对象,采集28个河流水库断面的悬移质泥沙,采用原子力显微镜测定泥沙微表面电荷量,探究澜沧江泥沙的微表面电荷性质,研究纳米尺度下泥沙的微表面特性。研究结果表明:(1)微观界面,形貌对表面电荷分布影响明显,在纳米尺度下电势图与相位差图均展现出明显非均匀分布特征;(2)在流域分布上,不同区域表面电荷存在较大差异,流域沿程变化对泥沙表面电荷产生重要影响,总体变化呈现先减小后增大的趋势,表面电势值变化范围为-201.47~35.34 mV,表面电荷密度范围为0.07~3.65 mC/m^(2),不同区域电荷特性差别明显;(3)在梯级水电筑坝影响下,坝上坝下泥沙颗粒电势差与水库库容存在较好的线性相关关系,相关系数为0.8214,且坝下电势普遍高于坝上区域;(4)泥沙表面电势与磷吸附之间具有较强相关性,其相关系数为0.6657,同时表现出较好的线性拟合关系。研究结论对深入理解水电大坝建设对流域内污染物的迁移转化及解释泥沙的表面电性特征与污染物的吸附解吸机制具有重要科学意义,同时也可为流域水沙环境调控提供理论依据。

Enhancing Geological Understanding and Identifying Gold Anomalies in the Ailaoshan Orogen

The Ailaoshan Orogen in the southeastern Tibet Plateau,situated between the Yangtze and Simao blocks,underwent a complex structural,magmatic,and metamorphic evolution resulting in different tectonic subzones with varying structural lineaments and elemental concentrations.These elements can conceal or reduce anomalies due to the mutual effect between different anomaly areas.Dividing the whole zone into subzones based on tectonic settings,ore cluster areas,or sample catchment basins(Scb),geochemical and structural anomalies associated with gold(Au)mineralization have been identified utilizing mean plus twice standard deviations(Mean+2STD),factor analysis(FA),concentration-area(CA)modeling of stream sediment geochemical data,and lineament density in both the Ailaoshan Orogen and the individual subzones.The FA in the divided 98 Scbs with 6 Scbs containing Au deposits can roughly ascertain unknown rock types,identify specific element associations of known rocks and discern the porphyry or skarn-type Au mineralization.Compared with methods of Mean+2STD and C-A model of data in the whole orogen,which mistake the anomalies as background or act the background as anomalies,the combined methods of FA and C-A in the separate subzones or Scbs works well in regional metallogenic potential analysis.Mapping of lineament densities with a 10-km circle diameter is not suitable to locate Au deposits because of the delineated large areas of medium-high lineament density.In contrast,the use of circle diameters of 1.3 km or 1.7 km in the ore cluster scale delineates areas with a higher concentration of lineament density,consistent with the locations of known Au deposits.By analyzing the map of faults and Au anomalies,two potential prospecting targets,Scbs 1 and 63 with a sandstone as a potential host rock for Au,have been identified in the Ailaoshan Orogen.The use of combined methods in the divided subzones proved to be more effective in improving geological understanding and identifying mineralization anomalies associated with Au,rather than analyzing the entire large area.

水处理中高密度沉淀池工艺的应用研究

针对当前很多企业的传统废水处理工艺已无法满足现代化废水处理要求和排放标准的情况,高密度沉淀池工艺自动化程度较高,且能有效处理废水悬浮物以及钙镁离子,在工业废水处理、生活废水处理等方面得到广泛应用。本次研究以某化工企业为研究对象,对高密度沉淀池工艺的应用进行研究,并分析应用效果,以期能够促进废水处理行业的发展。

三级AO+深度处理组合工艺在中小型城镇污水厂中的应用

由于排放标准的提高和进水水质的变化,成都市某污水厂需提标改造。改造后,处理规模为2 500 m^(3)/d不变,出水水质需达到《四川省岷江、沱江流域水污染物排放标准》(DB 51/2311—2016)。本工程采用充分利用原有的生化池,改建为三级AO池并新建深度处理设施的改造方式,该改造方式节省投资、不新征用土地、抗冲击负荷强,仅需约30 min短时间碰管停水,改造后工艺运行稳定可靠,达到DB 51/2311—2016的要求(CODCr≤30 mg/L,氨氮≤1.5 mg/L,总氮≤10 mg/L,总磷≤0.3 mg/L)。项目可为中小型城镇污水厂提标改造提供借鉴经验。

一体化多效澄清系统在水厂排泥水处理中的应用

老旧水厂新建排泥水设施大多面临用地紧张问题。针对南方某水厂排泥水浑浊度大、混凝程度高、分离性好的水质特点,以及污泥含水率低于80%、上清液SS质量浓度不高于50 mg/L的处理目标,某水厂采用了集成化设备处理工艺“一体化多效澄清系统+带式浓缩脱水”。该系统针对排泥水特点优化了混凝反应区和沉淀区以提高运行效率,项目运行稳定可靠,污泥含水率低于65%,上清液SS质量浓度低于15 mg/L,在同类型项目中具有投资低、占地小、处理效果好的优势。

中国近海主要表层沉积物类型的原位声学特性

海底表层沉积物的声学特性对于海洋声传播和声探测有重要影响。不同类型的海底沉积物表现出不同的声学特性。针对海洋声学研究对海底声学特性参数快速获取的需求,本文利用近年来获得的100个站位的声学特性原位测量和沉积物样品测试数据,统计了中国近海8种典型沉积类型的声速、声衰减系数等声学特性和平均粒径、密度等物理性质。通过与已有测量数据和统计结果的对比显示,其与多种原位测量系统获得的数据有很好的一致性,但Hamilton统计的声速比、声衰减因子等参数则显著偏高。基于VGS理论的频散模型计算结果表明:Hamilton统计结果的偏高并非完全由其较高的测量频率引起。对于缺少直接测量数据的海域,本文的统计结果提供了一种基于沉积物类型进行海底声学特性初步估计的方案。

终板体积骨密度在侧方入路腰椎椎体间融合术后Cage沉降的预测价值

目的探讨终板体积骨密度(endplate volumetric bone mineral density,EP-vBMD)对侧方入路腰椎融合(lateral lumbar interbody fusion,LLIF)术后Cage沉降的影响。方法选择2018年1月~2020年12月在本院接受LLIF手术治疗的151例患者进行回顾性分析,收集患者EP-vBMD、椎体体积骨密度(vertebral body volumetric bone mineral density,VB-vBMD)、年龄、性别、体质量指数(body mass index,BMI)、医学共病(糖尿病等)、吸烟、美国麻醉医师协会(american society of anesthesiologists,ASA)评分、查尔森共病指数(charlson comorbidity index,CCI)、手术节段、手术椎体和是否使用后路螺钉固定等资料。根据术后1年患者是否发生Cage沉降,将患者分为Cage沉降组和非沉降组,比较两组患者临床资料差异,将单因素分析P<0.2的变量进一步采用多因素Logsitic回归分析,观察EP-vBMD对终板沉陷的影响。结果Cage沉降患者的VB-vBMD和EP-vBMD水平均低于非Cage沉降患者,差异均有统计学意义(P<0.05)。Cage沉降组患者年龄高于非Cage沉降组患者,差异有统计学意义(P<0.05);Cage沉降组和非Cage沉降组患者性别、吸烟、糖尿病、后路螺钉固定等资料差异均有统计学意义(P<0.05)。多因素Logistic回归分析显示,EP-vBMD和应用后路螺钉固定均是Cage沉降的保护性因素(P<0.05)。结论低EP-vBMD是LLIF术后Cage沉降的风险因素,对患者进行LLIF时,应考虑术前EP-vBMD的测量。

生猪屠宰废水处理工程实例

某大型生猪屠宰企业生产废水具有浓度变化大、有机污染物浓度高、悬浮物多等特点,呈红褐色并有明显腥臭味,采用气浮-水解酸化-两级AO-高密度沉淀为主的组合处理工艺,当进水COD、BOD5、SS、氨氮、总磷、总氮质量浓度分别为1844、767、864、54.4、4.52、87.6 mg/L时,出水质量浓度分别为46、21.7、12、3.74、1.75、8.74 mg/L,均符合企业内控要求和GB 13457—1992《肉类加工工业水污染物排放标准》中三级排放标准,达标后的出水进入产业集聚区污水处理厂处理。该处理工艺运行稳定可靠,抗冲击能力强,处理效果好,便于自动化运行操作和维护管理。

广东离子吸附型稀土矿床特征及找矿预测

稀土是我国的优势矿种,尤以华南地区离子吸附型稀土矿产资源最为突出,广东省内的风化壳离子吸附型稀土矿床主要分布在韶关、河源、梅州、清远、潮州、揭阳、肇庆和茂名等地。水系沉积物地球化学异常是圈定矿床找矿远景区最有效且快速的一种手段,本次研究以广东省1∶20万水系沉积物地球化学数据为基础,将镧(La)和钇(Y)分别作为轻稀土(LREE)和重稀土(HREE)的特征元素,选取了34处稀土异常调查区(其中LREE异常区15处,HREE异常区19处),通过对人工剥土和人工冲击钻采样分析,初步评估了相应的稀土成矿潜力。139件样品分析结果显示,114个样品达到边界品位(≥0.02%),占送样总数的82.0%;71个样品达到工业品位(≥0.04%,最高可达0.27%),占送样总数的51.1%,新发现韶关乳源、潮州钱东、汕尾碣石、河源东源和河源龙川5个找矿远景区。为了更有效地圈定离子吸附型稀土矿床,结合稀土矿床找矿预测的标志,建议在1∶20万水系沉积物稀土元素地球化学异常区的基础上,开展低密度不规则网土壤地球化学测量,进一步浓缩异常范围并圈定离子吸附型稀土矿床找矿远景区,系统建立稀土资源潜力评价体系。

Inversion of river-bottom sediment parameters using mechanically sampled specimens and subbottom profiling data

The study of river dynamics requires knowledge of physical parameters, such as porosity, permeability, and wave propagation velocity, of river-bottom sediments. To do so, sediment properties are determined on mechanically sampled specimens and from subbottom profiling. However, mechanical sampling introduces disturbances that affect test results, with the exception of grain-size distribution. In this study, we perform inversion of acoustic data using the grain-size distribution of mechanically sampled specimens and the relation between porosity and permeability from the Kozeny-Carman equation as prior information. The wave reflection coefficient of the water-silt interface is extracted from the raw subbottom profile. Based on the effective density fluid model, we combine the Kozeny-Carman equation and the wave reflection coefficient. We use experimental data from two Yellow River reservoirs to obtain the wave velocity and density of multiple sections and their spatial variations, and find that the inversion and testing results are in good agreement.

Impact of utility-scale solar photovoltaic array on the aeolian sediment transport in Hobq Desert, China

Deserts are ideal places to develop ground-mounted large-scale solar photovoltaic (PV) powerstation. Unfortunately, solar energy production, operation, and maintenance are affected bygeomorphological changes caused by surface erosion that may occur after the construction of the solar PVpower station. In order to avoid damage to a solar PV power station in sandy areas, it is necessary toinvestigate the characteristics of wind-sand movement under the interference of solar PV array. The studywas undertaken by measuring sediment transport of different wind directions above shifting dunes andthree observation sites around the PV panels in the Hobq Desert, China. The results showed that the twoparameterexponential function provides better fit for the measured flux density profiles to the near-surfaceof solar PV array. However, the saltation height of sand particles changes with the intersection anglebetween the solar PV array and wind direction exceed 45°. The sediment transport rate above shifting duneswas always the greatest, while that around the test PV panels varied accordingly to the wind direction.Moreover, the aeolian sediment transport on the solar PV array was significantly affected by wind direction.The value of sand inhibition rate ranged from 35.46% to 88.51% at different wind directions. When theintersection angle exceeds 45°, the mean value of sediment transport rate above the solar PV array reducesto 82.58% compared with the shifting dunes. The results of our study expand our understanding of theformation and evolution of aeolian geomorphology at the solar PV footprint. This will facilitate the designand control engineering plans for solar PV array in sandy areas that operate according to the wind regime.

Influence of Sedimentation on Crystallization of Charged Colloidal Particles

The method of density matching between the solid and liquid phases is often adopted to effectively eliminate the effect of sedimentation of suspensions on dynamic behavior of a colloidal system. Experiments on crystallization of charged colloidal microspheres with di- ameter of 98 nm dispersed in density-matched and -unmatched media （mixtures of H20 and D20 in proper proportion） are compared to examine the influence of sedimentation. Reflection spectra of colloidal suspensions were used to monitor the crystallization process. Results showed that the crystal size of the density-unmatched （namely, in the presence of sedimentation） sample grew faster than that of the density-matched （in the absence of sedi- mentation） case at the initial stage of the crystallization, and then the latter overtook and outstripped the former. To explain these observations, we assume that in the settling of crystals sedimentation facilitates result in more particles getting into the crystal structures. However, as the crystals increase to varying sizes, the settling velocities become large and hydrodynamic friction strips off some particles from the delicate crystal structures. Overall, the sedimentation appears to accelerate the crystal size growth initially and then retard the growth. In addition, the crystal structures formed under microgravity were more closely packed than that in normal gravity.

Pyrolyzed Iron Phthalocyanine-Modified Multi-Walled Carbon Nanotubes as Composite Anode in Marine Sediment Microbial Fuel Cells and Its Electrochemical Performance

Improving the performance of anode is a crucial step for increasing output power of marine sediment microbial fuel cells(MSMFCs)to drive marine monitor to work for a long term on the ocean floor.A pyrolyzed iron phthalocyanine modified multi-walled carbon nanotubes composite(FePc/MWCNTs)has been utilized as a novel nodified anode in the MSMFC.Its structure of the composite modified anode and electrochemical performance have been investigated respectively in the paper.There is a substantial improvement in electron-transfer efficiency from the bacteria biofilm to the modified anode via the pyrolyzed FePc/MWCNTs composite based on their cyclic voltammetry(CV)and Tafel curves.The electron transfer kinetic activity of the FePc/MWCNTs-modified anode is 1.86 times higher than of the unmodified anode.The maximum power density of the modified MSMFC was 572.3±14 m W m^-2,which is 2.6 times larger than the unmodified one(218.3±11 m W m^-2).The anodic structure and cell scale would be greatly minimized to obtain the same output power by the modified MSMFC,so that it will make the MSMFC to be easily deployed on the remote ocean floor.Therefore,it would have a great significance for us to design a novel and renewable long term power source.Finally,a novel molecular synergetic mechanism is proposed to elucidate its excellent electrochemical performance.

Observed Suspended Sediment Dynamics during a Tidal Cycle above Submerged Asymmetric Compound Sand Waves

The data from Acoustic Doppler Current Profiler （ADCP） of the three-dimensional current-field, echo intensity, modulation of Suspended Sediment Concentration （SSC）, and related water levels and wind velocities have been analyzed as a function of water depth above submerged asymmetric compound sand waves during a tidal cycle in the Lister Tiefofthe German Bight in the North Sea. Signatures of vertical current component, echo intensities and calculated SSC modulations in the water column depend strongly on wind and current velocity. Bursts of vertical current component and echo intensity are triggered by sand waves itself as well as by superimposed megaripples due to current wave interaction at high current ≥ 1.0 m＇s1 and wind speeds ≥ 10.0 m·s^-1, preferably of opposite directions, measured at high spatial resolution. The magnitude of currents and SSC modulations during ebb and flood tidal current phases are only weakly time dependent, whereas the local magnitudes of these parameters are variable in space above the sand waves. Some hydrodynamic parameters are further investigated and analyzed, showing a consistence of ADCP measurements in the applied theory.