Greenhouse gas emissions from croplands of China

China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate. The impacts of agroecosystems on global climate attribute to emissions of three greenhouse gases, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)

Particulate Organic Carbon export flux in the Kuroshio Extension

真光层颗粒有机碳（POC，ParticulateOrganicCarbon）的输出通量反映了海区对大气CO2的吸收能力，因此常被用于评估海洋固碳能力。西北太平洋海域作为一个人为CO2重要的汇，吸引着众多海洋研究者的目光。但是针对碳通量的研究大多在其北方的黑潮-亲潮混合区中进行，其在南方的黑潮延续体区却鲜有人为之。黑潮延续体区中终年存在大量的中尺度行为，而中尺度行为，无论是气旋涡还是反气旋涡，都可能改变颗粒有机碳的输出通量。所以黑潮延续体区可能有较大的碳吸收潜力。本文使用234Th/238U不平衡法，对黑潮延续体内不同区域的真光层颗粒有机碳输出通量进行研究，探讨其控制因素，为更准确的评估西北太平...The magnitude of POC flux from the euphotic zone reflects the capacity of sequestration of atmospheric CO2. As an important sink of atmospheric CO2, the northwestern North Pacific has attracted the attention of numerous scientists. However, most of the previous investigations were conducted in the Kuroshio-Oyashio mixed regions and the Oyashio current. In comparison, few studies has been carried o...学位：理学硕士院系专业：海洋与地球学院_海洋化学学号：2232014115131

Preparation and Electromagnetic Wave Absorbing Property of SiC Fiber /Epoxy Resin Composites

本论文对碳化硅（SiC）纤维进行热处理，制备了不同电阻率的SiC纤维；利用不同电阻率的SiC纤维与环氧树脂复合，制备单层、两层和三层复合材料，测试其在X波段下的电磁参数及吸波性能；利用传输线理论，计算预测了纤维电阻率、纤维体积分数、材料厚度和叠层方式对复合材料吸波性能的影响规律，并将实验结果与理论计算结果进行了对比验证。 研究发现，在1000-1500C温度区间，随着热处理温度的升高，SiC纤维的电阻率大幅度降低。当热处理温度达到1500C时，纤维电阻率约为1ohm.cm。随着纤维电阻率的降低，复合材料的介电常数实部和虚部逐渐增大。当纤维的电阻率为1ohm.cm和10ohm.cm时，复合材料...This work modified the resistivity of SiC fibers by different heat treatment and the microwave absorption SiC fibers are obtained. Then these fibers are composed with epoxy resin to achieve single, double and three layer SiC fiber reinforced resin composites. The transmission line theory are extended to the situation of double and three layer composites to further study the effect of fiber resisti...学位：理学硕士院系专业：材料学院_高分子化学与物理学号：2072012115005

Polydopamine–Carbon Dots Conjugate: A New Kind Fluorescent Carbon Dots with Photothermal Conversion Property

荧光碳点（CarbonDots），即碳点，粒径约在2-8nm范围内，具有光致发光性能的一类类球形碳骨架材料，碳点具有较高的化学稳定性和荧光稳定性，大部分碳点均有典型的多色荧光性，即发射波长可随激发波长的调节而调节，且无明显生物毒性。此外，碳点由于自身表面缺陷（SurfaceEnergyTraps）作用，氨基的引入可以对碳点荧光强度起增强的作用。不同于传统半导体量子点大多含有有毒的金属元素，碳点的低毒性和良好的生物相容性使其替代传统半导体量子点得到更广泛的应用。 聚多巴胺（Polydopamine）是仿天然黑色素(真黑素)的一种，通过多巴胺氧化自聚而成。聚多巴胺在分子结构、光学以及生物相容性等...Carbon dots (C-dots), have drawn tremendous attention in nanotechnology field,with high chemical stability, remarkable advantage in stable photoluminescence and special optical properties. Fluorescent carbon dots based on carbon skeleton synthesized into spherical nanoparticles, with diameter lower than 10nm, broad excitation wavelength spectra, tunable emission wavelength and superior biocompatib...学位：理学硕士院系专业：材料学院_生物医学工程学号：3142013115013

Toxic effect of carbon dioxide and water soluble fractions of crude oil on marine madaka’s reproductive system

海洋酸化和原油污染对海洋鱼类的影响时有报道，但海洋酸化和原油污染及两者联合暴露对海洋鱼类生殖系统的影响却鲜见报道。本实验以黑点青鳉为实验动物模型，分别采用原油组（500μg/LWSF）、酸化组（1500ppmCO2）和混合暴露组（1500ppmCO2+500μg/LWSF）对黑点青鳉从受精卵开始暴露，探究海洋酸化和原油污染对海洋鱼类的生殖系统的毒性作用及可能机制，结果如下： 原油水溶性成分和二氧化碳暴露的雄鱼表现出精细胞的成熟延迟，并且精原细胞的分裂和分化都受到影响；雌鱼则表现出卵细胞的成熟加速，同时卵原细胞和卵母细胞在卵巢中所占的比例受到影响。通过对激素水平的研究发现，原油水溶性成分和二氧...There is some report about the influence caused by ocean acidificasion and crude oil pollution to marine fish, but few about combined effects. We use marine medaka (Oryzias latipes) as experimental animal, set three exposed groups as WSF (500 μg/L water soluble fractions of crude oil), CO2(1500 ppm CO2) and CO2+WSF(1500 ppm CO2 + 500 μg/L water soluble fractions of crude oil) from fertilized eggs,...学位：理学硕士院系专业：生命科学学院_生物化学与分子生物学学号：2162013115259

Study of Fluorinated Carbon as Cathode Materials for Sodium and Magnesium Battery

近年来锂离子电池应用领域不断扩展，锂资源匮乏以及伴随而来的锂离子电池成本较高等问题逐渐显现。发展替代锂元素的新型电池体系已成为各国都需面临的重要课题。钠、镁（离子）电池体系因为其较优异的电化学性能以及钠、镁元素在地壳中含量丰富等优势备受关注。氟化碳材料广泛应用于锂原电池正极材料，因其极高的理论比容量，是一类很有吸引力的钠、镁电池正极材料体系。本文制备氟化碳纤维和氟化乙炔黑两种高电压氟化碳材料，并采用XRD、SEM、XPS、sXAS、NMR并结合理论计算和充放电测试等技术，对材料的结构、电化学性能、高电压以及反应机理进行了较为系统的研究。 采用非晶相结构碳纤维作为碳源材料，通过气相高温氟化法制...With the increasing demand for lithium-ion batteries (LIBs) in applications such as electric vehicles and grid-scale energy storage, the scarcity of global lithium supplies and the resulting high costs of LIBs have become bottlenecks for their further development. It is thus necessary for researchers to advance novel energy storage systems as a substitute for LIBs. Abundant reserves of sodium and ...学位：工程硕士院系专业：能源学院_工程硕士(材料工程)学号：3242013115230

Impact of rain event on the land-ocean transfer of particulate and dissolved organic matter

河流向海洋输送有机质是全球碳循环中的重要过程，影响长时间尺度的气候变化。大部分有机碳快速的被降解氧化释放到大气中，一部分可以保存在海洋沉积物中，成为长时间尺度的碳埋藏；另一部分残留在水体中，特别是溶解态有机质，则会参与水环境的生物地球化学循环。物质从河流向海洋的输送受到极端降雨（例如台风）的影响，而在长时间尺度上，相对新鲜有机碳在海洋中的埋藏扮演了更重要的“碳汇”的作用。但是由于采样的困难，极端降雨对新鲜有机质输送的研究相对有限。 本研究通过对台湾高山河流流域内土壤样品中的木质素分析，发现大部分土壤中大部分木质素是分布在表层土壤，可以指征新鲜有机质。通过台风期间高密度的河流悬浮颗粒物样本中木...The transfer of organic matter from land to ocean is an important process in the global carbon cycle, which affects the long-term climate change in geological time scales. The majority of the organic matter transferred to the coastal region is degraded and returned to atmosphere, while a fraction of this organic matter can be buried in the sediment, act as long-term carbon sink, another fraction o...学位：博士后院系专业：海洋与地球学院_海洋化学学号：201317002

Defects Identification for Carbonization Bamboos Based on GLCM and SVM

针对碳化竹条瑕疵种类多,位置不确定且竹纹理干扰的问题,利用图像处理技术对竹条图像进行阈值分割,图像滤波等预处理,得到特征明显的图像,从而实现其表面瑕疵特征的识别。通过计算确定灰度共生矩阵的三个构造因子,提取了图像的三个纹理特征,采用一对一淘汰策略的多类SVM（support vector machine）学习模型进行分类识别竹条的瑕疵类型。实验结果表明,该方法对于碳化竹条的黑结、虫蛀、染色、霉点、裂痕等缺陷的正确识别率达到90.6%以上。In observation of realization of the surface flaw feature recognition, the bamboo original image was pretreated by image graying, Otsu threshold and mean filtering by taking into account of the effect from defects of carbonized bamboo and location uncertainties. Influences from various building factors on GLCM （gray level co-occurrence matrix） and its parameters were invetigated, and the method for establishment ofGLCM suitable for describing bamboo surface texture was presented. A class of SVM learning model with one to one replacement strategy was employed to classify and identify the defect types of bamboo. Result shows that the method can classify the five common types of the bamboo defects which includs black node, worm-hole, dyeing, mildew and crack with an accuracy higher than 90. 6%.福建省中青年教师教育科研项目（JA15364）;厦门市科技计划项目（3502Z20151241,3502Z20153021,3502Z20161186）;福建省科技厅对外合作项目（2017I1009

青藏高原土壤有机碳储量与密度分布

采用全国第二次土壤普查数据结合作者的实测数据,利用1∶100万土壤数据库对青藏高原土壤有机质层、土壤矿质层及整个剖面的土壤有机碳密度和土壤有机碳储量分别进行了估算。结果表明:青藏高原的平均土壤有机碳密度约为C7.2kgm-2,较前人的C8.01~19.05kgm-2全国平均土壤有机碳密度偏低。青藏高原总的土壤有机碳储量约为18.37Pg,其中有机质层土壤有机碳储量约占38.14%,矿质层土壤有机碳储量则占61.86%。中国科学院知识创新工程重要方向项目(KZCX3-SW-339-04);国家重点基础研究发展规划项目(2005CB422005)资

Distribution and Air-Sea Exchange Flux of CO2 over the Marginal Seas surrounding Taiwan during Late Spring through Early Summer, 2008

[[abstract]]The distribution of CO2 in the surface water and the sea-air flux exchange in the sea areas around Taiwan are investigated in this study, and to discuss the reason of variation and the relationship with the distribution of water mass. Automated Underway pCO2 System are used to detect the seawater and air fCO2 during the late spring and early summer of 2008, from May 28 to July 13, including the South China Sea(SCS), the West Philippine Sea(WPS), the Western Taiwan Coast(WTC), and the East China Sea(ECS). The range of the atmospheric fCO2 is 367.4~402.2 μatm and the peaks are found near lands (Taiwan, China, and Luzon Island), the difference of concentration up to 35 μatm. The ranges of the surface water fCO2 are as follows: SCS: 352.3~415.6 μatm(Avg.= 389.3±16.5, n=1400), WPS: 346.9~399.0 μatm(Avg.= 377.6±5.8, n=840), TS: 370.5~407.3 μatm(Avg.= 389.2±4.8, n=836), ECS: 162~707 μatm(Avg.=378±69, n=1497); and ECS has the highest variation up to 545 μatm. The lowest and second lowest values of fCO2(217、162 μatm) are found in Changjiang Plume and Minjiang Plume, increasing from west to east with longitude and opposite to the concentration of chl-a. It’s quite obvious that the gradient of seawater fCO2 increase with the decrease of the biomass of plankton. The high values of fCO2(707、676 μatm) are found in Changjiang Upwelling and Coastal Upwelling which have low temperature. These areas also have very low transmittance(13.9 %) and very high nutrients(NO2+NO3) and Chl-a(32.2 μM, 106.7 mg/m3). It’s speculated that the high fCO2 may come from the bottom water of Changjiang Upwelling and Coastal Upwelling. Water masses in SCS and WPS are more stable and have the fCO2 gradient increase from shelf to offshore because the low temperature and rich of chl-a in nearshore seawater make the fCO2 of water decrease. In offshore, the fCO2 of SCS and WPS are high in daytime and low at night(△fCO2 =7.9), mainly reflecting the temperature difference between day and night(0.2~0.3℃) because of low biological effect. The surface water fCO2 of WTC has few variations but the atmospheric fCO2 has regional peaks because it is influenced by terrigenous matter. Data in this study suggests that the sea areas around Taiwan served as a source of atmospheric fCO2 during late spring and early summer, and the sea-to-air CO2 flux in SCS is +1.74±2.06 mol C/m2/yr, in WPS is +0.54±0.59, in WTC is +0.29±0.18, and in the ECS is +0.28±4.94.