闽江河口区沉积物中的抗生素分布特征及生态风险评价

采用固相萃取和液相色谱串联质谱(HPLC-MS/MS)分析方法对闽江河口区域沉积物中8类54种抗生素的含量以及分布特征进行分析探讨,并利用熵值法对抗生素的生态风险进行评价。结果表明,闽江河口区域24个站点共检出6类(大环内酯类、磺胺类、喹诺酮类、氯霉素类、硝基咪唑类和苯并咪唑类)19种抗生素,总量范围在4.16~64.74 ng/g,平均值为17.35 ng/g;其中大环内酯类、喹诺酮类和硝基咪唑类抗生素检出频率达到100%。抗生素总量的空间分布情况呈闽江河口上游>北港>南港>河口下游的趋势,人口密集区生活污水和医疗废水排放是上游和北港沉积物大环内脂类和喹诺酮类抗生素含量较高的主要原因,而海水养殖过程中的直接投放可能是河口下游硝基咪唑类抗生素的主要来源;生态风险评价结果显示,大部分抗生素的生态风险值RQ<1,然而替米考星和甲硝唑在研究区域的RQ>1,具有一定的潜在风险,可能会对该区域生态环境产生负面效应。     

利用JPL行星/月球星历计算遥感水汽中的地球固体潮改正

简要介绍GPS遥感水汽的原理,详细讨论了计算地球固体潮改正模型的理论公式。介绍获取JPL星历的方法,以及如何利用JPL行星/月球星历来计算太阳和月亮的坐标,并逐步计算出地球固体潮改正。举例计算了地球固体潮改正,分析了其对水汽的影响,比较了太阳距离、月亮距离与地球固体潮改正的关系。     

基于卷积神经网络与条件随机场方法提取乡镇非正规固体废弃物

随着村镇经济建设发展,生活垃圾和工业固体废弃物造成的污染问题日益突出,已经成为制约新农村建设发展和生态文明建设的关键问题,而目前针对乡镇非正规固体废弃物的调查与统计主要依赖全国各乡镇相关部门逐级调查上报,工作量较大。本文基于高分辨率遥感影像,将深度学习模型和条件随机场模型相结合引入到乡镇固体废弃物的提取研究中,探索一种基于深度卷积神经网络的乡镇固体废弃物提取模型。由于固体废弃物在影像上表现为面积小,分布破碎等特点,为了提高工作效率,将模型特分为识别和提取2个部分：① 通过全连接卷积网络（CNN）对固体废弃物进行快速识别判断,筛选感兴趣区域影像块;② 在传统的全卷积神经网络(FCN)的基础上加入条件随机场模型(CRF)提取固体废弃物边界,提高整体分割精度。根据安徽、山西等地区相关部门上报固体废弃物堆放点以及住房与城乡建设部城乡规划管理中心进行野外检查的结果,实验最终识别精度达到86.87%以上;形状提取精度为89.84%,Kappa系数为0.7851,识别与提取精度均优于传统分类方法。同时,该方法已经逐步应用于住房和城乡建设部有关成都、兰州、河北等部分乡镇非正规固体废弃物的核查工作,取得了较为满意的结果。     

氮钾配施对生姜产量和砂姜黑土肥力的效应

研究了淮北平原砂姜黑土地区生姜氮钾配施的增产效应和对土壤养分的影响。结果表 明:氮钾配施可以大幅度提高生姜的产量,施钾的增产幅度,柴姜为15.3%～58.4%,平均增产率 为35.8%;狮子头姜产量提高18.2%～46.9%,平均增产28.7%。增施氮钾肥可有效提高土壤有 机质、全N、有效P、速效K、缓效K、有效Ca和有效Mg含量,降低NO3-盐含量,促使土壤pH趋于 中性,对全P和碱解N含量影响较小。土壤N素和P素大量盈余,不施钾时土壤K亏损严重,施钾 处理土壤钾基本上处于盈余状态,有利于维持和提高土壤肥力。     

Element mobility during continental collision: insights from polymineralic metamorphic vein within UHP eclogite in the Dabie orogen

Metamorphic dehydration and partial melting are two important processes during continental collision. They have significant bearing on element transport at the slab interface under subduction‐zone P–T conditions. Petrological and geochemical insights into the two processes are provided by a comprehensive study of leucocratic veins in ultrahigh‐pressure (UHP) metamorphic rocks. This is exemplified by this study of a polymineralic vein within phengite‐bearing UHP eclogite in the Dabie orogen. The vein is primarily composed of quartz, kyanite, epidote and phengite, with minor accessory minerals such as garnet, rutile and zircon. Primary multiphase solid inclusions occur in garnet and epidote from the both vein and host eclogite. They are composed of quartz ± K‐feldspar ± plagioclase ± K‐bearing glass and exhibit irregular to negative crystal shapes that are surrounded by weak radial cracks. This suggests their precipitation from solute‐rich metamorphic fluid/melt that involved the reaction of phengite breakdown. Zircon U–Pb dating for the vein gave two groups of concordant ages at 217 ± 2 and 210 ± 2 Ma, indicating two episodes of zircon growth in the Late Triassic. The same minerals from the two rocks give consistent δ¹⁸O and δD values, suggesting that the vein‐forming fluid was directly derived from the host UHP eclogite. The vein is much richer in phengite and epidote than the host eclogite, suggesting that the fluid is associated with remarkable concentration of such water‐soluble elements as LILE and LREE migration. Garnet and rutile in the vein exhibit much higher contents of HREE (2.2–5.7 times) and Nb–Ta (1.8–2.0 times) than those in the eclogite, indicating that these normally water‐insoluble elements became mobile and then were sunken in the vein minerals. Thus, the vein‐forming agent would be primarily composed of the UHP aqueous fluid with minor amounts of the hydrous melt, which may even become a supercritical fluid to have a capacity to transport not only LILE and LREE but also HREE and HFSE at subduction‐zone metamorphic conditions. Taken together, significant amounts of trace elements were transported by the vein‐forming fluid due to the phengite breakdown inside the UHP eclogite during exhumation of the deeply subducted continental crust.     

广西弧形构造探讨

广西构造实为一弧形构造,它由四个并排的北东—北西向的轭状弧带所组成。每个弧带的前部,为坚硬的岩块所组成,所产生的断裂及岩浆活动对寻找与火成岩有关的矿产有一定意义。每个弧带的后部,产生盆地型沉积,有利于沉积矿产的形成。     

矿石中金的在线固相萃取及缝管火焰原子吸收测定

介绍了将流动注射在线因相萃取预浓集与石英缝管火焰原子吸收相结合测定矿石中金的方法，用ＸＡＤ－８吸附树脂填充的微型柱（１００μｌ）在６ｍｌ／ｍｉｎ的流速下，从０．５ｍｏｌ／ＬＨＣｌ介质的试样溶液中浓集金氯络合物，再用乙醇洗脱，最后由火焰原子吸收检测，在采样频率为１０３样／ｈ的流速下灵敏度提高４７倍，分析精度为１．３％，检出限为１．０μｇ／Ｌ；在６５样／ｈ的采样频率下灵敏度提高９５倍，检出限可达０．７     

Surface wave propagation in a transversely isotropic elastic layer overlying a liquid saturated porous solid half-space and lying under the uniform layer of liquid

Dispersion of Rayleigh-type surface wave is studied in a homogeneous transversely isotropic elastic layer overlying a nondissipative liquid-saturated porous solid half-space and lying under a uniform layer of homogeneous liquid. The frequency equation in the form of ninth-order determinant is obtained.Special cases have been deduced by reducing the depth of the layers to zero and by changing the transverse isotropic layer to an isotropic layer. Dispersion curves for the phase velocity have been plotted for a particular model.