贵州省赫章县核桃农业园区富硒土地特征及开发建议   总被引：1，自引：0，他引：1       下载免费PDF全文

陆光艳  袁彬  黄林  孟庆田  任厚州 《贵州地质》2020,37(3):258-265

针对单一角度采集的图像检测样本存在的高误检率、错误率等问题，文章提出一种特殊的打光方案及相机安装方案，实现对胶囊360°全方位的缺陷检测,利用彩色相机填补了胶囊异色点、黑点，印字、小切口以及混批等缺陷不能检测的空白。在胶囊有序传送的前提下，提出“隔组间排”原理，以更多时间和空间使电磁铁伸缩杆完成踢废动作，平衡“传送效率”“检测效率”“踢废效率”三者之间的矛盾，提高设备的处理能力，实现胶囊的缺陷检测。  相似文献   

太空搭载海水钝顶螺旋藻诱变株H_(11)的室外产多糖特性研究     

谭丽  李涛  吴华莲  吴嘉仪  向文洲  刘德海 《海洋通报》2018,(3):328-334

本研究对一株经太空搭载后选育的海水钝顶螺旋藻诱变株H_(11)的室外产多糖能力进行了评估。结果显示,在广州秋季室外平均温度为27°C下,诱变株H_(11)的生物量产率、总糖含量、总多糖含量和水溶性多糖含量分别为19.09±0.03 mg/(L·d)、27.89±1.28%DW、20.95±0.87%DW和19.74±0.93%DW。与野生株WT相比,H_(11)的生物量、总糖、总多糖和水溶性多糖的产率分别提高了15.39%,148.93%,176.50%和187.70%。在冬季室外平均培养温度为17°C条件下,诱变株和野生株生长速率及多糖产率都有所降低,但诱变株在产多糖能力上仍显著高于野生株(P0.05)。研究表明海水钝顶螺旋藻诱变株H_(11)产多糖能力极高,具有可观的产业应用前景。  相似文献   

The cumulative characteristics of PAEs in PM2.5 in Changji,Northwest China     

Yuyan Liu  Caiye Ji  Bo Fu  Yongxin Yu  Haofeng Liu  Yaxing Shen 《自然地理学》2020,41(4):332-342

ABSTRACT

This paper discusses characteristics of the seasonal variation in phthalate acid esters (PAEs) in the PM_2.5 in the city of Changji, which is located an arid area of Xinjiang Province, northwest China. Samples were collected using a Laoying 2030 median discharge intelligent total suspended particulate (TSP) sampler and analyzed by a Shimadzu GC-2010 gas chromatograph. The results showed that PAEs in PM_2.5 were mainly composed of phthalic acid dibutyl phthalate (DBP) and phthalic acid (2-)ethyl hexyl ester (DEHP). DBP and DEHP are the most commonly used plasticizers, accounting for the majority of plasticizers used, and have large environmental emissions. Compared with the proportions of TSPs, proportions of DBP and DEHP in the PM_2.5 were lower, while the proportions of DMP and DEP were higher. A correlation exists between the distribution of PAEs and the particle size and concentration of atmospheric particulates. Seasonal variations in DBP and DEHP were the same, with lowest concentrations in the summer. Although seasonal variation in DMP was not the same as those of DBP and DEHP, the general trend was similar. Seasonal variation in DEP was different from those of other PAEs. This pattern is related to PAE characteristics and seasonal variations in their sources.  相似文献   

Biofilm mediated uptake of selenium in streams with mountaintop coal mine drainage     

《Limnologica》2017

Selenium (Se) may cause reproductive toxicity, yet the characteristics of Se bioaccumulation in aquatic food webs are understudied. Stream biofilms were grown in two reaches of Mud River, West Virginia (WV), including one downstream of a coal mine complex and an adjacent, unmined watershed. Mined stream biofilms contained significantly higher Se concentrations compared to unmined biofilms. An inverse relationship between water Se concentrations and biofilm accumulation factors was observed; mined-stream biofilms had an average bioconcentration factor (BCF) of 688 ± 350 fold while unmined-stream biofilms had an average BCF of 14505 ± 2700 fold.  相似文献   

莺歌海盆地乐东地区石英裂隙内流体包裹体特征及其对天然气成藏制约     

税蕾蕾  梁茹  孟祥豪  郭来源  许克伟 《沉积与特提斯地质》2020,40(1):45-52

莺歌海盆地乐东地区是我国典型高温超压天然气勘探领域,其关键储层黄流组砂岩以天然气富含CO_2为特征,对其中石英颗粒内裂隙包裹体的研究能为CO_2来源和天然气成藏信息提供重要线索。本文通过对黄流组砂岩石英颗粒内包裹体进行岩相学、显微测温与激光拉曼分析,结果表明黄流组砂岩石英颗粒内正常捕获流体包裹体均一温度主要分布在155～165℃与170～180℃两个温度区间,流体包裹体成分为CO_2(气)和H_2O(液)两种或CO_2(气)和CO_2(液)、H_2O(液)三种。这些特征表明乐东地区黄流组至少经历两期富含CO_2的热液活动,记录了埋藏晚期无机CO_2在火山活动或深大断裂发育期充注成藏的信息。  相似文献   

Accumulation and speciation of selenium in evaporation basins in California,USA   总被引：1，自引：0，他引：1  

Ji-Hun Ryu  Suduan Gao  Kenneth K. Tanji 《Journal of Geochemical Exploration》2011

The accumulation of selenium in evaporation basins (or ponds) in the San Joaquin Valley, California is of a great concern due to its potential hazards to environments. In this study, the accumulation, speciation and concentrations of Se were examined in waters as well as sediments in a system of the evaporation ponds. A significant decrease in the total dissolved Se concentration in Cell 1 in which drainage water with higher Se concentration was pumped from Inlet Channels indicated that the immobilization of Se was active in the Cell 1 and resulted in the higher Se concentration in sediments compared to the terminal cell such as Cell 9. The percentage of reduced Se species such as selenite [Se(IV)] and org-Se of total Se in drainage waters was also found increased in Cell 1 compared to Inlet Channels. The total dissolved Se concentrations in water along flow paths from Cell 1 were relatively constant except for terminal cells such as Cells 9 and 10, which showed higher total dissolved Se concentrations due to evapoconcentration. The percentage of reduced Se forms of total Se was inversely proportional to the percentage of Se(VI) depending on the redox condition of evaporation ponds along the flow paths. Sequential extractions of Se species in sediments indicated that organic associated Se and elemental Se were prevalent forms in sediments in the ponds system. The higher concentrations of elemental Se and organic associated Se in sediments in Cell 1 indicated that the immobilization of Se was active in the sediments compared to Cell 9, while the percentage of both fractions of total Se in sediments in Cells 1 and 9 was relatively constant. The organic materials from algae might provide carbon sources for Se reduction and Se sink in sediments in its elemental and organic associated forms.  相似文献   

长江三角洲晚第四纪地层沉积特征与生物气成藏条件分析     

林春明  张霞  徐振宇  邓程文  殷勇  承秋泉 《地球科学进展》2015,30(5):589-601

对长江三角洲晚第四纪地层沉积特征进行了精细研究,探讨了研究区层序地层格架,在此基础上分析了浅层生物气成藏条件、特征和分布规律。研究表明,长江三角洲晚第四纪发育3期下切河谷,形成了3套沉积层序;因后期河流的强烈下切破坏,早期沉积层序往往被剥蚀殆尽,仅残留下部的河床相粗粒沉积,造成不同期河床相的叠置;相对而言,末次冰期以来形成的下切河谷沉积层序以相对完整的沉积相组合被保存下来。长江三角洲浅层天然气是未经运移的原生生物气,其主要富集于末次冰期以来的沉积层序内,气藏为自生自储同生型的岩性圈闭。河口湾—河漫滩和浅海相泥质沉积物既是气源岩,又是盖层,后者可作为良好的区域盖层;河口湾—河漫滩和河床相砂质沉积物为主要储集层。因此,研究区晚第四纪多期下切河谷沉积层序有利于浅层生物气藏的形成,特别是晚期下切河谷内河口湾—河漫滩相砂质透镜体以及河床相砂体可作为优先勘探目标。  相似文献   

Growth, condition and energy stores of Arctic grayling fry inhabiting natural and artificial constructed Arctic tundra streams     

Kimberlea L.F. DriedgerLynn P. Weber  Ian K. BirtwellDavid M. Janz 《Limnologica》2011,41(1):63-69

Juvenile north-temperate and Arctic fishes are faced with trade-offs between energy allocation to growth and energy storage (primarily lipids) prior to over-wintering. We determined classical morphometric (fork length, body weight and condition factor) and biochemical (whole body triglycerides, muscle RNA/DNA ratio, muscle proteins) measures of growth and condition in individual young-of-the-year (YOY) Arctic grayling (Thymallus arcticus). Grayling were collected just prior to over-wintering in late August (approximately 50 days after swim-up) from two natural streams and five locations within a 3.4 km long artificial stream constructed as a fish habitat compensation project and diversion channel for the diamond mining industry in Northwest Territories, Canada (64°45′N). Fork lengths, body weights and whole body triglyceride levels in grayling collected from all sites along the artificial stream were significantly lower than fish collected from one of the natural streams. Condition factor (weight-at-length) was not different among grayling collected from natural and artificial streams. Muscle proteins were lower in grayling collected from four sites along the artificial stream compared to the natural streams. In contrast, muscle RNA/DNA ratios were greater in grayling collected from two sites in the artificial stream compared to natural streams. There were no consistent differences in any variable among grayling collected at the five artificial stream sites or among grayling collected from the two natural streams. The higher RNA/DNA ratios and lower fork lengths, whole body triglycerides and muscle proteins in grayling inhabiting the artificial stream are consistent with energy still being primarily allocated to growth in these fish at this late stage of summer. Individuals that are both larger and possess greater energy storage in the form of triglycerides are more likely to survive the long over-wintering period at this latitude. Our results suggest that YOY grayling using the artificial stream as nursery habitat will likely face increased over-winter mortality, thus raising concerns over the use of fish presence, spawning and rearing as criteria for the initial success of artificial streams as habitat compensation measures in Arctic tundra regions. Further research is needed to determine the potential consequences of reduced size and energy storage in juvenile fishes in order to assess the viability of stream fish habitat compensation and restoration projects associated with industrial development in Arctic tundra regions.  相似文献   

Vertical Distribution and Mobility of Heavy Metals in Agricultural Soils along Jishui River Affected by Mining in Jiangxi Province,China   总被引：1，自引：0，他引：1       下载免费PDF全文

Guannan Liu  Wei Xue  Li Tao  Xinhui Liu  Jing Hou  Meaghan Wilton  Ding Gao  Anjian Wang  Ruiping Li 《洁净——土壤、空气、水》2014,42(10):1450-1456

  相似文献   

Adsorption of Selenium Using Bagasse Fly Ash     

Kailas L. Wasewar  Basheshwar Prasad  Sekhararao Gulipalli 《洁净——土壤、空气、水》2009,37(7):534-543

The present work involves the study of Se(IV) adsorption onto bagasse fly ash. The adsorbents were coated with a ferric chloride solution for the effective removal of selenium. The physico‐chemical characterization of the adsorbent was carried out using standard methods, e. g., proximate analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, thermo‐gravimetric analysis and differential thermal analysis. Batch experiments were carried out to determine the effect of various parameters such as adsorbent dose, initial pH, contact time, and temperature on the adsorption process. Results obtained from these studies were analyzed using various kinetic models and isotherms. Se(IV) adsorption onto adsorbent was high at low pH values, and decreased with an increase in initial pH. A temperature study showed that the uptake of Se(IV) was greatest at 293 K, within the temperature range studied. The parameters of pseudo first order, pseudo second order, and Weber‐Morris intra‐particle kinetic models were determined. Equilibrium isotherms were analyzed using Langmuir, Freundlich, and Temkin isotherms. Error analyses were also carried out using hybrid fractional error function and Marquardt's percent standard deviation.  相似文献