4种海洋微藻对久效磷的抗性与其抗氧化能力的相关性   总被引：16，自引：2，他引：14  

唐学玺  李永祺 《海洋与湖沼》2000,31(4):414-418

于１９９４年８月－１９９５年１２月,动用生态毒理学和生物化学实验方法,选用扁藻、叉鞭金藻、三角褐指藻及盐藻４种海洋微藻为材料进行海洋微藻对效磷的抗性与抗氧化能力相关性的实验。结果表明,久效磷在协迫过程中,微藻细胞内产生了过量的对细胞有伤害作用的活性氧,４种海洋微藻细胞内活性氧清除酶－超氧化物歧化酶的活性高低依次为盐〉三角褐指藻〉叉鞭金藻〉扁藻。比较毒性实验证明：４种海洋微藻对久效磷的基本身抗氧化能  相似文献   

低纬子午环轴准直器稳定性的改善     

铁琼仙  张周生  冒蔚 《天文研究与技术》2000,(4)

本文介绍了低纬子午环设置轴准直器测定枢轴不规则影响的必要性以及对其光轴指向稳定性的要求,分析了存在不稳定现象的原因,叙述了消除不稳定现象的方法和实施的效果,最后给出了枢轴不规则影响的量级和修正精度.  相似文献   

Middle Stratospheric Polar Vortex Ozone Budget during the Warming Arctic Winter, 2002--2003   总被引：1，自引：0，他引：1  

LIU Yi  LIU Chuanxi  Xuexi TIE  GAO Shouting 《大气科学进展》2011,28(5):985-996

The ozone budget inside the middle stratospheric polar vortex(24-36 km) during the 2002-2003 Arctic winter is studied by analyzing Michelson Interferometer for Passive Atmospheric Sounding(MIPAS) satellite data.A comprehensive global chemical transport model(Model for Ozone and Related Chemical Tracers,MOZART-3) is used to analyze the observed variation in polar vortex ozone during the stratospheric sudden warming(SSW) events.Both MIPAS measurement and MOZART-3 calculation show that a pronounced increase(26-28 DU) in the polar vortex ozone due to the SSW events.Due to the weakening of the polar vortex,the exchange of ozone mass across the edge of the polar vortex increases substantially and amounts to about 3.0× 107 kg according to MOZART-3 calculation.The enhanced downward transport offsets about 80% of polar vortex ozone mass increase by horizontal transport.A "passive ozone" experiment shows that only ～55% of the vertical ozone mass flux in February and March can be attributed to the variation in vertical transport.It is also shown that the enhanced downward ozone above ～32 km should be attributed to the springtime photochemical ozone production.Due to the increase of air temperature,the NOx reaction rate increases by 40%-80% during the SSW events.As a result,NOx catalytic cycle causes another 44% decrease in polar vortex ozone compared to the net ozone changes due to dynamical transport.It is also shown that the largest change in polar vortex ozone is due to horizontal advection by planetary waves in January 2003.  相似文献   

川西雅江地区构造-岩石变形特征及其控灾机制     

熊小辉  白永健  铁永波 《现代地质》2021,35(1):145-152

川西雅江地区发育系列复式背斜、复式向斜及其伴生断裂的褶-断式构造组合样式。受强烈构造改造,岩石变形主要呈现出柔性滑脱、顺层剪切、脆性弯折、沿结构面强卸荷、大位移错动、断层破碎以及褶皱劈理化等7类样式。构造-岩石组合塑造着该区域雅砻江展布与深切河谷的演化,而河谷演化与构造改造共同控制着区域滑坡、崩塌等地质灾害的发育与分布。不同的岩石变形样式孕育不同类型的地质灾害,而岩性组合关系控制地质灾害发育的规模。受砂岩板岩互层弯折变形的控制,斜坡主要产生倾倒弯折→拉裂→滑移→失稳破坏→堵塞河道或阻断道路等多阶段变形破坏模式,形成雅江地区滑坡灾害最主要的成灾模式。  相似文献   

测定天文大气折射和建立电磁波折射延迟实测模型(Ⅰ)-观测原理和可行性     

冒蔚  李彬华  杨磊  铁琼仙  张捍卫 《天文研究与技术》2005,2(4):240-245

简述了天文大气折射和电磁波中性大气折射延迟的成因,以及不同观测站、不同方位的折射值存在差异的事实;根据测定瞬时天文大气折射、建立本地实测模型的观测原理和要求,分析了长期以来不能直接测定天文大气折射的几个主要障碍,介绍了现已具备的排除这些障碍的必要条件,为建立天文大气折射实测模型,和随观测站、随方位而异的电磁波折射延迟改正模型提供了保证。  相似文献   

电感耦合等离子体发射光谱法同时测定锡矿石中锡钨钼铜铅锌   总被引：5，自引：5，他引：0  

杨惠玲  夏辉  杜天军  白露  秦九红  铁锦林 《岩矿测试》2013,32(6):887-892

锡矿石是难分解的矿物,共生与伴生元素多,其中的锡钨钼在单一盐酸溶液中易沉淀,准确测定锡矿石中的主次量元素一直是分析技术难点。本文以过氧化钠为熔剂,高温熔融样品,在酒石酸-盐酸-双氧水体系中进行酸化,选用该矿种中仅含有少量的钴作为内标,建立了电感耦合等离子体发射光谱同时测定锡矿石中锡钨钼铜铅锌的分析方法。方法线性范围为0.00~40.0 mg/L;方法检出限为锡10 mg/kg,钨30 mg/kg,钼3.3 mg/kg,铜12 mg/kg,铅15 mg/kg,锌40 mg/kg;方法精密度(n = 9)小于5.0%,实际样品的测定值与传统化学方法及国家标准方法的测定值吻合较好。本方法采用过氧化钠碱熔锡矿石,溶样彻底,并省去了氢氟酸挥发硅的蒸酸过程,节约了样品处理时间;采用酒石酸-双氧水-盐酸体系溶解熔融物,有利于溶液中的锡钨钼形成稳定的络合物,避免了单纯盐酸体系下产生钨酸、钼酸和锡酸沉淀导致测定结果偏低的问题。  相似文献   

Study on the characteristics and formation mechanism of the typical post-fire debris flow in Lushan area of Xichang City: A case study of 3^# branch on the left bank of Xiangshuigou     

TIE Yongbo  XU Ruge  LIU Hong  WANG Jiazhu  BA Renji  XIANG Anping  YANG Jian  OUYANG Yuan  ZHANG Yu  WANG Hong 《中国地质调查》2014,7(3):82-88

On March 30, 2020, a forest fire broke out in Liangshan area of Xichang City in Sichuan Province. After the fire, the ash and burnt soil easily developed into debris flow in case of heavy rainfall, which brought potential geological hazard risks to the ecological environment of Lushan and safety of local people's lives and properties in Qionghai and Lushan areas. Taking 3^# branch on the left bank of Xiangshuigou in Anha Town as an example, the authors conducted field investigation, UAV aerial photography, geophysical exploration, field and indoor experiments to study the fluid characteristics, dynamic parameters and genetic mechanism of the post-fire debris flow on May 1, 2020. The features of movement, provenance scale and deduced precipitation were also systematically analyzed. This achievement could provide some reference for the study of the development trend of the post-fire debris flow and the mitigation of disasters in this area.  相似文献   

基于耳石形态的大泷六线鱼(Hexagrammos otakii)群体判别研究     

孔晓  王英俊  吴莹莹  刘童  宋爱环  唐学玺  刘洪军 《海洋科学》2022,46(4):34-43

  相似文献   

公路施工中预防水泥混凝土路面断板措施探讨     

帖金鑫 《安徽地质》2005,15(4):316-317

路面发生断板,致使水泥混凝土路面使用性能下降,严重影响了公路运输的效益和行车安全,本文根据多年施工经验,提出在施工中预防断板的有效措施,供水泥混凝土路面施工参考。  相似文献   

CLDASSD: Reconstructing Fine Textures of the Temperature Field Using Super-Resolution Technology     

Ruian TIE  Chunxiang SHI  Gang WAN  Xingjie HU  Lihua KANG  Lingling GE 《大气科学进展》2022,39(1):117-130

Before 2008,the number of surface observation stations in China was small.Thus,the surface observation data were too sparse to effectively support the High-resolution China Meteorological Administration’s Land Assimilation System(HRCLDAS)which ultimately inhibited the output of high-resolution and high-quality gridded products.This paper proposes a statistical downscaling model based on a deep learning algorithm in super-resolution to research the above problem.Specifically,we take temperature as an example.The model is used to downscale the 0.0625°×0.0625°,2-m temperature data from the China Meteorological Administration’s Land Data Assimilation System(CLDAS)to 0.01°×0.01°,named CLDASSD.We performed quality control on the paired data from CLDAS and HRCLDAS,using data from 2018 and 2019.CLDASSD was trained on the data from 31 March 2018 to 28 February 2019,and then tested with the remaining data.Finally,extensive experiments were conducted in the Beijing-Tianjin-Hebei region which features complex and diverse geomorphology.Taking the HRCLDAS product and surface observation data as the"true values"and comparing them with the results of bilinear interpolation,especially in complex terrain such as mountains,the root mean square error(RMSE)of the CLDASSD output can be reduced by approximately 0.1℃,and its structural similarity(SSIM)was approximately 0.2 higher.CLDASSD can estimate detailed textures,in terms of spatial distribution,with greater accuracy than bilinear interpolation and other sub-models and can perform the expected downscaling tasks.  相似文献