The Concurrent Record-breaking Rainfall over Northwest India and North China in September 2021     

Ying NA  Riyu LU 《大气科学进展》2023,40(4):653-662

Extremely heavy rainfall occurred over both Northwest India and North China in September 2021. The precipitation anomalies were 4.1 and 6.2 times interannual standard deviation over the two regions, respectively, and broke the record since the observational data were available, i.e., 1901 for India and 1951 for China. In this month, the Asian uppertropospheric westerly jet was greatly displaced poleward over West Asia, and correspondingly, an anomalous cyclone appeared over India. The anomalous ...  相似文献   

Assessment of putative endocrine disrupters in an in vivo crustacean assay and an in vitro insect assay     

Pounds NA  Hutchinson TH  Williams TD  Whiting P  Dinan L 《Marine environmental research》2002,54(3-5):709-713

Concern over endocrine disrupters in coastal ecosystems has stimulated global efforts to understand their potential impacts on fish and invertebrate communities. Given that marine crustaceans are sensitive to the effects of alkylphenols and other xenobiotics, we are currently investigating whether these responses may be caused via an endocrine mechanism. Tisbe battagliai (Copepoda: Harpacticoida) is representative of an ecologically important group of meiofauna, is sensitive to toxicants and is used as an international test species in marine ecotoxicology. A 21-day life-cycle test that incorporates assessment of survival, development, reproduction and sex ratios, has shown that populations of T. battagliai are not significantly affected by environmentally relevant levels of steroidal oestrogen agonists, or by related synthetic receptor agonists. The absence of in vivo effects due to these steroid agonists and antagonists prompted in vitro studies of ecdysteroid receptor activity of a range of reference compounds and environmental contaminants with an ecdysteroid receptor (EcR/USP)-based screening assay derived from the BII haemocyte line of Drosophila melanogaster. The implications for environmental monitoring of endocrine disrupters are discussed.  相似文献   

Methodological problems in the geography of labor resources     

Salikov NA 《Soviet geography》1977,18(6):296-402

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Solenites (Czekanowskiales) from the Late Mesozoic Jehol Biota of Southeastern Jilin, China and its Paleoclimatic Implications     

LI Yunfeng  an  SUN Chunlin  LI Tao  NA Yuling  CHEN Yuejun  XING Dehe 《《地质学报》英文版》2015,89(4):1088-1102

Situated at the easternmost area of the Late Mesozoic Jehol Biota, China, abundant fossils, including invertebrates, vertebrates and plants, were collected from the Early Cretaceous Yingzuilazi Formation of the Baishan Basin, southeastern Jilin. The faunal remains from this formation distinctly belong to the Early Cretaceous Lycoptera–Ephemeropsis–Eosestheria assemblage of the Jehol Biota. Based on the gross leaf morphology and epidermal structures, two new species and one indeterminate species of genus Solenites(Czekanowskiales), S. baishanensis sp. nov., S. gracilis sp. nov. and S. sp. are described in this paper. This is the first fossil plant of Czekanowskiales reported from this new fossil locality of the easternmost area of the Late Mesozoic Jehol Biota, China. The new discovery contributes to improve our knowledge for understanding of leaf morphology, epidermal characters and diversity of this genus during the Early Cretaceous time, and extends geologic and geographic distribution of Solenites in northern China and Eurasia. Along with consideration of associated plant and faunal assemblages and sedimentology, we suggest that the regional climate was warm and moderately humid with seasonal temperature and precipitation variations in warm–temperate zone during the Early Cretaceous.  相似文献   

Sedimentary Age of the Baoligaomiao Formation in the Zhanlantun Area,Inner Mongolia: Constraints by Fossil Assemblage and Zircon Geochronology     

QIN Tao  QIAN Cheng  LI Linchuan  JIANG Bin  SUN Wei  NA Fuchao  SI Qiuliang  MA Yongfei  ZANG Yanqing 《《地质学报》英文版》2018,92(3):1251-1254

正Objective The Baoligaomiao Formation is widely distributed from the East Wuqi to Zhanlantun area in the Xing'an Mongolian orogenic belt(Tian Shugang et al.,2016;Wei et al.,2017).This formation contains abundant Angara biological fossils which exhibit diachronism  相似文献   

不同功率风动冲击器组成的潜孔锤     

Bely.NA  张佳文 《岩土钻凿工程》2000,(5):43-44

本文介绍了一种由不同功率冲击器组成的潜孔锤的工作原理。这种潜孔锤设计简便、可靠性和生产效率均较高、可用于大直径孔钻进。  相似文献   

液体折射法：一种连续测量的方法     

Russo  NA 汪菊芳 《武测译文》1994,(3):40-42

本文介绍一种获取精确的液体折射率的实时测量数据的方法。它是以改进型薄耳弗里许折射计为基础的，在需要连续测量的场合，可把这种光学设备直接用于工业生产。本文提供的一些实验结果证明了这种方法的可行性。  相似文献   

The Conversion Relationship between the Local Earthquake Magnitude and Surface Wave Magnitude in the Inner Mongolia Digital Seismic Network     

LIU Fang  SU Riy  XU Xiquan  LI Hui  NA Re 《中国地震研究》2019,33(1):86-96

Using 116 earthquakes over M_L3.8 in the Inner Mongolia region from 2008 to 2015, the local earthquake magnitude M_L and surface wave magnitude M_S are remeasured. Based on norm linear regression(SR1 and SR2) and norm(OR) orthogonal regression method, we established the conversion relationship between M_L and M_S. The results were tested with Gaussian disturbance. The result shows that the orthogonal regression method(OR) result has the best fitting curve, and the conversion relation is M_S=0.96 M_L-0.10. The difference between our result and Guo Lücan's(M_S=1.13 M_L-1.08) may be caused by regional tectonic characteristics. M_(S Inner Mongolia) value is significantly higher than the M_(S empirical) value, with an average difference of 0.23, the difference distribution of empirical relation and the rectified relation is in the range of 0.2-0.3.  相似文献   

中国东部晚前寒武纪古构造及其演化     

杨振升  俞保祥 《吉林大学学报(地球科学版)》1984,(2)

本文所涉及的范围为东径102°—107°以东的我国广大地区。讨论的时限是25亿年至7亿年这段晚前寒武纪地质历程。对这将近20亿年的地壳构造特征及其发展历史的研究,许多学者已从不同角度进行过总结(1、2、3、4、5、6、7、8、9、10)。由于近几年来,在这一领域内的研究工作,出现了一些新的进展。因此,有可能在前人工作基础  相似文献   

Navy sonar and cetaceans: just how much does the gun need to smoke before we act?     

Parsons EC  Dolman SJ  Wright AJ  Rose NA  Burns WC 《Marine pollution bulletin》2008,56(7):1248-1257

Cetacean mass stranding events associated with naval mid-frequency sonar use have raised considerable conservation concerns. These strandings have mostly involved beaked whales, with common pathologies, including "bubble lesions" similar to decompression sickness symptoms and acoustic traumas. However, other cetacean species have also stranded coincident with naval exercises. Possible mechanisms for the strandings include a behavioral response that causes deep divers to alter their diving behavior, which then results in decompression sickness-like impacts. Current mitigation measures during military exercises are focused on preventing auditory damage (hearing loss), but there are significant flaws with this approach. Behavioral responses, which occur at lower sound levels than those that cause hearing loss, may be more critical. Thus, mitigation measures should be revised. A growing number of international bodies recognize this issue and have urged increasing scrutiny of sound-producing activities, but many national jurisdictions have resisted calls for increased protection.  相似文献