基于罗德里格矩阵的混合最小二乘方法在三维激光中的应用

介绍了基于罗德里格矩阵的混合最小二乘坐标转换模型及精度,通过三维激光点云配准与坐标转换实验的结果表明,基于罗德里格矩阵的混合最小二乘方法的效果及精度明显高于基于罗德里格矩阵的最小二乘方法,说明该方法的可行性。     

五种中草药复方体外激活花鳗鲡(Anguilla marmorata)外周血白细胞活性的评价

作为典型的降河洄游鱼类,花鳗鲡(Anguilla marmorata)在我国主要分布于长江下游及以南水域。中草药作为抗生素等化学类渔药的绿色替代品,对养殖鱼类具有抗菌、消炎、促生长等多种功效。为研究中草药复方在花鳗鲡病害防治中的作用,扩大水产养殖业渔药研制与应用的选择,采用非连续性密度梯度离心法对花鳗鲡外周血白细胞的分离体系进行了优化,试验设置了密度分别为1.031、1.043、1.056、1.067、1.090 g/mL的五种分离液,分别采用染色观察法和流式细胞术检测各分离液中白细胞浓度;以浓度1.0mg/mL的五种复方药液分别与10⁵cell/mL的白细胞悬液共孵育2h后,分别采用NBT法和流式细胞术测定白细胞的呼吸暴发活性和吞噬能力,评价五种中草药复方(多糖复方Dt,白头翁复方Btw,板蓝根复方Blg,大黄复方Dh,百里酚复方Blf)对花鳗鲡外周血白细胞的激活作用。结果显示:1.043g/mL和1.056g/mL的分离液所分离获得白细胞浓度均接近10⁵cell/mL,可在后续实验中叠加使用该两个浓度的分离液分离获得白细胞;流式细胞术检测白细胞浓度比染色观察法更为灵敏准确;5种复方均能显著提高花鳗鲡外周血白细胞的呼吸暴发活性(P<0.05),大小依次为Blg>Dt>Btw>Blf>Dh;Dt和Blg能显著提高白细胞吞噬率(P<0.05),Btw、Blf、Dh也能提高白细胞吞噬率,但差异不显著(P>0.05);5种复方对发生吞噬白细胞比率的影响差异不显著(P>0.05)。     

Settlement distribution and its relationship with environmental changes from the Neolithic to Shang-Zhou dynasties in northern Shandong, China

In this paper, the spatial and temporal distribution of the settlement sites of six periods from the Neolithic Age to the Shang and Zhou dynasties in northern Shandong was investigated using the ArcGIS program, and the relationship between settlement distribution and environmental changes was discussed, based on the proxy records of climatic and environmental change contained in the sediments from three sections at the Shuangwangcheng site and the previous work. The results show that the climate was warm and humid and the sea level was relatively high during the period of 8000-5000 a BP in the study area, and the ancient people lived in the relatively flat （slope of 〈2°） areas at high elevation （20-300 m above sea level）, such as diluvial tableland and alluvial plain. On the other hand, few archaeological sites in the low-lying plain in the west of the study area indicate that few people lived there during that period. This might be attributed to frequent flooding in the area. After 5000 years ago, the scope of human activity extended to the area close to the sea because the relatively colder and drier climate results in sea-level fall, meanwhile the low-lying plain in the west was occupied by the ancient people. The study area of this period was characterized by the rapid development of prehistoric culture, the intensified social stratification and the emergence of early city-states. However, around 4000 a BP, the abrupt change in climate and the increase in frequency and intensity of floods severely disrupted human activities, and eventually led to the decline of the Yueshi culture. During the Shang and Zhou dynasties, the climatic conditions gradually stabilized in a mild-dry state, which promoted the redevelopment and flourish of the Bronze Culture. The previous situation, which was characteristic of sparse human settlements due to freshwater shortage and unfitted conditions for sedentary agriculture, changed during the Shang and Zhou dynasties in northern coastal wetlands.Local residents effectively adapted themselves to the tough environmental conditions by producing sea-salt, which led to the rapid growth of human activities.     

Different discretization method used in coupled water and heat transport mode for soil under freezing conditions

A coupled water and heat transport mode is established based on the Richards equation to study water flow and heat transport in soil during freezing process. Both the finite difference and finite element method are used in the discretization, respectively. Two different computer programs are written and used to simulate an indoor unidirectional frozen test. The freezing depth, freezing rate and temperature variation are compared among lab tests, finite difference calculation simulation and finite element calculation simulation. Result shows that: the finite difference method has a better performance in freezing depth simulation while the finite element method has a better performance in numerical stability in one-dimensional freezing simulation.     

On the relation of mid-infrared emission with the gamma-ray properties of Fermi-detected BL Lac objects

We present the Wide-field Infrared Survey Explorer (WISE) photometric data of 158 Fermi-detected BL Lacs and investigate the nature of their mid-infrared (MIR) continuum emission. In the [3.4]-[4.6]-[12] μm color–color diagram, nearly all their colors lie within the WISE Blazar strip (WBS), which is an effective diagnostic tool to separate sources dominated by non-thermal radiation from those dominated by thermal radiation. This feature indicates that their MIR emission is predominantly non-thermal. This argument is further supported by the strong radio-MIR flux correlation. We derive their MIR spectral indices and compare them with the near-infrared (NIR) spectral indices. We find that there is a prevalent steepening from MIR spectrum to NIR spectrum. The low-frequency-peaked BL Lacs (LBLs) have on average a larger MIR spectral index and a higher MIR luminosity than the high-frequency-peaked BL Lacs (HBLs), and the intermediate-frequency-peaked BL Lacs (IBLs) appear to bridge them. The MIR-γ-ray flux correlation is highly significant. A strong positive correlation is also found between the MIR and γ-ray spectral indices. The γ-ray-MIR loudness is significantly correlated with the synchrotron peak frequency. Finally we propose that the γ-rays are highly associated with the MIR emission from the jet, and the γ-ray emission is likely from the synchrotron self-Compton process for the Fermi-detected BL Lacs in our sample.     

Geomorphic and stream flow influences on large wood dynamics and displacement lengths in high gradient mountain streams (Chile)

Understanding large wood (LW; ≥1 m long and ≥10 cm in diameter) dynamics in rivers is critical for many disciplines including those assessing flood hazard and risk. However, our understanding of wood entrainment and deposition is still limited, mainly because of the lack of long‐term monitoring of wood‐related processes. The dataset presented here was obtained from more than 8 years of monitoring of 1,264 tagged wood pieces placed in 4 low‐order streams of the Chilean mountain ranges and was used to further our understanding of key factors controlling LW dynamics. We show that LW displacement lengths were longer during periods when peak‐flow water depths (H_max) exceeded the bankfull stage (H_Bk) than in periods with H_max ≤ H_Bk and that these differences were significantly higher for smaller wood pieces. LW length and length relative to channel dimensions were the main factors governing LW entrainment; LW displacement lengths were inversely related to the ratio of piece length to H_15% (i.e., the level above which the flow remains for 15% of the time) and to the ratio of H_15% to bankfull width. Unrooted logs and LW pieces located at the bankfull stage travelled significantly longer distances than logs with attached rootwads and those located in other positions within the bankfull channel. A few large logjams were broken during the period of observation, and in all occasions, LW from these broken logjams did not travel over longer distances than other pieces of LW moved in the same periods and in the same stream segments. Most importantly, our work reveals that LW dynamics tend to be concentrated within a few reaches in each stream and that reaches exhibiting high wood dynamics (extensive entrainment, deposition, or repositioning of LW) are significantly wider and less steep than less dynamic reaches.     

~5.9 cal ka bp Towada-Chuseri tephra from Towada volcano: a mid-Holocene marker layer from Japan to northeast China

Far-travelled ash layers from explosive volcanic eruptions can provide invaluable marker horizons for dating and correlating regional to global sedimentary archives. Here, we present a new cryptotephra associated with the ~5.9 cal ka bp Towada-Chuseri eruption (To-Cu) in a peat sediment record from northeast China. This tephra exhibits a rhyolitic glass composition that can be distinguished from other widespread tephra layers around the region of Japan and northeast China. Our findings extend the known range of this ash significantly, making it now traceable about 1200 km from its source, Towada volcano, Japan. Notably, this tephra provides an important isochron for synchronising palaeoenvironmental studies during the mid-Holocene period from the western Pacific, central Japan, Japan Sea and northeast China.     

浙江田螺山遗址古盐度及其环境背景同河姆渡文化演化的关系(英文)

Paleosalinity records of the Tianluoshan site are derived from measurations data of clay mineral,boron,strontium,barium,after field sampling in three profiles of the Tianluoshan site.The relative sea level changes are discussed according to the lab results.The record indicates that the region where the Tianluoshan site located has witnessed at least three times of relative sea level high-stand before,during and after the Hemudu period.Based on previous researches,this paper also focuses on discussing severa...