基于空间句法耦合SLEUTH模型的新老城区扩展模拟研究——以开封市为例     

张宸铭  高尚  何贝  高建华 《地理研究》2021,40(5):1372-1386

在快速城镇化背景下,历史文化名城常扩建新区并形成新老城区联动发展格局,新建城区以“飞地”形式扩张,不易被传统的元胞自动机方法准确模拟。空间句法是基于空间拓扑的整体性交通网络研究方法,其自上而下的建模策略与元胞自动机自下而上的邻域转换规则起到了互补,两种模型相结合提供了解决上述问题的途径。本文在验证交通土地空间关联的基础上,将句法变量融入SLEUTH模型的排除图层,对开封城市扩张进行了综合模拟。研究结果表明：① 交通增量与用地扩张具有显著的正相关,其关联度随研究单元粒度的扩大而提升。② 在城市从飞地新区扩建到后续填补开发的过程中,与用地扩张关联最高的交通类型由穿行性交通转向到达性交通,且遍历全局的计算结果方位指向性特征更加明显,遍历局部的计算结果片区集聚性特征更加明显。③ 将空间句法与SLEUTH模型松散耦合,可以有效捕捉飞地型城市新增团块,开封市中心城区空间扩张类型可被解读为老城区边缘型增长和新城区飞地型增长并存的模式。④ 空间句法模型不仅能够反演城市交通流,而且对城市产业布局、规划现状与演化轨迹具有间接指向性,这对城市增长模拟十分重要。  相似文献   

Architecture,deformation style and petrophysical properties of growth fault systems: the Late Triassic deltaic succession of southern Edgeøya (East Svalbard)     

《Basin Research》2018,30(5):1042-1073

The Late Triassic outcrops on southern Edgeøya, East Svalbard, allow a multiscale study of syn‐sedimentary listric growth faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The faults, characterized by mutually influencing deformation envelopes over space‐time, generally show SW‐ to SE‐dipping directions, indicating a counter‐regional trend with respect to the inferred W‐NW directed progradation of the associated delta system. The down‐dip movement is accommodated by polyphase deformation, with the different fault architectural elements recording a time‐dependent transition from fluidal‐hydroplastic to ductile‐brittle deformation, which is also conceptually scale‐dependent, from the smaller‐ (3rd order) to the larger‐scale (1st order) end‐member faults respectively. A shift from distributed strain to strain localization towards the fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho‐structural facies across and along the fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second‐ and third‐order listric fault nucleation points appear to be located above blind fault tip‐related monoclines involving cemented organic shales. Close to planar, through‐going, first‐order faults cut across this boundary, eventually connecting with other favourable lower‐hierarchy fault to create seismic‐scale fault zones similar to those imaged in the nearby offshore areas. The inferred large‐scale driving mechanisms for the first‐order faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine‐grained, water‐saturated, low‐accommodation, prodeltaic depositional environment. In synergy to this large‐scale picture, small‐scale causative factors favouring second‐ and third‐order faulting seem to be related to mechanical‐rheological instabilities related to localized shallow diagenesis and liquidization fronts.  相似文献   

Age, growth and reproduction of the sand smelt Atherina boyeri Risso, 1810 in the Gomishan wetland – southeast Caspian Sea     

Rahman Patimar  Morteza Yousefi  Seyyed Morteza Hosieni 《Estuarine, Coastal and Shelf Science》2009,81(4):457-462

A total of 2256 specimens of Atherina boyeri caught in Gomishan wetland (a marsh lagoon located at the southeast Caspian Sea) during spawning season from February to August 2007 were examined for life-history attributes. The population has a 4-year life cycle. Length–weight relationship was estimated as W = 0.0053TL^3.0181 for males and W = 0.0050TL^3.063 for females, being allometrically positive for both sexes. The von Bertalanffy growth function fitted to back-calculated size at age data was: Lt = 155.17[1 − exp − 0.28(t + 0.738)] and Lt = 162.77[1 − exp − 0.27(t + 0.727)] for males and females respectively. The sex ratio was 1:1.30 in favor of females. The reproductive season, evaluated from GSI, extended from March to July, with a peak in March. The average absolute and relative fecundities were 2976 eggs and 874 eggs g⁻¹ of body weight respectively. The diameter of oocytes ranged from 0.03 to 0.20 mm with a mean value of 0.68. The life-history patterns of A. boyeri in the population under study imply that the population of this species in the southeast Caspian Sea differs markedly from those of other localities of its range distribution. The differences were thought to be due to differences in geographical locations.  相似文献   

Influence of combined changes in salinity and copper modulation on growth and copper uptake in the tropical green macroalga Ulva reticulata     

Florence Mamboya  Thomas J. Lyimo  Tommy Landberg  Mats Bjrk 《Estuarine, Coastal and Shelf Science》2009,84(3):326-330

The influence of salinity on growth and Cu uptake in the green macroalga Ulva reticulata collected from the intertidal area in the Western Indian Ocean was studied under controlled laboratory conditions. Exposure concentrations ranged from 5 to 500 μg Cu l⁻¹ at five salinities (ranging 20–40). The accumulation of Cu increased with decreasing salinity, so that the uptake at 500 μg Cu l⁻¹ was approximately 2.7, 2.4 and 2.0 times higher at salinities of 20, 25, and 30 respectively, than uptake at salinity of 35, and with uptake being lowest at salinity of 40. Ulva maintained a positive growth rate over the whole salinity range (20–40), with highest rates at salinity of 35. When exposing to Cu at low salinities (20 and 25), the growth rate of Ulva was strongly inhibited suggesting an increase in toxicity of Cu with decreasing salinity. EC50 and NOEC increased with increase in salinity, implying a reduced Cu toxicity at high salinities. It was concluded that salinity needs to be considered when using macroalgae, such as U. reticulata, as a bioindicator of heavy metals in areas with heavy rainfall, underground fresh water intrusion or in estuaries, as they might accumulate more metals and be more negatively affected.  相似文献   

人工养殖条件下达氏鳇杂交种幼鱼生长特性的初步研究   总被引：6，自引：0，他引：6  

石振广  董双林  鲁宏申  王云山  李文龙 《中国海洋大学学报(自然科学版)》2008,38(1):33-38

为了解在人工养殖条件下达氏鳇(Huso dauricus)杂交种(达氏鳇♂×天然杂交种♀(达氏鳇♀×史氏鲟♂) )的生长特性,在水温11～22 ℃时,对达氏鳇杂交种体长和体重的生长进行实验研究.应用计算机软件Excel和SPSS对测量的数据进行处理分析,结果表明:平均全长为33.32 cm、平均体重为145.83 g的139日龄幼鱼经75 d的人工饲养长成平均全长为48.79 cm、平均体重为437.36 g的个体,全长与日龄之间呈线性关系L=3.292 7t 30.517,R2=0.959 4,其全长日均增长量为2.06 mm、平均瞬时增长率为 0.076 3,体重与日龄呈指数函数关系,Wgc=119.74e0.234 6t,R2=0.956;体重日均增长量为3.887 1 g、平均瞬时生长率为0.219 7;体重与全长的回归曲线为WwL=0.005 6L2.892 9,R2=0.998 2,幂指数接近于3,表明该鱼体重与全长的立方呈正相关系,属于等比生长类型.  相似文献   

Effects of basic fibroblast growth factor and insulin-like growth factor on cultured cartilage cells from skate Raja porasa     

Fan Tingjun  Jin Lingyun  Wang Xiaofeng 《中国海洋湖沼学报》2003,21(4):305-311

Effects of basic fibroblast growth factor (bFGF) and insulin-like growth factor II (IGF-II) on cartilage cells from proboscis of skate,Raja porasa Günther, were investigated in this study. The cartilage cells were cultured in 20% FBS-supplemented MEM medium at 24°C. Twelve hours after culture initiation, the cartilage cells were treated with bFGF and IGF-II at different concentration combinations. It was found that 20 ng/ml of bFGF or 80 ng/ml of IGF-II was enough to have obvious stimulating effect on the growth and division of skate cartilage cells. Test of bFGF and IGF-II together, revealed that 20 ng/ml of bFGF and 80 ng/ml of IGF-II together had the best stimulating effect on the growth and division of skate cartilage cells. The cartilage cells cultured could form a monolayer at day 7. This work was partially supported and funded by the China Education Committee as the “Imbursement Project for Studied Abroad Returnees”.  相似文献   

外商直接投资与经济增长的关系研究——基于分省和分区数据的检验   总被引：1，自引：0，他引：1  

杨柳勇  陈立慧  楼惠新 《地球信息科学学报》2008,10(3):350-356

论文分别以分省和分区（东、中、西部）1992～2004年的面板数据,利用我们修正过的De Mello模型和更为稳健的模型检验方法,研究了我国利用外商直接投资对经济增长的影响作用。研究结果发现,利用分省数据的模型证明了FDI对我国经济增长的正向积极作用,这一点与其他研究结果相同,但是利用分区数据的研究表明,虽然我国西部仍然是FDI作用最弱的区域,但是东部与中部比较,GDP增长率变动对FDI增长率变动的敏感性不明显,有别于中部,这在一定程度上可以说明东部地区存在FDI过密和外商投资产业的过度竞争问题。  相似文献   

Observations on shell growth and morphology of the bivalve Ruditapes philippinarum     

范德江  张爱滨  杨作升  孙效功 《中国海洋湖沼学报》2007,25(3):322-329

The bivalve Ruditapes philippinarum is not only one of the main mollusc species in the west Pacific Ocean, but also one of the main species for aquaculture in China. Knowledge of growth of the R. philippinarum shell will improve our understanding of the shell as an environmental archive. It is also useful for the aquaculture of R. philippinarum. In this research, a hanging box culture method was introduced in the culture of R. philippinarum. The bivalves were cultured for 126 days, from March 31 to August 3, 2002. The average growth rates of shell width, height, and thickness were 0.069, 0.046, and 0.032 mm/d, respectively. The mean increase of average individual wet mass was 0.028 g/d. The largest growth rates of both shell and average individual wet mass occurred in June, indicating that water temperature and bivalve reproduction were 2 important factors. The shell morphology underwent significant changes with shell growth. The ratio of height to thickness (value of B/C) shifted 1.58 in the first 60 days to 1.54 in the last 30 days, which was resulted from the change in major shell growth direction. Periodic changes in the B/C ratio led to corrugated shell form, which could be used to determine the age of the shell.  相似文献   

饲料中添加胜肽和益生菌对大黄鱼生长性能和体组成的影响          下载免费PDF全文

柯巧珍  余训凯  张永兴  潘滢  陈秋平  黄匡南  陈佳  翁华松  包欣源  韩坤煌  刘永裕  刘家富 《应用海洋学学报》2018,37(1):141-145

以初始体重为48.23±1.25 g的大黄鱼(Larimichthys crocea)为试验对象,研究饲料中添加胜肽和益生菌对大黄鱼生长性能、体组成的影响.添加胜肽试验组所用饲料为添加500mg/kg胜肽产品配制成软颗粒饲料;添加胜肽-益生菌试验组所用饲料为添加500mg/kg胜肽产品和500mg/kg益生菌产品配置成的软颗粒饲料;对照组所用饲料为未添加胜肽和益生菌产品而以相同配方配制成的软颗粒饲料.整个养殖试验的周期为12周,并于海水浮式网箱中进行.结果表明,饲料中添加胜肽和胜肽-益生菌均显著提高大黄鱼的终末体质重(FW)、特定生长率(SGR)、鱼体增重率(WGR)、饲料效率(FE)和粗脂肪含量(p0.05);饲料中添加胜肽对大黄鱼水分、粗蛋白、灰分、肝脏指数(HSI)、内脏指数(VSI)和肥满度(CF)的影响不显著(p0.05);添加胜肽-益生菌饲料组VSI显著高于添加胜肽饲料组和对照组(p0.05).  相似文献   

Anchor ice formation in streams: a field study     

Morten Stickler  Knut T. Alfredsen 《水文研究》2009,23(16):2307-2315

In northern steep streams anchor ice is commonly observed during winter, and plays a key role when considering in‐stream conditions. The understanding, however, of the nature of anchor ice formation is less understood, in particular, under natural conditions. In the following, observations of anchor ice formation in three stream environments with different physical characteristics are presented. Results demonstrate that anchor ice not only form in riffle areas, but also in shallow and slow running stream sections. No linkage between spatial distribution of anchor ice and calculated dimensionless numbers (Froude and Reynolds number) was found. Furthermore, analyses on growth and density showed that anchor ice may be distinguished by two main types. (1) Type I: Lower density forming on top of substrata. (2) Type II: Higher density forming between the substrata filling interstitial spaces. Distribution of anchor ice Types I and II suggests a relation between intensity of turbulence expressed by the Reynolds number, growth pattern and density. As anchor ice has both physical and biological implications on in‐stream environments, findings from the present study may be of particular interest to cold region freshwater stream management. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献