新疆巴楚气象因子对棉花发育期及产量的影响分析

利用巴楚国家基本气候站1961—2013年53 a的气温、降水量等资料,结合1981—2013年的棉花发育期、单位面积产量,采用线性倾向估计计算、检验方法、气候趋势系数和气候倾向率方法,对1961年以来巴楚气候变化特征、1981年以来棉花发育期、产量进行分析,探讨了巴楚近期气候变化对棉花生产的影响。结果表明:近53 a来,巴楚年和各季平均气温、平均最高气温、平均最低气温总体呈线性上升趋势,其中年平均最低气温的升温率最明显;各季节中春、秋季平均最低气温的升温率最大;年、各季节降水量呈明显的增多趋势,季节中夏季降水量的增幅最大,为3.25 mm/10 a;初霜日的变化呈推后趋势(1.2 d/10 a)、而终霜日呈提前趋势(-2.4d/10 a),使无霜期明显延长(1.1 d/10 a)。近33 a来,巴楚县棉花各发育期均表现出不同程度的提前趋势,其中现蕾期的提前趋势最明显,为4.8 d/10 a(P0.01);棉花停止生长期呈延迟趋势,延迟幅度为3.7 d/10 a(P0.01)。初、终霜冻日、无霜期与棉花产量总体呈正相关,初霜日推后、终霜日提前、无霜期延长,棉花产量增多。     

钦州市2000年春播期天气特征成因分析及其前兆信号

分析 2 0 0 0年春播期环流形势及其前兆信号得出 :南支槽较活跃 ,冷空气在江南堆积是形成钦州市 2月下旬长低温阴雨过程的机制 ;高空北支槽经向度加大 ,南支槽不活跃 ,东亚大槽明显偏东造成了 4月钦州市降雨量的偏少 ;前一年 9月 5 0 0 h Pa环流形势 ,拉尼娜现象 ,前一年秋冬季的副高、极涡以及本地气候异常是次年春播天气的前兆信号。同时通过对预报思路的分析和回顾 ,为以后的预报提供了新思路。     

SURFACE OZONE CHARACTERISTICS AT THREE STATIONS IN GAW OF WMO IN CHINA

The characteristics of surface O_3 on clear days at Waliguan Observatory,Lin'an regionalstation and Longfengshan regional station in China were analyzed in this paper.The three stationsbelong to Global Atmospheric Watch(GAW)of WMO.There was obvious daily variation on cleardays at Lin'an.with maximum(42.9 ppb)and minimum(20.3 ppb)of daily range appearing inspring and summer.respectively.The daily variation was more regular at Lonfengshan than atLin'an.The maximum(about 27 ppb)appeared in autumn at Longfengshan.There was noobvious daily variation and also daily range was smaller in other seasons except weaker dailyvariation in summer at Waliguan.But the surface O_3 concentration(SOC)in summer was higherthan that in winter at Waliguan.The SOC on clear days of summer at Waliguan was over 20 ppbhigher than at Longfengshan and Lin'an.The global radiation and NO_x concentration were themain factors which control the SOC on clear days at Longfengshan and Lin'an.and playedimportant role in different seasons and areas.The transportation of air flow around the area ofQinghai-Xizang(Tibet)Plateau was the main cause for high SOC and weak daily variation insummer at Waliguan.The similar effect of transportation was obtained at the Mauna LoaObservatory.The distribution characteristics of SOC increasing with height in the tropospheredetermined the difference of SOC between East China and West China.     

The role of spatial effects in the empirical analysis of regional concentration

 Economists have recently devoted an increasing attention to the issue of spatial concentration of economic activities. However, surprisingly enough, most of the empirical work is still based on the computation of very basic statistical measures in which the geographical characteristics of data play no role. By making use of a series of empirical examples we show that spatial concentration consists of two different features that are rarely kept as separate in the statistical analysis: an a-spatial concept of variability which is invariant to permutations, and the concept of polarization that refers to the geographical position of observations. Received: 8 August 2000 / Accepted: 20 June 2001     

MODELING OF THE HIGH CONCENTRATION LAYER OF COHESIVE SEDIMENT UNDER THE ACTION OF WAVES AND CURRENTS

MODELING OF THE HIGH CONCENTRATION LAYEROF COIIESIVE SEDMNT UNDER Tus ACTIONOF WAVES AND CURRENTSQinghe ZHANG', Yongsheng WU', Jiian LIAN1 and Pingxing DING3Abstract:High concenhation layer of cohesive sediment frequenhy occurs in muddy estUaries and coastalzones, and causes raPid siltation of the waterways. A one dimensional vertical coupled modeldescribing the interactions betWeen waves, currentS and suspended cohesive sediment is develoPed inthe pre…     

THEORETICAL ANALYSIS ON THE VERTICAL DISTRIBUTION OF PARTICLE CONCENTRATION

1 wrRonvCTIoxIn steady solid-liquid tuIbulen flows, tWo twcal pattems of particle concentration distribuhon, namelypattem I and pattem II, have been found by man investigatOI'S (e.g. Bouvard & Petkovic l985, Wang &Ni l990), as shown in Fig.l. Genend sPeaking, pattem II is conunn, and most inveshgators fOcused theirefforts on this pattem. Vedous theories such as the diffesion theory, the ndxtUre theory, the enery theory,the sindlarity theory and the stochashc theory among others have co…     

活性炭吸附分离—分光光度法测定硫化矿和土壤中的痕量铊

详细研究并确定了在HCl介质中,活性炭吸附Tl及草酸铵解吸Tl的诸条件,使T1与干扰元素分离而预富集,回收率在99.6%～116.3%.以镉试剂2B为显色剂,准确测定了硫化矿和土壤中的Tl.考察了两个样品测定5次的相对标准偏差＜6%,试样分析结果与原子吸收法、等离子体质谱法及泡沫塑料吸附分离-镉试剂2B光度法结果基本一致.     

Correlation between geology and radon levels in groundwater, soil and indoor air in Bhilangana Valley, Garhwal Himalaya, India

 Radon concentrations were measured in soil, air and groundwater in Bhilangana Valley, Garhwal Himalaya, India by using an LR-115 plastic track detector and radon emanometer. Radon concentrations were found to vary from 1 KBq/m³ to 57 KBq/m³ in soil , 5 Bq/l to 887 Bq/l in water and 95 Bq/m³ to 208 Bq/m³ in air. The recorded values are quite high due to associated uranium mineralization in the area. Radon concentration was also found to depend on the tectonic structure and geology of the area. Received: 22 July 1996 · Accepted: 8 January 1997     

松辽盆地西部斜坡区坳陷期层序地层发育控制因素分析

松辽盆地西部斜坡区坳陷期的低位体系域是半干热气候下构造沉降速率较大时的产物；湖进体系域是构造沉降率较大、气候温湿及海侵补给的共同作用结果，其中海侵补给是主要因素，构造沉降和气候条件是基本因素；高位体系域是湿热气候下构造沉降与沉积物供给持平时的产物；湖退体系域是气候由湿热渐变干热时，沉积物供给速率及其与构造沉降速率的比值均较大时的产物     

塔里木河现代河道冲淤变化的探讨

通过对现代塔里木河干流河道大断面的泥沙堆积情况、河道的基本特征和上游来水来沙条件的研究，认为塔里木河河道冲淤较大，主槽摆动频繁；涨水时低滩地淤积，落水时冲刷；每经一个汛期，滩面有所抬高；长时期内滩槽相对高差变化不大；河道淤积量大小主要取决于上游来沙、来水量，尤其是汛期水沙量对河道变迁的意义重大