Combined impact of climate change,cultivar shift,and sowing date on spring wheat phenology in Northern China

Distinct climate changes since the end of the 1980s have led to clear responses in crop phenology in many parts of the world. This study investigated the trends in the dates of spring wheat phenology in relation to mean temperature for different growth stages. It also analyzed the impacts of climate change, cultivar shift, and sowing date adjustments on phenological events/phases of spring wheat in northern China (NC). The results showed that significant changes have occurred in spring wheat phenology in NC due to climate warming in the past 30 years. Specifically, the dates of anthesis and maturity of spring wheat advanced on average by 1.8 and 1.7 day (10 yr)^?1. Moreover, while the vegetative growth period (VGP) shortened at most stations, the reproductive growth period (RGP) prolonged slightly at half of the investigated stations. As a result, the whole growth period (WGP) of spring wheat shortened at most stations. The findings from the Agricultural Production Systems Simulator (APSIM)-Wheat model simulated results for six representative stations further suggested that temperature rise generally shortened the spring wheat growth period in NC. Although the warming trend shortened the lengths of VGP, RGP, and WGP, the shift of new cultivars with high accumulated temperature requirements, to some extent, mitigated and adapted to the ongoing climate change. Furthermore, shifts in sowing date exerted significant impacts on the phenology of spring wheat. Generally, an advanced sowing date was able to lower the rise in mean temperature during the different growth stages (i.e., VGP, RGP, and WGP) of spring wheat. As a result, the lengths of the growth stages should be prolonged. Both measures (cultivar shift and sowing date adjustments) could be vital adaptation strategies of spring wheat to a warming climate, with potentially beneficial effects in terms of productivity.     

云南夏季降水量在21世纪初的突变减少及原因分析

利用1960—2013年云南125个台站观测资料和美国环境预报中心/国家大气研究中心再分析资料,以及1960—2013年美国国家海洋和大气管理局(NOAA)提供的逐月平均全球海表温度资料,分析了云南地区降水量变化的特征以及与之相关联的大气环流背景场。分析结果表明:云南降水量在2002年发生了一次显著减少的突变,而这次突变主要是由于夏季降水的明显减少而形成的。进一步的分析揭示了该地区夏季降水减少主要与印度洋热带赤道地区低层东风加强和高空西风加强有关,亚洲地区中高纬度温度的升高也对该地区夏季降水量显著减少有重要作用。     

航空重力GPS测速多粗差探测方法

GPS速度测量在航空重力测量中具有重要的作用。根据飞机平稳飞行的状态,建立了严密的状态方程,利用常加速度模型的速度预测值,构建了观测值验前残差检验量Q,并给出其误差源:观测误差与速度预测误差,根据检验量Q的统计特性结合IGGⅢ抗差方案,对含粗差的观测值作降权处理。采用静态数据分析观测误差的统计特性,并给出其模型参数,同时分析了理想运动状态下的速度预测精度以及数据采样率与新方法粗差探测能力之间的关系。通过静态和动态算例表明,新方法能有效探测出小于1周的粗差。     

EFFECTS OF PHOTOPERIOD AND SALINITY ON GROWTH AND UPTAKE OF 60Co AND 137Cs FOR CHLORELLA SP.

The effects of three photoperiods (24 hr illumination, 12 hr illumination + 12 hr darkness and 24 hr darkness) and three salinities (20‰, 30‰ and 35‰) on the uptake of 60Co and 137Cs for Chlorella sp. and on the growth of its algae are studied. The uptake of 60Co for the algae is two orders of magnitude higher than that of 137Cs. Of factorial effects, the effect of photoperiod is most significant either on the uptake of the radionuclides or on the growth of the algae; the effect of salinity comes next in order and that of their interaction remains with the last. The uptake of the two radionuclides increases with extended photoperiod while the uptake of 137Cs declines with increasing of salinity. The growth of the algae appears to be the best under the conditions of 24 hr illumination and 30‰ salinity.     

新的高压海水状态方程

新的高压下水和海水状态方程已从迈阿密大学,米勒罗及其同事以及伍兹霍尔海洋研究所的布雷德肖和施莱歇的实验结果中推导出来。状态方程的形式为含二次项的正割体积模量。 K=Pv~o/(v~o-v~p)=K~o AP BP~2 K~o=K~ow aS bS~(3/2) A=Aw cS dS~(3/2) B=Bw eS 其中v和v~p为O压和P压下的比容,S为盐度(‰)。方程的纯水部分的系数K~o_W,A_N,B_W是温度的多项式函数。纯水状态方程V~o_W的标准误差为4.3×10~(-6)cm~3g~(-1)由高压海水测定值得到由温度决定的参数a.b.c.d.e的值。海水状态方程V~()的总的误差为9.0×10~(-6)cm~3g~(-1)。就海洋中温、压、盐的范围来说,V~p的标准误差为5.0×10~(-6)cm~3g~(-1)。联合国教科文组织海洋学常用表及标准联合专家小组最近(1979)已向各海洋团体推荐使用新的高压海水状态方程。     

浅论东海盆地海礁凸起的含油气性

勘探资料证实 ,西湖凹陷内生成的油气由生烃深凹向西部和南部的古斜坡带运移。凹陷内的局部构造大多形成于中新世末期的龙井运动 幕 ,圈闭形成期晚于油气主运移期 ,致使油气运移到比斜坡带更高的海礁凸起上保存或散失了。作者利用现有东海地震资料及西湖凹陷钻井、测井及油气资源评价结果从油气运移、聚集、保存等方面探讨东海陆架盆地海礁凸起油气勘探的良好前景     

病毒虾池底泥对对虾的影响试验

１９９３年全国暴发的对虾流行病，主要是由病毒病引起的，其传播速度之快，流行面之广，危害之大，前所未有①现已认识到，对虾病毒病是通过多种途径传播的。其中，虾池底泥是其传播途径之一。室内试验证实：病毒通过虾池底泥的传播．可使健康虾感染对虾肝胰腺小病毒病（ＨＰＶ）②鉴于病毒可通过底泥传播、扩散，危害养虾业。因而．如何采取有效措施，严格控制病毒传播，减轻对生态环境的威胁，并进而预防病毒的感染，是当前对虾养殖业的重要研究课题。１材料与方法１．１材料１．１．１对虾对虾于１９９３年７月１０日取自青岛流亭镇双埠…     

论东海陆架盆地玉泉运动

据地质及地球物理勘探资料，并结合周围邻近盆地的对比研究后提出：（１）目前确定的新玉泉运动，其影响比前人描述的轻微得多；（２）以前所确定的原（老）玉泉运动的活动强度比新玉泉运动强烈得多，不应将原（老）玉泉运动取消，而应将新、老玉泉运动的间隔期视为构造变革过渡期。     

基隆凹陷油气资源潜力

概述了基隆凹陷的地质、含油气概况，并与勘探程度较高的西湖凹陷作了对比，指出基隆凹陷两侧斜坡、台北构造带、安平斜坡及东侧的断阶带为有利的勘探区。     

海滩盐度对两种红树叶的碳水化合物和含氮化合物含量的影响

本文探讨福建九龙江口不同地段海滩盐度的变化对两种红树植物(秋茄和桐花树)的叶片中碳水化合物和含氮化合物含量的影响。试验结果表明:当土壤盐度(3—12‰)逐渐上升时,叶片中总糖量、淀粉量和可溶性糖含量随之上升;反之,当土壤盐度上升时,叶片中总氮量和可溶性蛋白质含量却下降。但它们在土壤盐度10‰时,都有一个波动反应的现象。