为了明确水稻灌浆期高温下钾肥运筹对籽粒灌浆及垩白的影响,本研究设置环境温度和灌浆期高温20 d 2个温度处理。并在不同温度下设置3种钾肥运筹方式,K1(基肥∶促花肥为10∶0)、K2(基肥∶促花肥为7∶3)和K3(基肥∶促花肥为3∶7),测定各...为了明确水稻灌浆期高温下钾肥运筹对籽粒灌浆及垩白的影响,本研究设置环境温度和灌浆期高温20 d 2个温度处理。并在不同温度下设置3种钾肥运筹方式,K1(基肥∶促花肥为10∶0)、K2(基肥∶促花肥为7∶3)和K3(基肥∶促花肥为3∶7),测定各处理下籽粒的灌浆进程和垩白。结果表明,灌浆期高温缩短籽粒活跃灌浆期,提前到达最大灌浆速率,提高花后15 d以内的灌浆速率,但花后15 d以后的灌浆速率迅速下降,降低花后20 d以后的灌浆速率,灌浆曲线起伏大,提高籽粒垩白米率和垩白度。在高温条件下,与K1相比,K2和K3均延长籽粒活跃灌浆期,推迟到达最大灌浆速率的时间,降低花后20 d以内的灌浆速率,缓解灌浆期高温对水稻造成的高温逼熟效应,且到达灌浆高峰后,灌浆速率下降更加平缓,灌浆速率下降较慢,提高花后20 d以后籽粒的灌浆速率,降低籽粒垩白的发生,并且垩白米率和垩白度随着促花肥比例的提高而降低。灌浆期高温下,虽然K3可以最大程度减少籽粒垩白的发生,但产量与K1无显著差异。因此,综合产量和品质,在水稻生产实践中,钾肥应按照基肥∶促花肥为7∶3比例施用,若灌浆期遭遇高温,可喷施磷酸二氢钾缓解高温胁迫的危害。展开更多
探讨北京市义务教育全年龄段学生有氧耐力发展趋势,同时建立相应评价标准。方法:以北京市4658名儿童与青少年为研究对象,以15 m渐进性有氧耐力跑为测试项目,采集其5次有氧耐力成绩,运用“LMS chartmaker”软件构建以15 m PACER为测试项...探讨北京市义务教育全年龄段学生有氧耐力发展趋势,同时建立相应评价标准。方法:以北京市4658名儿童与青少年为研究对象,以15 m渐进性有氧耐力跑为测试项目,采集其5次有氧耐力成绩,运用“LMS chartmaker”软件构建以15 m PACER为测试项目的北京市义务教育全年龄段学生有氧耐力百分位数曲线和评价常模。结果:运用LMS法拟合的北京市6~15岁学生有氧耐力发展曲线趋势均呈稳步上升-趋于平缓-再上升,男生曲线波动滞后女生1岁,且始终位于女生曲线上方,2条曲线呈“收腰喇叭状”形态;女生相较于男生,群体内部有氧耐力水平分化更为明显。基于上述研究,划定了6~15岁学生15 m PACER成绩的四级评价标准。结论:构建了北京市6~15岁儿童与青少年有氧耐力发展曲线,划定了区分性别和年龄的15 m PACER评价标准,对义务教育阶段儿童与青少年的体质健康和体能的筛查、分析及监测具有实用价值。展开更多
To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNram...To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNramp5 mutants(nramp5×7 and nramp5×9) were evaluated for grain Cd accumulation and agronomic performances. In paddy field soil containing approximately 0.9 mg/kg Cd, lct1×1 grains contained approximately 40%(0.17 mg/kg) of the Cd concentration of the wild type parental line, less than the China National Food Safety Standard(0.20 mg/kg). Both OsNramp5 mutants showed low grain Cd accumulation(< 0.06 mg/kg) in the paddy(approximately 0.9 mg/kg Cd) or in pots in soil spiked with 2 mg/kg Cd. However, only nramp5×7 showed normal growth and yield, whereas the growth of nramp5×9 was severely impaired. The study showed that lct1×1 could be used to produce rice grains safe for human consumption in lightly contaminated paddy soils and nramp5×7 used in soils contaminated by much higher levels of Cd.展开更多
In this paper, starting from a function analytic in a neighborhood of the unit disk and based on Bessel functions, we construct a family of generalized multivariate sinc functions, which are radial and named radial Be...In this paper, starting from a function analytic in a neighborhood of the unit disk and based on Bessel functions, we construct a family of generalized multivariate sinc functions, which are radial and named radial Bessel-sinc (RBS) functions being time-frequency atoms with nonlinear phase. We obtain a recursive formula for the RBS functions in R d with d being odd. Based on the RBS function, a corresponding sampling theorem for a class of non-bandlimited signals is established. We investigate a class of radial functions and prove that each of these functions can be extended to become a monogenic function between two parallel planes, where the monogencity is taken to be of the Clifford analysis sense.展开更多
In this paper, based on existing symmetric multiwavelets, we give an explicit algorithm for constructing multiwavelets with high approximation order and symmetry. Concretely, suppose Φ(x):= (φ1(x), ..., φr(x)) T is...In this paper, based on existing symmetric multiwavelets, we give an explicit algorithm for constructing multiwavelets with high approximation order and symmetry. Concretely, suppose Φ(x):= (φ1(x), ..., φr(x)) T is a symmetric refinable function vectors with approximation order m. For an arbitrary nonnegative integer n, a new symmetric refinable function vector Φnew(x):= (φ 1 new (x), ..., φ r new (x)) T with approximation order m + n can be constructed through the algorithm mentioned above. Additionally, we reveal the relation between Φ(x) and Φnew(x). To embody our results, we construct a symmetric refinable function vector with approximation order 6 from Hermite cubics which provides approximation order 4.展开更多
文摘探讨北京市义务教育全年龄段学生有氧耐力发展趋势,同时建立相应评价标准。方法:以北京市4658名儿童与青少年为研究对象,以15 m渐进性有氧耐力跑为测试项目,采集其5次有氧耐力成绩,运用“LMS chartmaker”软件构建以15 m PACER为测试项目的北京市义务教育全年龄段学生有氧耐力百分位数曲线和评价常模。结果:运用LMS法拟合的北京市6~15岁学生有氧耐力发展曲线趋势均呈稳步上升-趋于平缓-再上升,男生曲线波动滞后女生1岁,且始终位于女生曲线上方,2条曲线呈“收腰喇叭状”形态;女生相较于男生,群体内部有氧耐力水平分化更为明显。基于上述研究,划定了6~15岁学生15 m PACER成绩的四级评价标准。结论:构建了北京市6~15岁儿童与青少年有氧耐力发展曲线,划定了区分性别和年龄的15 m PACER评价标准,对义务教育阶段儿童与青少年的体质健康和体能的筛查、分析及监测具有实用价值。
基金supported by the Zhejiang Provincial S & T Project on Breeding of Agricultural (Food) Crops (Grant No. 2016C02050-2)
文摘To explore how rice(Oryza sativa L.) can be safely produced in Cd-polluted soil, OsLCT1 and OsNramp5 mutant lines were generated by CRISPR/Cas9-mediated mutagenesis. One of OsLCT1 mutant(lct1×1) and two of OsNramp5 mutants(nramp5×7 and nramp5×9) were evaluated for grain Cd accumulation and agronomic performances. In paddy field soil containing approximately 0.9 mg/kg Cd, lct1×1 grains contained approximately 40%(0.17 mg/kg) of the Cd concentration of the wild type parental line, less than the China National Food Safety Standard(0.20 mg/kg). Both OsNramp5 mutants showed low grain Cd accumulation(< 0.06 mg/kg) in the paddy(approximately 0.9 mg/kg Cd) or in pots in soil spiked with 2 mg/kg Cd. However, only nramp5×7 showed normal growth and yield, whereas the growth of nramp5×9 was severely impaired. The study showed that lct1×1 could be used to produce rice grains safe for human consumption in lightly contaminated paddy soils and nramp5×7 used in soils contaminated by much higher levels of Cd.
基金National Natural Science Foundation of China (Grant Nos. 61072126 and 11126343)Natural Science Foundation of Guangdong Province (Grant No. S2011010004986)+2 种基金Guangxi Natural Science Foundation (Grant No. 2013GXNSFBA019010)University of Macao (MYRG) MYRG 116(Y1-L3)-FST13-QTMacao Science and Technology Research Fund FDCT 098/2012/A3
文摘In this paper, starting from a function analytic in a neighborhood of the unit disk and based on Bessel functions, we construct a family of generalized multivariate sinc functions, which are radial and named radial Bessel-sinc (RBS) functions being time-frequency atoms with nonlinear phase. We obtain a recursive formula for the RBS functions in R d with d being odd. Based on the RBS function, a corresponding sampling theorem for a class of non-bandlimited signals is established. We investigate a class of radial functions and prove that each of these functions can be extended to become a monogenic function between two parallel planes, where the monogencity is taken to be of the Clifford analysis sense.
基金supported by the Natural Science Foundation of Guangdong Province (Grant Nos. 05008289,032038)the Doctoral Foundation of Guangdong Province (Grant No. 04300917)
文摘In this paper, based on existing symmetric multiwavelets, we give an explicit algorithm for constructing multiwavelets with high approximation order and symmetry. Concretely, suppose Φ(x):= (φ1(x), ..., φr(x)) T is a symmetric refinable function vectors with approximation order m. For an arbitrary nonnegative integer n, a new symmetric refinable function vector Φnew(x):= (φ 1 new (x), ..., φ r new (x)) T with approximation order m + n can be constructed through the algorithm mentioned above. Additionally, we reveal the relation between Φ(x) and Φnew(x). To embody our results, we construct a symmetric refinable function vector with approximation order 6 from Hermite cubics which provides approximation order 4.
