This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation ...This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3℃ and 0.7℃, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56°± 0.42℃（100 yr）^（-1）; however, temperatures recorded in the 20 th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD1201–70 are comparable to the present. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern： dry south of 25°N, wet from 25°–30°N, and dry to the north of 30°N. However, for all centennial cold periods, this spatial pattern also exhibits a meridional distribution. The increase in precipitation over the monsoonal regions of China associated with the 20 th century warming can primarily be attributed to a mega El Nino–Southern Oscillation and the Atlantic Multidecadal Oscillation. In addition, a significant association between increasing numbers of locusts and dry/cold conditions is found in eastern China. Plague intensity also generally increases in concert with wetness in northern China, while more precipitation is likely to have a negative effect in southern China.展开更多
Consumption pattern of beta carotene rich foods from 500 households of Coimbatore district was elicited. Through market surveys in four seasons namely: summer, south-west monsoon, north-east monsoon and winter, a year...Consumption pattern of beta carotene rich foods from 500 households of Coimbatore district was elicited. Through market surveys in four seasons namely: summer, south-west monsoon, north-east monsoon and winter, a year calendar of beta carotene rich foods was developed. The total and beta carotene contents of five commonly consumed beta carotene rich foods both in raw and cooked states were determined. Results indicated that greens were mainly purchased from market and consumed 2-3 times per week. Cooking loss was maximum in boiling and minimum in shallow fat frying. Curry leaves (Murraya koenigii),amaranth tender (Amaranthus gangeticus), agathi (Sesbania grandopra), and ponnanganni (Alternanthera sessilis) were the carotene rich foods available round the year. Cost of most greens was highest in summer and lowest in north-east monsoon. Within a cost of 13-14 ps in summer, 4-10 ps in south-west monsoon and north-west monsoon and 4-12 ps in winter season, the entire day's requirement of beta carotene (2400μg) could be obtained in the form of agathi/amaranth throughout the year: in the form of drumstick leaves and mint in south-west monsoon; as curry leaves and coriander leaves in winter and as agathi,paruppukeerai and amaranth in summer. From this year calendar, according to seasonal availability and cost, low-cost high carotene foods can be selected and used for increasing the beta carotene intake in the intervention programmes and in the community展开更多
[目的]探究不同年型下饲用燕麦产量对各生育期降水变化的响应,为饲用燕麦抗旱与高效生产提供参考。[方法]利用作物生长机理模型APSIM(agricultural production systems simulator),以山西省朔州市右玉县1980—2009年的历史气候气象数据...[目的]探究不同年型下饲用燕麦产量对各生育期降水变化的响应,为饲用燕麦抗旱与高效生产提供参考。[方法]利用作物生长机理模型APSIM(agricultural production systems simulator),以山西省朔州市右玉县1980—2009年的历史气候气象数据作为原始情景,将饲用燕麦生育期划分为4个阶段[阶段1(播种—拔节)、阶段2(拔节—抽穗)、阶段3(抽穗—灌浆)、阶段4(灌浆—收获)],并提取典型气候条件(干旱、平水、丰水)建立12个新的气候情景并进行模拟,分析饲用燕麦产量受降水变化的影响。[结果]在干旱情景(DS)中,产量与水分利用效率(water use efficiency,WUE)较原始情景分别下降了38.0%~60.9%与31.8%~16.9%(P<0.01),其中,抽穗—灌浆期采用历史数据时,指标的下降幅度最小。对于平水情景(NS)来说,产量相对原始情景的变化为-3.4%~20.0%,WUE为0~10.0%,拔节—抽穗期及灌浆—收获期采用历史数据时指标的变化显著(P<0.05)。丰水情景(WS)中,饲用燕麦产量与WUE相对原始情景均显著提升(P<0.01),幅度分别达到33.3%~60.5%与6.8%~14.8%,且播种—拔节期的降水变化对指标有相对明显的影响(R^(2)=0.3777,P<0.01)。[结论]饲用燕麦产草量和水分利用效率WUE在干旱、平水、丰水年型中都对灌浆—收获期的降水变化没有明显的敏感性;在干旱和平水年型下,饲草产量对抽穗—灌浆期的干旱更为敏感,WUE则对拔节—抽穗期及抽穗—灌浆期的干旱更为敏感;在丰水年型下,燕麦饲草产量对干旱最敏感的时期是播种—拔节期。有限的灌溉条件下,可将灌溉集中于WUE对降水变化最为敏感的阶段3(抽穗—灌浆)。展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA050800)the Key Program of the Chinese Academy of Sciences (Grant No. KJZD-EW-TZ-G10)the National Natural Science Foundation of China (Grant No.41671201 and 91525101)
文摘This paper presents new high-resolution proxies and paleoclimatic reconstructions for studying climate changes in China for the past 2000 years. Multi-proxy synthesized reconstructions show that temperature variation in China has exhibited significant 50–70-yr, 100–120-yr, and 200–250-yr cycles. Results also show that the amplitudes of decadal and centennial temperature variation were 1.3℃ and 0.7℃, respectively, with the latter significantly correlated with long-term changes in solar radiation, especially cold periods, which correspond approximately to sunspot minima. The most rapid warming in China occurred over AD 1870–2000, at a rate of 0.56°± 0.42℃（100 yr）^（-1）; however, temperatures recorded in the 20 th century may not be unprecedented for the last 2000 years, as data show records for the periods AD 981–1100 and AD1201–70 are comparable to the present. The ensemble means of dryness/wetness spatial patterns in eastern China across all centennial warm periods illustrate a tripole pattern： dry south of 25°N, wet from 25°–30°N, and dry to the north of 30°N. However, for all centennial cold periods, this spatial pattern also exhibits a meridional distribution. The increase in precipitation over the monsoonal regions of China associated with the 20 th century warming can primarily be attributed to a mega El Nino–Southern Oscillation and the Atlantic Multidecadal Oscillation. In addition, a significant association between increasing numbers of locusts and dry/cold conditions is found in eastern China. Plague intensity also generally increases in concert with wetness in northern China, while more precipitation is likely to have a negative effect in southern China.
文摘Consumption pattern of beta carotene rich foods from 500 households of Coimbatore district was elicited. Through market surveys in four seasons namely: summer, south-west monsoon, north-east monsoon and winter, a year calendar of beta carotene rich foods was developed. The total and beta carotene contents of five commonly consumed beta carotene rich foods both in raw and cooked states were determined. Results indicated that greens were mainly purchased from market and consumed 2-3 times per week. Cooking loss was maximum in boiling and minimum in shallow fat frying. Curry leaves (Murraya koenigii),amaranth tender (Amaranthus gangeticus), agathi (Sesbania grandopra), and ponnanganni (Alternanthera sessilis) were the carotene rich foods available round the year. Cost of most greens was highest in summer and lowest in north-east monsoon. Within a cost of 13-14 ps in summer, 4-10 ps in south-west monsoon and north-west monsoon and 4-12 ps in winter season, the entire day's requirement of beta carotene (2400μg) could be obtained in the form of agathi/amaranth throughout the year: in the form of drumstick leaves and mint in south-west monsoon; as curry leaves and coriander leaves in winter and as agathi,paruppukeerai and amaranth in summer. From this year calendar, according to seasonal availability and cost, low-cost high carotene foods can be selected and used for increasing the beta carotene intake in the intervention programmes and in the community
文摘[目的]探究不同年型下饲用燕麦产量对各生育期降水变化的响应,为饲用燕麦抗旱与高效生产提供参考。[方法]利用作物生长机理模型APSIM(agricultural production systems simulator),以山西省朔州市右玉县1980—2009年的历史气候气象数据作为原始情景,将饲用燕麦生育期划分为4个阶段[阶段1(播种—拔节)、阶段2(拔节—抽穗)、阶段3(抽穗—灌浆)、阶段4(灌浆—收获)],并提取典型气候条件(干旱、平水、丰水)建立12个新的气候情景并进行模拟,分析饲用燕麦产量受降水变化的影响。[结果]在干旱情景(DS)中,产量与水分利用效率(water use efficiency,WUE)较原始情景分别下降了38.0%~60.9%与31.8%~16.9%(P<0.01),其中,抽穗—灌浆期采用历史数据时,指标的下降幅度最小。对于平水情景(NS)来说,产量相对原始情景的变化为-3.4%~20.0%,WUE为0~10.0%,拔节—抽穗期及灌浆—收获期采用历史数据时指标的变化显著(P<0.05)。丰水情景(WS)中,饲用燕麦产量与WUE相对原始情景均显著提升(P<0.01),幅度分别达到33.3%~60.5%与6.8%~14.8%,且播种—拔节期的降水变化对指标有相对明显的影响(R^(2)=0.3777,P<0.01)。[结论]饲用燕麦产草量和水分利用效率WUE在干旱、平水、丰水年型中都对灌浆—收获期的降水变化没有明显的敏感性;在干旱和平水年型下,饲草产量对抽穗—灌浆期的干旱更为敏感,WUE则对拔节—抽穗期及抽穗—灌浆期的干旱更为敏感;在丰水年型下,燕麦饲草产量对干旱最敏感的时期是播种—拔节期。有限的灌溉条件下,可将灌溉集中于WUE对降水变化最为敏感的阶段3(抽穗—灌浆)。
