草莓汁加工过程中Vc变化及其控制的研究

以新鲜草莓果实为原料,对草莓汁加工过程中的Vc含量变化及其控制方法进行了研究。结果表明,清洗方式对草莓Vc含量有明显的影响,快速清洗有利于草莓果中Vc的保存;不同的热烫方式对草莓Vc含量亦有较大影响,热水热烫、蒸汽热烫均可使草莓的Vc含量降低,而微波热烫较热水热烫及蒸汽热烫的Vc保存率高,且微波热烫后草莓果中的Vc含量还较原始果中提高了1.77%～5.31%;热压榨方式有利于保持草莓的Vc含量;澄清工序中,冷却澄清结合添加0.03%EDTA+0.03%植酸有利于保持草莓中的Vc;草莓汁灭菌时采用90℃灭菌15min的效果最好,而且其Vc保存率可达98.56%;灭菌后快速冷却有利于草莓汁中的Vc保存。     

福州市气候变化特征及其对农业的影响

以福州市34年的降水和气温基本气象资料,分析了气候变化的特征和规律。福州市年平均气温呈现上升趋势,主要集中于春、冬季;年降水量主要集中在春季和夏季,近期呈现减少趋势。文中并指出了气候变化对农业产量、气象灾害等方面的影响。     

气候变迁对农业的冲击与调适

工业革命以来,随着大量能源和自然资源的消耗,导致大气中温室气体增加,全球暖化,海平面上升;气候变迁对人类生存环境产生了巨大的影响和冲击。本文从气候变迁与农业生产关系入手,分析了气候变迁对农业正负两面的效应,并着重分析气候变迁对农业生产面和农村经济社会的负面影响,最后从生态保育与绿色农业的发展思路出发,提出调整农业资源利用和生产方式,以应对气候变迁对农业的冲击。     

西吉气候变化及其对马铃薯产量的影响

结合西吉1961-2008年的气象资料和同期的马铃薯产量资料,分析了西吉气候变化的主要特征以及马铃薯产量与不同气候因子的相关关系.结果表明:近50年来,西吉地区的年平均气温与地温均有不同幅度的升高,10℃初日明显提前、积温增加,降水则呈下降趋势,相对湿度变化不显著,日照时数与平均风速变化较小.除发芽期的日照时数对马铃薯...     

加强气候变化背景下植物病原真菌控制技术的创新和突破

全球气候变化是现代农业生态系统目前面临的主要威胁之一。一方面,气候变化正在重塑植物与微生物的互作,诱导某些共生微生物转变为病原微生物,提升植物真菌病害发生的频率和程度;另一方面,气候变化降低植物的免疫力和抗病性,导致植物更严重的真菌病害。本文将重点讨论气候变化如何影响共生真菌与作物的互作,如何驱动植物真菌病害的发生和传播,以及采取何种调控措施从源头上预防病原真菌的危害。     

Climate change and distribution shifts in marine fishes

We show that the distributions of both exploited and nonexploited North Sea fishes have responded markedly to recent increases in sea temperature, with nearly two-thirds of species shifting in mean latitude or depth or both over 25 years. For species with northerly or southerly range margins in the North Sea, half have shown boundary shifts with warming, and all but one shifted northward. Species with shifting distributions have faster life cycles and smaller body sizes than nonshifting species. Further temperature rises are likely to have profound impacts on commercial fisheries through continued shifts in distribution and alterations in community interactions.     

气候变化对苹果生长的影响及对策研究

随着经济的快速发展,特别是全球工业化社会的不断进步,全球正在变暖,这给人类的生产生活带来了很大的影响,并且这种影响将会持续下去。苹果收到气候变暖的影响及一些极端天气的影响,将会给苹果的生长及生产带来一定的负面影响,主要分析了近几年气候变化给苹果带来的影响,同时提出了一些建议。     

气候变化与中国荒漠化防治

全球气候正在变暖 .过去 10 0多年中 ,全球平均气温上升了 0 6℃ .根据全球多种气候模式的预测 ,到 2 1世纪中期 ,全球年平均气温将要升高 1～ 3℃ ,全球降水量增加 3 %～ 15 % .对我国未来气候变化的预测 ,到 2 0 5 0年我国大部分地区将增暖 0 5～ 1 0℃ ,年降水量有所减少 ,2 0 5 0年以后年均温可能增加 2～ 3℃ ,降水量减少 1%～7 5 % ,未来我国气候变化趋势呈变暖变干 ,我国西北广大地区与东部相比将更暖更干 .因此 ,在西部大开发 ,从事生态建设和防沙治沙过程中 ,要充分考虑未来我国气候的这种变化 ,做出具体的战略部署 ,采取强有力的战术措施 ,在立足于保护好现有绿洲和植被的前提下 ,进一步搞好西部生态建设 ,促进防沙治沙和沙产业的发展     

C3和C4植物中PEPC的生物信息学分析

PEPC是C4光合途径中的关键酶之一,为研究C3和C4植物PEPC功能上的差异,利用一系列的生物信息学软件分别分析了4种C3和C4植物PEPC基因编码蛋白的氨基酸组成、等电点、结构域、二级结构、空间结构等性质,并进行两类植物蛋白质的比对.结果表明,PEPC基因编码蛋白为不稳定蛋白质;二级结构主要是以无规则卷曲为主.同时...     

Covariant glacial-interglacial dust fluxes in the equatorial Pacific and Antarctica

Dust plays a critical role in Earth's climate system and serves as a natural source of iron and other micronutrients to remote regions of the ocean. We have generated records of dust deposition over the past 500,000 years at three sites spanning the breadth of the equatorial Pacific Ocean. Equatorial Pacific dust fluxes are highly correlated with global ice volume and with dust fluxes to Antarctica, which suggests that dust generation in interhemispheric source regions exhibited a common response to climate change over late-Pleistocene glacial cycles. Our results provide quantitative constraints on the variability of aeolian iron supply to the equatorial Pacific Ocean and, more generally, on the potential contribution of dust to past climate change and to related changes in biogeochemical cycles.     

大豆植株中酰脲含量变化动态研究

试验对大豆植株各部位的酰脲含量进行了测定分析.结果表明,荚果和茎部酰脲含量高于叶片和叶柄,从苗期茎酰脲含量开始逐渐增加,至R5或R6期达到最高值;叶片酰脲含量在整个生育期中变化较小;叶柄酰脲含量呈先降低后增加的趋势,并于R6期达到最大值;荚果酰脲含量于R4或R5期达到最大值.大豆植株各部位尿囊酸与尿囊素的比例不同,叶片中尿囊酸含量与尿囊素含量相近,茎、叶柄、荚果尿囊酸含量显著高于尿囊素含量,其顺序为：茎＞荚果＞叶柄＞叶片.尿囊酸含量与酰脲含量呈显著正相关.     

Study on Transpiration and Stomatal Conductance Characteristics of C3 and C4 Plant

The transpiration experiment was done under greenhouse conditions with a C3 plant sweet pepper （Capsicum annuum Linn.） and two C4 plants, sorghum （Sorghum bicolor L.Moench） and maize （Zea mays Linn.）. Three species were irrigated with three different water treatment levels of 100%, 66% and 33% which gave a comparison of tolerance and adaptation to irrigation and two different levels of water stress. The measurements of transpiration rate and stomatal conductance were done between 8.00 a.m. and 16.00 p.m. with measurements about each 1.5 h with an infrared gas analyzer. The results showed that Z. mays probably due to a higher leaf area had very low values and was significantly different （LSD pairwise comparison） from C. annuum and S. bicolor. The hypotheses that C4 plants and C3 plants have different transpiration rates and stomatal conductance could not be shown with the results. However, the hypotheses that for the same species, the highest values in transpiration rate and stomatal conductance were with the 100% irrigation treatment and the lowest values were with the 33% irrigation treatment could be accepted due to the results of this trial.     

珍稀濒危植物金花猕猴桃优势群落特征

 在样方调查的基础上,对金花猕猴桃Actinidia chrysantha优势群落的物种组成、垂直结构、生活型、乔木层重要值和年龄结构等进行了分析。结果表明：在600 m²的样地内,共有维管束植物77种,隶属于34科56属;群落垂直结构复杂,可分为乔木层、灌木层、草本层和藤本植物,乔木层又可划分为3个亚层;群落生活型以高位芽为主,占总数的76.7%;重要值分析的结果显示,金花猕猴桃在群落中的优势度最高;金花猕猴桃种群年龄结构目前为稳定型,有衰退的趋势,应对其进行合理保护。图2表1参19     

Climate change, deforestation, and the fate of the Amazon

The forest biome of Amazonia is one of Earth's greatest biological treasures and a major component of the Earth system. This century, it faces the dual threats of deforestation and stress from climate change. Here, we summarize some of the latest findings and thinking on these threats, explore the consequences for the forest ecosystem and its human residents, and outline options for the future of Amazonia. We also discuss the implications of new proposals to finance preservation of Amazonian forests.