近十年国际精品植物科学期刊发展态势分析

统计国际植物科学精品期刊近十年的影响因子, 以时间为横坐标变量, 影响因子为纵坐标变量做图, 并作线性回 归方程, 解析方程的截距和斜率分析其发展的动态变化态势, 以期更全面深入了解国际植物科学领域精品期刊的成长过程, 为中国植物学期刊实现国际化提供借鉴

渭河流域植被净初级生产力时空格局及影响因素分析

利用GIS技术将遥感数据和各种观测数据对渭河流域净初级生产力(NPP)进行估算并分析其时空格局及影响因素。结果表明,(1)整个流域12个月总的NPP平均值为473gC/(m~2&middot;a),空间分布特点是北部和西北部的黄土高原低,中部六盘山、子午岭和南部秦岭高;不同生态系统的平均NPP呈现为无植被地段61&lt;草地376&lt;农业植被440&lt;灌丛483&lt;森林692;(2)研究区NPP的积累期主要发生在4&mdash;10月份,其NPP占了全年NPP总量的90%;从季节来看,流域内春(3&mdash;5月)、夏(6&mdash;8月)、秋(9&mdash;11月)、冬(12&mdash;2月)4个季节的NPP各占全年总量的20.34%,52.51%,22.66%,4.49%;(3)渭河流域NPP与温度、降水和太阳辐射的相关性分析表明温度和降水是影响渭河流域NPP的2个重要影响因子。</p

长江三角洲上新世以来磁性地层及天文调谐年代标尺

长江三角洲地区的磁性地层认识存在很大不确定性.为建立一个可靠的年代标尺,为区内沉积环境和气候演化研究提供约束,在年代地层和磁性地层基础上,以频率磁化率为信号源、ETP为靶曲线,通过轨道调谐方法对区内LZK1孔开展了天文年代标尺研究,建立了年代序列框架.结果显示,M/B界线埋深约为143.0m、Ga/M界线埋深约为219.0m、Gi/Ga界线埋深约为296.6m.受气候和沉积环境控制,沉积旋回特征清楚,沉积速率具有明显的阶段性.调谐后的频率磁化率显示了显著的125ka、96ka、41ka、23ka、22ka、18ka等轨道周期,并在轨道周期上与ETP曲线高度相关,相关性超过了95%检验标准. 100ka、41ka和23ka周期的带通滤波曲线与偏心率、斜率和岁差在振幅和相位上吻合较好,但局部时间段有差异,可能与低沉积速率、沉积速率突变或短时间尺度的地层缺失等因素有关.研究表明,在具有短暂沉积缺失的持续沉降区域,只要保证样品分辨率,可以通过轨道调谐方法建立可靠的年代框架.</p

典型工业城市土壤黑碳含量、分布特征及来源分析——以黄石市为例

以黄石市3种不同类型土壤(红壤土、潮土、水稻土)为研究对象,采用热光反射法测定土壤中黑碳、焦炭和烟炱含量,研究有机碳、黑碳、焦炭和烟炱的空间分布特征,同时分析黑碳、焦炭、烟炱与有机碳之间的相互关系及黑碳的可能来源.结果表明:黄石市表层土壤中黑碳含量的变化范围为0.01~5.79 g/kg,平均值为1.06g/kg.其中水稻土黑碳含量最高,潮土次之,红壤最低.黑碳在有机碳中所占比例的变化范围为0.53% ~ 89.54%,平均值为25.29%,说明黑碳对土壤有机碳库有较大的贡献.不同土壤类型黑碳/总有机碳(BC/TOC)比值存在较大的差异,红壤BC/TOC平均值最大(36.70%),其次为水稻土(25.25%),潮土最低(18.25%),这可能与土壤质地有关.黑碳、焦炭与烟炱含量和BC/TOC比值的空间变异性与区域的产业结构及工业布局有关.黑碳、焦炭与烟炱含量之间呈显著正相关,说明它们可能有共同的来源.焦炭/烟炱比值(char/soot)分析结果表明土壤中的黑碳受人为源的影响很大,主要来源于化石燃料燃烧(工业燃煤及机动车尾气排放).</p

原料压榨制油的预处理方式对核桃多肽功能特性 和ACE抑制活性的影响Effect of raw material pretreatment method in oil pressing on functional characteristics and ACE inhibitory activity of walnut polypeptide

旨在研究原料压榨制油的预处理方式对核桃多肽性质的影响。对核桃仁分别进行未预处理、去衣、焙烤预处理后，进行压榨提油，以提油后的饼为原料，经正己烷脱脂，碱性蛋白酶酶解制备核桃多肽，测定核桃多肽的功能特性和ACE抑制活性。结果表明：与未预处理、焙烤预处理比较，去衣预处理的核桃多肽的持水性(50 ℃，5.11 g/g)、吸油性(50 ℃，3.25 g/g)、乳化性(pH 9.0,6257%)、乳化稳定性(pH 9.0,84.51%)、起泡性(pH 9.0,117.49%)及ACE抑制率（63.04%）最高。综上，以去衣预处理压榨制油后的核桃饼为原料制备的核桃多肽具有良好的功能特性和ACE抑制活性。The aim was to study the effect of pretreatment methods of raw material pressing for oil on the properties of walnut polypeptide. The walnut kernels were untreated, peeled and roasted respectively,then pressed to extract oil.The cake after oil extraction was defatted by n-hexane and hydrolyzed by alkaline protease to produce walnut polypeptide, and the functional properties and ACE inhibitory activity of walnut polypeptide were determined. The results showed that compared with no treatment and roasting pretreatment, walnut polypeptide obtained by peeling of raw material had the highest water holding capacity (50 ℃, 5.11 g/g), oil absorption (50 ℃,3.25 g/g), emulsifying ability (pH 9.0, 62.57%), emulsifying stability (pH 9.0, 84.51%), foaming ability (pH 9.0, 117.49%) and ACE inhibitory rate( 63.04%). In conclusion, the walnut polypeptide prepared from walnut cake after peeling and pressing for oil production had good functional properties and ACE inhibitory activity

会宁胡麻油产地环境及产品特征 Production environment and product characteristic of Huining flaxseed oil

为提高会宁胡麻油品牌知名度和影响力，探究了地理标志产品会宁胡麻油的产地环境、种植方式及生产管理过程和品质特性。以会宁县17个乡镇的土壤和胡麻油为试验材料，采用国家相关标准对产地环境及胡麻油品质进行分析并采用气相色谱-质谱法对胡麻油风味物质进行分析。结果表明：会宁胡麻油的产地环境和产品安全指标均达到绿色食品标准；会宁胡麻油中α-亚麻酸平均含量为54.24%，不同产地间存在一定差异；会宁胡麻油含有65种风味物质，香味浓郁，其中己醛、正己醇、2-甲基吡嗪、γ-己内酯和3-甲基巴豆腈对会宁胡麻油独特的香味有重要影响。综上，会宁胡麻生长环境好，会宁胡麻油香味浓郁、营养价值高。In order to improve the brand awareness and influence of Huining flaxseed oil, the production environment, cultivation method and production management process, and quality characteristics of Huining flaxseed oil, a geographical indication product, were explored.The soil and flaxseed oil from 17 townships in Huining county were used as test materials, and the production environment and product quality were determined by the relevant national standards, and the flavor compounds of flaxseed oil were determined by GC-MS method.The results showed that the production environment and product safety indicators of Huining flaxseed oil could meet the standards of green food; the average content of α-linolenic acid in Huining flaxseed oil was 54.24%, moreover, there was difference among different townships.Furthermore, the flaxseed oil of Huining contained 65 flavor compounds and had aromatic flavor, of which hexanal, hexyl alcohol, 2-methylpyrazine, γ-caprolactone, and 3-methyl crocetonitrile had important effect on the unique scent of Huining flaxseed oil.In summary, the flaxseed of Huining grows in a good environment and the oil has a rich aroma and high nutritional value