基于UHPLC-Q-TOF/MS的不同产地普洱生茶化学成分差异研究

为了更加全面地了解产地对普洱生茶品质与化学成分的影响,本研究选取来自临沧市、普洱市、西双版纳州三大产区12个茶山(自然村)的普洱生茶样品,采用超高效液相色谱-四级杆-飞行时间质谱(UHPLC-Q-TOF/MS)对不同产地普洱生茶的非挥发性代谢物表型进行了研究。结果表明:不同产地普洱生茶的化学成分在含量上具有较大差异,且具有明显的产地特征。采用主成分分析,可以对来自西双版纳自治州(包括勐腊县、勐海县、景洪市)、普洱市、临沧市3个地级行政区的普洱生茶进行有效区分,也可以对来自普洱茶产区的东南、西南、西北3个区域的普洱生茶进行有效区分。进一步鉴定了普洱生茶中79种主要成分,并对其在12个茶山(自然村)的普洱生茶中的含量分布,以及与不同产地普洱生茶滋味品质的关系进行了分析。本研究表明,基于UHPLC-Q-TOF/MS的茶叶非挥发性化学成分轮廓可以作为普洱生茶产地判别的依据。     

Evidence of clandestine harvest and failure of conservation policies for Argopecten purpuratus in the Rinconada Marine Reserve (Chile)

1. The study of Argopecten purpuratus reproduction, post‐larval settlement, stock size, and population size structure and shell growth was undertaken in the 2000s in the Rinconada marine reserve (Chile) to evaluate the effectiveness of scallop recruitment and self‐sustainability.
2. The results highlight strong seasonal and inter‐annual variations of environmental conditions and scallop gonadosomatic index, spat collection, benthic distribution, total abundance and population size structure.
3. The Von Bertalanffy growth parameters were L_∞ = 120.12 mm and K = 0.9681; commercial size would be reached in about 17.2 months in the bay. Substrate availability, meteorological conditions, hydrodynamics and illegal harvesting explain spatial and temporal variations in scallop distribution and abundance.
4. Recruitment strength depends on one main cohort from year to year. While recruitment made up 81% and 94% of total abundances in May 2002 and May 2003, respectively, there were no overall density‐dependent relationships between stock size and recruitment. Spawning asynchrony in the bay supports the hypothesis that multiple gamete releases form part of a reproductive strategy in response to environmental variability.
5. The massive disappearance of large‐sized scallops during the study periods was direct evidence of overfishing owing to clandestine harvesting within the marine reserve. The failure of current legislation, strategies and policies for scallop conservation requires new regulations to restore scallop stock size, maintain its reproductive performance and limit illegal harvesting in the Rinconada.
6. A scenario allowing harvesting regulated by stock‐dependent fishing quotas would more efficiently ensure stock recovery and self‐sustainability. The modalities of this new policy are discussed.

     

五指山耕地土壤养分现状调查与评价

为了明确海南山区耕地土壤养分空间分布特征，为热带山区耕地土壤养分管理提供思路。以海南五指山市耕地为研究对象，采用野外调查、采样和室内分析相结合的方法，阐述土壤养分现状，探讨其土壤养分分布规律。结果表明：五指山耕地土壤总体呈酸性，其pH值为5.1；土壤有机质、有效磷、速效钾和中量元素(钙、镁、硫)含量均为中等或偏下水平，土壤有效铜和有效锌含量较为丰富。五指山耕地土壤酸化和养分含量分布不均主要与气候、母质分布和施肥不平衡有关。     

黑龙江省国有林区脆弱异质性家庭对停伐政策的态度及影响因素研究

基于2016年黑龙江省重点国有林区348户家庭的微观调查数据,实证分析黑龙江省国有林区脆弱异质性家庭对停伐政策的态度及影响因素。采用因子分析与综合评价法将348户职工家庭分为脆弱性家庭和非脆弱性家庭,描述性分析2组样本家庭对停伐政策的态度及认知情况,利用多元有序logit模型分析脆弱性与非脆弱性家庭对停伐政策态度的影响因素。结果表明:非脆弱性家庭对停伐政策的了解程度及执行情况的评价均高于脆弱性家庭,脆弱性家庭相对非脆弱性家庭对停伐政策的认可度较高,但是应对风险冲击的能力相对较低。脆弱性家庭和非脆弱性家庭对停伐政策的态度受户主特征、家庭特征以及政策认知特征变量的显著影响,但脆弱性家庭变量参数估计绝对值相对更大,因而停伐政策对脆弱性家庭有着更为敏感和强烈的冲击。     

Examining horizontal and vertical social ties to achieve social–ecological fit in an emerging marine reserve network

1. Most MPA networks are designed only with ecological processes in mind to increase their conservation utility. However, since MPA networks often involve large geographic areas, they also affect and involve multiple actors, institutions, and policy sectors.
2. A key challenge when establishing an effective MPA network is to align the ‘social system’ with the biophysical MPA network (the ‘ecological system’). This challenge is often denoted as ‘social–ecological fit’.
3. Facilitating collaborative social interactions among various actors and stakeholders (social connectivity) is equally as important as accomplishing ecological connectivity. New analytical approaches are required to effectively examine this ‘social’ dimension of fit.
4. An emerging marine reserve network in Jamaica and the recent invasion of Indo‐Pacific lionfish are used as a case study to: (1) examine the extent to which horizontal and vertical social ties bring local and national actors together to collaborate, coordinate, and share knowledge; and (2) assess the extent to which different attributes and features of such multilevel social networks may enhance or inhibit particular aspects of social–ecological fit.
5. Findings suggest that multilevel linkages have played the greatest role in relation to enhancing fit in the marine reserve network in the context of the recent lionfish invasion. However, the long‐term propensity of the multi‐actor and multilevel networks to enhance social–ecological fit is uncertain given the prevalence of weak social ties, lack of a culture of information sharing and collaboration, and limited financial resources.

     

我国特大城市建成区土地集约利用研究

运用因子分析法对我国16个特大城市建成区的土地集约利用水平进行综合评价和排序.结果表明：我国特大城市建成区土地集约利用效率呈现总体水平偏低、地区差异明显及各大城市影响因素侧重点不同等3大特征.因此,需合理调整各大城市产业结构,以促进城市经济可持续发展;积极开展城市土地整理,以提高土地利用效率;加大城市生态环境保护力度,以优化土地利用生态效益.     

中国玉米市场形势分析与未来10年展望

2013年,中国玉米产量再创新高,消费需求相对低迷,进出口同比下降,供求关系较为宽松,价格总体弱势运行。预计未来10年,中国玉米生产继续稳步增长,消费需求增速较快但将明显放缓,价格总体继续上涨,玉米进口将进一步扩大。最后,指出影响未来玉米市场走势的因素主要包括气象、政策、贸易以及通胀、汇率等不确定性因素。     

温度对住宅区气体污染物扩散的影响

温度在气体污染物扩散的过程中起一定的作用。在现实生活中,由于日晒和地表辐射的存在,使得地面、建筑物外表面都与空气存在一定的温差。温差的存在会改变地表及壁面附近的流场,从而对住宅区污染物的扩散产生影响。利用理论推导对热力因素及扩散因素的关系进行了研究,并且与数值模拟的试验结果进行比较。结果发现理论推导与试验结果整体趋势相一致。这表明在与无温差情况相比较,温差存在时,地表及壁面附近流场更加紊乱;温差与气体污染物的扩散具有正相关性,对住宅区污染物的稀释起积极作用。     

宁远县水稻机械插秧优化配套技术研究

从栽培管理措施、产量及效益比较和机械插秧增产机理等方面介绍了宁远县丘陵山区水稻机械育插秧示范的基本情况,在此基础上总结了一套适宜在丘陵山区推广的水稻机械育插秧高产栽培技术,并提出了搞好宣传发动和技术培训工作、开展试验研究和推广示范等加快丘陵山区水稻机械插秧推广速度的措施建议。     

恩施与国外白肋烟中性致香成分含量的差异比较

为明确恩施白肋烟中性致香成分组分和含量及与国外白肋烟的异同,以恩施不同产区及美国、马拉维白肋烟样品为材料,采用气质联用仪对样品的中性致香成分含量进行分析测定,结果表明:恩施白肋烟中性致香成分总量及各组分含量在产地之间存在一定差异,其中香叶基丙酮、苯甲醛、糠醇等单一致香成分含量的变异较大。以巨豆三烯酮为代表的类胡萝卜素类降解产物含量以美国烟叶最高,恩施次之,马拉维最低;恩施白肋烟苯丙氨酸类、棕色化反应产物含量均高于美国和马拉维,而西柏三烯的主要降解产物茄酮则低于国外烟叶。聚类分析将供试样品分为3类,80%的恩施样点与美国同属一类,表明恩施白肋烟中性致香成分含量与美国具有较高的相似性。