2017年1-12月中国大豆进出口数据分析

本文主要阐述了2017年1—12月大豆进口与出口情况,同时分析了大豆贸易的主要特点,以期为农业科技工作者提供相关参考。     

昆明市云龙水库径流区氮磷非点源污染负荷分析

云龙水库是昆明市最大的城市集中式饮用水源地。水源区农业非点源污染是影响水库水质的主要来源,因此分析水库径流区氮磷非点源污染负荷与来源构成,可为饮用水源区水质保护提供科学依据。采用输出系数模型法,对昆明市云龙水库径流区氮、磷负荷的产生量与入库量进行了估算。结果表明:(1)云龙水库径流区氮、磷非点源污染负荷产生量分别为2079.8和454.32t/a,入库量分别为207.98和24.73t/a。(2)从不同乡镇分析,撒营盘镇的氮、磷负荷产生量最高,云龙乡和茂山镇产出量较低,其余乡镇产生量相近。(3)从不同污染源类型分析,该区非点源污染的主要污染源为农村生活污染和畜禽粪便污染。     

股权集中度、债务约束与技术创新——基于战略性新兴产业上市公司的经验证据

基于对出口价值构成中行业增加值出口的形式、流向以及途径的区分,从价值链的视角改进了传统的显性比较优势指数,测算12个主要贸易大国1995~2011年制造业和服务业各行业的显性比较优势。结果表明：贸易格局的总体趋势表现为发达国家在巩固制造业高端环节优势的同时又将服务业特别是金融服务业、信息服务业以及商务网络等方面的优势渗透进来,建立起服务于全球的新体系,新兴市场国家则逐渐在不同要素密集度以及不同层次的制造业方面加紧布局。加强贸易与产业的结合,有助于我国通过增加值间接出口的方式参与国际竞争。     

Compact plant type rice has higher lodging and N resistance under machine transplanting

To identify the major factors that contribute to the difference in lodging among different rice varieties under machine transplanting and their responses to nitrogen(N), field experiments were conducted at Danyang County(a representative eco-site of the Lower Yangtze River) in Jiangsu Province, China in 2017 and 2018, 22 hybrid indica varieties(HIs), 22 inbred japonica varieties(IJs) and two indica japonica hybrid varieties(IJHs) were transplanted by machine with three N rates(N0, N150 and N300, 0, 150 and 300 kg ha–1, respectively). Lodging-related physical parameters, morphological characteristics and apparent transport rates of dry matter were examined. Significant difference in yield was observed among different types of rice, and followed by IJsHIsIJHs. The average lodging index(LI) of hybrid varieties(HIs and IJHs) was higher than that of the inbred varieties(IJs) with higher plant height; moreover, lower apparent export rate of dry matter resulted lower LI in IJHs than in HIs. The HIs had a large difference in the LI, which came from the difference in bending stress(BS) induced by the difference in the apparent export rate of dry matter, varieties with lower leaf angle of upper three leaves possess strong lodging resistance capacity; however, the gap among the IJs was due to the difference in the cross section modulus(Z). The LI in the IJs or IJHs increased slightly with the increased N application, and there was no lodging incidence under the high N level, which was due to the low leaf angle and barely changed under high N; there was a significant interaction between varieties(HIs) and N rates in lodging rate and LI, varieties with lower leaf angle of upper three leaves were resistant to high N. These results suggest that compact plant type rice has higher lodging and N resistance at machine-transplanting method.     

我国对虾产品贸易结构与出口竞争力分析

随着我国对虾养殖业的迅猛发展,对虾贸易也呈快速增长的趋势.我国是对虾贸易有较大顺差的国家,近年来对虾贸易顺差在逐渐拉大.对我国对虾出口贸易结构的分析表明,出口商品出现了由粗加工产品向深加工产品的结构转变:出口地区呈明显的沿海性分布;出口市场主要集中在日本、美国、欧盟、韩国和香港等传统市场.实证分析表明,我国对虾产品出口有中等比较优势,但我国的RCA和CA指数较其他主要对虾出口国明显落后.     

FTA 背景下中国对韩国水产品出口贸易增长研究———基于CMS模型的实证分析

在中日韩自由贸易协定(FTA)的背景下,利用修正后的CMS模型,对2002-2012年中国对韩国水产品出口贸易的情况进行分析.结果表明:结构效应是中国对韩国水产品出口增长的主要因素;与此同时,中国偏低的竞争力和竞争与结构交叉效应,在一定程度上又阻碍了中国对韩国水产品出口的快速增长,但在固定水产品类别上的优势,保证了中国对韩国水产品出口的稳定增长.为此,政府部门应加强水产品食品安全工作,建立交流平台,实现信息公开化,以及加大对水产品自主品牌的建立.     

安徽省农产品出口贸易发展状况及区域差异

加入WTO以来,安徽农产品出口贸易发展迅猛,但存在省内不同区域明显的发展差异。面临经济增长持续放缓预期愈加强烈,安徽农产品出口贸易亟需向提高发展质量、提升核心竞争力、进一步挖掘出口比较优势的方向转变。对加入WTO以来安徽农产品出口贸易结构、比较优势、竞争优势,并利用区位熵指数、修正的泰尔指数等测度区域贸易差异的指标分析发现,安徽出口贸易额在全国处于中游,具有较强比较优势的产品较少,整体农产品贸易竞争力弱。建议通过发展加工贸易、构建质量提升的内涵发展路径等促进安徽农产品出口贸易良性发展。     

中国大米国际竞争力研究 ——基于同印度、巴基斯坦、泰国和越南的比较分析

稻谷是中国主要的粮食生产作物,具有较强的创造经济效益的能力。从联合国粮农组织和世界贸易组织的相关数据上来看,中国大米产量与中国大米的出口量存在着明显的不对称。笔者从研究国际竞争力的显示性指标出发,选择了亚洲最大的5个大米出口国作为研究对象,运用了国际市场占有率、贸易竞争指数、显示性比较优势指数、进出口价格比4个指标对中国大米的国际竞争力作了实证分析。结果表明,中国大米与印度、巴基斯坦、泰国和越南4国相比,不具有国际竞争力优势。     

Na+ and Cl−: Leaf extrusion,retranslocation and root efflux in diplachne fusca (kallar grass) grown in NaCl

Abstract

Groups of “Kallar”; grass plants were subjected to various treatments of 100 mM NaCl simultaneously labelled with ²²Na⁺ and ³⁶Cl^?. On the basis of the specific activity, the distribution of Na and Cl^? in the tissue was followed during and after treatment, i.e. after transfer of some groups to an identical but inactive solution. Sequential collections of leaf washes showed that both Na and Cl^? were extruded at a somewhat constant rate. Leaf sheaths accumulated more Na⁺ and Cl^? than the leaf blades and the amounts of Na⁺ and Cl^? in the leaf sheaths as a percentage of their total plant content (i.e. 28% and 31%) approximated the amounts of Na and Cl^? extruded by the leaves (i.e. 23%). Moreover, almost equivalent amounts of Na⁺ (21%) and Cl^? (29%) were removed by root efflux which continued even several days after transfer of the plants to the inactive, saline solution. Part of the Na⁺ and Cl^? was retranslocated from the tops to the roots and was attributed to phloem export.

Tolerance of Kallar grass to NaCl was thus related to preventing the tissue from accumulating high concentration by extrusion of both Na⁺ and Cl^? by the leaves and their efflux by the roots in addition to an equivalent retention in the leaf sheaths.     

中美贸易摩擦对广东省输美水产品贸易的影响及对策研究

【目的】通过分析中美贸易摩擦对广东省输美水产品贸易的影响,提出相关对策与建议以缓和中美贸易摩擦带来的负面影响,促进广东省水产品企业转型升级。【方法】结合统计数据及半结构式实地调研情况,运用TC指数方法,分析广东省输美水产品贸易现状,从宏观到微观深入探讨中美贸易摩擦背景下广东省输美水产品市场所受到的影响,并从企业、行业和政府层面提出对策与建议。【结果】2018年中美贸易摩擦发生后,广东省水产品出口贸易面临更大的不确定性,宏观上导致水产品竞争力下降,贸易顺差转为逆差,水产品出口美国受阻,内销比例增大,部分出口美国的水产品转向东盟和澳大利亚市场;微观上对水产品上中下游各环节造成负面影响,非美和国内市场有所拓宽,加工量减少,养殖计划不明确。【结论】广东省水产品企业应兼顾国内外市场,激发消费潜力;带领养殖户转变养殖模式,提高抗风险能力;加大科研力度,从根本上提升核心竞争力。行业协会应发挥带头作用,共同防范风险。建议政府出台相关扶持政策,携手企业以更从容的姿态应对中美贸易摩擦。