土壤有机质含量对化肥氮素转化的影响

采用室内好气培养,分期采样,室内分析的研究方法,研究了土壤有机质含量对化肥氮素形态转化的影响。结果表明,化肥施入土壤后,土壤铵态氮供出量在培养前期(20d)随有机质含量的增加而增加,在培养中后期则并未表现出这种趋势;在不同培养阶段土壤硝态氮供出量与土壤有机质含量相关系数在0.8325￣0.9953之间,呈显著正相关;土壤无机氮供出量在培养至第7天、第20天时,与土壤有机质含量相关系数分别为0.973、0.9854,其相关性达到了极显著,不过在培养的中后期,二者的相关性并不明显。     

Empirical Study on the Macroeconomic Performance of China''s FDI

The problem on performance of foreign direct investment is the heart of matters, which are further expanding foreign direct investment in China and strengthen international competitive ability of Chinese enterprises. The empirical study on macro performance shows that foreign direct investment in China has made no difference to economic growth and export promotion, both long term and shot term; for a long term, it has no remarkable effect on foreign exchange reserve, but remarkable and negative effect in a short term. It has no any effect on domestic investment in long or short term. There is no balance relation in long term and no cause and effect relation either between foreign direct investment and FDI inflow, or between foreign direct investment and total factor productivity. Foreign direct investment in China has no remarkable effect on macro performance.     

Assessment of genetic variation in a collection of lentil using molecular tools

A collection of lentil landraces, mostly from Italy, but including Mediterranean and foreign germplasm as reference, was evaluated using RAPDs, microsatellite-primed PCR and ISSRs. A low level of useful polymorphic bands was detected with the former two markers, whereas ISSRs revealed a higher degree of variation. The UPGMA trees, based on Jaccard similarity index matrices, obtained with RAPD and ISSR respectively, did not produce similar clusters. However, in both cases, the accession which differentiated the most from the others was from Ethiopia, a country where also other cultivated species have shown a remarkable degree of variation. On the other hand, Italian accessions showed a trend to group together. ISSR markers proved to be useful for distinguishing closely related genotypes, and possibly for substantiating the genetic peculiarity of ecotypes applying for the obtainment of origin and quality marks. This revised version was published online in July 2006 with corrections to the Cover Date.     

广东农业传媒与传播学科发展现状与战略规划研究

笔者简述国内外农业传媒与传播学科的发展现状,包括国外传媒传播数字化发展趋势及国内传媒传播机构培育及技术进展等方面;从媒体数字化、农业科技传播推广、理论水平与基层服务等方面分析广东农业传媒与传播发展情况。在对该学科建设发展需求分析的基础上,拟订出广东省农业传媒与传播学科发展的战略规划,包括指导思想、建设原则、研究领域规划、发展目标与研究战略重点等方面,以期为今后广东农业传媒与传播学科的科学发展提供战略指导与理论支撑。     

氮沉降对北方森林土壤氮收支的影响研究进展

氮沉降增加是全球气候变化的重要情景之一,已经对全球氮素循环产生了严重的影响,可能会显著改变生态系统的健康和服务。北方森林,作为地球上仅次于热带森林的第二大生物群区,占全球森林面积的30%,其土壤分系统在调节森林生态系统氮循环和应对全球气候变化中起着重要作用。氮沉降对北方森林土壤氮收支的影响已被广泛关注,并成为全球变化科学领域的热点问题。同时,土壤氮收支作为土壤物质交换和能量转换的主要环节,对氮沉降的响应复杂而多变。因此,为深入了解大气氮沉降对北方森林土壤氮收支的影响,笔者综述了国内外近年来的相关研究成果,分别从土壤氮输入(生物固氮和凋落物分解)、氮固存(微生物固存和外生菌根固存)、氮输出(矿化作用、硝化作用、反硝化作用以及淋溶)以及土壤总氮库的变化趋势等方面分析了土壤氮收支对大气氮沉降的响应,可为科学评估氮沉降对北方森林土壤氮收支的影响提供参考数据。     

Internal and external constraints of the Cuban production sector

This paper aims to explain the growth of the Cuban production sector between 1975 and 2014 by considering both demand and supply factors simultaneously. The research provides new empirical data on this topic through the application of a simultaneous equation model that considered the effect on the product of internal and external constraints most relevant to the Cuban economy, and the impacts of these over time. Its results confirm that the growth of the Cuban production sector was primarily limited by two factors: On the one hand, an overly centralized regulatory framework that reduces the global efficiency of the Cuban economy; and, on the other hand, a foreign exchange deficit that restricts its import capacity and the sustained growth of the Cuban capital stock. Therefore, the Cuban production sector's growth could be fostered by both a greater decentralization of its regulatory framework and the implementation of industrial and commercial policies geared to make Cuban exports more competitive.     

近 60年大连市不同等级降水量与降水日数的变化特征

为了研究掌握不同等级降水量和降水日数演变规律,合理利用降水资源,更好地服务于农业生产。根据大连市1951—2010年逐日降水资料,利用线性趋势和Mann-Kendall突变检验等方法,对大连市不同等级降水量和降水日数的变化特征进行分析。结果表明：年降水量和降水日数均呈减少趋势,降水日数的减少更加显著。小雨量和大雨量（日数）显著减少,中雨量（日数）则呈增加趋势,暴雨量（日数）减少趋势不明显。降水量（日数）的季节变化明显,其中夏、秋、冬季降水量（日数）呈减少趋势,而春季降雨量（日数）呈增加趋势。降水强度春季显著增大,夏、秋季显著减小,而冬季有微弱的下降趋势。春季发生极端降水事件的概率增加,尤其是进入21世纪以来更加明显。年降水日数在1978年发生1次明显突变。     

Research on the Forecasting Model of Foreign Exchange Income in Chongqing

It is very imporfand to monitor the exchange of the foreign trade income when the convertibikty of current account has been realied.In order to enforce the monitoring of the settlement of foreign exchange income in Chongqing, Grey Model and Auto-Regression Model have been built based on the characteristics of local data, which focus on the forecasting of the local settlement of foreign exchange of foreign trade income. From different aspects, these two models efficiently forecast the variation, in short run and middle run, of the exchange of foreign trade income in Chongqing. Based these analyses, this paper suggests the combination of two models and enforcing the monitoring of the settlement of foreign exchange of cooperation of enterprises and banks.     

中国粮食市场的供需结构、趋势及政策需求分析——基于ARIMA-GRNN模型的预测

在对粮食市场的供需结构和发展趋势进行分析的基础上,建立ARIMA-GRNN模型等对粮食供求的未来中短期趋势进行了预测。预测结果表明：中国粮食市场近期供给没有问题,但长期供求形势不容乐观。随着科技发展水平到达一定的程度,单产拉动型增产方式并不可持续;工业用粮将会大幅度增长,成为未来粮食消费的一个最主要部分。因此,未来粮食宏观调控的重点应从“供给侧”适当向“需求侧”转变,并要进一步注重调节粮食结构性问题。     

Determining resistance to <Emphasis Type="Italic">Fusarium verticillioides</Emphasis> and fumonisin accumulation in African maize inbred lines resistant to <Emphasis Type="Italic">Aspergillus flavus</Emphasis> and aflatoxins

Fusarium verticillioides and Aspergillus flavus cause Fusarium ear rot (FER) and Aspergillus ear rot (AER) of maize, respectively. Both pathogens are of concern to producers as they reduce grain yield and affect quality. F. verticillioides and A. flavus also contaminate maize grain with the mycotoxins fumonisins and aflatoxins, respectively, which has been associated with mycotoxicosis in humans and animals. The occurrence of common resistance mechanisms to FER and AER has been reported. Hence, ten Kenyan inbred lines resistant to AER and aflatoxin accumulation were evaluated for resistance to FER, F. verticillioides colonisation and fumonisin accumulation; and compared to nine South African lines resistant to FER and fumonisin accumulation. Field trials were conducted at three localities in South Africa and two localities in Kenya. FER severity was determined by visual assessment, while F. verticillioides colonisation and fumonisin content were quantified by real-time PCR and liquid chromatography tandem mass spectrometry, respectively. Significant genotype x environment interactions was determined at each location (P ≤ 0.05). Kenyan inbred CML495 was most resistant to FER and F. verticillioides colonisation, and accumulated the lowest concentration of fumonisins across localities. It was, however, not significantly more resistant than Kenyan lines CML264 and CKL05015, and the South African line RO549 W, which also exhibited low FER severity (≤5%), fungal target DNA (≤0.025 ng μL^?1) and fumonisin levels (≤2.5 mg kg^?1). Inbred lines resistant to AER and aflatoxin accumulation appear to be promising sources of resistance to F. verticillioides and fumonisin contamination.     

青椒果实性状遗传参数的分析

本文对青椒单果重、果长、果宽和果肉厚等4个果实性状的遗传参数进行了分析.结果表明:①4个果实性状的Vg/Vs比值均大,说明这些性状受基因加性效应影响大.一般配合力较高的亲本参与的组合,其F_1在这一性状上的实测值也较高.各性状配合力总效应值与实测值呈极显著的正相关.②4个果实性状的狭义遗传力较高,因此这4个性状的变异,大部分可固定遗传给后代,由F_1表现可以预测F_2表现的趋势.③4个果实性状的亲子间呈显著正相关,可根据双亲的平均值(MP)推断F_1相应的表现.     

The relationship between foreign direct investment and domestic entrepreneurship: The impact and scale of investments in China

Both entrepreneurship and foreign direct investment (FDI) are frequently identified as being sources of local and regional economic growth. However, the relationship between the two is not always clear, with a negative competition effect and a positive demand effect potentially present. China provides an interesting case to study with its large state-owned sector, combined with a recent history of successfully attracting considerable FDI. This study examines the relationship between self-employment and different elements of foreign influence (FI) at a provincial level. The results imply that foreign investment reduces the level of self-employment, whilst the number of foreign enterprises and foreign exports have positive effects. The results therefore show the importance in considering multiple perspectives in terms of FI. It appears that policies that attract individual large investments suppress the development of domestic enterprise as predicted by the competition effect, but where more foreign enterprises are present, and a cluster starts to develop, a demand effect appears to take over. This means that provincial government policy may need to be more nuanced to avoid economies being highly reliant on a limited number of what might be quite footloose larger foreign employers.     

《华北农学报》引文分析

用文献计量学的原理和方法，对１９８６～１９９３年《华北农学报》发表的论文及其引文进行了分析，结果表明，《学报》刊登论文６５１篇，引文共３９４７篇，平均引文数为６．０６篇，其中，中文占引文总数的６０．０７％，外文占３９．９３％。在引文中期刊占６９．７８％，图书和特种文献占３０．２２％。自引率较低。另外，对不同省、市、区所报道的重点统计分析表明，其选题新颖，具有地方特色。     

非淀粉多糖酶对牙鲆生长和饲料利用率的影响

摘 要：以初始平均体重(2.04 ± 0.02)g的牙鲆(Paralichthys olivaceus)为实验对象,进行为期70天的摄食生长实验,研究不同添加方式的非淀粉多糖酶对牙鲆生长和饲料利用率的影响。在5000.0 g豆粕中添加25.0 g非淀粉多糖酶,然后用产朊假丝酵母(Candida utilis)进行发酵预处理,得到非淀粉多糖酶预处理豆粕。共制作4种等氮等能饲料,其中以全鱼粉饲料为对照饲料,用豆粕蛋白替代45%的鱼粉蛋白配制成豆粕组饲料;在豆粕组饲料中添加0.2%非淀粉多糖酶配制成非淀粉多糖酶组饲料;用非淀粉多糖酶预处理豆粕蛋白替代45%的鱼粉蛋白配制成非淀粉多糖酶预处理豆粕组饲料。结果表明,用豆粕蛋白替代饲料中45%的鱼粉蛋白,若不添加非淀粉多糖酶则显著降低牙鲆的特定生长率(P<0.01)、饲料效率、蛋白质效率和氮贮积率(P<0.05);在含豆粕饲料中添加0.2%非淀粉多糖酶显著提高牙鲆的特定生长率(P<0.01)、饲料效率、蛋白质效率、氮和磷贮积率,显著降低氮和磷排放率(P<0.05);在饲料中添加非淀粉多糖酶预处理豆粕显著提高牙鲆的特定生长率(P<0.01),但对饲料效率、蛋白质效率无显著的影响(P>0.05)。     

插电式混合动力汽车能量管理策略研究现状和发展趋势

目前国内外学者对插电式混合动力汽车能量管理策略进行了较为广泛和深入的研究，取得了良好的节能减排效果，为进一步提升其性能，有必要对插电式混合动力汽车能量管理策略的研究现状进行总结并对其发展趋势进行分析。首先对插电式混合动力汽车动力源能量流分配方法进行了归纳和分析，指出了当前插电式混合动力汽车能量管理策略两个亟待解决的问题：未考虑发动机冷却液温度和三元催化器温度等温度因素对油耗和排放影响；当前插电式混合动力汽车能量管理策略是以行驶功率需求作为输入，忽略了驾驶室制冷/供暖功率需求。最后提出了计及发动机冷却液温度和三元催化器温度等温度因素的能量管理策略和计及驾驶室制冷/供暖功率需求的能量管理策略两个未来研究方向。     

新疆阿克苏市城市化发展与耕地资源协调性

为了正确认识干旱区绿洲城市化与耕地资源之间的矛盾,对推进城市化进程提供科学依据,以新疆阿克苏市为研究对象,以阿克苏市社会经济统计数据和1990、2000、2010、2014 年4 期Landsat TM、ETM+、OLI遥感数据为基础,研究阿克苏市城市化水平和耕地资源的动态变化情况,并通过回归模型和协调度分析法分析二者间的相关性与协调性。近26 年（1989—2014 年）数据的分析结果表明：阿克苏市的城市化水平处于“增长—下降—增长”的波动性增长态势,年均增长率达到0.36%,其中2001 年后的增长是第二和第三产业的迅速发展而引起;耕地面积也处于“增长—下降—增长”态势,其中2004 年前后耕地面积下降的主要原因是部分耕地资源被划归于阿拉尔市,2007 年后回升的原因是阿克苏市社会经济发展需求的增加;耕地资源与城市化之间的关系1989—2003 表现为正相关,2004—2014 年表现为负相关。它们之间的协调性主要体现出基本协调和不协调的更迭式发展状态。     

基于SPI的大兴安岭林区气候干湿状况时空变化研究

明确气候变化背景下大兴安岭林区气候干湿状况的变化特征,可为更好的预测森林火灾、保护森林资源提供科学依据。利用黑龙江省大兴安岭林区6个气象站1974—2016年的逐日降水量资料,采用标准化降水指数(SPI),分析了该区域近43年气候干湿状况的变化规律。结果表明：近43a,黑龙江省大兴安岭林区气候总体呈湿润化趋势,但阶段性变化明显,特别是进入21世纪以来,气候干湿波动剧烈。年尺度上,仅呼玛的气候呈不明显的干旱化,其他各站的气候状况均表现为湿润化趋势;季节尺度上,呼玛夏季、塔河秋季的气候表现为不同程度的干旱化趋势,其他各站点各季节的气候均表现为不同程度的湿润趋势。且相关分析结果表明,夏季降水对年气候干湿状况的变化起到决定性的作用,为大兴安岭林区气候湿润化的主要贡献者。     

主要农作物秸秆资源调查及能源化利用评价——以安徽省为例

秸秆资源统计是其综合利用的前提。按照农业部标准NY/T 1701-2009《农作物秸秆资源考察与评估技术规范》中的技术方法,以安徽省为例,采用2013 年《安徽统计年鉴》提供的统计数据,对主要农作物秸秆资源进行了统计分析与能源化利用评价。结果表明：安徽省主要农作物秸秆年理论资源量4487.99 万t,年可收集资源量3878.84 万t,年人均资源量72.88 kg/人;水稻、小麦和玉米秸秆是安徽省主要的作物秸秆资源,3 者合计可占秸秆资源总量的82.23%,年可收集量分别为1567.86、1539.43 和582.98 万t;皖北地区秸秆资源占全省资源总量的49.75%;江淮之间为32.08%;皖南山区为18.17%,呈现出明显的由北向南逐步递减的整体趋势。在此基础上,结合秸秆能源化利用方式,将安徽省秸秆资源利用能源化利用划分为重点开发区（A区）、适度开发区（B区）和限制开发区（C区）等3 个区域。为安徽省秸秆资源开发及能源化利用提供参考。     

苏云金芽孢杆菌Cry1Ab和Cry1C同源重组及转化大豆

在研究和确定Cry1Ab和Cry1C蛋白对甜菜夜蛾和斜纹夜蛾协同杀虫作用的基础上,利用同源重组技术进行Cry1Ab和Cry1C之间的结构域交换获得高效融合蛋白,利用农杆菌介导的子叶节法将融合抗虫基因表达载体导入大豆中,从而获得抗虫转基因大豆新材料。采用PCR及蛋白试纸条检测法对获得的大豆再生植株进行鉴定,测得结果初世代阳性植株为121株。对部分后代转基因植株的遗传分析表明外源基因能够稳定遗传。室内接种斜纹夜蛾鉴定表明,含有重组基因的转基因大豆对斜纹夜蛾有较强的抗性。因此,利用同源重组技术进行Cry1Aa和Cry1C之间的结构域交换,是获得高抗食叶性害虫大豆的有效途径。     

中国罗非鱼产品出口贸易情况分析及展望

为了引导罗非鱼产业健康持续发展,分析了中国罗非鱼产品出口的基本情况、出口区域情况、出口目标国情况,并对罗非鱼的贸易发展趋势进行展望。分析显示,中国罗非鱼产品供应以国际市场为主。2002 年以来,对外贸易基本表现出良好的发展势头,但增长速度在逐步放缓。在国际市场需求的带动下,中国罗非鱼出口产品已转为以冻罗非鱼片为主,罗非鱼出口省份有广东、海南、广西和福建4 个省份,这4 个省份的出口产品也基本以冻罗非鱼片为主。中国罗非鱼最大的出口国是美国,出口目标国的增加也代表着中国罗非鱼市场正趋于多元化。与此同时,中国罗非鱼在未来发展面临着很多问题,如贸易竞争国竞争力的提高、贸易竞争品种对有限市场的挤占、严峻的国际环境对罗非鱼产业的考验等。罗非鱼产业的持续稳定发展必然要依靠国内外市场的开拓、产品品质的提升和营销渠道的构建等。