气候变暖对阿勒泰地区春玉米播种期和种植布局的影响--测试文章

采用阿勒泰地区7个气象站1961—2010年逐日平均气温资料,使用线性趋势分析、累积距平、t检验并基于Kriging插值法,分析近50年日平均气温稳定通过≥10℃的初日、终日、持续日数和积温的时空变化特征,揭示春玉米播种期及种植布局的变化规律。结果表明,阿勒泰地区近50年≥10℃积温呈现初日提前、终日推迟、持续日数延长、积温增加的现象,其倾向率分别为0.3、1.3、1.6 d·10a^-1和57.1℃·10a^-1,且突变年份均发生在20世纪90年代中期。各县市春玉米播种期提前3～8 d,生长季延长6～11 d。突变前青河东部不能种植春玉米,晚熟品种不能种植或种植风险较大。随着气候不断变暖,春玉米不同熟性品种可种植区逐渐东扩,各县市春玉米在品种熟性上均发生了改变,表现为由不能种植到种植早熟、早熟向中（晚）熟、中晚熟向晚熟品种的变化。     

近50年河南省夏玉米生产潜力及产量差时空变化特征--测试文章

利用河南省96个县1961—2010年气象资料和夏玉米实际产量，采用逐步订正模型，计算了近50年河南省夏玉米光温生产潜力和气候生产潜力，分析了光温生产潜力与气候生产潜力、光温生产潜力与实际产量两种产量差的时空变化特征。结果表明：(1) 光温生产潜力由北向南、由东向西递减，近50年呈极显著下降趋势，全省平均每10 a减少696.8 kg·hm^-2，北、中大部分站点和南部的部分站点下降幅度较大。(2) 气候生产潜力南部高于北部、东部高于西部，近50年变化趋势不明显。光温生产潜力与气候生产潜力之间的产量差呈极显著下降趋势，平均每10 a减少958.7 kg·hm^-2。(3) 夏玉米实际产量极显著增加，光温生产潜力与实际产量之间的产量差极显著下降，平均每10 a减少1 718.0 kg·hm^-2，但71.9%的站点产量差大于24 000 kg·hm^-2，产量潜力仍有较大提升空间。降水是制约河南省西部夏玉米产量的主要因素，可通过灌溉提高产量；后期热量不足影响北部玉米产量进一步提高，选用中早熟品种和改进栽培技术是提高产量的途径；东部可通过增加灌溉面积、选用优良品种和科学施肥等措施缩小产量差。     

北疆春播、麦后复播青贮玉米物质生产和温光生态效应利用的比较--测试文章

以新玉15号为供试品种,研究了春播和麦后复播青贮玉米（复播1期,6月30日播种;复播2期,7月10日播种）在产量、干物质积累和光温气候资源利用等方面的差异。结果表明：春播、复播1期、复播2期的群体干物质产量分别为15 615、17 615、14 671 kg·hm^-2,春播、复播1期、复播2期鲜重产量53 988、67 251、68 327 kg·hm^-2;复播青贮玉米生育期明显缩短,光合有效辐射和≥10℃积温较春播少;复播1期苗期、穗期、灌浆期均处于最适温度范围之内;春播、复播1期、复播2期的LAI峰值为5.01、5.72、6.36,总光合势分别为2.45×10⁶、2.84×10⁶、3.37×10⁶ m²·d^-1·hm^-2。复播青贮玉米的产量潜力主要在于大口期之前生育期优越的光温资源条件,且大口期之前干物质积累速率较春播快。     

基于净初级生产力的春小麦生产潜力及估产研究——以甘肃省白银区为例--测试文章

利用2010年白银区春小麦生长季（4—7月）空间分辨率为250 m的MODIS影像和气象站点的气象数据,通过CASA模型建立了基于MODIS数据的春小麦净初级生产力遥感估算模型,估算出白银区春小麦生长季的净初级生产力（NPP）,通过春小麦NPP与干物质转换关系计算出春小麦生产潜力。结果表明：白银区南部春小麦的NPP和生产潜力均大于北部地区,其NPP最小值为42 gC·m^-2·a^-1,最大值为402 gC·m^-2·a^-1,且春小麦的生产潜力有明显的季节性规律。根据春小麦生产潜力与实际产量的拟合关系建立了产量估测模型,并对该模型做了精度验证与实用性评价,结果显示该估产模型均方根误差RMSE为76.33 g·m^-2,相对均方根误差RMSEr为23.51%。     

甘肃省春油菜生育及产量形成对气候变化的响应--测试文章

利用甘肃省春油菜种植区甘肃民乐县1987—2006年、合作市1987—1999年油菜生育期、产量资料及光温水气象资料，分析了气候变化特征及与油菜生长发育、产量形成之间的相互关系。结果表明：气候变暖背景下，甘肃油菜产区气温呈升高趋势，气温倾向率在0.28～0.31℃·10a^-1，河西民乐产区气温增幅大于甘南合作产区。降水基本稳定，两地增（民乐）、减（合作）幅较小。关键生育期——苔花期降水民乐呈减少趋势，合作呈增加趋势；气候变暖使油菜生育进程加快，民乐现蕾—开花、开花—绿熟间隔日数减少趋势明显，1997—2006年平均日数较1986—1996年分别减少13 d和4 d；单位气候要素变化导致气候产量敏感程度不一，民乐产区降水影响以正效应为主，水分不足是产量提高的主要限制因子，最大影响时段出现在苔花期。合作产区光温影响以正效应为主，光温条件不足是主要限制因子，其次是现蕾—开花期降水呈正效应。总体而言，气候变化对高寒阴湿区油菜产量增加和品质形成更为有利，不利于温带草原气候区油菜生产，温带草原气候区应积极采取抗旱保墒、播种期提前等应对措施。     

湖北恩施不同海拔烟区气候因素综合评价

对恩施不同海拔烟区气候适生性进行了综合评价,并与国外优质烟区气候进行相似性比较与分析,结果表明:1)随着海拔的升高,烟叶各生育期的平均气温和≥10℃积温呈降低趋势,烟叶大田期日照时数和各生育期的降雨量则呈上升趋势;恩施各生育期均温、各生育期降雨量、大田期日照时数、≥10℃的积温和无霜期在不同海拔间均存在显著差异.2)随着海拔的升高,恩施气候适生性指数值(CFI)呈降低趋势,以低海拔地区的CFI值(0.903)最大,高海拔地区的CFI值(0.660)最小,不同海拔气候适生性差异显著.3)恩施烟区气候与津巴布韦烟区的气候相似距离平均值最小,低、中、高海拔地区气候相似距离分别为0.383,0.402和0.431,恩施低海拔烟区气候与国外优质烟区气候的相似程度最高,高海拔烟区相似程度最低.     

硼改性酚醛树脂在机油滤纸中的应用

本研究采用水杨醇法制备硼改性酚醛树脂（BPF）,并将其应用于机油滤纸以增强其物理性能。研究结果表明,最佳的BPF合成条件为：苯酚：甲醛：硼酸物质的量比1.0∶1.4∶0.2、反应温度110℃、反应时间1.5 h,其在800℃的残余质量为68.4%。当固化温度180℃,上胶量（24±1）%时,BPF浸渍固化滤纸性能最佳,耐破指数达2.67 kPa·m²/g,抗张指数达50.2 N·m/g,滤纸纵向挺度为6.37 mN·m。180℃老化试验（老化12 h）后滤纸耐破指数为1.38 kPa·m²/g,抗张指数为44.4 N·m/g。且在150℃的机油中老化192 h后,耐破度为196 kPa,满足JB/T 12651.1中对机油滤纸的质量要求。     

磷钾肥对云南旱作马铃薯产量和养分吸收的影响--测试文章

在云南省曲靖地区的低肥力和中高肥力试验地分别开展旱作马铃薯的田间小区试验,研究磷钾施用量对马铃薯生物量、养分利用、产量和经济效益的影响。结果表明：相同施肥量的条件下,中高肥力试验地的东山组马铃薯产量远高于低肥力的越州组,产量相差10 305.00～20 140.20 kg·hm^-2;越州组NP2K3(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 405 kg·hm^-2)处理产量产值最高,NP2K1(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 135 kg·hm^-2)处理净收益最高; 东山组NP2K2(N,150 kg·hm^-2; P₂O₅,90 kg·hm^-2; K₂O, 270 kg·hm^-2)处理产量、产值及净收益均是最高; 两组试验的马铃薯干重变化趋势相似,NP2K2处理的干重积累量较多,无钾无磷处理干重积累少;马铃薯体内累积K最多,其次为N,最后为P, NPK养分吸收积累的高峰期在马铃薯块茎膨大期到淀粉积累期; 东山组的马铃薯PK利用效率明显高于越州组。NP1K2(N,150 kg·hm^-2; P₂O₅,45 kg·hm^-2; K₂O, 270 kg·hm^-2)处理的P肥利用率和P素农学效率较高,P肥利用率和P素农学效率都有随施P量增加而降低的趋势。NP2K1处理的K肥利用率和K素农学效率最高,K肥利用率和K素农学效率均有随施K量增加而降低的趋势。     

玉米/鹰嘴豆间作条件下不同施磷量对灌耕灰钙土无机磷组分的影响--测试文章

在甘肃引黄灌区的灌耕灰钙土区域,通过玉米/鹰嘴豆间作种植,采用蒋柏藩、顾益初石灰性土壤无机磷分级方法研究了施磷水平和间作种植方式对玉米、鹰嘴豆土壤无机磷素形态的影响。结果表明：研究区各无机磷形态含量顺序为O-P＞Ca₁₀-P＞Ca₈-P＞Al-P＞Fe-P＞Ca₂-P,施磷能够显著提高玉米和鹰嘴豆土壤中Ca₂-P、Ca₈-P、Al-P和Fe-P的含量,O-P和Ca₁₀-P的含量不随施磷量增加发生显著性变化;与单作相比,间作种植对鹰嘴豆土壤带各无机磷组分含量没有显著影响,但间作玉米种植带土壤各组分无机磷含量均低于单作土壤,其中不施磷肥处理下Fe-P、施纯磷 40 kg·hm^-2处理下Al-P及施纯磷 80 kg·hm^-2处理下Ca₁₀-P的含量显著低于单作土壤。     

秸秆还田下减量施氮对作物产量及养分吸收利用的影响--测试文章

秸秆还田条件下,采用多年田间定位试验研究了N肥减量施用对作物产量、养分吸收利用以及土壤表观N平衡的影响,旨在为关中小麦/玉米一年二熟轮作区合理施用N肥提供依据。结果表明：与常规施N处理(玉米季施氮187.5 kg·hm^-2,小麦季施氮150 kg·hm^-2)相比,2008—2011年三年中,15%减N、30%减N两个处理均未显著降低作物籽粒与秸秆产量;2010—2011年生长季中,15%减N处理降低了作物秸秆N、P、K周年总吸收量,增加了籽粒N、P、K周年总吸收量,其中籽粒P周年总吸收量增加达显著性水平;30%减N处理显著降低了籽粒N和秸秆N、K周年总吸收量,降幅分别为12.9%、41.9%、18.5%,在小麦收获后,30%减N处理的N素盈余量只有11.3 kg·hm^-2,有潜在缺N危险。综合考虑产量、养分吸收利用及土壤表观N平衡,在秸秆还田条件下,15%减N处理的施N量（即玉米季施氮159 kg·hm^-2,小麦季施氮127.5 kg·hm^-2）为本地区最佳N肥用量。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

低温带皮菜籽粕微粉的不同粒级部分的功能特性

为研究低温带皮菜籽粕微粉的不同粒级部分的功能特性,以经低温脱脂的带皮菜籽粕为原料,经微粉碎后筛分成212~425μm、150~212μm和106~150μm的3个不同粒级的微粉样品,检测这些样品的吸水性、吸油性、乳化性和乳化稳定性、蛋白质体外消化率。结果表明:1 3个不同粒级的微粉样品之间的粗纤维含量存在显著差异,表明三者的结构组成成分有一定差异。23个微粉样品的乳化活性和乳化稳定性随粒度级别的减小而显著增加(P0.01)。33个微粉样品的蛋白质体外消化率随粒度级别的减小而显著增加(P0.01)。4不同粒级带皮菜籽粕微粉样品的吸水性与吸油性受其结构组成物质不同和粒度的双重影响,与粒度的相关性不明显。     

Microbiology of food taints

Fresh and processed foods are often spoilt by the presence of undesirable flavours and odours caused by microbial action. The aim of this paper is to review the current knowledge of microbiologically induced taints that occur in a wide range of foodstuffs, including meats, poultry, fish, crustaceans, milk, dairy products, fruits, vegetables, cereals and cereal products. Examples have been chosen where the compounds responsible for the taint have been identified and sufficient data obtained to demonstrate the involvement of microorganisms. However, in some cases the full identity of the causative organism may not have been elucidated. The types of microorganisms covered by this review include bacteria, fungi, yeasts, actinomycetes and cyanobacteria. Although cyanobacteria do not in general infect foods, their presence in aqueous systems and water supplies can lead to off-flavours in aquatic organisms and processed foodstuffs. Several examples of each of these processes are discussed. Wherever possible, the likely biosynthetic pathway used by the microorganism to produce the offending compound in a foodstuff is indicated.     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. I: Interlaboratory studies of methods of analysis

This paper describes the first part of a project undertaken to develop mussel reference materials for Paralytic Shellfish Poisoning (PSP) toxins. Two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin (STX) and decarbamoyl-saxitoxin (dc-STX) in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the second part of the project: the certification exercise. In the first study, 18 laboratories were asked to measure STX and dc-STX in rehydrated lyophilized mussel material and to identify as many other PSP toxins as possible with a method of their choice. In the second interlaboratory study, 15 laboratories were additionally asked to determine quantitatively STX and dc-STX in rehydrated lyophilized mussel and in a saxitoxin-enriched mussel material. The first study revealed that three out of four postcolumn derivatization methods and one pre-column derivatization method sufficed in principle to determine STX and dc-STX. Most participants (13 of 18) obtained acceptable calibration curves and recoveries. Saxitoxin was hardly detected in the rehydrated lyophilized mussels and results obtained for dc-STX yielded a CV of 58% at a mass fraction of 1.86 mg/kg. Most participants (14 out of 18) identified gonyautoxin-5 (GTX-5) in a hydrolysed extract provided. The first study led to provisional criteria for linearity, recovery and separation. The second study revealed that 6 out of 15 laboratories were able to meet these criteria. Results obtained for dc-STX yielded a CV of 19% at a mass fraction of 3.49mg/kg. Results obtained for STX in the saxitoxin-enriched material yielded a CV of 19% at a mass fraction of 0.34mg/kg. Saxitoxin could not be detected in the PSP-positive material. Hydrolysis was useful to confirm the identity of GTX5 and provided indicative information about C1 and C2 toxins in the PSP-positive material. The methods used in the second interlaboratory study showed sufficiently consistent analysis results to undertake a certification exercise to assign certified values for STX and dc-STX in lyophilized mussel.