首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
大理州植烟土壤有效锌分布特征及其影响因素分析   总被引:2,自引:0,他引:2  
为明确大理州植烟土壤有效锌的分布特征、合理调控土壤锌平衡,采集并分析了1 131个土壤样品。结果表明:1大理州植烟土壤有效锌含量平均为3.11 mg/kg,变幅为0.07~72.92 mg/kg,变异系数146.95%,只有少部分烟区土壤缺锌,具体分布在云龙、永平、漾濞、祥云、巍山和宾川6个县;2不同类型植烟土壤有效锌含量依次为紫色土水稻土红壤新积土黄壤;3不同海拔高度植烟土壤有效锌分布依次为高海拔(2 100 m)低海拔(1 700 m)中海拔(1 700~2 100 m);4p H在5.0~7.0范围内的土壤有效锌含量较高,比例占总样品数的70.55%;5土壤有效锌含量随土壤有机质含量的增加而提高。  相似文献   

2.
湖南省邵阳烟区土壤有效锌含量时空特征及其影响因素   总被引:4,自引:0,他引:4  
为了解邵阳烟区植烟土壤有效锌含量分布状况,测试了邵阳烟区1790个土壤样品的有效锌含量,采用传统统计学和地统计学方法分析了邵阳烟区植烟土壤有效锌含量丰缺状况、空间分布、演变趋势及p H值、有机质组的影响。结果表明:1邵阳烟区植烟土壤有效锌含量总体上丰富,平均值为3.15 mg/kg,变异系数为73.18%,处于适宜范围内的样本占92.57%。2邵阳县和新宁县植烟土壤有效锌含量极显著高于隆回县。3植烟土壤有效锌含量呈斑块状分布,总体上具有从中部分别向西南部和北部递减的分布趋势。4植烟土壤有效锌含量年度变化呈上升趋势。5植烟土壤有效锌含量有随p H值升高而降低的趋势。6植烟土壤有效锌含量有随有机质提高而增加的趋势。  相似文献   

3.
大理烟区不同类型植烟土壤养分状况分析   总被引:2,自引:0,他引:2  
对大理烟区1111个土壤样品的养分状况进行分析。结果表明,(1)大理烟区主要土壤类型为红壤、水稻土、新积土和紫色土,4种土壤类型p H值介于4.66~8.46之间,不同土壤类型p H值适宜烤烟生长(5.5~7.0)的比例分别为红壤67.22%、新积土63.49%、紫色土61.91%、水稻土57.80%;(2)4种土壤类型有机质含量整体较为丰富,含量高低依次为水稻土(42.55g/kg)红壤(36.04 g/kg)新积土(35.51 g/kg)紫色土(28.76 g/kg);(3)土壤碱解氮、速效磷平均含量均以水稻土最高,紫色土最低;土壤速效钾平均含量以红壤最高,紫色土最低;(4)土壤水溶性氯偏高的土壤(30 mg/kg)所占比例分别为水稻土19.7%、红壤16.8%、紫色土9.09、新积土8.72%;(5)4种土壤类型有效锌含量整体较为丰富,除紫色土有效锌含量低于临界值(0.5mg/kg)的土壤比例达6.06%以外,其余3种土壤类型有效锌含量低于临界值的土壤比例均较低;有效硼含量低于临界值(0.5mg/kg)的比例以红壤最高达51.79%,其余土壤类型在38.87%~43.29%之间;4种土壤类型有效钼含量低于临界值(0.15mg/kg)的比例均较高,分别为紫色土89.18%、新积土77.78%、水稻土68.54%、红壤56.47%。  相似文献   

4.
通过对云南曲靖烟区不同海拔植烟土壤有效硼和对应的烤烟硼含量的分析研究,得出该区土壤和烟叶中硼素分布的基本状况,在此基础上研究了土壤有效硼对烟叶硼含量的影响,并对不同海拔烟区的土壤有效硼含量和烟叶硼含量的分布特点进行了研究。结果表明:(1)曲靖植烟土壤有效硼平均含量基本处于适宜范围,平均为(0.46±0.25)mg/kg,但变幅较大(0.01~3.31 mg/kg);其中37.19%的土壤样本存在不同程度的缺硼(≤0.40 mg/kg)或硼含量偏高(1.0 mg/kg),该地区能够满足优质烟叶正常生长发育所需的土壤有效硼含量土壤占62.81%,其余土壤需对硼素进行适当调整;(2)曲靖烟区烟叶的硼含量平均为(24.06±11.09)mg/kg,变幅为3.22~66.44 mg/kg,有81.42%的烟叶样本硼含量在10.00~40.00 mg/kg范围内;(3)研究表明烟叶的硼含量与土壤有效硼含量间呈极显著正相关关系;(4)在曲靖地区土壤有效硼和烟叶硼含量均表现出随海拔高度降低而逐渐降低的变化趋势,特别是在1300~1500 m的海拔范围内表现得尤为明显。  相似文献   

5.
为揭示邵阳烟区植烟土壤有机质含量时空特征及与其他土壤养分的关系,采用传统统计学、地统计学及分组回归、灰色关联分析方法分析了邵阳烟区植烟土壤有机质含量丰缺状况、空间分布、演变趋势及与土壤养分的定量关系。结果表明:①邵阳烟区植烟土壤有机质含量总体上适宜,平均值为28.19g/kg,变幅为10.20~70.90 g/kg,变异系数为36.51%,处于适宜范围内的样本占42.91%。②邵阳县植烟土壤有机质含量极显著高于隆回县和新宁县。③邵阳烟区植烟土壤有机质含量呈斑块状分布态势,总体上从东部和西部向中部呈现减少的趋势,在新宁县的西部和邵阳县的东部各有一个高值区。④邵阳烟区植烟土壤有机质含量年度演变总体呈上升趋势。⑤土壤碱解氮、有效锌、水溶性氯、有效磷含量随着土壤有机质含量提高而增加,存在显著的正相关。⑥土壤养分与土壤有机质含量的关联度大小依次为:碱解氮有效锌水溶性氯有效磷速效钾交换性镁有效硼。  相似文献   

6.
为了明确重庆烟区土壤速效养分含量的主要影响因子,采用典型相关分析的方法研究了海拔高度、耕层厚度、pH、有机质等对土壤有效养分含量的影响。结果显示,重庆部分烟区土壤酸化严重,速效氮、磷、钾含量丰富,除有效硼、钼和水溶性氯外其他中微量元素含量均为丰富或很丰富。典型相关分析显示,土壤碱解氮、有效铜、有效锌、有效铁、有效硼含量随有机质的增加而增加;土壤速效钾和有效锌含量随海拔升高而增加;土壤pH的降低将导致有效磷、有效铁含量的降低,交换性钙含量的增加;土壤交换性镁等养分含量随耕层厚度的增加而增加。因此,生产上应着重解决土壤酸化、有机质低、耕层浅等问题,并合理布局植烟区域,以提供烟草产质量形成的适宜环境。  相似文献   

7.
遵义烟区土壤有效硅含量评价   总被引:2,自引:0,他引:2  
为了查明遵义烟区土壤有效硅的分布状况,在遵义县和仁怀市共采集87份耕层土壤样品并进行了分析。结果表明,土壤有效硅含量在30.24~444.89 mg/kg之间,平均值为169.75 mg/kg,变异系数为73.27%。如果以100 mg/kg作为烟区土壤有效硅的临界值,则有20.69%的土壤缺硅。不同类型土壤有效硅含量平均值黄壤最高,石灰土次之,水稻土最低。不同母质发育的土壤有效硅含量从高到低依次为页岩>石灰岩>白云岩>泥灰岩>白云质灰岩>第四纪粘土>黄色砂岩。在酸性至中性土壤中,有效硅含量与pH存在极显著正相关关系。  相似文献   

8.
重庆植烟土壤有效态微量元素状况分析   总被引:7,自引:0,他引:7  
为摸清重庆烟区土壤微量元素的分布规律,对该区不同植烟县不同土壤类型的155份土壤样品微量元素含量状况、分布规律及影响因素进行了分析.结果表明:80%~90%的土壤有效锌、有效钼、水溶性氯、有效铁和有效锰的含量较丰富和极其丰富;土壤严重缺硼,75.38%的土壤在不同程度上缺乏有效硼.微量元素含量在不同植烟县和土壤类型上差异均达到极显著水平.不同土壤类型间微量元素综合指数排序为:紫色土(9.92)>山地黄棕壤(7.54)>黑土(5.47)>黄壤(4.86)>石灰性土(3.60).因此,可针对重庆土壤有效硼、钼含量偏低的植烟县和不同土壤类型增施硼、钼肥.针对重庆土壤铁、锰含量过高的现状,生产上可考虑选取偏碱性(pH>7)、有机质含量低的土壤植烟来缓解铁、锰含量过高对烟叶的危害.  相似文献   

9.
粤北始兴烟区植烟土壤养分状况分析   总被引:1,自引:0,他引:1  
为进一步彰显始兴烟叶浓香型风格,明确始兴烟区土壤养分状况,对始兴烟区156个具有代表性的土壤养分含量进行分析,结果表明:始兴烟区土壤pH 4.62~8.33基本适宜烟叶正常生长发育;有机质、水解氮含量偏高,速效磷含量除有15.4%土壤低于10 mg/kg处于极度缺磷外,其余土壤磷含量丰富;速效钾、有效硼含量普遍缺乏,是影响始兴烟区烟叶质量的主要土壤因子;钙、镁、锌含量丰缺不一。不同土壤类型养分状况差异较大,生产上要根据土壤特性进行合理施肥,可加强该区紫色土优质浓香型特色烟叶的开发,但应注意适当增施腐植酸及硼肥;对其他类型土壤养分应进行有效调节,适当控制牛肝土田、黄泥田、麻沙泥田的氮肥和有机肥施用量,增施钾肥;黄泥田、麻沙泥田应适当增施钙镁肥;同时针对始兴烟区普遍缺硼的问题生产中要适当增施硼肥。  相似文献   

10.
湖南郴州烟区土壤养分状况分析   总被引:7,自引:0,他引:7  
对郴州主产烟县(区)734个土壤样品养分进行了分析。结果表明,郴州烟区土壤略偏碱;有机质总体上较丰富,平均为42.30 g/kg,高于湖南省平均值;土壤全氮和碱解氮含量较高;全磷含量平均为0.93 g/kg,速效磷在土壤中的分布极不均衡,适宜范围10~20 mg/kg的土壤样品只占20.84%;土壤全钾及速效钾含量偏低,由南到北,由西到东呈逐渐增加的趋势。烟区土壤普遍缺硼,有91.28%的土壤样品低于缺硼临界值0.30 mg/kg;有效锌含量总体上较高,2~4 mg/kg丰富含量范围内的土壤样品占52.04%;有效锰含量高于20 mg/kg以上的样品占37.53%;有效铜总体上含量丰富,高于1 mg/kg的土壤样品所占比例高达79.57%;有效铁含量平均为87.23 mg/kg,处于极丰富水平。花岗岩发育的红壤含镁量很低,烟株总体上缺镁。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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。  相似文献   

15.
Microbiology of food taints   总被引:2,自引:0,他引:2  
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.  相似文献   

16.
Polymers intended for food contact use have been analysed for organic residues which could be attributed to a range of substances employed as polymerization aids (e.g. initiators and catalysts). A wide range of polymers was extracted with solvents and the extracts analysed by gas chromatography-mass spectrometry (GC-MS). The overwhelming majority of substances identified were not derived from aids to polymerization but were oligomers, additives and adventitious contaminants. However, a small number of substances were identified as initiator residues. These included tetramethylsuccinonitrile (TMSN) which was observed in two polymers and it derived from recombination of two azobisisobutyronitrile (AIBN) initiator radicals. Methyl benzoate, benzoic acid, biphenyl and phenyl benzoate were detected in one poly(methyl methacrylate) sample and in two polyvinylchlorides and they are thought to be derived from benzoyl peroxide initiator. TMSN was subsequently targeted for analysis of poly-(methyl methacrylate) plastics using proton nuclear magnetic resonance spectrometry (1  相似文献   

17.
Experiments were performed to characterize the kinetics of the permeation of different medium molecular weight model permeants: bisphenol A, warfarin and anthracene, from liquid paraffin, through a surrogate potential functional barrier (25 microns-thick orientated polypropylene--OPP) into the food simulants olive oil and 3% (w/v) acetic acid. The characterization of permeation kinetics generally observed the permeation models previously reported to explain the experimental permeation results obtained for a low molecular weight group of model permeants. In general, the model permeants exhibited behaviour consistent with their relative molecular weights with respect to (a) the time taken to attain steady-state permeation into the food simulant in which they were more soluble, (b) their subsequent steady-state permeation rates, and (c) their partition between liquid paraffin and the OPP membrane.  相似文献   

18.
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.  相似文献   

19.
《造纸信息》2014,(8):80-80
On December 27t", 2013, the Ministry of Environmenta Protection announced that, in order to implement "The Environmental Protection Law of the People' s Republic of China", improve the working system in environmenta protection technologies, and promote technologica advancement in pollution prevention, the Ministry of Environmental Protection sponsored the formulation of three guiding technical documents including "Feasible Technology Guidelines for Pollution Prevention and Contro n Wood Pulping Process of the Paper Industry (Trial)"  相似文献   

20.
正On April 29th,2014,Intelli-Tissue EcoEc tissue machine supplied by PMP Group successfully put into operation at Hebei Xuesong Paper Co.,Ltd.,this is the first such kind of paper machine of PMP Group in China.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号