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1.
为探求和估算我国主要农作物化肥用量,本文分析了30多年来我国农作物化肥使用现状和不同类型农作物的化肥使用情况。结果发现我国农作物化肥使用量增长迅速,从1980年的1 269.4万t增长到2014年的5 995.9万t,增长了4.7倍,年均增长率为4.67%。谷类作物化肥用量仍然是农作物化肥使用总量的主要贡献者,其化肥用量从1980年2 712.41万t增加到2014年的3 415.35万t,但其所占农作物化肥总用量的比重却下降明显,从60.02%(1998年)降至49.75%(2014年)。蔬菜和水果的化肥用量增长最为迅速,其中蔬菜化肥用量1998年为604.51万t,2014年增加到1 291.36万t,增加了2.1倍,其化肥用量占农作物化肥总用量从1998年的13.38%增加至2014年的18.81%;水果化肥用量1998年为531.55万t,至2014年增加到1 223.42万t,增加了2.4倍,其化肥用量占农作物化肥总用量从1998年的11.76%增长到2014年的17.82%。同时,我国不同区域化肥用量差异较大,从化肥施用总量来看,大体上呈现从东到西的递减趋势,其中华东地区和华中地区用量较高,从单位面积化肥用量来看,呈现从东到西递减趋势,同时从南到北也呈现了递减趋势,用量较高区为华南和华东地区。 相似文献
2.
Flavor release in the presence of melanoidins prepared from L-(+)-ascorbic acid and amino acids 总被引：1，自引：0，他引：1
Obretenov C Demyttenaere J Tehrani KA Adams A Kersiene M De Kimpe N 《Journal of agricultural and food chemistry》2002,50(15):4244-4250
High-molecular-weight (HMW) water-soluble melanoidins were prepared from model systems of L-(+)-ascorbic acid-glycine, L-(+)-ascorbic acid-lysine, L-(+)-ascorbic acid-glutamic acid, and glucose-glycine using a very recently approved standard protocol. The amount of HMW water-soluble melanoidins prepared from L-(+)-ascorbic acid was over 5-15 times higher than the amount obtained from glucose. The study of the release of a model flavor compound, namely isoamyl acetate, from melanoidins by solid-phase microextraction (SPME) showed that SPME is a suitable technique for the analysis of flavor release from melanoidin-containing solutions. From the studies on the retention capacity of the melanoidins toward isoamyl acetate, an increased release of the flavor compound was observed from the melanoidins prepared from the L-(+)-ascorbic acid-glycine model system, whereas the opposite effect was observed from the melanoidins prepared from the L-(+)-ascorbic acid-lysine/glutamic acid model systems. The melanoidins prepared from the glucose-glycine model system had the same effect as the melanoidins prepared from the L-(+)-ascorbic acid-glycine model system. 相似文献
3.
Adams A Bouckaert C Van Lancker F De Meulenaer B De Kimpe N 《Journal of agricultural and food chemistry》2011,59(20):11058-11062
The formation of 2-alkylfurans from the corresponding lipid-derived α,β-unsaturated aldehydes under dry-roasting conditions was investigated in detail. The addition of an amino acid to an α,β-unsaturated aldehyde drastically increased 2-alkylfuran formation. Peptides and proteins as well were able to catalyze 2-alkylfuran formation from the corresponding α,β-unsaturated aldehydes. Further investigation of 2-alkylfuran formation showed the need of oxidizing conditions and the involvement of radicals in the reaction. This way, the formation of 2-methylfuran from 2-pentenal, 2-ethylfuran from 2-hexenal, 2-propylfuran from 2-heptenal, 2-butylfuran from 2-octenal, 2-pentylfuran from 2-nonenal, and 2-hexylfuran from 2-decenal was shown. The impact of amino acids on 2-alkylfuran formation from lipid-derived α,β-unsaturated aldehydes represents an interesting example of the complex role of amino acids in the multitude of chemical reactions occurring during thermal processing of lipid-rich foods. 相似文献
4.
水稻长穗颈不育系主要农艺性状配合力分析 总被引：1，自引：0，他引：1
应用半双列杂交的设计分析了采用直接辐射诱变育成的水稻长穗颈不育系的 1 9个农艺性状的配合力。分析表明 ,含有eui1基因的长穗颈不育系Ⅱ 32eA1的株高、穗颈伸出度、剑叶、倒 2叶、穗长、倒 1节、着粒密度及生育期等 8个性状的一般配合力效应值表现不同于Ⅱ 32A ;而含eui2基因的协青早eA2只有株高、倒 1节、生育期的一般配合力效应值同协青早A差异显著。两个长穗颈不育系的株高、穗颈伸出度、剑叶长、倒 2叶、倒 3叶、穗长、倒 1节、倒 2节、倒 4节、倒 5节、千粒重和结实率等性状的一般配合力效应值都大于原不育系。其余性状一般配合力效应值的变化依两个长穗颈不育系有所不同。结果表明 ,采用核辐射诱变的育种技术路线选育水稻长穗颈不育系是可行有效的。 相似文献
5.
喀斯特山区不同母质(岩)发育的土壤主要理化性质差异性分析 总被引：10，自引：2，他引：8
在贵阳市乌当区采集了白云岩、石灰岩、钙质紫色砂页岩等9种母质(岩)上发育的土壤样品763个,分别进行了土壤主要理化性质的测定和差异性分析。结果表明不同母质(岩)发育的土壤理化性质具有很大的差异:红色粘土、老风化壳和页岩上发育的土壤pH值均为酸性至强酸性,有机质和CEC含量中等,土壤质地较粘重;石灰岩、白云岩和钙质紫色砂页岩上发育的土壤pH值为中性至微碱性,有机质和CEC含量较高,质地较为适中;砂页岩和河流冲积物上发育的土壤pH值为酸性至中性,其余理化性质为中等水平;砂岩发育的土壤pH值为强酸性,其余理化性质均较差。 相似文献
6.
Marfil R Cabrera-Vique C Giménez R Bouzas PR Martínez O Sánchez JA 《Journal of agricultural and food chemistry》2008,56(16):7279-7284
Metal content was determined in 26 samples of virgin argan oil from Morocco. An ETA-AAS with previous sample dilution with MIBK technique was used. In oil obtained by traditional method, Fe ranged from 0.8 to 4.0 mg/kg, Cu from 160.4 to 695.7 microg/kg, Cr from 10.3 to 55.3 microg/kg, Mn from 18.1 to 70.8 microg/kg, and Pb from 28.5 to 450.0 microg/kg. In oil obtained by a half-industrialized method, Fe ranged from 0.8 to 1.7 mg/kg, Cu from 158.4 to 385.0 microg/kg, Cr from 10.0 to 48.1 microg/kg, Mn from 15.0 to 68.5 microg/kg, and Pb from 32.0 to 100.0 microg/kg. Acidity value, peroxide index, K270 and K232, humidity and sludge volatile, and insoluble sludges in petroleum ether were also determined. A high variability in these quality parameters and a decrease of the quality in the oils obtained by the traditional method were observed. 相似文献
7.
川中丘陵区城墙岩群和蓬莱镇组紫色岩上土壤性质研究 总被引：1，自引：0，他引：1
采用野外调查、取样和室内实验分析相结合的方法,研究了川中丘陵区白垩系城墙岩群(K1cg)和侏罗系蓬莱镇组(J3p)两种紫色母岩上土壤理化性质特征和差异,结果表明:两种紫色岩母质发育的土壤粘粒含量低,而砂粒含量高;土壤有机质和氮素含量低,而矿质养分含量丰富;在相同的地形部位上,J3p发育的土壤粘粒、全钾、速效钾和速效磷含量高于K1cg发育的土壤,而K1cg发育的土壤pH和土壤全磷均高于J3p发育的土壤,两种紫色岩母质形成的土壤有机质和氮素差异不明显。从丘顶到丘脚,土层逐渐增厚,土壤粘粒含量逐渐递增,砂粒含量逐渐递减;土壤有机质及各种矿质养分含量均呈递增趋势。 相似文献
8.
Mohammad Arshad Muhammad Ashraf Niala Arif 《Genetic Resources and Crop Evolution》2006,53(8):1589-1596
Sixty-two accessions of Prosopis cineraria, collected from different areas of the Cholistan desert and from the vicinity of Islamia University, Bahawalpur during June,
2002 were evaluated for agro-morphological diversity. Data collected revealed considerable variation for pod length, pod thickness,
number of seeds per pod, pod weight, 100-seed weight, seed size, number of pinnules, length of pinnae, length of the pinnulae,
and breadth of the pinnulae. Accessions GD-1 and GD-2, collected from Gadhen Wala Toba, KWT-1, KWT-3, KWT-4, KWT-6, from Khokhran
Wala Toba, TWT-2, TWT-7, TWT-8, from Taraway Wala Toba, CSW-2, CSW-7, CSW-8, from Chah Sulleh Wala, and IUB-5, IUB-9, from
Islamia University, Bahawalpur, showed very high variation. Overall, accessions KWT-6 from Khokhran Wala Toba, and TWT-7,
from Taraway Wala Toba, (both from Cholistan desert), appeared as best genotypes based on their morphological variation detected
in this study. 相似文献
9.
Fan X 《Journal of agricultural and food chemistry》2003,51(20):5946-5949
A study was conducted to investigate irradiation-induced formation of malondialdehyde (MDA), formaldehyde (FA), and acetaldehyde (ACT) from fructose, sucrose, glucose, and malic acid solutions. MDA and FA were generated from the carbohydrate solutions upon irradiation while little was formed from malic acid solution. On the other hand, a much higher amount of ACT was formed from malic acid than from the carbohydrate solutions. The G values (number of molecules formed per 100 eV radiation) for MDA were 0.042, 0.0066, and 0.0026 from 0.9 mg mL(-1) fructose, sucrose, and glucose solutions at pH 3.5, respectively. The G values for FA formation were 0.134, 0.233, and 0.0081 from the fructose, sucrose, and glucose solutions, respectively. As concentration of sugars in solutions increased from 0 to 90 mg mL(-1), the formation of these compounds increased rapidly. A further increase in sugar concentration from 90 to 900 mg mL(-1) resulted in a lower rate of increase in MDA and FA formation. pH had a profound effect on the irradiation-induced formation of these compounds from carbohydrates, especially on MDA formation. The minimum amount of MDA from fructose and glucose solutions was observed at pH 5 while formation of MDA from sucrose solution decreased as pH decreased from 7 to 2. The results can be used by the food industry to optimize food formulation in order to minimize formation of these compounds. 相似文献
10.
基于修正SCS-CN模型集雨垄径流预测 总被引：1，自引：0，他引：1
为了探寻半干旱区垄沟集雨种植控制水土流失和增产的机理,利用前2年(2012—2013年)日降雨量、实测径流和修正SCS—CN模型,率定集雨垄的径流模型参数CN、λ和α,然后利用后3年(2014—2016年)日降雨量和实测径流资料检验该模型有效性,预测不同覆盖材料(土壤结皮、生物可降解地膜和塑料地膜)和不同垄宽(30,45,60 cm)集雨垄的径流量。结果表明,土壤结皮覆盖集雨垄、生物可降解膜覆盖集雨垄和塑料地膜覆盖集雨垄的CN取值范围分别为82.0~82.9,97.9~98.8,98.3~99.9,λ取值范围分别为0.045~0.071,0.251~0.327,0.189~0.213,α取值范围分别为2.35~2.89,4.21~4.82,3.32~3.99。通过对模型有效性进行评价,土壤结皮覆盖集雨垄、生物可降解膜覆盖集雨垄和塑料地膜覆盖集雨垄的平均相对误差取值范围分别为1.36%~3.41%,1.21%~3.42%,2.48%~5.42%,纳什效率取值范围分别为0.97~0.98,0.97~0.98,0.96~0.98。日降雨量等级对修正SCS—CN模型参数CN、λ和α的影响不明显,不同覆盖材料之间的CN、λ和α差异远大于不同垄宽之间的CN、λ和α差异。修正SCS—CN模型集雨垄径流预测的相对误差满足要求(≤20%),可信度较高(纳什效率≥0.95),可以用于半干旱区集雨垄的径流预测,为控制水土流失和提高降水利用效率提供科学方法。 相似文献
11.
To investigate the contribution of paternal alleles to the DNA content of olive oil, genetic analyses of olive DNA samples from fruits, leaves, and oil derived from the same tree (cv. Leccino) were carried out. DNA extracted from maternal tissues--leaves and flesh--from different fruits showed identical genetic profiles using a set of DNA markers. Additional simple sequence repeat (SSR) alleles, not found in the maternal samples, were amplified in the embryos (stone), and they were also detected in DNA extracted from the paste obtained by crushing whole fruits and from the oil pressed from this material. These results demonstrate that the DNA profile obtained from olive oil is likely to represent a composite profile of the maternal alleles juxtaposed with alleles contributed by various pollen donors. Therefore, care needs to be taken in the interpretation of DNA profiles obtained from DNA extracted from oil for resolving provenance and authenticity issues. 相似文献
12.
13.
通过对洛阳市城区居民区、商业区、工业区、风景区4种功能类型区中的11个采样点中的10～15年生雪松松针（SA）、地面落针（SB）和20～30年生雪松松针（SC）、地面落针（SD）中重金属Pb含量的测定,分析了洛阳市城区大气中Pb污染现状。结果表明：洛阳市城区雪松松针Pb含量平均为1.606mg/kg,属重金属轻度污染;居民区、商业区、工业区、风景区雪松松针Pb含量差异显著,表现为工业区〉居民区〉商业区〉风景区;松针中Pb含量主要受冶炼、工业废气、汽车尾气排放等人为活动因素影响。雪松松针Pb含量分异性可以客观反映城市不同区域内大气Pb污染程度,这为城市环境保护研究提供了新方法,值得推广使用。 相似文献
14.
在硅、镁、硼营养较缺乏的甘蔗田，进行硅肥、镁肥、磷肥的施肥效应试验，结果表明：硅、镁、硼肥及其不同施肥水平对甘蔗的株高、茎径、锤度、产量和产糖量有明显的影响。施用硅肥使甘蔗锤度、产量和理论产糖量分别比对照增加0.42～1．11，11．04～14．96t／hm^2和1．84～2．10t／hm^2；施用镁肥分别比对照增加0.93～1．26，4．02～9．55t／hm^2和0．99～1．53t／hm^2；施用硼肥分别比对照增加0．41～1．20，5．00～10．00t／hm^2和0．80～1．82t／hm^2。 相似文献
15.
R. Ortiz José Crossa Jorge Franco Ricardo Sevilla Juan Burgueño 《Genetic Resources and Crop Evolution》2008,55(1):151-162
The maize of Latin America, with its enormous diversity, has played an important role in the development of modern maize cultivars of the American continent. Peruvian highland maize shows a high degree of variation stemming from its history of cultivation by Andean farmers. Multivariate statistical methods for classifying accessions have become powerful tools for classifying genetic resources conservation and the formation of core subsets. This study has two objectives: (1) to use a numerical classification strategy for classifying eight Peruvian highland races of maize based on six vegetative traits evaluated in two years and (2) to compare this classification with the existing racial classification. The numerical classification maintained the main structure of the eight races, but reclassified parts of the races into new groups (Gi). The new groups are more separated and well defined with a decreasing accession within group × environment interaction. Most of the accessions from G1 are from Cusco Gigante, all of the accessions from G3 (except one) are from Confite Morocho, and all of the accessions from G7 are from Chullpi. Group G2 has four accessions from Huayleño and four accessions from Paro, whereas G4 has four accessions from Huayleño and five accessions from San Geronimo. Group G5 has accessions from four races, and G6 and G8 formed small groups with two and one accession each, respectively. These groups can be used for forming core subsets for the purpose of germplasm enhancement and assembling gene pools for further breeding. 相似文献
16.
Gregory C. Pratt 《Water, air, and soil pollution》1984,23(3):339-348
Air parcel back trajectories were used to quantify the contributions of major source areas to the chemical composition of rainwater in an area of central Minnesota. Air masses arriving from the SW contributed the majority of the rain, and the rain contained the highest concentrations of the chemical components. However, rain from the SW quadrant was less acidic than rain arriving from other quadrants because it contained a disproportionate amount of alkaline cations. It was inferred from meteorological evidence that components in rain arriving at the study site from the SW quadrant may have come from eastern and southern U.S.A. sources and been transported around a high pressure system to Minnesota. Rain from the SE quadrant was the most acidic. Concentrations of substances in rain arriving from the NW were higher than expected, consistent with a possible impact from western coal development. 相似文献
17.
Amino acid composition of soil organic matter 总被引：5，自引：0，他引：5
This study investigated the amino acid composition of soil organic matter extracted from ten surface soils in addition to
surface soils from two long-term cropping systems [continuous corn (CCCC), corn-soybean-corn-soybean (CSCS), and corn-oats-meadow-meadow
(COMM)] at two sites in Iowa: the Clarion-Webster Research Center (CWRC) and the Galva-Primghar Research Center (GPRC). Results
showed that, with the exception of asparagine pluse aspartic acid and glutamine plus glutamic acid, the other 13 amino acids
studied, expressed as perecentages of total amino acids extracted, were generally very uniform among the soils. The total
amino acids extracted from the ten soils were significantly correlated with organic carbon (C) ( and clay content (, but not with total nitrogen (N), pH, or sand content. Expressed as percentages or organic C and N in soils, the amounts
extracted ranged from 10.9% to 32.4% and from 12.0% to 27.4%, respectively. The amino acid N identified, expressed as percentages
of organic N extracted, ranged from 32% to 50% and the C/N ratios of the extracted organic matter ranged from 10.1 to 14.9.
The type of rotation did not significantly affect the total amino acid content of the soils from the same N treatment, but
it did affect the total amino acid content of soils from the control plots. The total amino acids measured under the different
crop rotations at the CWRC site were in the order: COMM>CCCC>CSCS. The order for the GPRC site was: CSCS>COMM>CCCC. The amino
acid N identified, expressed as percentages of organic N extracted from soils at the CWRC site, ranged from 33.1% to 50% and
for the GPRC site ranged from 26.5% to 51.4%. The C/N ratios of the organic matter extracted ranged from 10.4 to 14.1 and
from 6.5 to 14.3 for the soils from CWRC and GPRC sites, respectively.
Received: 26 May 1997 相似文献
18.
Sánchez-Moreno C Satué-Gracia MT Frankel EN 《Journal of agricultural and food chemistry》2000,48(11):5581-5587
Wines contain phenolic compounds that may be useful for preventing lipid oxidation as dietary antioxidants. This study was aimed at evaluating the antioxidant activity in corn oil emulsions of seventeen selected Spanish wines and two California wines. The inhibition of hydroperoxide formation at 10 microM gallic acid equivalents (GAE) varied from 8.4% to 40.2% with the red wines, from 20.9% to 45.8% with the rosé wines, and from 6.5% to 47.0% with the white wines. The inhibition of hydroperoxide formation at 20 microM GAE varied from 11.9% to 34.1% with the red wines, from 0.1% to 34. 5% with the rosé wines, and from 3.3% to 37.2% with the white wines. The inhibition of hexanal formation at 10 microM GAE varied from 23. 6% to 64.4% with the red wines, from 42.7% to 68.5% with the rosé wines, and from 28.4% to 68.8% with the white wines. The inhibition of hexanal formation at 20 microM GAE varied from 33.0% to 46.3% with the red wines, from 11.3% to 66.5% with the rosé wines, and from -16.7% to +21.0% with the white wines. The antioxidant effect decreased with increasing concentration. This antioxidant activity was related to the five main groups of phenolic compounds identified in wines by HPLC. The relative antioxidant activity correlated positively with the total phenol content of wines (by the Folin-Ciocalteu method and by HPLC), benzoic acids, anthocyanins, flavan-3-ols, and flavonols, for the inhibition of hydroperoxides and hexanal at 10 and 20 microM GAE. 相似文献
19.
Deibler KD Lavin EH Linforth RS Taylor AJ Acree TE 《Journal of agricultural and food chemistry》2001,49(3):1388-1393
The volatile content of the effluent from the retronasal aroma simulator (RAS) was compared with that of human breath using mass spectroscopy (MS-Nose). The ratios of volatile compounds from the RAS were closely related to those from the panelists' breath with the correlation coefficients ranging from 0.97 to 0.99 from model food systems. A greater sensitivity using the RAS was achieved because higher concentrations of volatiles in the MS-Nose were produced from the RAS than from the breath. In analyzing the effects on volatility of RAS parameters including airflow rate, temperature, saliva ratio, and blending speed, airflow rate had the greatest effect. The correlation coefficients for the real food systems studied ranged from 0.83 to 0.99. The RAS gives a good approximation of time-averaged flavor release in the mouth as defined by breath-by-breath measurements. 相似文献
20.
中国等高熊虫属缓步动物两个新记录种记述 总被引：2，自引：0，他引：2
本文报道了中国缓步动物门等高熊虫属(Isohypsibius)两个新记录种。它们是马氏等高熊虫I. marcellinoi Binda & Pilato和吴氏等高熊虫I. woodsae Kathman。马氏等高熊虫的模式标本来自意大利的西西里岛,吴氏等高熊虫的模式标本来自加拿大。中国标本与模式标本个体大小接近,但中国标本腿上的角质条在中部有显著的弯曲,表皮上的多角形纹饰也较模式标本的排列致密。 相似文献