共查询到20条相似文献，搜索用时 78 毫秒
1.
近年来,广东省主要农产品消费需求呈现新特征,主要农产品消费量走势各异,水稻与蔬菜的消费量平稳波动,食用油、肉类、水果和水产品消费总量均呈现不同程度的增长趋势。从消费结构角度看,城乡农产品消费结构存在较大差异,比如稻米、蔬菜城镇人均消费趋稳,农村居民消费开始下降。消费结构的转变导致了广东省主要农产品进出口情况转变,目前广东主要农产品进出口呈逆差状态,大部分小麦等粮食需从外省调入。采用GM(1,1)模型对广东主要农产品消费做出需求预测,发现未来10年的稻谷、蔬菜、食油、肉类、水果和水产品的消费需求均呈现平缓增加的趋势,并根据上述预测结果做出相应的政策建议。 相似文献
2.
3.
分析全球天然橡胶的生产、进出口贸易、消费和库存情况，对未来天然橡胶产量、消费量和价格进行估计；并预测和展望今后全球天然橡胶的供求情况。 相似文献
4.
最近几年(1979～1983年)世界棉花的生产和消费,进出口贸易变化不大;在纺织原料价格增长不大的情况下,国家棉花市场贸易处于稳定,棉花消费量只稍微有些增长。许多国家棉花播种面积缩减,棉花价格提高,是由于世界棉花生产国家能源紧张和原料危机引起的。世界棉花生产水平,以1981/82年度为最高,皮棉总产量比1980/81年度增加13％,棉花播种面积只增加1％,主要是棉花单位面积产量提高。从表1资料可见,美国这几年皮棉产量由242.8万吨,增加到340.6万 相似文献
5.
6.
英国是西方世界茶叶贸易与消费的典型代表。本文引用近40年来英国茶叶进口、转口和消费数据,阐述英国茶叶进出口贸易和国内市场流通现状、变化趋势。百余年来茶叶进口来源的二次大转移。伦敦茶叶拍卖市场的衰退,被产地市场取代的原因。英式传统饮茶文化及近年受到的冲击。以及三百年来中英茶叶贸易的变迁,和复兴贸易须改进的方向。 相似文献
7.
8.
世界花生的贸易格局分析 总被引：4，自引：1，他引：3
世界花生的生产和出口比较集中,中国、美国、阿根廷和印度既是主产国也是主要的花生出口国。各个主要花生出口国的花生出口价格差异较大。中国是世界花生的最大出口国,研究世界花生的进出口贸易格局,有利于了解我国花生出口面临的国际市场环境。 相似文献
9.
欧洲是世界上主要的茶叶消费区域之一,目前大多数欧洲市场仍以消费红茶为主。随着人们对健康的重视,欧洲茶叶市场呈现一些新的趋势,终端消费市场上,欧洲消费者对饮茶有益健康的意识增强,茶叶消费呈现品质化、多样化和便利化趋势,相应地,对茶叶贸易的可追溯和可持续的需求增加,相关认证日益重要。 相似文献
10.
大麦籽粒的品质是决定其食用价值、饲用价值和酿造产品质量的主要因素。过去,大麦主要用于食用或喂饲牲口。随着啤酒工业的发展,大麦逐步转化为工业原料,对大麦品质提出了新的要求。世界各大麦生产国针对不同用途大麦品种的品质要求,积极开展专用大麦的品质育种研究以及相关理论和方法的研究,取得显著进展,本文从不同用途大麦的品质要求、品质育种、品质遗传和品质分析四个方面概述大麦育种的主要研究进展。 相似文献
11.
12.
《Journal of Crop Improvement》2013,27(2):81-114
Summary The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices. 相似文献
13.
Lakshman Lal 《Potato Research》1987,30(2):329-334
Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong
(1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage,
sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over
45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield
of a subsequent crop. 相似文献
14.
15.
Novel food and non-food uses for sorghum and millets 总被引：4，自引：3，他引：4
Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity. 相似文献
16.
M. I. Siri P. Villanueva M. J. Pianzzola L. Franco Fraguas G. Galván M. Acosta F. Ferreira 《Potato Research》2004,47(3-4):127-138
Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results
for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin
presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear
relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins
and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds. 相似文献
17.
Alejandro Carlos Tozzini María Fernanda Ceriani María Verónica Saladrigas H. Esteban Hopp 《Potato Research》1991,34(3):317-324
Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets
that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and
slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging
toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta.
Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X1 (also called RXact). 相似文献
18.
Rita Favas Janaína Morone Rosrio Martins Vitor Vasconcelos Graciliana Lopes 《Marine drugs》2022,20(3)
The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O2•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O2•− scavenging, (IC50 = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC25 = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC50 = 863 µg/mL; elastase, IC50 = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O2•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms. 相似文献
19.
Alejandro M. S. Mayer Abimael D. Rodríguez Orazio Taglialatela-Scafati Nobuhiro Fusetani 《Marine drugs》2013,11(7):2510-2573
The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories. 相似文献
20.
Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase). 相似文献