D-草铵膦的除草活性研究

采用室内盆栽法,测定了D-草铵膦对麦苗的抑制作用以及对马唐、牛筋草、苘麻、反枝苋的除草活性,比较评价了L-草铵膦和D-草铵膦的除草活性.试验结果发现D-草铵膦具有一定除草活性,尤其对马唐有相对较高的防效.D-草铵膦对马唐、牛筋草、苘麻、反枝苋的除草活性分别为L-草铵膦的0.33、0.09、0.10、0.001倍.     

草铵膦铵盐的高效液相色谱测定

建立了用高效液相色谱分析草铵膦铵盐的方法.使用Nucleosio SB离子交换柱,柱温室温;以0.1 mol/L的磷酸二氢钾水溶液为流动相,流速1.0 mL/min;紫外检测器,检测波长195 nm,外标法对草铵膦铵盐的有效成分进行定量分析.结果表明,草铵膦的线性范围为0.254～2.496 g/L,相关系数为0.99914,13.5%草铵膦水剂的标准偏差为0.152,变异系数为1.137%,草铵膦原药的标准偏差为0.2013,变异系数为0.2113%,平均回收率:13.5%草铵膦水剂为100.5%,95%草铵膦原药为99.5%.此方法可用于原药和制剂的分析检测.     

精草铵膦绿色生物合成技术及应用前景

高效、低毒的灭生性除草剂草铵膦是世界第二大转基因作物耐受除草剂。草铵膦具有L-型和D-型2种对映异构体，但只有L-型具有除草活性。精草铵膦即L-草铵膦，除草活性是DL-草铵膦的2倍，其产业化合成工艺受到广泛关注。通过比较精草铵膦各合成技术的优缺点，生物合成工艺具有显著优势，同时介绍了精草铵膦近年市场概况并分析了其发展趋势。     

草铵膦与其他除草剂互作

选用喹禾灵和2甲4氯分别与草铵膦混用,以稗草和反枝苋为试材,探讨这两种除草剂与草铵膦的联合作用.用剂量添加模型分析,草铵膦与喹禾灵在(53.3～3.3):1范围内混用对稗草有显著的增效作用,草铵膦与喹禾灵最佳配比为9.99:1(有效用量比),增效倍数达0.45;草铵膦与喹禾灵在(26.6～3.3):1范围内对反枝苋表现为增效.草铵膦与2甲4氯以2:1和1:1比例混用时,对稗草表现为增效作用,而以1:2和l:4混用时,对稗草表现为拮抗作用;草铵膦和2甲4氯混用对反枝苋作用表现为加成趋势.     

草铵膦企业扩产涌热潮 产品登记现井喷

<正>"盛况空前"存隐忧随着草甘膦抗性难除杂草增多、百草枯禁用水剂,草铵膦作为比较理想的替代品成为业界关注的热点。不少业内专家认为,除草剂有可能进入草铵膦时代。在潜在市场空间诱惑、利益驱使之下,近年来,草铵膦产业发展空前。专家在看好草铵膦未来市场的同时,为草铵膦产业愈演愈烈的盲目扩张表示担忧。著名农药专家张一宾教授认为,草铵膦与草甘膦就像兄弟俩,草铵膦产业千万不可走草甘膦产业的     

Cu2+、pb2+与2种除草剂单一及复合污染对蚯蚓的急性毒性

[目的]旨在探讨Cu~(2+)、Pb~(2+)与2种除草剂单一及复合污染对蚯蚓的急性毒性。[方法]以赤子爱胜蚓为材料,采用滤纸法测定不同浓度Cu~(2+)、Pb~(2+)与草甘膦、草铵膦单一及复合污染对蚯蚓的急性毒性。[结果]单一污染试验结果显示:Cu~(2+)、Pb~(2+)、草甘膦和草铵膦对蚯蚓急性毒性48 h-LC_(50)分别为1. 287、16. 344、118. 311、238. 713μg/cm~2。Cu~(2+)和Pb~(2+)对蚯蚓的毒性比草甘膦和草铵膦更大,草甘膦和草铵膦对赤子爱胜蚓表现为低毒。复合污染试验结果显示,在低浓度草甘膦、草铵膦胁迫下,草甘膦、草铵膦可以降低Cu~(2+)、Pb~(2+)对蚯蚓的毒性;在高浓度草甘膦、草铵膦胁迫下,添加Cu~(2+)、Pb~(2+)可以降低草甘膦、草铵膦对蚯蚓的毒性。[结论] Cu~(2+)、Pb~(2+)与草甘膦、草铵膦复合后对蚯蚓的毒性降低是由于拮抗作用。     

辽宁省玉米田4种禾本科杂草对草铵膦的敏感性测定

[目的]明确辽宁省不同地区玉米田稗草、马唐、野黍和野稷对草铵膦的敏感性,为转基因抗草铵膦玉米的商业化种植的杂草防除提供依据。[方法]采用整株生物测定法检测4种禾本科杂草对草铵膦的敏感性。[结果]稗草、马唐、野黍和野稷对草铵膦的GR50值范围分别为9.89～96.06、33.45～126.58、9.11～65.86、7.70～85.31 g a.i./hm2;平均GR50值分别为31.79、65.11、33.28、36.91 g a.i./hm2。[结论]辽宁省地区玉米田中稗草、马唐、野黍和野稷种群对草铵膦的敏感性存在差异。     

近年来全球草铵膦的市场及发展趋势

描述了近年全球草铵膦市场;粗析了草铵膦与草甘膦、百草枯的关系;介绍了草铵膦的发展趋势。     

草铵膦:年内产能释放有限,价格先涨后稳,市场春天将至

<正>草铵膦是一种有机磷类广谱灭生性除草剂,具有活性高、吸收好、杀草谱广、低毒、环境友好等特点。近两年,草铵膦逐渐引起人们的重视,媒体一度赞誉草铵膦为除草剂的新贵和未来之星。基于对草铵膦非常火热的市场预期,企业之间进行了火热的登记竞赛,短短2-3年的时间,草铵膦已经发展成为近200个登记证的大产品,我国实属不多见。全球草铵膦市场增量需求是受草甘膦抗性增加的替代、百草枯水剂退出的替代以及耐草铵膦转基因作物积极推广等因素引起的,位于草甘膦、百草枯之后的第三大灭生性除草剂草铵膦获得了巨大发展空间。     

离子色谱法测定草铵膦含量

[目的]建立草铵膦原药和草铵膦水剂的离子色谱定量分析方法.[方法]采用8 mol/L氢氧化钾水溶液为流动相,AS-11离子色谱柱(含AG-11保护柱)以及电导检测器对其有效成分草铵膦进行外标法定量分析.[结果]方法线性相关系数为0.9995(50～250 mg/L),标准偏差均小于0.08,变异系数均小于0.15％,平均回收率为100.26％.[结论]该方法可用于测定草铵膦原药或草铵膦水剂中的有效成分,具有精密、准确、简便易行的特点.     

松香基表面活性剂研究进展

松香是一类产量丰富、价格低廉的可再生林产资源,被广泛地应用于食品、农业、橡胶、油墨、涂料等领域。松香的三环二萜结构具有超强的疏水性,通过催化异构、Diels-Alder加成等手段引入亲水基团可制备高附加值、易生物降解的绿色表面活性剂。本文从阴离子、阳离子、非离子和两性离子表面活性剂4个大类对松香基表面活性剂应用的文献及专利进行综述,重点分析了羧酸盐、磺酸盐、硫酸盐和磷酸盐4种阴离子型表面活性剂和季铵盐阳离子型表面活性剂,多元醇型和聚氧乙烯型非离子表面活性剂,以及甜菜碱型和氧化胺型两性离子表面活性剂。剖析松香基表面活性剂产业化开发的新技术及新产品概况,提出松香基表面活性剂替代传统表面活性剂的潜在应用领域。同时,对松香基表面活性剂的研究发展与产业化发展进行了评价与展望。     

生物质热解制生物油及其提质研究现状

生物质能源作为可再生能源的重要组成部分,其综合高效利用在能源替代与补充、保护生态环境等方面具有重要的战略意义。生物油是生物质通过热裂解技术获得的液体产物,具有能量密度较高、环境友好、可再生及可直接输送等优点,可替代传统化石燃料推广使用,解决日益严重的能源紧缺与环境污染等问题。生物质热解制油技术的开发与利用,已成为新世纪可持续能源研究领域的重要课题之一。总结了近年来生物质热解制油技术的主要研究进展,重点关注热解反应器、催化热解技术与生物油的提质利用方面的研究,介绍了碱金属、氧化物和分子筛3种生物质热解催化剂,以及乳化、催化加氢、催化裂解、催化酯化和重整制氢5种生物质提质方法,最后对生物质热解技术的现状及发展趋势进行了总结和概括。     

木质纤维生物质半纤维素分子模拟应用研究进展

木质纤维生物质资源是重要的可再生生物质资源,主要包含纤维素、半纤维素和木质素。半纤维素含量仅次于纤维素,是一种丰富、可再生的植物资源,其可水解制备重要化学品以及改性制备多功能材料。本文综述了生物质半纤维素分子模拟应用研究进展,从半纤维素大分子形态及其与纤维素结合方式的分子模拟研究和半纤维素制备化学品及材料的分子模拟研究2个方面进行阐述,从模拟结果可以看出半纤维素在细胞壁中与纤维素和木质素的相互作用及其本身的大分子形态对木质纤维生物质三大素的提取利用具有显著影响。分子模拟有利于理解过程机理,对反应效率的提高具有重要理论指导意义。最后对分子模拟在半纤维素研究的发展应用进行了展望,指出目前半纤维素分子模拟的空白领域,主要包括半纤维素液化生产生物油、木糖异构化生产木酮糖、半纤维素与木质素之间的结合方式以及其他的半纤维素基材料等,这些有待进一步的探索与研究。     

Melatonin and Microglia

Melatonin interacts in multiple ways with microglia, both directly and, via routes of crosstalk with astrocytes and neurons, indirectly. These effects of melatonin are of relevance in terms of antioxidative protection, not only concerning free-radical detoxification, but also in prevention of processes that cause, promote, or propagate oxidative stress and neurodegeneration, such as overexcitation, toxicological insults, viral and bacterial infections, and sterile inflammation of different grades. The immunological interplay in the CNS, with microglia playing a central role, is of high complexity and includes signaling toward endothelial cells and other leukocytes by cytokines, chemokines, nitric oxide, and eikosanoids. Melatonin interferes with these processes in multiple signaling routes and steps. In addition to canonical signal transduction by MT₁ and MT₂ melatonin receptors, secondary and tertiary signaling is of relevance and has to be considered, e.g., via the upregulation of sirtuins and the modulation of pro- and anti-inflammatory microRNAs. Many details concerning the modulation of macrophage functionality by melatonin are obviously also applicable to microglial cells. Of particular interest is the polarization toward M2 subtypes instead of M1, i.e., in favor of being anti-inflammatory at the expense of proinflammatory activities, which is well-documented in macrophages but also applies to microglia.     

Trace element affinities in two high-Ge coals from China

The Lincang (Yunnan Province, Southwest China) and Wulantuga (Inner Mongolia, Northeast China) coal deposits are known because of the high-Ge content. These coals have also a high concentration of a number of other elements. To determine the mode of occurrence of the enriched elements in both coals, six density fractions from <1.43 to >2.8 g/cm³ were obtained from two representative samples using heavy-liquids. A number of peculiar geochemical patterns characterize these high-Ge coals. Thus, the results of the chemical analysis of these density fractions showed that both coals (very distant and of a different geological age) are highly enriched (compared with the usual worldwide coal concentration ranges) in Ge, As, Sb, W, Be, and Tl. This may be due to similar geochemistry of hydrothermal fluids influencing the Earth Crust in these regions of China. Moreover, Wulantuga coal (Early Cretaceous subbituminous coal) is also enriched in Ca, Mg, and Na, and Lincang coal (Neogene subbituminous coal) in K, Rb, Nb, Mo, Sn, Cs, and U. A group of elements consisting of Ge, W, B, Nb, and Sb mostly occur with an organic affinity in both coals. Additionally, Be, U, and Mo (and partially Mn and Zn) in Lincang, and Na and Mg in Wulantuga occur also with a major organic affinity. Both coals have sulfide-arsenide mineral assemblages (Fe, S, As, Sn, and Pb, and in addition to Tl, Ta, and Cs in the Lincang coal). The occurrence of Al, P, Li, Sc, Ti, V, Cr, and Zr in both coals, and Ba in Lincang, are associated with the mineral assemblage of silico-aluminates and minor heavy minerals. Furthermore, P, Na, Li, Sc, Ti, Ga, Rb, Zr, Cr, Ba, Th, and LREE (La, Ce, Pr, Nd, and Gd) in Lincang are associated with mineral assemblages of phosphates and minor heavy minerals. The two later mineral assemblages are derived from the occurrence of detrital minerals. Finally, the two coal samples have also the sulfate mineral assemblage (Ca and Sr) that probably occur as a consequence of a diagenetic oxidation and alteration of the coal seams. The enrichment of Ge in coal occurred when the organic matter was still reactive to trap Ge, but several features indicate that the enrichment was diagenetic.     

废加氢催化剂的回收现状与研究进展

废加氢催化剂因含难降解有机物和Mo、W、Ni、Co、V等战略金属,是危险废弃物和重要的二次资源,资源化利用具有显著的经济、社会和环境效益。本文介绍了加氢催化剂概况,综述了废加氢催化剂的回收现状,包括酸浸出、碱浸出、焙烧-浸出、火法富集。文章指出,回收前需采用溶剂洗涤法、机械法或焙烧法进行有机物脱除。酸法浸出酸浓度较高,对设备腐蚀性大;碱法浸出对Ni和Co的回收率低,采用碱法、酸法两步浸出可实现多金属高效回收;但湿法回收存在废水量大、污染严重等问题。焙烧-浸出是目前主流回收方法,已产业化应用,但存在回收流程长、后续浸出废水量大等问题。针对现有技术废水量大、污染严重等问题,本文提出了碳热还原富集回收有价金属、尾渣用于绿色建材的方法。     

我国橡胶防老剂和促进剂的进出口情况

介绍近年来我国橡胶防老剂和促进剂进出口情况。2013年,我国防老剂和促进剂进口量分别为19046.61 t和14984.44 t,同比分别增长16.12%和11.64%;进口金额分别为6202.02万美元和7391.97万美元,同比分别增长14.76%和1.39%;出口量分别为29070.40 t和89942.59 t,同比分别增长62.68%和45.72%;出口金额分别为6794.43万美元和27885.34万美元,同比分别增长60.45%和50.17%。我国进口防老剂主要来自中国大陆(以国货复进口形式进口)、美国、韩国以及中国台湾省等,进口促进剂主要来自中国台湾省、美国、韩国、日本以及德国等,防老剂主要出口日本、泰国、印度尼西亚和韩国等,促进剂主要出口美国、韩国、巴西、泰国和日本等。     

Selected Quality Attributes of Dried Foods

Major quality parameters associated with dried food products are the color, visual appeal, shape of product, flavor, microbial load, retention of nutrients, porosity bulk density, texture, rehydration properties, water activity and chemical stability, preservatives, and freedom from pests, insects and other contaminants, as well as freedom from taints and off-odors. These parameters need to comply with the specifications of customers and regulations of different importing countries and often can adversely affect the acceptability of dried products. Therefore, quality of dried food products depends on many factors, such as raw materials, processing environment, packaging, microbial stability, use of additives, and temperature of storage. This review highlights selected quality attributes of dried food products and discusses ways of optimizing them.     

Soil nutrient depletion by agricultural production in Southern Mali

The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.