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1.
草甘膦合成工艺现状及展望   总被引:1,自引:0,他引:1  
对除草剂草甘膦合成的主要工艺亚氨基二乙酸法(IDA法)和甘氨酸法作简要介绍和评述。在分析草甘膦合成工艺的基础上,对草甘膦环境友好的合成工艺进行了展望。  相似文献   

2.
<正>草甘膦是中国农药生产领域一个标志性产品,2013年农药行业在化工行业整体低迷的情况下仍然保持较快速度的增长,草甘膦起到了指标性的引领作用。但是草甘膦在2013年也经历了大起大落,价格从高处跌落,市场进入低迷期。人们对草甘膦后市多因素交织的不确定性感到迷茫,草甘膦2014年价格走势已成为业内关注的焦点。草甘膦原药的价格趋势有可能影响整个行业未来的发展前景,所以在人们对草甘膦行情热切期待的同时,有必要对2014年草甘膦市场作冷静的分析。一、2013年草甘膦价格呈现"过山车"行情2013年草甘膦行情轨迹与2008年的暴涨暴跌  相似文献   

3.
我国草甘膦生产工艺及其技术进步   总被引:30,自引:10,他引:20  
雷崧僧  陈学军 《农药》1999,38(4):6-9
对我国二十年来草甘膦生产发展概况,以及目前存在的几种不同草甘膦生产工艺作了简要评述,重点介绍了甘氨酸-亚磷酸二甲酯生产工艺的生产技术改进。  相似文献   

4.
国内草甘膦生产工艺述评   总被引:6,自引:5,他引:1  
胡跃华 《农药》1996,35(8):33-35
对国内三种生产草甘膦方法作了简明述评,烷基酯法在目前仍是生命力的生产工艺,IDA法是值得发展的,具有竞争力的生产工艺,并对国内的草甘膦剂型提出了建议。  相似文献   

5.
由于草甘膦本身在水中的溶解度很低,因此在实际应用中通常将草甘膦酸配制成水溶性的盐类。其中草甘膦异丙胺盐、草甘膦铵盐、草甘膦钾盐和草甘膦钠盐是日前使用最广泛的草甘膦盐,且商品主要以草甘瞵异丙胺盐水剂和草甘膦钠盐水剂为主。由于水剂包含大量溶剂水从而带来包装、运输以及储存等多方面的不便。随着市场的需要,需要开发高含量的草甘膦固体制剂。以下就浙江新安化工集团股份有限公司开发草甘膦钾盐原药的工艺作一介绍。  相似文献   

6.
亚硝化滴定法分析草甘膦   总被引:1,自引:0,他引:1  
目前国内用各种工艺路线生产草甘膦的产品分析,采用紫外分光光度法,茚满三酮显色比色法及络合滴定法等。生产中需要快速准确、容易拿握的方法。因此对用亚硝酸钠直接滴定分析草甘膦的方法进行了研究。在试验中以经二次重结晶得到的草甘膦做为纯品(98.75%)找出分析条件,并与紫外分光光度法分析结果作了比较。利用此方法还可测定各种草甘膦制剂,如10%草甘膦铵盐水剂、41%草甘膦异丙胺盐水剂、30%可溶性粉剂等。不受其中的添加剂的干扰,也不受产品本身颜色的干扰。  相似文献   

7.
抗草甘膦作物的现状和未来   总被引:2,自引:0,他引:2  
抗草甘膦作物自1996年起在美国和南美得到迅速发展。至2006年种植抗草甘膦大豆达5420万hm^2,已占世界大豆种植面积的64%。种植抗草甘膦玉米达1320万hm^2,占世界玉米种植面积的61%。种植抗草甘膦棉花达510万hm^2、种植抗草甘膦油菜达230万hm^2、种植抗草甘膦苜蓿也有10万hm^2。就抗草甘膦作物现状和未来,尤其是第二代抗草甘膦作物作一简述。  相似文献   

8.
叶萱 《世界农药》2014,(3):12-15
随着抗草甘膦转基因作物种植面积的不断扩大,草甘膦已成为全球第一大农药品种。草甘膦不但具有优异的除草活性,还有一定的抗菌活性。介绍了草甘膦对5-烯醇丙酮莽草酸-3-磷酸合酶有抑制作用,对与作物抗病性有关的微营养的影响,对病原菌侵染量的影响;进而介绍了草甘膦对非抗草甘膦植物和抗草甘膦作物抗病性的影响以及抗草甘膦性状对抗草甘膦作物抗病性的影响。  相似文献   

9.
<正>草甘膦是美国孟山都公司开发的非选择、灭生性除草剂,对多年生根杂草非常有效,广泛用于橡胶、桑、茶、果园及甘蔗地等。草甘膦合成过程中,容易产生杂质甲基草甘膦。我们合成了甲基草甘膦,然后参考草甘膦液相国标检测方法对草甘膦原粉和草甘膦母液中的甲基草甘膦进行了相应的分析研究,研究结果可用于草甘膦原料药的质量控制,也可指导相关技术员进行工艺改进。  相似文献   

10.
作为国内外销量最大的草甘膦异丙胺盐中的一种,450 g/L草甘膦异丙胺盐水剂在澳洲占据了很大一部分市场份额,为了解决该产品质量稳定性差的难题,决定开发该新产品的生产工艺技术,本试验主要从草甘膦原药、色浆筛选及产品pH的控制方面展开研究。最后确定最佳生产工艺条件为:使用Na+含量2000 mg/kg以内的草甘膦原药,Colanyl Blue A2R蓝色色浆,制剂pH控制在4.6~4.8。此外,用新产品进行柑橘园杂草防除试验,与市售450 g/L草甘膦异丙胺盐水剂作对比,结果表明新产品对柑橘生长安全,对杂草的防效与市售样品无显著差异。  相似文献   

11.
2004~2005年国外塑料工业进展   总被引:1,自引:0,他引:1  
收集了2004年7月-2005年6月国外塑料工业的相关资料,介绍了2004年~2005年国外塑料工业的发展情况。提供了世界几大区域塑料的产量、增长率及所占份额;美国、德国、日本、韩国、法国、比利时、印度、西班牙、中国台湾、加拿大、巴西、英国等国家和地区的不同树脂的产量及消费量;各国、各地区塑料原料的产量、进出口量、国内消费量和人均消费量;日本塑料原料的生产情况。按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、通用热固性树脂(酚醛、聚氨酯、不饱和树脂、环氧树脂)、特种工程塑料(聚苯硫醚、液晶聚合物、聚醚醚酮、聚砜)的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。  相似文献   

12.
沥青质引发的蜡油体系结蜡层分层现象及分层规律   总被引:1,自引:1,他引:0       下载免费PDF全文
李传宪  蔡金洋  程梁  杨飞  张皓若  张莹 《化工学报》2016,67(6):2426-2432
利用自主研发的Couette结蜡装置,对蜡含量相同的油样1(不含沥青质)和油样2[含0.75%(质量分数)沥青质]进行结蜡实验,并研究其结蜡层的分层现象和分层规律。通过对油样1和油样2结蜡表层和底层的宏观形貌、DSC放热、析蜡量、蜡晶微观形貌的分析发现:油样1结蜡层无明显分层现象,而油样2结蜡层分层现象明显,沥青质的加入导致了结蜡层的分层。与结蜡表层相比,油样2结蜡底层的析蜡点、蜡含量与沥青质含量显著升高,蜡晶形貌发展为致密的类球状大蜡晶。油样2结蜡表层沉积量随壁温的升高、油壁温差和转速的增大而减小;结蜡底层沉积量随壁温升高而减小,随油壁温差和转速的增大而增大;总的蜡沉积量随壁温的升高和转速的增大而减小,随油壁温差的增大先增大后减小。  相似文献   

13.
Protein solubility is based on the compatibility of the specific protein surface with the polar aquatic environment. The exposure of polar residues to the protein surface promotes the protein’s solubility in the polar environment. The aquatic environment also influences the folding process by favoring the centralization of hydrophobic residues with the simultaneous exposure to polar residues. The degree of compatibility of the residue distribution, with the model of the concentration of hydrophobic residues in the center of the molecule, with the simultaneous exposure of polar residues is determined by the sequence of amino acids in the chain. The fuzzy oil drop model enables the quantification of the degree of compatibility of the hydrophobicity distribution observed in the protein to a form fully consistent with the Gaussian 3D function, which expresses an idealized distribution that meets the preferences of the polar water environment. The varied degrees of compatibility of the distribution observed with the idealized one allow the prediction of preferences to interactions with molecules of different polarity, including water molecules in particular. This paper analyzes a set of proteins with different levels of hydrophobicity distribution in the context of the solubility of a given protein and the possibility of complex formation.  相似文献   

14.
姚翰林  辛忠 《化工学报》2022,73(8):3518-3528
以碳酸钙水相合成为模型反应,借助对流动反应过程的放大观测,从沉淀悬浮液的流变特性分析了液相沉淀反应在毫米级管式微通道中的流动行为特征以及通道堵塞的过程机理。结果表明,碳酸钙-水悬浮体系的黏度在低剪切速率下随固含率的增加而飙升,而反应通道堵塞的本质可归因于在壁面和流动主体区形成了固含率较高的局部高黏区,使流动性严重恶化。提高反应的流速加快了壁面沉积层和沉淀颗粒团聚体的形成,反而加快了堵塞;其中团聚体的形成远快于沉积层的积累,使团聚体的“架桥”虽晚于沉积层出现,却成为管路堵塞的主要因素。基于破坏流动壁面和主体的局部高黏区,设计了两种新型的微通道反应器模型,有可能为解决反应通道堵塞这一难题提供新的思路。  相似文献   

15.
ACR对PVC加工性能的影响   总被引:1,自引:0,他引:1  
详细研究了丙烯酸酯类PVC加工助剂———ACR的特性黏度、组成对PVC共混物加工性能的影响。结果表明,随着甲基丙烯酸甲酯用量的下降和丙烯酸丁酯用量的提高,其塑化速度增大,但熔体强度降低,在组成相同的情况下,特性黏度越大,塑化越慢,熔体强度越大;丙烯酸酯类加工助剂对PVC制品的拉伸强度和维卡软化点无明显影响,高黏度的加工助剂有提高PVC制品拉伸强度和维卡软化点的趋势。  相似文献   

16.
Processing of concentrated lignocellulosic biomass suspensions typically involves the conversion of the cellulose into sugars and sugars into ethanol. Biomass is usually pretreated via methods like comminution or steam explosion to form fine cellulosic fibers to be dispersed into an aqueous phase for further treatment. The resulting cellulose suspensions need to be pressurized and pumped into and out of various processing vessels without allowing the development of flow instabilities that are typically associated with “demixing”, that is, the segregation of the cellulosic biomass from the aqueous phase via the formation of mats of cellulosic fibers and the filtration of the aqueous phase. Such demixing can prevent continuous processing at high rates. Here, the development of flow instabilities via the demixing effect for cellulose suspensions is demonstrated using capillary and compressive squeeze flows. It is shown that the use of a gelation agent, hydroxypropyl guar gum, at the critical concentration of 0.5 wt% or higher significantly affects the viscoelastic material functions of cellulosic suspensions, improves the dispersive mixing of the fibers within the aqueous phase, and results in the elimination of the flow instabilities and associated demixing effects that are ubiquitously observed during the pressurization and processing of cellulosic suspensions.  相似文献   

17.
One of the fundamental questions discussed in the course of the development towards Industry 4.0 is that of responsibility for machines. The inner-juridical discussion of this issue suffers from the unclear concept of artificial intelligence and the fascination about the creation of very high technical performance while lightning-fast access to a huge amount of information or the determination of previously undiscovered correlations between individual phenomena is no indication of the appearance of the superhuman. Technicians, on the other hand, are confused about the differentiations by which lawyers approach the question of responsibility. This article aims at bridging the gap in order to strengthen the interdisciplinary dialogue.  相似文献   

18.
Molecular mechanics modelling is used to calculate the energies of interaction, hence the molecular level energy of adhesion at the interface with crystalline cellulose I of three different photopolymerizable primers and of a polyester varnish at the interface with the primer/cellulose assembly. The energy of interactions for just one of the primers with the statistically most common conformation of amorphous cellulose has also been obtained for comparison. Experimental results of adhesion by a standard peel test and by thermomechanical analysis, in which the effect of viscoelastic energy dissipation by crack tip propagation has been respectively minimized or is not present, hence in which the energy of interfacial interaction is nothing else but the work of adhesion, correlated well with the energies of interaction calculated by molecular mechanics. An equation correlating the energy of interaction at each finish/cellulose interface with the deflection derived by thermomechanical analysis, and with the number of internal bond rotational degrees of freedom as well as the degree of networking of the finish, has been derived and is presented. A relationship between the intrinsic fracture energy Go and the molecular mechanics-derived energy of interaction at the interface equating this to the square of the work of adhesion is obtained and is presented.  相似文献   

19.
The rate of hydrolysis of the abundant foliar protein, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBPC), in enzymatically active gut fluid ofManduca sexta larvae is very rapid and is unaffected by the presence of tannic acid, even when tannic acid is present in the incubation mixture in amounts in excess of the amount of RuBPC. When this protein is dissolved in the denatured gut fluids ofM. sexta larvae orSchistocerca gregaria nymphs, large amounts of tannic acid must be added to bring about the precipitation of significant quantities of protein. The ability of insect gut fluid to prevent the formation of insoluble tannin-protein complexes is due to the presence of surfactants. On the basis of our results and a review of the findings of other investigators, we argue that there is no evidence that tannins reduce the nutritional value of an insect's food by inhibiting digestive enzymes or by reducing the digestibility of ingested proteins and, further, that the failure of tannins to interfere with digestion is readily explained on the basis of well-documented characteristics of the digestive systems of herbivorous insects. In challenging the currently popular notion that tannins are digestibility-reducing substances, we do not challenge the general utility of either the apparency theory or resource availability theory of plant defense. In debating the merits of these two analyses of plant-herbivore interactions, however, the demise of tannins as all-purpose, dose-dependent, digestibility-reducing defensive substances must be taken into account.  相似文献   

20.
牟新竹  陈振乾 《化工学报》2020,71(z2):241-252
由于在超声波声场中污泥微粒会发生分层现象,声互作用力使得微粒于超声传播方向相垂直的平面上发生凝聚,因此污泥厚度大小对超声波辅助热风干燥污泥特性有着重要的影响。通过实验的方法,对不同厚度污泥在超声波声场中的分层凝聚现象进行观察,发现污泥内部结构的分层现象随其厚度的增加而明显。研究了超声波对不同厚度污泥干燥过程中各时期干燥时长、干燥速率的影响效果,以及分析了湿分有效扩散系数(Deff)随污泥厚度变化的情况。从实验结果中可以发现,在超声波功率小于135 W范围内,污泥厚度越大,干燥过程中第一降速期时间越长,干燥速率提升效果越差,而对恒速干燥期内干燥速率提升效果更明显;在5、10以及15 mm厚度的污泥中,10 mm厚度的污泥在超声波功率小于90 W的条件下总干燥时长降低幅度最大,干燥速率在各阶段提速也较快;污泥厚度越小,超声波功率对污泥湿分有效扩散系数影响越小,反之影响越大。  相似文献   

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