Laboratory simulated dissipation of metsulfuron methyl and chlorimuron ethyl in soils and their residual fate in rice, wheat and soybean at harvest

Two sulfonylurea herbicides, metsulfuron methyl （Ally 20 WP） and chlorimuron ethyl （Classic 25 WP） were evaluated for their dissipation bchaviour in alluvial, coastal saline and laterite soils under laboratory incubated condition at 60% water holding capacity of soils and 30 ℃ temperature was maintained. In field study herbicides were applied twice for the control of grasses, annual and perennials broad leaves weeds and sedges in rice, wheat and soybean to find out the residual fate of both the herbicides on different matrices of respective crops after harvest. Extraction and clean up methodologies for the herbicides were standardized and subsequently analyzed by HPLC. The study revealed that the half-lives of metsulfuron methyl and chlorimuron ethyl ranged from 10.75 to 13.94 d irrespective of soils and doses applied. Field trials with rice, wheat and soybean also revealed that these two herbicides could safely be recommended for application as no residues were detected in the harvest samples.     

4-甲基吡啶杂多酸盐的合成及其酯化催化性能研究

利用1-(3-磺酸基)丙基-4-甲基吡啶与磷钨酸、磷钼酸和硅钨酸反应获得3种不同的4-甲基吡啶类杂多酸盐,考查了其催化合成尼泊金酯的催化性能.实验表明,3种4-甲基吡啶类杂多酸盐都具有反应控制相转移的优点,其中4-甲基吡啶磷钨酸盐的反应控制相转移能力最佳.当反应条件为n(醇):n(酸):n(催化剂)=3:1:0.03,反应时间为8h,反应温度为120℃时,1-(3-磺酸基)丙基-4-甲基吡啶磷钨杂多酸盐催化合成尼泊金乙酯的产率可达到87.7%.     

微波辐射固体超强酸SO42-/TiO2-La3+催化合成苯甲酸乙酯

以自制的固体超强酸SO4^2-／TiO2-La^3 作催化剂，通过微波辐射加热合成了苯甲酸乙酯,结果表明，该方法比用硫酸催化法的酯化率高，酯产率达85％．反应条件：苯甲酸0．1mol，乙醇0．3mol，固体超强酸SO4^2-／TiO2-La^3 0．8g，微波辐射功率200W，间歇辐射时间8min。     

Graft Copolymerization of Ethyl Acrylate onto Hydroxypropyl Methylcellulose Using Potassium Persulfate as Initiator

Cellulose is one of the mostabundantnatural pol-ymers that have received much attention in research tomodify its physical and chemical structures to improveits properties and broaden its applications. A lot ofwork[1—5]has been reported on the modification viagraft copolymerization of vinyl monomers onto cellu-lose, often using different initiator systems. Variousvinyl monomers such as methyl methacrylate[6,7], 4-vinylpyridine[8], acrylonitrile[9,10], and styrene[11]have been used for cellulos…     

硫酸氢钠催化合成乙酸乙酯

在一水硫酸氢钠存在下由乙醇与乙酸酯化合成乙酸乙酯。研究了乙醇、乙酸与硫酸氢钠摩尔比、反应时间对其收率的影响。当乙酸、乙醇和硫酸氢钠的物质的量之比为1：1．65：0．073，回流1h，酯收率达到57．4％。     

2-（1-（（2-胺基苯基）亚胺基）乙基）-5-甲氧基苯酚及其配合物的合成和抑菌活性研究

采用液相合成出2-（1-（（2-胺基苯基）亚胺基）乙基）-5-甲氧基苯酚,通过IR,H1-NMR表征其结构,进一步合成其5种金属配合物（M=Cu^2＋,Mn^2＋,Ni^2＋,Zn^2＋,CO^2＋）,大肠杆菌的生物活性实验表明：配体与锰形成的配合物对大肠杆菌的抑菌活性比配体强．     

硫酸铁铵催化合成氯乙酸乙酯

报道了十二水合硫酸铁铵在氯乙酸与乙醇酯化中的应用 ,讨论了其催化合成氯乙酸乙酯的条件 .研究结果表明 ,其催化活性良好 .     

头孢他啶侧链酸乙酯合成工艺研究

以去甲氨噻肟酸乙酯为原料,在碱性条件下与α-澳代异丁酸叔丁酯合成了头孢他啶侧链酸乙酯,分析了不同溶剂、碱的用量对反应收率的影响．较佳的反应条件为：溶剂DMF350mL,摩尔比为去甲氨噻肟酸乙酯：α-澳代异丁酸叔丁酯：无水碳酸钾=1：1．2：2,反应温度45℃,反应时间24h．在此条件下,反应收率达89．6％．     

甲基纤维素、羧甲基纤维素钠和羟乙基纤维素溶液粘度的实验研究

:研究了甲基纤维素、羧甲基纤维素纳和羟乙基纤维素等三种典型纤维素溶液的粘度受基浓度、温度和无机盐影响的规律 ,讨论了它们作为增稠剂使用时各自的特点性     

甲乙酮生产可行性分析

本文对甲乙酮的市场、技术及发展前景等方面进行了较为全面的分析，认为甲乙酮在我国是有市场的，从我国甲乙酮生产和消费的现状来看建设该项目也是可行的。