66 research outputs found
Plant Regeneration in vitro of Cuscuta chinensis Lam.
选取萌发3~5d、长度3~5cm的中国菟丝子(Cuscuta chinensis Lam.)幼苗,将其分为上、中、下3部分并作为外植体进行离体培养与植株再生研究。结果表明,其上、中部片段更适宜愈伤组织诱导;诱导培养基以添加1mgL-1NAA和1mgL-1BA的MMS培养基效果最好,此培养基也可用于愈伤组织的继代培养,愈伤组织在上述培养基中已生长一年之久。分化培养基为添加1mgL-1BA的MMS培养基,平均每块愈伤组织可以产生2.8株植株。An efficient method of callus induction and plant regeneration of Cuscuta chinensis was established.The seedlings germinated for 3~5 d and about 3~5 cm length were selected as explants,and then divided into three parts,upper,middle and lower.Callus were inducted from upper or middle parts of seedlings on a modified Murashige and Skoog(MMS)medium supplemented with 1 mg L-1 NAA and 1 mg L-1 BA.The calli have been subcultured on such medium for over a year.Shoot regeneration from callus was achieved on MMS medium containing 1 mg L-1 BA and could obtain 2.8 shoots per callus
Study on dissolution behaviors of chalcopyrite in acid solution
为了探索黄铜矿低温常压湿法氧化(O2)浸出的可行性,研究了黄铜矿在酸性介质中的溶解行为,考察了温度、酸浓度及溶浸时间等对黄铜矿酸浸行为的影响,计算了酸浸过程中铜的浸出率,分析了元素硫的变化行为及残渣微观结构。结果表明,黄铜矿常压湿法氧化(O2)浸出过程的酸浸阶段会产生硫化氢;黄铜矿的溶解能力随温度变化先快后慢,后段接近线性增长,溶解主要发生在前2小时;低温有利于溶解,而最适酸浸pH约-0.4。pH对溶解的影响小于温度的影响。The dissolvability behaviors of chalcopyrite in acid solvent,including the influences of temperature,pH value and the acidic leaching time on the dissolvability behaviors of chalcopyrite,are studied to probe the feasibility of hydro-oxidation leaching at normal pressure and low-temperature.The changing behaviors of elemental sulfur and the microstructure of the residue are also analyzed.The results show that:①sulfureted hydrogen can be produced in the acidic leaching of chalcopyrite's wet oxidation at ordinary pressure and low-temperature;②the dissolvable capacity of chalcopyrite change with time fleetly at first then slowly,which is linear increase at the later part,the dissolution occurs mostly at 2 hours afore;③low temperature is beneficial to the dissolution and the optimum pH value is-0.4.And the influence of temperature is stronger than that of pH
Preparation of potassium diformate by methyl formate and potassium hydroxide
联系人:李清彪. 第一作者:詹国武(1986—),男,学士.[中文文摘]本研究采用甲酸甲酯、氢氧化钾、甲酸为原料,一步反应制备二甲酸钾。系统地考察了影响产品收率的主要因素,优化了工艺条件,结果表明,当n(MF)/n(KOH)=1.20,n(HCOOH)/n(KOH)=1.44,反应时间为30min,反应温度为55℃时,二甲酸钾产品收率可达
98.8%。产品经红外光谱分析及成分测定,符合质量标准。[英文文摘]In this study, methyl formate, potassium hydroxide and formic acid were used as raw materials for one-step synthesis of potassium diformate. The main factors affecting the quality and yield of product were investigated. The optimal conditions for reaction were: molar ratio of MF to
KOH 1.20:1, molar ratio of HCOOH to KOH 1.44:1, reaction time 30 min and reaction
temperature 55℃. The product met the quality standard of potassium diformate after infrared spectrum analysis and composition determination.厦门大学创新性实验计划资助项
黑曲霉负载银纳米颗粒的制备及其抗菌性能
采用非酶还原法,以黑曲霉菌原位还原银氨离子制备一种新型银纳米颗粒(AgNPs)/菌体复合抗菌材料,着重考察了反应温度与pH值对还原过程和所得复合材料的抗菌性能及稳定性的影响。结果表明,在温度为30℃、60℃和pH 9.5、11.5条件下,能够合成出粒径为6.9~8.2nm的近球形AgNPs。该AgNPs均匀地分布在菌体表面上,对E.coli显示出高的抗菌性能:最小抑菌浓度(MIC)为217~434mg·L-1(以菌粉总质量表示)或8~20mg Ag·L-1(以银含量表示)。提高反应温度有利于提高菌体银负载量,但AgNPs粒径增大,抗菌性能有所下降;提高反应pH值有利于提高还原速率,而对抗菌性能影响不显著。复合材料中AgNPs与菌体结合牢固,单位质量复合材料释出的Ag+含量为1.7~6.8mg.g-1,提高反应温度和pH值后Ag+的释出均减少
低龄DDH患儿初次开放复位术中股骨截骨必要性的前瞻性随机对照试验研究方案
回顾性研究发现,股骨截骨术并非低龄DDH患儿手术治疗所必须的,而应根据患儿具体情况合理选择;本研究通过多中心前瞻性研究进一步探讨对于18个月至3岁DDH患儿是否要行股骨截骨术。FSODDH项目为一项多中心前瞻性随机对照临床试验研究。研究设计拟招募200名单侧低龄DDH患儿,随机分成股骨截骨组(n=100)和股骨不截骨组(n=100)。股骨截骨组患儿全部采取髋关节开放复位术、骨盆截骨术及股骨截骨术治疗;股骨不截骨组患儿全部采取髋关节开放复位术及骨盆截骨术治疗;术后定期随访至少2年。收集术前、术后1周、术后1个月、术后3个月、术后6个月、术后1年及术后2年的髋关节正位X线影像资料,比较两组患儿的髋臼指数、股骨头坏死率、再脱位率、术中出血量、手术时间和住院天数等临床指标。这一多中心前瞻性研究将能为低龄DDH患儿是否需行股骨截骨术提供循证医学证据
Species composition and ecological distribution of planktonic diatoms in the Changjiang River estuary during Spring
20 0 2年春季 ,在长江口附近海域典型赤潮高发区 2 8个大面站位采集了 5 3个样品 ,从中共鉴定出隶属于 31个硅藻属的 80个种和变种 ;其中种类多样性较高的属为圆筛藻属 (Coscinodiscus) ,有 17个种 ,斜纹藻属 (Pleurosigma) ,有 8个种和变种 ;数量上较优势的种为柔弱拟菱形藻 (Pseudo nitzschiadeli catissma) ,为 3.4 8× 10 3 cells·L-1,占 2 8.5 4 % ;具槽直链藻 (Melosirasulcata) ,为 1.4 3× 10 3 cells·L-1,占16 .98% ;尖刺拟菱形藻 (Pseudo nitzschiapungens) ,为 0 .71× 10 3 cells·L-1,占 9.85 % .它们在大部分站位中都有出现 ;柔弱拟菱形藻和尖刺拟菱形藻的高细胞密度区主要出现在 12 30E断面的站位 ,而具槽直链藻则主要出现在长江口的 31~ 32°N断面的站位 .浮游硅藻总细胞丰度变化于 0 .4 3× 10 3 ~ 2 3.3× 10 3 cells·L-1,平均 4 .6 1× 10 3 c...
【英文摘要】 water samples were collected from 28 stations in typical regions where redtide frequently occurred in the Changjiang River estuary during Spring, 2002. In total, 80 diatom species and varieties belonging to 31 genera were identified, among which, genera with high species biodiversity included Coscinodiscus which contained 17 species and Pleurosigma which contained 8 species and varieties. Quantitative analysis of diatom cell density showed that Pseudo-nitzschia delicatissma (3.48×10 3cells·L -1, 28.54%...国家重点基础研究发展规划资助项目 ( 2 0 0 1CB40 970 1)
Determination of Trace Metal Elements in Crude Oils by Microwave Digestion-Inductively Coupled Plasma-Mass Spectrometry Assisted with Organic Solvent
李景喜( 1980 - ) ,男,山东临沂市人,研究实习员,从事分析化学研究。E-mail: jxli@fio.org. cn。[中文摘要]建立了二氯甲烷溶剂辅助微波消解-电感耦合等离子体质谱法测定原油中V、Cr、Fe、Ni、Cu、Zn、Mo、Co、Pb等16种微量金属元素。研究表明,用CH2Cl2分散原油样品,以浓HNO3-H2O2为消解体系,采用CEM微波消解系统消解样品,各元素线性关系良好,相关系数≥0.9995;检出限可达ng/L;方法精密度较高,相对标准偏差(RSD,n=3)<5.0%;回收率为92%~110%。以w(Ni)/w(V)与w(Fe)/w(V)比值为变量参数对不同原油样品进行聚类分析,表明国内与国外不同地区原油样品中各金属元素含量差异较大。[英文文摘]A method for determination of V,Cr,Fe,Ni,Cu,Zn,Mo Co,Pb,etc in different crude oils was established by inductively coupled plasma-mass spectrometry assisted with organic solvent microwave digestion.The oil sample was digested by microwave using HNO3-H2O2 as oxidant after dispersing in organic solvent(CH2Cl2).The results showed that the detection limits of the method reached ng/L level for sixteen elements.The linear correlation of the method was preferable with the correlation coefficient of better than 0.9995. The recoveries of the method were in the range of 92% ~ 110% with the precision of less than 5.0% RSD (n=3).The ratios of w(Ni)/w(V) and w(Fe)/w(V) were distinct in different crude oil samples from oversea and domestic,and the index can be used to the cluster analysis for differencing the crude oil samples.国家海洋局第一海洋研究所基本科研业务费专项资助(2010G23);海洋公益性行业科研专项资助(200705011);海洋溢油鉴别与损害评估技术重点实验室开放基金资助(200920
Approach to Robotization of Concrete Boom Truck for Construction
对混凝土泵车布料机构的运动姿态调整采取了最优控制 ,解决了泵车机器人化的运动分析的臂解问题 ,论述了泵车动态分析中应解决和注意的问题 ,给出了泵车控制自动化的程序流程图和控制系统图 ,从而为提高泵车施工过程的自动化和泵车的机器人化提出了新的思
- …