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Search Results: 1 - 10 of 193089 matches for " 陆晓华 "
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偏最小二乘吸光光度法测定钴、镍、铜

分析化学 , 1991,
Abstract: 本文用偏最小二乘法研究了钴、镍、铜三组分体系吸光光度同时测定的方法,获得满意结果。文章还讨论了偏最小二乘法中各参数的取值对未知样品预报结果准确度的影响。
两次双波长分光光度法同时测定钴、镍、铜
,纪元
分析化学 , 1989,
Abstract: 本文用两次双波长分光光度法实现了三组分混合体系的同时测定.结果表明,两次双波长测量信号△A1和△A2的线性组合与混合体系中各组分浓度呈线性关系.该法用于钻、镍、铜三组分同时测定,定量结果令人满意.
绿色氧化法制备HNS的催化体系
,婷婷,
含能材料 , 2015, DOI: 10.11943/j.issn.1006-9941.2015.08.004
Abstract: 以六硝基联卞(HNBB)为原料,4-羟基-2,6,6-四甲基哌啶-N-氧自由基(4-OH-TEMPO)和氯化亚铁(FeCl2)为催化剂,在二甲亚砜(DMSO)中通过氧气氧化HNBB脱氢制备了六硝基茋(HNS),收率为81%。确定了最佳反应条件:溶剂为DMSO,催化剂组合及其比例为n(4-OH-TEMPO)∶n(FeCl2)=4∶6时,在55℃下以25mL·h-1的速率通入氧气反应8h。推测了可能的反应机理:亚铁离子结合氧气直接氧化底物HNBB脱氢得到HNS,4-OH-TEMPO在这个过程中起到一个促进FeCl2循环加速氧化脱氢的助催化作用。
优质饼干、糕点专用小麦新品系—“90—85”
,
麦类作物学报 , 2001, DOI: 10.7606/j.issn.1009-1041.2001.02.053
Abstract: “90-85”系扬州大学农学院农学系从扬麦1号辐照突变株选育成的白软麦,具有优质、高产、繁茂性好、抗逆性强等特点,是目前长江中下游地区较为理想的优质饼干、糕点专用小麦品种。1 特征特性1.1 基本特征 春性,主茎总叶数11张左右,叶色淡绿,叶片宽,剑叶长度18~20cm,宽度1.8~2.0cm,倒2叶长度25cm左右,宽度1.6~1.8cm,倒3叶长度20~22cm,宽度1.5cm左右。最大叶面积指数在6左右。分蘖性强,低位分蘖发生率高,第一分蘖缺位率小于50%,第二分蘖缺位率小于20%。株高85~90cm,基部节间短,充实…
痕量碲的示波极谱测定
光汉,
分析化学 , 1987,
Abstract: 极谱法测定啼已有不少报道[1,2],但在草酸一次甲基蓝介质中,示波极谱法测定痕量磅未见资料介绍。我们发现,在草酸一次甲基蓝溶液中,在电位-0.75V(vs.SCE)处,有一清晰的导数极谱波。Te02的浓度在2.0×10-7-1.2×10-5mg/ml之间与波高成线性关系。检测下限达5×10-8mg/ml,该法用于小麦面粉和纯秘中痕量啼的测定。结果表明,该法具有灵敏、快速、准确之特点。
多波长K系数法同时测定去痛片中四组分
,李春华,李翱
分析化学 , 1991,
Abstract: 本文用多波长K系数法对非那西丁、氨基比林、咖啡因和苯巴比妥进行同时测定。对人工合成试样和实际样品的测定均获满意结果。
联机卡尔曼滤波法分辨铅锡重叠极谱波
,田诚,陈晔
分析化学 , 1996,
Abstract: 在0.5mol/LHCl底液中,Pb(Ⅱ)和Sn(Ⅱ)极谱波峰电位分别为-0.47V和-0.50V(vs.SCE),难以用常规的极谱法进行两组分同时测定。本文通过接口电路实现微机对MP-1溶出分析仪联机数据采集和信号处理,并用卡尔曼滤波法分辨Pb(Ⅱ)和Sn(Ⅱ)的重叠极谐波,实现了铅锡两组分同时测定,取得较好结果。
2716名中小学生乙型肝炎病毒感染的现况调查
,
宁夏医科大学学报 , 2007,
Abstract: 为了解平罗县陶乐地区中小学生HVB感染情况,为防治措施提供依据,于2005年10月对陶乐地区17所中小学2716名学生进行了乙型肝炎检查。采用ELISA方法检测学生乙肝两对半。结果,学生乙型肝炎表面抗原(HBsAg)的携带率为2.32%,接种过乙肝疫苗学生乙型肝炎表面抗原携带率低于未接种者,其差异有统计学意义(P<0.01)。未接种过乙肝疫苗两对半全阴性百分率高于接种乙肝疫苗者,差异有统计学意义(P<0.01)。学生HBsAg携带率比成人自然感染率低,接种乙肝疫苗是预防乙型肝炎最有效的方法,加强学生病毒性肝炎的预防工作非常必要。更多还原
基于时间延迟模型的多目标优化检查决策方法
Multi-objective optimization inspection decision-making method based on delay-time model

,左洪福,白芳
- , 2016,
Abstract: 根据某航空公司货运机队的某型发动机HPTACC系统在某一周期内的预防性检查计划、检查发现的缺陷以及失效维修记录,分析了系统在运行过程中将缺陷延迟发现时间作为安全性优化目标、将检修费用作为经济性优化目标的可行性。在预防性检查时刻发现缺陷的检修策略下,推导了在各检查时刻基于时间延迟模型的缺陷数期望值和缺陷延迟发现时间期望值概率计算式。在缺陷退化为失效被及时发现并进行更换维修的检修策略下,推导了在各检查间隔期内基于时间延迟模型的失效发生次数期望值概率计算式。基于2种检修策略下的概率公式,建立了系统在给定寿命周期内的似然函数,建立了检修费用和缺陷延迟发现时间的期望值双优化目标函数式,运用了改进的非支配排序遗传算法优化得到双目标函数的Pareto最优解集。根据决策者的目标偏好及其分界值对应的检修费用及缺陷延迟发现时间的经验估计值,分别确定了系统在寿命周期内的检修费用和缺陷延迟发现时间的目标偏好函数,通过目标偏好函数划分区间确定Pareto最优解集中各最优解的偏好区间。基于收集的检修信息和提出的方法,对决策者将缺陷延迟发现时间期望值目标偏好定为一般、将检修费用期望值目标偏好定为很好的偏好要求进行实例分析。分析结果表明:最优检查间隔决策约为67、70或77次起降循环,这些检查间隔为决策者进行多目标相对最优的精确决策提供细化和更精简的选择参考。
In accordance with the preventive check plans, the defects detected in the course of inspection, and the repairing and renewing records in a certain cycles for the HPTACC system of a type of aeroengine of an airline freight fleet, the feasibilities for regarding the delayed time for the defects detected and the inspection and repairing costs as safety and economy optimization objectives were analyzed respectively. Under the inspection and repairing strategy of defects detected at the moments of preventive inspection, the probability expressions of expected number of defects and the delayed time for defects detected based on the delay-time model at any inspection moment were deduced. Under the inspection and repairing strategy of defects degrading into failure and then being found timely and renewed at once, the probability expression of expected number of failure occurring based on delay-time model in every inspection interval was deduced. Based on the probability expressions under 2 inspection and repairing strategies, the likelihood function for the system in a given life cycle was build. The double optimization objective functions including inspection and repairing costs and expected delayed time for detected defects were formed. A Pareto optimal solution set of double objective functions were derived by using the improved non-dominated sorting genetic algorithm. According to the deciders’ objective preference options and the empirical estimates of inspection and repairing costs and the delayed time for detected defects corresponding to their boundary values, the objective preference functions of inspection and repairing costs and the delayed time for detected defects in certain life cycles were determined respectively. The preference interval for every value in the Pareto optimal solution set was determined by using the objective preference function. Based on the collected inspection and repairing data and the proposed methods, an example was analyzed, in which the objective
土工格室生态挡墙工程性状分析
,,俞永
公路交通科技 , 2004,
Abstract: 应用Marc软件,通过模拟土工格室生态挡墙墙体、加筋层与填土的相互作用,对生态挡墙墙背的位移和应力性状进行分析,并结合实体工程进行墙背侧向土压力测试。结果表明土工格室生态挡墙在外荷载的作用下,除了刚体位移之外,还会发生挠曲变形,具有柔性支挡结构的特点;墙背侧向土压力随着距墙顶距离的增大而增大;数值计算与现场测试得到的墙背侧向土压力变化规律一致,表明本文采用的数值模型是合理的。
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