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Search Results: 1 - 10 of 45389 matches for " 于佳琪 "
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脂肪酶催化一步酯化协同拆分合成S-萘普生淀粉酯前药
王艳,辛嘉英,
分子催化 , 2015,
Abstract: 利用CRL脂肪酶选择性催化外消旋萘普生甲酯与玉米淀粉进行转酯化反应合成光学纯S-萘普生淀粉酯前药,同时达到拆分外消旋萘普生的目的。考察了有机溶剂、脂肪酶用量、底物浓度比、反应温度对酯化协同拆分反应的影响,结果表明在异辛烷中脂肪酶CRL可以催化S-萘普生甲酯与淀粉发生转酯化反应同时完成外消旋萘普生的拆分,并且在脂肪酶用量为10%、底物浓度比为1:3、异辛烷用量为15mL、反应温度为60℃的条件下反应6d,外消旋萘普生甲酯的转化率为27.2%,产物对应体过量值eep高达99.4%可以作为萘普生的前药进行应用。
锅炉热水供热系统能耗机器学习诊断模型
Energy consumption diagnosis methodology model of boiler hot water heating system

邬棋帆,,
- , 2018, DOI: 10.11835/j.issn.1674-4764.2018.04.011
Abstract: 供热系统能耗诊断是一个难点。提出一种基于机器学习算法的能耗诊断标准模型结构,通过聚类或分类算法,从采集的诊断数据中筛选出节能特性较好的运行数据,基于回归模型建立能耗诊断模型对被诊断数据进行诊断。研究发现:1)经K-means聚类筛选数据并基于贝叶斯正则化训练的人工神经网络建立拟合模型,R值分别达到了0.975 6、0.970 5、0.921 4和0.910 1,模型拟合度较高;2)模型经过3个被诊断数据集验证,经过筛选的数据建立诊断模型,节能率指标分别10.7%、17%和4%,累积误差指标达到了-149 498.67、-86 526、-4 052.27 kW,诊断效果优于未经聚类的数据建立的模型;3)对诊断结果进行分析,发现供热系统二次换热端热水流量变频节能控制措施节能效率较低,一次供热端热水流量人工调节是造成能耗过高的主要原因。这种数据建模诊断的方式是基于输入、输出变量之间的物理响应关系而不受数据时间特性的影响。
To solve the energy diagnosed problem of boiler hot water heat supply, a energy consumption diagnosed method based on machine learning algorithm was proposed, firstly filtrating the data which has better energy-conservation performance from all data based on clustering or classification method. Then based on the regression model, the informant data had been tested has been test. though Through the four case study, these conclusion conclusions can be gained:1) The R value of model which is built by artificial neutral neural network(ANN), which was trained by Bayesian regularization method based on the data clustered by K-means algorithm was is up to the 0.976, 0.970 5, 0.921 4, 0.910 1; 2) though the test by the three data gather Model validated with 3 diagnosed datasets, the energy conservation ratio were are 10.7%, 17%, 4%, the accumulation error has been is up to the -149 498.67,-86 526,-4 052.27 kW, the effect of new model is better than before; 3) the artificial control of first heating supply is the mainly reason, which cased the high heating energy. The model based on the physical response between input and output variable, which has higher robustness in time series can be widely employed in energy consumption diagnosed of boiler hot water supply system,and by the developing of data technology, the model based on the data machine learning can supply some idea ideas for the similar system.
基于Lyapunov函数的三电平SAPF控制策略
,李勇,曹一家,晶荣,徐勇
- , 2017,
Abstract: 提出了一种基于Lyapunov函数的三相中点箝位型三电平并联有源电力滤波器(Neutral-Point Clamped Shunt Active Power Filter,NPC-SAPF)的控制策略.建立了NPC-SAPF的数学模型并在此基础上构建包含输出电流和直流电压误差项的能量函数;进一步推导出关于控制增益的特征方程,并绘制出其三维函数图,结合Lyapunov大范围渐进稳定条件和系统极点位置得到控制增益选取范围,在此区间选取合适的控制参数,保证系统在不同负载类型下动态和稳态性能.针对NPC特有的中点电位平衡问题,采用连接直流电压中点与配电变压器中点并引入中性点电位误差反馈控制的方法实现中点电位平衡.对电压源型和电流源型这两类非线性负载的动态和稳态性能进行了仿真和实验,结果表明:该控制策略对电流型和电压型非线性负载均取得较好的谐波补偿效果.
A Lyapunov-function-based control strategy for NPC-SAPF was proposed. The mathematical model of NPC-APF was built, and Lyapunov energy function including the tracking error of compensation currents and DC voltage was also constructed. Characteristic equation including control permanents was derived and plotted. Linear range of control permanents were also obtained after the overall consideration of system globally asymptotically stable conditions and pole location. Error feedback control technique was then utilized to keep neutral point potential balanced. In order to verify the compensation performance of the proposed current control scheme, nonlinear loads including diode bridge rectifier with an inductive load and a capacitive load was simulated and tested. Simulation and experimental results show that the proposed control strategy is effective in the nonlinear loads of both current-source type and voltage-source type.
锌基底上含金属锡的超疏水表面的制备
卢士香,师晓峰,苏丹,许斯,,徐文国
北京理工大学学报 , 2012,
Abstract: 针对超疏水金属表面广阔的应用前景,采用氯化亚锡的丙酮溶液,十八硫醇的丙酮溶液为疏水剂在锌基底上构建了超疏水表面,通过X-射线衍射(XRD)和扫描电镜(SEM)进行了结构表征和疏水性能测试.结果表明,超疏水表面具有微纳米阶层结构,静态接触角为158°,滚动角小于5°.
β-紫罗兰酮诱导人乳腺癌细胞(ER+)凋亡作用
董宏伟,, 金德利, 徐子茗, , 陈炳卿, 吴永会, 刘家仁
中国公共卫生 , 2015, DOI: 10.11847/zgggws2015-31-02-18
Abstract: ?目的为了研究β-紫罗兰酮对雌激素阳性的人乳腺癌细胞(MCF-7)凋亡诱导作用的影响。方法采用细胞生长曲线,凋亡细胞的荧光显微镜和电镜观察,TUNEL方法及流式细胞光度术以及Westernblot的检测方法,观察了用不同浓度β-紫罗兰酮(25、50、100和200μmol/L)对MCF-7细胞的抑制作用及诱导该细胞产生凋亡情况。结果β-紫罗兰酮可明显抑制MCF-7细胞生长,抑制率分别为6.57%、34.58%、65.22%和81.87%。通过荧光显微镜和电镜技术观察到了MCF-7细胞有凋亡的形态特征;TUNEL(末端脱氧核苷酸转移酶缺口末端标记)方法和流式细胞光度术均检测到β-紫罗兰酮可诱导MCF-7细胞产生凋亡,并随着β-紫罗兰酮浓度的增加,细胞凋亡率逐渐增加。TUNEL凋亡指数(AI)分别为20.74%(24h)和33.15%(48h);流式细胞光度术的凋亡指数(AI)分别为27.96%(24h)和38.59%(48h)。通过Westernblotting方法观察到β-紫罗兰酮可对MCF-7的细胞增殖相关蛋白PCNA及bcl-2蛋白表达有明显地抑制作用,呈现明显地剂量-反应关系。结论β-紫罗兰酮可明显地抑制雌激素阳性(ER+)人乳腺癌MCF-7细胞的增殖,并诱导该细胞产生凋亡,其作用机制需要进一步探讨。
基于傅里叶变换红外光谱的食用油常温氧化动力学研究
Oxidation Kinetics of Edible Oils Based on Fourier Transform Infrared Spectroscopy during Ambient Temperature

李孟俊,寇宇星,,,,,呼延宗尧,修烛,栾广忠
- , 2018, DOI: 10.7606/j.issn.1004-1389.2018.12.017
Abstract: 为了研究食用油在常温条件下氧化动力学规律,选取菜籽油、花生油、大豆油、亚麻籽油为研究材料,利用傅里叶红外光谱(FTIR)技术对其在常温氧化动力学进行研究。结果表明:在常温条件下,菜籽油、大豆油和亚麻籽油的氢过氧化物特征吸收峰变化符合0级反应动力模型;4种食用油对应氢过氧化物、游离脂肪酸、反式双键、顺式双键和碳链骨架的特征吸收峰变化均符合1级反应动力学模型;亚麻籽油和菜籽油的氢过氧化物特征吸收峰变化符合2级反应动力模型;花生油的氢过氧化物、游离脂肪酸、反式双键及顺式双键的特征吸收峰变化符合2级反应动力模型;4种食用油碳链骨架振动官能团在721 cm-1特征峰变化均符合0级、1级和2级反应动力学模型,模型拟合效果较好。表明利用FTIR光谱构建食用油常温氧化动力学模型是可行的。
In order to better study the kinetics of oxidation of edible oils at ambient temperature, rapeseed oil, peanut oil, soybean oil, and linseed oil were used as materials based on Fourier transform infrared spectroscopy(FTIR). The results showed that under the normal temperature condition, the change of hydrogen peroxide characteristic absorption peak of rapeseed oil, soybean oil and linseed oil accords with the zero level reaction dynamic model; the absorption peak of hydroperoxides, free fatty acids(C=O), trans double bonds, cis double bonds, and carbon chain skeleton of four edible oil are consistent with the primary level reaction kinetics model; the change of the absorption peak of hydroperoxide in linseed oil and rapeseed oil accords with the secondary level reaction dynamic model; the change of the absorption peak of hydroperoxide, free fatty acids(C=O), trans double bonds, and cis double bonds in peanut oil accords with the secondary level reaction dynamic model; the changes of characteristic peaks of four edible oil (rapeseed oil, peanut oil, soybean oil, and linseed oil)carbon chain backbone vibration functional groups in accordance with the zero, primary and secondary level reaction kinetic models, and the model fitting effect was better. It also shows that the FTIR technology can be used to develop an oxidative kinetic model of edible oil at room temperature by FTIR spectroscopy.
城市快速路指路系统优化设计——以宁波北外环快速路为例
The Optimization of Urban Expressway’s Guiding System: A Case Study of North External Ring in Ningbo
 [PDF]

, 张水潮, 蒋英杰,
Open Journal of Transportation Technologies (OJTT) , 2015, DOI: 10.12677/OJTT.2015.46013
Abstract:
针对驾驶员在快速路下错出口匝道,未能第一时间到达理想的地面道路等情况,对城市快速路指路系统进行一系列的优化设计,最大限度地发挥指路系统的作用。同时,以宁波北外环快速路为例,将设计理念运用于实践。经过优化设计后的指路系统为车辆驾驶员提供全面准确的道路信息,引导车辆高效出行,进而有效缓解地面道路的交通压力。
According to the situation that drivers pick wrong off-ramps on the expressways and fail to reach the perfect ground roads in the first time, the paper takes a series of optimization on the guiding system of urban expressways in order to make it work at maximum limit. At the same time, illustrated by the example of Ningbo north external ring, this paper takes design concepts into practice. The optimized guiding system offers overall and accurate road information, guides vehicles to trip efficiently, and effectively mitigates traffic pressure of ground roads.
一种新型的基于预测的卫星资源分配方法

南京航空航天大学学报 , 2012,
Abstract:
Design and measurement of a piezoresistive triaxial accelerometer based on MEMS technology
基于MEMS的压阻式三轴加速度计的设计与测试

Du Chunhui,He Changde,Yu Jiaqi,Ge Xiaoyang,Zhang Yongping,Zhang Wendong,
杜春晖
,何常德,,葛晓洋,张永平,张文栋

半导体学报 , 2012,
Abstract: 随着微机电(MEMS)产业的兴起,加速度计正在向微型化,集成化,高可靠性,高灵敏度的方向发展,具有广泛的军事和民用前景。在此提出了一种压敏电阻完全对称分布的“8梁—质量块”结构的硅微压阻式三轴加速度计,与传统的单悬臂梁结构或悬臂梁—质量块结构相比,这种结构具有更高的灵敏度和更小的轴间耦合度。介绍了采用ANSYS软件进行结构分析的过程,给出了三轴加速度计敏感单元的制作工艺流程。通过对加速度计的静态测试得出X、Y、Z轴的灵敏度分别为SX=48*10-6V/g, SY=54*10-6V/g, SZ=217*10-6V/g,非线性度分别为0.4%,0.6%,0.4% 。
The design and test of MEMS piezoresistive ultrasonic sensor arrays
MEMS压阻式超声传感器阵列的设计与测试

Lian Deqin,He Changde,Zhang Hui,Yu Jiaqi,Yuan Kejing,Xue Chenyang,
廉德钦
,何常德,张慧,,宛克敬,薛晨阳

半导体学报 , 2013,
Abstract: The design, fabrication and packaging of a type of MEMS piezoresistive ultrasonic transducer array are introduced. The consistency of the resonance frequency and the sensitivity of the array are tested. Moreover, we detect the directivity and the multi-target identification ability of the array. The results of the consistency of the resonance frequency and the sensitivity show that there is a gap between the practical and theoretical results. This paper analyzes this problem in detail and points out the direction of improvement. As for the directivity, the actual result is consistent with the theoretical one. The results of multiple target distinguishing tests demonstrate that the smallest resolution angle of the array is 5.72° when the distance between the sensor array and measured objects is 2 m.
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