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Search Results: 1 - 10 of 209608 matches for " 高晓明 "
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陀螺仪漂移系数的多位置离心机标定方法及误差分析
Calibration Method and Error Analysis for Multi-Positional Method on Centrifuge of Gyroscope’s Drift Coefficients
 [PDF]

王世,
Dynamical Systems and Control (DSC) , 2016, DOI: 10.12677/DSC.2016.53008
Abstract:
为了准确标定陀螺仪漂移系数,本文在带反转平台的精密离心机上建立坐标系,并在考虑离心机误差源的情况下分析了坐标系间的位置关系。用齐次变换法推导出了陀螺仪各轴上精确的角速度输入并给出了比力输入标称值,再结合陀螺仪静态误差模型推导出含有陀螺仪漂移系数的各次谐波幅值表达式,通过离心机提供两种向心加速度获得陀螺仪各采样时刻的输出,应用谐波分析法可以求得各次谐波幅值大小,从而利用最小二乘估计对各漂移系数进行辨识。试验仿真表明采用带反转平台的离心机对陀螺仪漂移系数标定时可以有效的规避离心机误差,离心机误差只对于DI、DS和DOS的标定有影响,且影响非常大,须在考虑离心机误差的情况下才能够实现精确标定;对于其他系数标定没有影响。实际标定时需要精确测量反转平台回转轴与盘面的垂直度误差,反转平台回转轴倾角回转误差以及反转平台角速率与主轴角速率的大小之差等以满足标定精度要求。
In order to calibrate the drift coefficients of gyro precisely, in the paper, the coordinate systems on precision centrifuge with counter-rotating platform were established, and the positional relationships were analyzed in consideration of centrifuge errors. The accurate angular velocity along each axis of gyro was derived by using homogeneous transformation method and the nominal value of input specific force was given, and each harmonic amplitude expression containing drift coefficients of gyro was derived combining the static error model of gyro. The output at each sampling time of gyro was acquired by providing two centripetal accelerations on centrifuge, and each harmonic amplitude’s value was calculated by using harmonic analysis, thus each drift coefficient could be identified by least squire evaluation. The simulation results show that the method using the counter-rotating platform can avoid the centrifuge errors’ influences and the errors mainly impact on the DI, DS and Dos significantly which should be precisely calibrated in consideration of centrifuge errors; and the errors have no impacts on other coefficients. In real calibration, the perpendicularity between rotating axis of counter-rotating platform and the disk surface, the wobbles of rotating axis of counter-rotating platform and the difference between the angular rate of counter-rotating platform and the main axis should be measured precisely in order to meet the requirement.
基于历史开销的虚拟路由器控制平面流量隔离机制研究
Research on the Mechanism of Virtual Router Control Plane Traffic Isolation Based on Historical Cost
 [PDF]

陈科,,
Software Engineering and Applications (SEA) , 2016, DOI: 10.12677/SEA.2016.52014
Abstract:
为了保障虚拟路由器控制平面链路带宽资源的公平性以及流量隔离,本文在Linux系统上设计并实现了虚拟控制平面实例与逻辑转发引擎间的通信中间层——VNETDEV内核模块。在此基础上本文提出了一种基于历史开销的虚拟控制平面实例间流量隔离机制。通过在LinuxLXC虚拟机环境下部署VNETDEV内核模块,对多个的虚拟控制平面实例进行的流量测试验证能够保证各虚拟控制平面实例间的流量公平性和隔离性。
In order to ensure the fairness of the virtual router to control the bandwidth resource of the planar link and the traffic isolation, in this paper, we design and implement the middle tier of communication, VNETDEV kernel module, between the virtual control plane and the logical forwarding engine based on the Linux system. On this basis, this paper proposes a traffic isolation mechanism in virtual control plane instances based on the historical cost. Through arranging the VNETDEV kernel module under the LinuxLXC virtual machine environment, verification of flow test for multiple virtual control plane instances can ensure the fairness and isolation of traffic between each virtual control plane.
网络学习中效用价值干预对学习兴趣及学习效果的影响
The Effect of Utility Value Intervention on Situational Interest and Learning Outcome in Online Learning Environment
 [PDF]

苗苗, 熊俊梅,
Advances in Psychology (AP) , 2016, DOI: 10.12677/AP.2016.610139
Abstract:
本文基于两位数乘法心算方法专题学习网站,采用情境实验法考察网络学习中效用价值干预对不同期望水平学生的情境兴趣和学习效果的影响。结果发现:效用价值干预显著提高学生在网络学习中的效用价值,尤其是低期望学生的效用价值;效用价值干预对激发性情境兴趣和维持性情境兴趣的主效应显著;干预条件能显著提高学习满意度,尤其是低期望学生的学习满意度。研究表明:效用价值干预是提升学生网络学习兴趣及学习满意度的关键因素,且干预对低期望学生尤为有效。
Based on the learning website for double-digit multiplication arithmetic method, this study used a situational experiment method to examine whether a utility value intervention can affect situa-tional interest and learning outcomes in online learning environment, and whether the interven-tion will be stronger for students who have low expectancies for success. The results showed that in the online learning context, the utility value intervention can improve students’ utility value, particularly for students who have low expectancies for success. Besides, there was a main effect of the intervention condition on triggered and maintained situational interest. Finally, the inter-vention condition can significantly affect student’s learning satisfaction, particularly for students who have low expectancies for success. So the utility value intervention is the key factor to improve students’ online learning interest and learning satisfaction, especially for students who have low expectancies for success.
I-RDX及其PBX老化研究进展
,
含能材料 , 2010, DOI: 10.3969/j.issn.1006-9941.2010.02.025
Abstract: 总结了降感黑索今(I-RDX)及其高聚物黏结炸药(PBX)老化研究成果,从RDX晶体特性及其评价方法、I-RDX及其PBX老化前后的晶体特性、冲击波感度特性方面进行了综述,认为I-RDX晶体中不含奥克托今(HMX)或含有微量HMX、或机械混入少量HMX时,材料老化后的冲击波感度特性没有明显变化,最后对I-RDX晶体中HMX的影响机理进行了讨论。
A Study of the Karyotypes and C-bands of Paramesotriton caudopunclatus
尾斑瘰螈的核型和C带研究

,
遗传 , 1997,
Abstract: The karyotpe and C-bands of Paramesotriton caudopunclatus Liu et Hu were studied by means of both conventional Giemsa staining and BSG technique.The diploid number of this species is 24,consisting of 9 pairs of metacentric and 3 pairs of submetacentric elements.All chromosomes have an inserted pericentric band in both chromosome arms except that Nos.11 and 12 chromosomes have an inserted pericentric band only in one chromosome arm.Besides the main bands,weak centromeric bands appear in all of the chromosomes.The karyotype and C-bands of Paramesotriton caudopunclatus indicated the dissimilary with other examined species in Chinese salamandrids.No heteromorphic pair of chromosomes was detected between male and female karyograms.
贵州疣螈的核型和C-带研究
,
动物学研究 , 1997,
Abstract: 贵州疣螈的核型和C-带研究ASTUDYONKARYOTYPESANDC-BANDINGSOFTylototritonkweichowensis关键词贵州疣螈,核型,ZW-染色体,C-带KeywordsTylototritonkweichowensis...
Characterization of a key gene in membrane lipid cycle in Synechocystis sp. PCC6803
集胞藻PCC6803膜脂循环关键基因酶学性质和生理功能

倩倩,,吕雪峰
生物工程学报 , 2012,
Abstract: Free fatty acid profiles of wild type and fatty acyl-ACP synthase deletion mutant strain of Synechocystis sp. PCC6803 indicated that one origin of these fatty acids is the process of lipid remodeling or lipid degradation. Lipase is the key enzyme involved in this process. The gene sll1969 is the sole gene encodes a putative lipase in Synechocystis sp. PCC6803. To identify the function of this gene and its role in fatty acid metabolism, we cloned the sll1969 from genomic DNA, overexpressed it in Escherichia coli BL21 (DE3) using pET expression system and purified this recombinant enzyme with Nickel-nitrilotriacetic acid affinity chromatography. The enzyme activity was assayed by spectrophotometric with p-nitro-phenylbutyrate as substrate. The Km and kcat of the enzyme is (1.16±0.01) mmol/L and (332.8±10.0)/min, respectively toward p-nitro-phenylbutyrate at 30 oC. The optimal temperature of the enzyme is 55 oC. To investigate the biological role of Sll1969 in fatty acid metabolism in cyanobacteria, we constructed sll1969 deletion and overexpression mutant strains in the background of fatty acyl-ACP synthase deletion mutant of Synechocystis sp. PCC6803. The analyses of the content of free fatty acids in different mutant strains showed that the contents of Sll1969 and free fatty acid are positively correlated. The free fatty acid profiles of the sll1969 mutant strains suggested this enzyme is not the sole enzyme for degrading lipid in Synechocystis sp. PCC6803.
动脉血气分析在新生儿窒息中的临床研究
Clinical Research of Arterial Blood Gas Analysis for Neonatal Asphyxia
 [PDF]

尹延娥, 刘文静, 张立, 赵伟,, 荣荣
Asian Case Reports in Pediatrics (ACRP) , 2014, DOI: 10.12677/ACRP.2014.24006
Abstract:
目的:探讨动脉血气分析在新生儿窒息中诊断中的临床价值。方法:选取2013年10月到2014年4月在我院产科出生的1分钟Apgar ≤ 7分的40例新生儿为窒息组,其中3 < Apgar评分 ≤ 7分者为轻度窒息组,≤3者为重度窒息组,同期选择Apgar评分 ≥ 8分者50例生后无窒息、病情相对稳定的新生儿为对照组,分别于生后1小时内行血气分析,并将与Apgar评分进行相关性分析。结果:窒息组与对照组相比,其PH、PO2、BE、HCO3、乳酸值降低,PCO2则升高,P < 0.05差异有统计学意义,而重度窒息组比轻度窒息组降低(或升高)更明显。结论:动脉血气分析联合Apgar评分有助于新生儿窒息的诊断及客观的反应新生儿缺氧缺血的性质及严重程度,并有利于预测新生儿预后。
Objective: To explore the clinical value of arterial blood gas analysis in the diagnosis of neonatal asphyxia. Method: Choose 40 infants born from October, 2013 to April, 2014 in our hospital with 1 min Apgar score ≤ 7 as asphyxia group, within which 3 < 1 min Apgar score ≤ 7 as mild asphyxia group, Apgar ≤ 3 as severe asphyxia group; at the same time, choose 50 infants with 1 min Apgar score ≥ 8 points, and without symptoms of asphyxia, relatively stable as contrast group. One hour after the infants born, we carry out an analysis of blood gas, and make a relevant analysis with Apgar evaluation. Results: The result comes out that compared with the contrast group, infants in asphyxia group have decreased value in PH, PO2, BE,HCO3 and Lactic acid, and have increased value in PCO2. While, severe asphyxia group has more obvious changes in values. Conclusion: Ar-terial blood gas analysis, together with Apgar evaluation can help to diagnose neonatal asphyxia. What’s more, they can reflect the quality and severity of HIE more objectively, and help to predict the prognosis of neonatal.
重庆市植烟土壤有效态微量元素含量评价
, ,慈 恩
中国生态农业学报 , 2007,
Abstract: 对重庆市14个县(区)的334个植烟土壤样品的有效态微量元素Fe、Mn、Cu、Zn、B和Mo的含量状况和分布特征进行分析,结果表明,重庆市20%以上植烟土壤缺Mo、Zn,75%以上土壤缺B,有效铁、锰含量较丰富,有效铜极丰富。有效铁、锰、铜、锌含量均与土壤pH值呈负相关关系,有效钼含量与土壤pH值呈正相关关系,有效硼含量在pH<7.0时随pH的增加而增加,但在pH>7.0时含量下降。植烟土壤中有效铁和有效铜含量与有机质含量呈极显著正相关关系,而有效锰、硼和钼与有机质无明显相关性。
钻孔灌注桩桩底压浆的施工技术
,
重庆交通大学学报(自然科学版) , 2004,
Abstract: :?通过工程实践,对桩底灌浆提高钻孔灌注桩承载力的原理和施工工艺进行探讨,并结合工程实测资料对比进行分析。
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