NEW ALGORITHM FOR RECEIVER AUTONOMOUS INTEGRITY MONITORING

A new integrity metric for navigation systems is proposed based on the measurement domain. Proba-hilistic optimization design offers tools for fault detection by considering the required navigation performance （RNP） parameter and the uncertainty noise. The choice of the proper performance parameter provided the single-valued mapping with the missed detection probability estimates the probability of failure. The desirable characteristics of the residual sensitivity matrix are exploited to increase the efficiency for identifying erroneous observations. The algorithm can be used to support the performance specification and the efficient calculation of the integrity monitoring process. The simulation for non-precision approach （NPA） validates both the viability and the effectiveness of the proposed algorithm.

预测换算周转量的三因素相关模型

本文针对目前采用的换算周转量预测方法存在的问题，探讨换算周转量与装车数、接运重车数和旅客发送人数三因素的相关模型，用回归法计算出更为精确的预测换算周转量。

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凭借SKF在旋转设备领域掌握的上百年的工作经验,SKF服务部状态监测团队以数十年的现场经验为后盾,向客户提供全面的各系列产品和现场服务。SKF通过以下不同类型的监测系统用于设备状态监测,以降低设备的风险：点巡检系统Microlog Inspector、便携式精密数据采集分析仪Microlog系列、无线泵群监测系统、无线在线监测系统、实时在线监测系统IMX系列、保护系统DMX系列、变送器系列、激光对中仪器TKSA系列、在线和离线电机分析仪baker系列。

选择最佳PH与温度降低5—羟甲基糖醛含量

葡萄糖注射液是临床常用的制剂,在制备过程中常用溶液的调节不当或灭菌时温度控制不稳而导致成品溶液发黄,这是由于萄葡糖分解形成5—羟甲基糖醛,这种物质对人体有一定的毒害,我国八五年版药典已对5-羟甲基糖醛作了限度规定。本文就葡萄糖注射液制备中影响5—羟甲基糖醛的二个主要因素进行测定,找出制备过程中最佳值和温度。

Investigation on Non-covalent Complexes of Cyclodextrins with Li＋ in Gas Phase by Mass Spectrometry

To investigate the non-covalent interaction between cyclodextrins （CD） and lithium ion, a stoichiometry of α-CD, β-CD, heptakis（2,6-di-O-methyl）-β-CD （DM-β-CD）, or heptakis（2,3,6-tri-O-methyl）-β-CD （TM-β-CD） was mixed with lithium salt, respectively, and then incubated at room temperature for 10 min to reach the equilibrium. In posi- tive mode, the electrospray ionization mass spectrometry （ESI-MS） results demonstrated that lithium ion can conjugate to α-, β-, DM-β- or TM-β-CD and form 1：1 stoichiometric non-covalent complexes. The binding of the complexes was further confirmed by collision- induced dissociation. The dissociation constants Kdl of four complexes （Li＋α-CD, Li＋β- CD, Li＋DM-β-CD, and Li＋TM-β-CD） were determined by mass spectrometric titration. The results showed Kdl were 18.7, 26.7, 33.6, 30.5 μmol/L for the complexes of Li＋ with α-CD, β-CD, DM-β-CD, and TM-β-CD, respectively. Kdl for the Li＋ complexes of/3-CD is smaller than that of DM-β-CD due to its steric effect of the partial substituted -CH3. The Kdl for the Li＋ complexes of DM-β-CD is nearly in agreement with that of TM-β-CD, indicating Li＋ is more likely to locate in the small rim of DM-β-CD＇s hydrophobic cavity. The DFT results showed through electrostatic interaction, one Li＋ can strongly conjugate to four neighboring oxygen atoms. For the （α-CD＋Li）＋ complex, one Li＋ may also situate the small rim of α-CD＇s hydrophobic cavity to form a non-specific host-guest complex.

Precision bending of high-quality components for volume applications

Recent new technology developments were presented in the field of industrial bending operations,including flexible stretch forming and 3D rotary stretch forming.Attempts were made to give an overview of different mechanisms that influence dimensional accuracy,including local cross-sectional deformations such as suck-in and volume conservation effects,along with global deformations such as springback.An analytical model was developed to determine the particular influence of different material,geometry and process parameters on dimensional variability of bent components.The results were discussed in terms of overall process capability(Cp) and associated process windows.The results show that different governing mechanisms prevail in various bending operations,meaning that attention has to be placed on controlling those process parameters that really are important to part quality in each specific case.Several strategies may be defined for reducing variability.One alternative may be to design more robust process and tool technology that reduce the effect of upstream parameters on dimensional variability of the formed part.The results show that optimal tool design and technology may in specific cases improve the dimensional accuracy of a formed part.Based on the findings discussed herein,it is concluded that advances in industrial bending operations require focus on improving the understanding of mechanical mechanisms,including models and parameter development,new technology developments,including process,tool,measurement and control capabilities,and process discipline at the shop floor,combined with a basic philosophy of controlling process parameters rather than part attributes.

Die design for cold precision forging of bevel gear based on finite element method

The finite element analysis （FEA） software Ansys was employed to study the stress state of the dies of both plane and non-plane parting face structures with uniform interference and the die of plane parting face structure with non-uniform interference. Considering the symmetry of the die, a half gear tooth model of the two-ring assembled die with 2.5 GPa inner pressure was constructed. Four paths were defined to investigate the stress state at the bottom comer of the die where stress concentration was serious. FEA results show that the change of parting face from non-plane to plane can greatly reduce the stress at the teeth tips of the die so that the tip fracture is avoided. The interference structure of the die is the most important influencing factor for the stress concentration at the bottom comer. When non-uniform interference is adopted the first principal stress at the comer on the defined paths of the die is much lower than that with uniform interference. The bottom hole radius is another important influencing factor for the comer stress concentration. The first principal stress at the comer of the plane parting face die with non-uniform interference is reduced from 2.3 to 1.9 GPa when the hole radius increases from 12.5 to 16.0 mm. The optimization of the die structure increases the life of the die from 100 to 6 000 hits.

Research on a High-Precision Delay Circuit in Data Acquisition Systems

This paper presents a novel precision delay circuit design for high-speed data acquisition systems. Many studies have suggested that various advanced electronic measurement apparatuses require that the delay circuit should have a high precision and a short delay interval. Practically, however, such measurement apparatuses are low in preci- sion and long in delay interval at present. The structure and function of a data acquisition system is introduced first; then the principle of ramp-based precision delay circuits and the digitally programmable delay generator is studied and the precision delay circuit is designed. The authors also demonstrated 8-bit programmable delay circuits with a timing pre- cision of 10 ps. Therefore the programmable precision delay circuit here presented has a higher precision, shorter inter- val and more detectable function than any other precision delay circuit.

Average Channel Capacity of Composite κ-μ/Gamma Fading Channels

A new analytical expression is presented for the instantaneous power Probability Density Function （PDF） of receiver signals over composite K-u/gamma fading channels. Moreover, the exact expression of channel capacity is derived in the form of an infinite series, while an accurate approximation expression is obtained in closed form. To reveal the implications of the model parameters on capacity, we provide an expression for the case of a high-SNR environment. The relationship of the presented results with previously reported results on generalised-K and K fading channels is also discussed. Finally, numerical and simulation results are presented to prove the correctness of our derived expressions.

Prediction model for permeability index by integrating case-based reasoning with adaptive particle swarm optimization

To effectively predict the permeability index of smelting process in the imperial smelting furnace, an intelligent prediction model is proposed. It integrates the case-based reasoning （CBR） with adaptive par- ticle swarm optimization （PSO）. The nmnber of nearest neighbors and the weighted features vector are optimized online using the adaptive PSO to improve the prediction accuracy of CBR. The adaptive inertia weight and mutation operation are used to overcome the premature convergence of the PSO. The proposed method is validated a compared with the basic weighted CBR. The results show that the proposed model has higher prediction accuracy and better performance than the basic CBR model.

Study on Programming of CNC Turning and Processing Techniques

Due to its high efficiency, high precision and high flexibility, CNC lathe is widely used in the machinery manufacturing industry increasingly, and becomes one of CNC machine too[s that most widely used. However, to give full play to the role of CNC lathes, the key is programme, that is, preparing the reasonable and efficient processing procedures depending on the features and precision parts. This paper discussed the problems of programming and processing techniques of the CNC lathe parts.

Mr.Dandy 胡榛 绅士的品格

见到Mr.Dandy的设计师胡榛时,他干练地迈着大步走进房间,身着高级定制的精致西装,合体剪裁,修身线条,考究装饰……无不以一种无言的话语传递着Mr.Dandy品牌精神,以及诠释了胡榛对高级定制西装及对男人的理解。Mr.Dandy意为＂喜好精致衣物的男人＂,更代表了＂顶级的,做工精致的事物＂。他们对生活有着独到的理解和深层次的追求,渴望着内心深处的优雅。真正的高贵源于绅士的内心,绝非表面的浮华,他们追求的高级时装也绝不是一时的惊艳。

Extraction of line-of-sight ionospheric observables from GPS data using precise point positioning

Here we propose a method for extracting line-of-sight ionospheric observables from GPS data using precise point positioning(PPP).The PPP-derived ionospheric observables(PIOs) have identical form with their counterparts obtained from leveling the geometry-free GPS carrier-phase to code(leveling ionospheric observables,LIOs),and are affected by the satellite and receiver inter-frequency biases(IFBs).Based on the co-location experiments,the effects of extracting error arising from the observational noise and multipath on the PIOs and the LIOs are comparatively assessed,and the considerably reduced effects ranging from 70% to 75% on the PIOs with respect to the LIOs can be verified in our case.In addition,based on 26 consecutive days' GPS observations from two international GNSS service(IGS) sites(COCO,DAEJ) during disturbed ionosphere period,the extracted PIOs and LIOs are respectively used as the input of single-layer ionospheric model to retrieve daily satellite IFBs station-by-station.The minor extracting errors underlying the PIOs in contrast to the LIOs can also be proven by reducing day-to-day scatter and improving between-receiver consistency in the retrieved satellite IFBs values.

便携式血糖仪与全自动生化仪血糖检测的对比

目的:探究便携式血糖仪与全自动生化仪血糖检测的对比效果。方法:选取本院2019年1月~2020年1月所收录的50例内科患者进行研究,根据患者血糖浓度不同进行随机分组,分为对照组和观察组,各25例,对照组为血糖值≤4.2mmol/L的患者,观察组为血糖值>4.2mmol/L的患者,观察两组患者检查后的精密数据对比情况。结果:在经过血糖仪检测后,观察组患者的血糖精密数据与对照组患者相比,其结果未产生明显变化(P>0.05),两组患者数据对比无统计学意义。结论:通过采用便携式血糖仪与全自动生化仪对患者进行血糖检测,两种检测方式的检测结果不会产生较大的差异,而且都能够在允许范围内,对于临床检测均具有较高的使用性,但便携式血糖仪更易被普及和使用,因此对于患者的血糖监测,可选用便携式血糖仪进行。

Thermospheric mass density derived from CHAMP satellite precise orbit determination data based on energy balance method

In this article, the energy balance method is used to retrieve thermospheric mass density from CHAMP satellite precise orbit determination(POD) data during 2007–2009. The retrieved thermospheric mass densities are compared with those from accelerometer data and an empirical model. The main conclusions are as follows:(1) Thermospheric mass density can be retrieved from POD data by the energy balance and semi-major axis decay methods, whose results are consistent.(2) The accuracy of the retrieved densities depends on the integration time period, and the optimal period for CHAMP density retrieval from POD data is about 20 minutes.(3) The energy balance method can be used to calibrate accelerometer data.(4) The accuracy of retrieving thermospheric density from POD data varies with satellite altitude and local time.

Exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes

We find exact solutions to the Klein-Gordon equation in the vicinity of Schwarzschild black holes.For particles with a zero angular momentum,the convergence range of the solution is r < 4M.One of the solutions describes an exponential enhancement of the density of particles in the vicinity of Schwarzschild black holes,which might be the mechanism of gamma-ray bursts.