On Control System Design for the Conventional Mode of Operation of Vibrational Gyroscopes

This paper presents a novel control circuitry design for both vibrating axes (drive and sense) of vibrational gyroscopes, and a new sensing method for time-varying rotation rates. The control design is motivated to address the challenges posed by manufacturing imperfection and environment vibrations that are particularly pronounced in microelectromechanical systems (MEMS) gyroscopes. The method of choice is active disturbance rejection control that, unlike most existing control design methods, does not depend on an accurate model of the plant. The task of control design is simplified when the internal dynamics, such as mechanical cross coupling between the drive and sense axes, and external vibrating forces are estimated and cancelled in real time. In both simulation and hardware tests on a vibrational piezoelectric beam gyroscope, the proposed controller proves to be robust against structural uncertainties; it also facilitates accurate sensing of time-varying rotation rates. The results demonstrate a simple, economic, control solution for compensating the manufacturing imperfections and improving sensing performance of the MEMS gyroscopes

On Control System Design for the Conventional Mode of Operation of Vibrational Gyroscopes

This paper presents a novel control circuitry design for both vibrating axes (drive and sense) of vibrational gyroscopes, and a new sensing method for time-varying rotation rates. The control design is motivated to address the challenges posed by manufacturing imperfection and environment vibrations that are particularly pronounced in microelectromechanical systems (MEMS) gyroscopes. The method of choice is active disturbance rejection control that, unlike most existing control design methods, does not depend on an accurate model of the plant. The task of control design is simplified when the internal dynamics, such as mechanical cross coupling between the drive and sense axes, and external vibrating forces are estimated and cancelled in real time. In both simulation and hardware tests on a vibrational piezoelectric beam gyroscope, the proposed controller proves to be robust against structural uncertainties; it also facilitates accurate sensing of time-varying rotation rates. The results demonstrate a simple, economic, control solution for compensating the manufacturing imperfections and improving sensing performance of the MEMS gyroscopes

An update of the catalog of radial velocity standard stars from the APOGEE DR17

We present an updated catalog of 46,753 radial velocity (RV) standard stars selected from the APOGEE DR17. These stars cover the Northern and Southern Hemispheres almost evenly, with 62% being red giants and 38% being main-sequence stars. These RV standard stars are stable on a baseline longer than 200 days (54% longer than one year and 10% longer than five years) with a median stability better than 215 m s$^{-1}$. The average observation number of those stars are 5 and each observation is required to have spectral-to-noise-ratio (SNR) greater than 50 and RV measurement error smaller than 500 m s$^{-1}$. Based on the new APOGEE RV standard star catalog, we have checked the RV zero points (RVZPs) for current large-scale stellar spectroscopic surveys including RAVE, LAMOST, GALAH and Gaia. By carefully analysis, we estimate their mean RVZP to be $+0.149$ km s$^{-1}$, $+4.574$ km s$^{-1}$ (for LRS), $-0.031$ km s$^{-1}$ and $+0.014$ km s$^{-1}$, respectively, for the four surveys. In the RAVE, LAMOST (for MRS), GALAH and Gaia surveys, RVZP exhibits systematic trend with stellar parameters (mainly [Fe/H], $T_{\rm{eff}}$, log $g$, $G_{\rm{BP}}-G_{\rm{RP}}$ and $G_{\rm{RVS}}$). The corrections of those small but clear RVZPs are of vital importances for these massive spectroscopic surveys in various studies that require extremely high radial velocity accuracies.Comment: 10 pages, 7 figures, 2 tables, accepted by RAA; full table can be accessed from https://nadc.china-vo.org/res/r101244

Active Disturbance Rejection Control for MEMS Gyroscopes

A new control method is presented to drive the drive axis of a Micro-Electro-Mechanical Systems (MEMS) gyroscope to resonance and to regulate the output amplitude of the axis to a fixed level. It is based on a unique active disturbance rejection control (ADRC) strategy, which actively estimates and compensates for internal dynamic changes of the drive axis and external disturbances in real time. The stability analysis shows that both the estimation error and the tracking error of the drive axis output are bounded and that the upper bounds of the errors monotonously decrease with the increase of the controller bandwidth. The control system is simulated and tested using a field-programmable-gate-array-based digital implementation on a piezoelectric vibrational gyroscope. Both simulation and experimental results demonstrate that the proposed controller not only drives the drive axis to vibrate along the desired trajectory but also compensates for manufacture imperfections in a robust fashion that makes the performance of the gyroscope insensitive to parameter variations and noises. Such robustness, the fact that the control design does not require an accurate plant model, and the ease of implementation make the proposed solution practical and economic for industrial applications

A regioselectivity switch in Pd-catalyzed hydroallylation of alkynes.

By exploiting the reactivity of a vinyl-Pd species, we control the regioselectivity in hydroallylation of alkynes under Pd-hydride catalysis. A monophosphine ligand and carboxylic acid combination promotes 1,5-dienes through a pathway involving isomerization of alkynes to allenes. In contrast, a bisphosphine ligand and copper cocatalyst favor 1,4-dienes via a mechanism that involves transmetalation. Our study highlights how to access different isomers by diverting a common organometallic intermediate

The Application of Resonance Light Scattering Technique for the Determination of Tinidazole in Drugs

A resonance light scattering technique to determine tinidazole in drugs was developed by tetraphenylboron sodium (TPB). Tinidazole was found to bind B(C6H5)−4 anion and transformed to tinidazole-TPB aggregate which displayed intense resonance scattering light. Effects of factors such as wavelength, acidity, stabilizers, and interferents on the RLS of tinidazole TPB were investigated in detail. The RLS intensity of the tinidazole-TPB suspension was obtained in sulfuric acid solution (pH = 1.44). The resonance scattering light intensity at the maximum RLS peak of 569.5 nm was linear to the concentration of tinidazole in the range of 10.0–30.0 μg mL−1 with a detection limit of 5.0 μg mL−1. Good results were also obtained with the recovery range of 95.13–106.76%. The method was applied to determine tinidazole in injections and tablets, showing high sensitivity and accuracy compared with the high performance liquid chromatography method (HPLC) according to Chinese Pharmacopoeia

The practice exploration of case teaching mode in the environmental monitoring course teaching

In view of that short and strong practical nature of the core courses in the environmental monitor, and the shortcomings of the case teaching modes of the project completion environmental protection acceptance case in the present individual application project, the project completion acceptance actual case method is set up in the course of the course of the course of environmental monitoring, and the practical case of the project completion acceptance test for the project completion of the project completion of the project is set up in the practical case, which is proved by the practice of the project completion environmental protection acceptance monitoring report of the packaging material of jiangsu shentai packaging material co., LTD. The project has been done with the study of the environment and the teaching model of the project, and it has been applied to the students as the main subject, and it has been taught to do a better job in monitoring the environment after graduation. Keywords Environmental monitoring; The acceptance of the environmental protection project case; The teaching method DOI: 10.7176/JEP/10-6-1

(E)-2-(2-Chloro-3,3,3-trifluoro­prop-1-en­yl)-N-(2,4-dimethyl­phen­yl)-3,3-dimethyl­cyclo­propane-1-carboxamide

The title compound, C17H19ClF3NO, crystallizes with three mol­ecules in the asymmetric unit. The aromatic ring makes dihedral angles of 38.69 (13), 46.68 (12) and 50.52 (11)° with the plane of the cyclo­propane ring in the three mol­ecules. The crystal packing is stabilized by inter­molecular N—H⋯O hydrogen bonds

Exploration of Training Mode of Applied Talents in Environmental Engineering Specialty

According to the characteristics of environmental engineering in universities, combined with the characteristics of social requirements, a new type of environmental engineering specialty curriculum system is constructed. The curriculum system agrees with the position of running a school and aims of personnel training in the application- oriented universities, providing practical and suitable way to cultivate high- level application- oriented talents for the market and production. Keywords:Application teaching, Environmental engineering specialty, curriculum syste