Orbital stability of S-type circumbinary planets

Nowadays, more than 4,000 exoplanets have been discovered, including a hundred of circumbinary planets. In the following work, the orbital variations of 67 S-type circumbinary planets have been studied. Their orbital evolutions for a thousand years are simulated using the REBOUND package. The published physical and orbital parameters of the systems are used to computed the systems’ orbital instability limits: Roche limit and Hill’s sphere. From 67 systems, there are two unstable circumbinary systems: Kepler-420 and GJ 86. Kepler-420 Ab orbit passes into the system’s Roche limit due to its high orbital eccentricity. For GJ 86 Ab, the planet orbits outside its Hill’s sphere. The instability of GJ 86 Ab might be caused by an inaccurate measurement of GJ 86 A physical parameters. Using the GJ 86 A mass obtained from Farihi et al., the planet orbits in the stable orbit zone.

Deep High-moisture Soil pH Test Equipment and Method

Excessive use of chemical fertilizers in the soil will cause excessive residues of heavy metals, soil hardening and high soil alkalinity. A soil pH tester is generally used to test the soil pH scale to ensure the normal growth of crops. However, the tester cannot be used directly in the case of soil hardening and the soil should be moistened before measurement. In addition, existing soil pH testers can only perform single-point tests, and multiple tests are generally required in order to obtain accurate experimental data. Common deep soil pH test devices are difficult to use and have the problem of inaccurate measurement results due to excessive impurities in the soil in the process of use, resulting in errors in soil analysis which require secondary revision to improve the soil environment. To make up for the defects of existing technologies, this study designs a deep high-moisture soil pH tester, which has the advantage of high soil impurity filtering performance and addresses the problem of inaccurate measurement results due to excessive impurities in the soil.

Design of Remote Intelligent Meter Reading System

This paper discusses the design of a remote intelligent meter reading system, remote intelligent meter reading system by automatic meter data and remote transmission of the way, can solve the problem of the household metering, with automatic meter reading, automatic charging, prepaid management, arrears cut function. The design solves the inaccurate measurement and data change two technical problems of smart meter reading system, remote meter reading system is mainly composed of the meter measuring sensor, meter reading collector, bus adapter, water and gas meter measuring signal is converted to electrical signals by meter measurement sensor, carries on two times of measurement through meter reading collector, bus adapter connected all the meter reading acquisition, and then is connected with the computer management, so as to realize the reading meter data "remote" function.

Gel Pen Smoothness Automatic Measuring Device Based on LabVIEW

The paper introduced the status quo of the gel pen smoothness; developed a new measuring device - smoothness tester for the status quo of the inaccurate measurement; described the measuring principle and system design of the smoothness instrument. Experimental data showed the superiority of the measurement. It basically solved the inaccurate measurement situation. The repeatability is less than 15%, and the correlation with the feeling is not more than 2%.

Biology and Management of Dogfish Sharks

Abstract.—Counts of annuli that form on the mantle of the second dorsal spine of 59 spiny dogfish <em>Squalus acanthias </em>that had been at liberty for up to 20 years after marking with oxytetracycline in most cases corresponded to the years at liberty (87% within 1 year). These results confirm the pattern of annual band formation on the second dorsal spine and validate its use in age estimation. We identified two potential sources of error when estimating the number of annuli on the spine: 1) inaccurate annuli counts near the base of the spine due to irregular enamel deposition and 2) inaccurate location of the no-wear point and subsequent inaccurate measurement of the spine diameter at the no-wear point, which affects estimation of missing annuli using the no-wear point algorithm. In addition, we confirm the validity of Ketchen’s (1975) no-wear point algorithm for the estimation of missing annuli on the worn portion of the distal tip of the spine.