The Flotation Modification Test of Chrysocolla Research on RSM

This study is focused on the flotation of a cooper mineral.Chrysocolla is poor flotability, surface porous, high porosity, nonuniform property, so it has strong hydrophilic and difficult dissolution. XRD and SEM were used to detect the properties and surface morphology of chrysocolla. The paper make an experiment, it contain modified polymer adsorption - intermediate metal copper ion connection - collector adsorption testing program. The experiment can exchange mineral surface property which enhancing mineral flotation and hydrophobicity. With the conclusion, the results have a trend that increasing the agents can increase mineral recovery, then mineral recovery reach the stable trend. In the simulation of RSM, mineral recovery is based on 3 factors ammonium, xanthate and agent, those factors interact with each other, simulation find the main factor is agent. RSM response surface method has the function of optimizing test results, improving test efficiency, inputting test influence factors and results, and getting the best test factors and results through test simulation.

Research on calibration method of uniformity of radiation interference field of intense electromagnetic pulse

With the rapid development of electronic and electrical products, the working frequency of ite products is higher and higher, the influence frequency range of interference between electronic products is also expanding, the test frequency range of radiation anti-interference is improving, at the same time, more and more attention is paid to the requirements of radiation anti-interference test site. At present, the uniformity of radiation field is mainly realized by single point multiple test, which will inevitably lead to the measurement error due to the time-varying characteristics of the radiation signal itself; In addition, the test time is greatly increased and the test efficiency is low. In order to solve these problems, this paper designs a device which can realize multi-point test at one time and can automatically adjust the test area. The simulation shows that the device can meet the requirement of 9point uniformity test of radiation field in 500mm × 500mm ~ 1500mm × 1500mm area. On this basis, experiments are carried out in 1000mm × 1000mm test area for 1.35GHz and 2.88GHz. The experiments show that the test device can meet the requirement of 9point uniformity test and greatly improve the test efficiency and automation.

Risk stratification by anamnesis increases SARS-CoV-2 test efficiency in cancer patients

Purpose To evaluate the impact of testing asymptomatic cancer patients, we analyzed all tests for severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) before and during radiotherapy at a tertiary cancer center throughout the second wave of the pandemic in Germany. Methods Results of all real-time polymerase chain reaction (RT-PCR) tests for SARS-CoV‑2 performed at our radio-oncology department between 13 October 2020 and 11 March 2021 were included. Clinical data and anamnestic information at the time of testing were documented and examined for (i) the presence of COVID-19-related symptoms and (ii) virus-related anamnesis (high-risk [prior positive test or contact to a positive tested person within the last 14 days] or low-risk [inconspicuous anamnesis within the last 14 days]). Results A total of 1056 SARS-CoV‑2 tests in 543 patients were analyzed. Of those, 1015 tests were performed in asymptomatic patients and 41 tests in patients with COVID-19-associated symptoms. Two of 940 (0.2%) tests in asymptomatic patients with low-risk anamnesis and three of 75 (4.0%) tests in asymptomatic patients with high-risk anamnesis showed a positive result. For symptomatic patients, SARS-CoV‑2 was detected in three of 36 (8.3%) low-risk and three of five (60.0%) high-risk tests. Conclusion To the best of our knowledge, this is the first study evaluating the correlation between individual risk factors and positivity rates of SARS-CoV‑2 tests in cancer patients. The data demonstrate that clinical and anamnestic assessment is a simple and effective measure to distinctly increase SARS-CoV‑2 test efficiency. This might enable cancer centers to adjust test strategies in asymptomatic patients, especially when test resources are scarce.

Integrative modelling of reported case numbers and seroprevalence reveals time-dependent test efficiency and infection rates

Mathematical models have been widely used during the ongoing SARS-CoV-2 pandemic for data interpretation, forecasting, and policy making. However, most models are based on officially reported case numbers, which depend on test availability and test strategies. The time dependence of these factors renders interpretation difficult and might even result in estimation biases. Here, we present a computational modelling framework that allows for the integration of reported case numbers with seroprevalence estimates obtained from representative population cohorts. To account for the time dependence of infection and testing rates, we embed flexible splines in an epidemiological model. The parameters of these splines are estimated, along with the other parameters, from the available data using a Bayesian approach. The application of this approach to the official case numbers reported for Munich (Germany) and the seroprevalence reported by the prospective COVID-19 Cohort Munich (KoCo19) provides first estimates for the time dependence of the under-reporting factor. Furthermore, we estimate how the effectiveness of non-pharmaceutical interventions and of the testing strategy evolves over time. Overall, our results show that the integration of temporally highly resolved and representative data is beneficial for accurate epidemiological analyses.

Experimental Investigation of the Technical Performances of SRX-Stabilized Graded Macadam

The technical performances of Solution Road RomixSoilfix- (SRX-) stabilized graded macadam (SSGM) are investigated to promote its application. The specimen curing conditions were proposed to improve the test efficiency by analyzing the influence of curing temperature on the unconfined compressive strength and moisture content variation. Moreover, the mechanical properties (e.g., CBR, strength, and resilient modulus) and pavement performances (e.g., temperature shrinkage, water stability, and freezing stability) of SSGM were evaluated through laboratory tests. The results show that the recommended curing temperature in the drying oven should be 100°C ± 2°C and the recommended curing time should not be less than 16 h. Furthermore, the CBR, unconfined compressive and splitting strengths, and resilient modulus of SSGM increase with the content of SRX stabilizer. The temperature shrinkage coefficient is approximately 15% of the cement-stabilized grading crushed stone. The dry-wet recovery strength ratio is approximately 96% after four dry-wet cycles. The freeze-thaw recovery strength ratio is approximately 58% after five freeze-thaw cycles. The freezing stability of SSGM can be improved by increasing the content of SRX stabilizer. The technical performances of SSGM should fulfill the technical requirements.

Research on Test Method for Low Altitude Wireless Network Signal

Objective: In recent years, with the large-scale construction of large venues, high-rise office buildings, residential quarters, and the development of networked UAV, the demand and complaints of users for air network coverage are increasing. The existing road test instruments are designed for ground coverage based on mobile app and PC software, which is not suitable for low altitude signal. In order to shorten the test cycle of low altitude network signal and improve the test efficiency, a new low altitude network signal test method is proposed, and a test system suitable for low altitude network signal coverage and quality detection is developed. Methods: The present study investigated a system that uses airborne measuring instrument to complete data acquisition, and returns real-time data to the processing cloud platform through 5g cellular network. The signal quality and capacity of low altitude network are detected on the cloud platform. Results: The test results show that the proposed method and the developed airborne measuring instrument can complete the low altitude network signal test work and effectively improve the test efficiency. Conclusion: The research on test method for low altitude wireless network signal plays an important role in the optimization of low altitude network and fine management of tower base station information.