Time Synchronous Averaging Based on Cross-power Spectrum

Periodic components are of great significance for fault diagnosis and health monitoring of rotating machinery.Time synchronous averaging is an effective and convenient technique for extracting those components.However,the performance of time synchronous averaging is seriously limited when the separate segments are poorly synchronized.This paper proposes a new averaging method capable of extracting periodic components without external reference and an accurate period to solve this problem.With this approach,phase detection and compensation eliminate all segments'phase differences,which enables the segments to be well synchronized.The effectiveness of the proposed method is validated by numerical and experimental signals.

One-Step Preparation of Green Fabric for Continuous Antibacterial Applications

Polypropylene(PP)scaffolds are the most commonly used biomedical scaffolds despite their disadvan-tages,which include problems with adhesion,infection,and inflammatory responses.Here,we report on the successful development of a facile one-step method to fabricate a series of novel triclosan poly-dopamine polypropylene(TPP)composite scaffolds and thereby effectively improve the biocompatibility and long-term antibacterial properties of PP scaffolds.The antibacterial triclosan can effectively interact with dopamine during biocompatible polydopamine formation on the PP scaffold by one-step green fab-rication.Thanks to the sustained release of triclosan from the biocompatible polydopamine coating,a 5mm×5mm sample of TPP-coated scaffold made with a triclosan concentration of 8 mg-mL^(-1)(referredto herein as TPP-8)exhibited a continuous antibacterial effect against both Escherichia coli(E.coli)and Staphylococcus aureus(S.aureus)for more than 15d,at maximum antibacterial volumes of 2 and 5mL,respectively.Our study establishes a new direction for facile long-term antibacterial studies for medical applications.

Innovations of Agricultural Scientific Research Institutions in Management of Special Materials

In recent years,the Ministry of Agriculture has increased input in agricultural scientific research projects.As a result,the procurement amount and quantity of special materials are increasing gradually,and the management of special materials becomes more standardized.In order to do well in management of special materials,the authors made exploration and thinking about further strengthening management of special materials in combination with actual conditions,including establishing regulations and systems,enhancing procurement process,strengthening requisition and safekeeping,and reinforcing general ledger management of special materials.

Digital twin model of gas turbine and its application in warning of performance fault

The digital twin-driven performance model provides an attractive option for the warn gas-path faults of the gas turbines.However,three technical difficulties need to be solved:(1)low modeling precision caused by individual differences between gas turbines,(2)poor solution efficiency due to excessive iterations,and(3)the false alarm and missing alarm brought by the traditional fixed threshold method.This paper proposes a digital twin model-based early warning method for gas-path faults that breaks through the above obstacles from three aspects.Firstly,a novel performance modeling strategy is proposed to make the simulation effect close to the actual gas turbine by fusing the mechanism model and measurement data.Secondly,the idea of controlling the relative accuracy of model parameters is developed.The introduction of an error module to the existing model can greatly shorten the modeling cycle.The third solution focuses on the early warning based on the digital twin model,which self-learns the alarm threshold of the warning feature of gas-path parameters using the kernel density estimation.The proposed method is utilized to analyze actual measured data of LM2500+,and the results verify that the new-built digital model has higher accuracy and better efficiency.The comparisons show that the proposed method shows evident superiority in early warning of performance faults for gas turbines over other methods.

The Scholar＇s Robe： Material Culture and Political Power in Early Modern China

This essay explores the history of the scholar＇s robe as a nexus of material culture and political power. It focuses on the controversial garment --called ren 衽-found pervasively in the Confucian canon and confirmed in archaeological findings. But for hundreds of years there have been disagreements and changes concerning which specific term is identified with which part of the robe, especially involving the use of ren in the scholar＇s robe. The bulk of my analysis deals with two prominent scholars＇ monographs on the robe： Huang Zongxi＇s Investigation of the Robe （Shenyi kao） and Jiang Yong＇s pointed rebuttal titled Mistakes in ＂Investigation of the R obe＂ （ Shenyi kao wu）. The intellectual and political configurations of both works are analyzed in depth in order to contrast two options of cultural identity： Chinese superiority versus cosmopolitan universalism.

A novel measurement method of temperature model for bioreactor

A novel measurement method of temperature model for bioreactor has been proposed.Temperature is the key parameter in monitoring the bioreactor operation.However,the system input signal of bioreactor is delayed,and model parameters are uncertain,so the output of temperature is non-steady-state.Many dynamic measurements are not steady so that it cannot be described by variables constant in time.In this paper,we adopt the monopulse signal as input so that the output of the bioreactor system is steady.This method has a powerful ability to steady the output of the bioreactor.In view of the measurement results,it can be seen that the model dynamic measurement approaches the real process.The analytical expression of the monopulse response for the temperature model of the bioreactor is obtained.The novel measurement approach is simple and can be easily adopted by industry.