Dynamic test on waste heat recovery system with organic Rankine cycle

Dynamic performance is important to the controlling and monitoring of the organic Rankine cycle(ORC) system so to avoid the occurrence of unwanted conditions. A small scale waste heat recovery system with organic Rankine cycle was constructed and the dynamic behavior was presented. In the dynamic test, the pump was stopped and then started. In addition, there was a step change of the flue gas volume flow rate and the converter frequency of multistage pump, respectively. The results indicate that the working fluid flow rate has the shortest response time, followed by the expander inlet pressure and the expander inlet temperature.The operation frequency of pump is a key parameter for the ORC system. Due to a step change of pump frequency(39.49-35.24 Hz),the expander efficiency and thermal efficiency drop by 16% and 21% within 2 min, respectively. Besides, the saturated mixture can lead to an increase of the expander rotation speed.

Atmospheric Degradation and Performance Recovery of Two-Dimensional MoS2 Field Effect Transistor

Two-dimensional(2D)transition metal dichalcogenides(TMDCs)showed great potentials in 2D nanoelectronic devices due to their abundant and unique properties.The performance stability of the 2D TMDCs devices turns into one of the keys for their practical applications but has been rarely explored.Here,we investigated stability of MoS_(2)devices in ambient condition and contributed the device performance degradation to the surface oxidation of the contact metals with low work function,which increased the contact barrier and hindered the electron injection.We developed a new approach to recover the performance of the aged devices through the selective doping of contacts with organolithium,which prolonged the lifetime of MoS_(2)devices.Our work not only provides important insights into the stability of 2D TMDCs devices,but also opens up a new avenue for optimizing the performance of 2D MoS_(2)devices.

Unified control and detection framework and its applications: a review, some new results, and future perspectives

Initiated three decades ago,integrated design of controllers and fault detectors has continuously attracted research attention.The recent development of the unified control and detection framework with an observer-based residual generator in its core gives a more general form of the previous works.Its applications to residual centred modelling of uncertain control systems,fault detection in feedback control systems with uncertainties,fault-tolerant control(FTC)as well as control performance degradation monitoring,detection and recovery are introduced.In conclusion,some future perspectives are proposed.

Production Remains Stable and Investment Shows Recovery Signs The analysis of economic performance of China’s cotton textile industry

Indeed,there is some evidence the government’s stimulus package is producing results.Investment of cotton textile industry shows recovery progress and production remains stable.