Combination of heat treatment and chitosan coating to improve postharvest quality of wolfberry (Lycium barbarum)

The synergistic application of hot water dip at 42 °C for 30 min and 1% chitosan coating on differentiation in postharvest quality traits, microstructure as well as microbiological evolution of wolfberry fruits was investigated. Fresh wolfberry fruits were stored at 2 ± 0.5 °C and 90% relative humidity (RH) for 28 days. Results indicated the combination of prestorage heat treatment and chitosan coating maintained higher levels of ascorbic acid, total phenolic contents and antioxidant capacity as well as lower decay, compared with untreated wolfberry fruits. The possible mechanism was that the heat treatment almost sealed open stomata to limit the sites of pathogen penetration into fruits independently, followed by the biofilm formed by chitosan which controlled secondary infections as well as slowed changes in fruit respiration and metabolic activity in wolfberries. The synergistically treated fruit also exhibited a higher acceptability obtained by sensory analysis after cold storage. In this sense, the integrated application of heat treatment and chitosan coating could be regarded as an effective strategy to extend storage life and maintain the postharvest quality of wolfberry fruits.     

Flotation Behavior,Collector Adsorption Mechanism of Quartz and Feldspar-Quartz Systems Using PEA as a Novel Green Collector

Silicon - A novel green cationic surfactant Poly (propylene glycol) bis (2-aminopropyl ether) (PEA) with multiple amine groups was utilized as a collector for flotation separation of quartz from...     

A dual-mode bandpass filter with enhanced capacitive perturbation

A dual-mode ring bandpass filter with two pairs of capacitors has been designed. The capacitors are used to control the location of the even- and odd-mode frequencies independently, allowing weak coupling for narrow-band filter design with realizable capacitance values. Theoretical expressions have been derived for these frequencies. A 4% bandwidth bandpass filter centered at 1.9 GHz was designed and tested with good agreement between theoretical and measured results.     

Laminated Reservoir Fracturing Technique

IntroductionOil production from laminated reservoirs is significant in Daqing Oilfield in the high water cut period. Hydraulic fracturing is a very efficient way to stimulate these laminated reservoirs. Daqing Oilfield is a multi-zone sandstone     

气相起爆系统现场应用试验研究

在现场试验的基础上,对气相起爆系统的实际应用性能进行了初步研究.分析和探讨了该系统安全使用条件和尚存在的诸多技术问题.此外,还介绍了我国首批研制成功的气相雷管及其性能.     

Arterial oxygen desaturation during non-sedated diagnostic upper gastrointestinal endoscopy

We studied oxygen saturation (SaO2) using a pulse oximeter in 120 patients undergoing non-sedated diagnostic upper gastrointestinal endoscopy. The baseline SaO2 was 98.3 +/- 1.0%. During the procedure, absence of oxygen desaturation (SaO2 > or = 95%) was found in 56%, mild oxygen desaturation (95% > SaO2 > or = 90%) in 35%, and severe oxygen desaturation (SaO2 < 90%) in 9%. Age (p = 0.56), gender (p = 0.47), smoking (p = 0.35), hemoglobin level (p = 0.52), body mass index (p = 0.27), or total endoscopy time (p = 0.72) was not related to the degree of oxygen desaturation. These results suggest that oxygen desaturation is frequently observed during non-sedated diagnostic upper gastrointestinal endoscopy although severe oxygen desaturation, which may induce rare but serious cardiopulmonary events, is not common. Furthermore, we cannot predict in which patients desaturation will occur. We therefore recommend continuous monitoring of arterial oxygenation in all patients during the procedure.     

Turbulent Details Simulation for SPH Fluids via Vorticity Refinement

A major issue in smoothed particle hydrodynamics (SPH) approaches is the numerical dissipation during the projection process, especially under coarse discretizations. High‐frequency details, such as turbulence and vortices, are smoothed out, leading to unrealistic results. To address this issue, we introduce a vorticity refinement (VR) solver for SPH fluids with negligible computational overhead. In this method, the numerical dissipation of the vorticity field is recovered by the difference between the theoretical and the actual vorticity, so as to enhance turbulence details. Instead of solving the Biot‐Savart integrals, a stream function, which is easier and more efficient to solve, is used to relate the vorticity field to the velocity field. We obtain turbulence effects of different intensity levels by changing an adjustable parameter. Since the vorticity field is enhanced according to the curl field, our method can not only amplify existing vortices, but also capture additional turbulence. Our VR solver is straightforward to implement and can be easily integrated into existing SPH methods.     

An online multiple object tracker based on structure keeper net

We propose a novel online multiple object tracker taking structure information into account. State-of-the-art multi-object tracking (MOT) approaches commonly focus on discriminative appearance features, while neglect in different levels structure information and the core of data association. Addressing this, we design a new tracker fully exploiting structure information and encoding such information into the cost function of the graph matching model. Firstly, a new measurement is proposed to compare the structure similarity of two graphs whose nodes are equal. With this measurement, we define a complete matching which performs association in high efficiency. Secondly, for incomplete matching scenarios, a structure keeper net (SKnet) is designed to adaptively establish the graph for matching. Finally, we conduct extensive experiments on benchmarks including MOT2015 and MOT17. The results demonstrate the competitiveness and practicability of our tracker.