Significantly improved high-temperature energy storage performance of commercial BOPP films by utilizing ultraviolet grafting modification

Commercial biaxially oriented polypropylene (BOPP) film capacitors have been widely applied in the fields of electrical and electronic engineering. However, due to the sharp increase in electrical conduction loss as the temperature rises, the energy storage performance of BOPP films seriously degrades at elevated temperatures. In this study, the grafting modification method is facile and suitable for large-scale industrial manufacturing and has been proposed to increase the high-temperature energy storage performance of commercial BOPP films for the first time. Specifically, acrylic acid (AA) as a polar organic molecular is used to graft onto the surface of commercial BOPP films by using ultraviolet irradiation (abbreviated as BOPP−AA). The results demonstrate that the AA grafting modification not only slightly increases the dielectric constant, but also significantly reduces the leakage current density at high-temperature, greatly improving the high-temperature energy storage performance. The modified BOPP−AA films display a discharged energy density of 1.32 J/cm3 with an efficiency of >90% at 370 kV/mm and 125 °C, which is 474% higher than that of the pristine BOPP films. This work manifests that utilizing ultraviolet grafting modification is a very efficient way to improve the high-temperature energy storage performance of commercial BOPP films as well as provides a hitherto unexplored opportunity for large-scalable production applications

Spatial distribution of per- and polyfluoroalkyl compounds in coastal waters from the East to South China Sea

The spatial distribution of per- and polyfluoroalkyl compounds (PFCs) were investigated in coastal waters collected onboard research vessel Snow Dragon from the East to South China Sea in 2010. All samples were prepared by solid-phase extraction and analyzed using high performance liquid chromatography/negative electrospray ionization-tandem mass spectrometry (HPLC/(-)ESI-MS/MS). Concentrations of 9 PFCs, including C4 and C8 (PFBS, PFOS) perfluoroalkyl sulfonate (PFSAs), C 5-C9 and C13 (PFPA, PFHxA, PFHpA, PFOA, PFNA, PFTriDA) perfluoroalkyl carboxylates (PFCAs), and N-ethyl perfluorooctane sulfonamide (EtFOSA) were quantified. The 危PFC concentrations ranged from 133 pg/L to 3320 pg/L, with PFOA (37.5-1541 pg/L), PFBS (23.0-941 pg/L) and PFHpA (0-422 pg/L) as dominant compounds. Concentrations of PFCs were greater in coastal waters along Shanghai, Ningbo, Taizhou, Xiamen and along coastal cities of the Guangdong province compared to less populated areas along the east Chinese coast. Additionally, the comparison with other seawater PFC measurements showed lower levels in this study. 漏 2011 Elsevier Ltd. All rights reserved

Numerical Study on Acoustic Resonance Excitation in Closed Side Branch Pipeline Conveying Natural Gas

Flow-induced acoustic resonance in the closed side branch of a natural gas pipeline can cause intensive vibration which threatens the safe operation of the pipeline. Accurately modeling this excitation process is necessary for a workable understanding of the genetic mechanism to resolve this problem. A realizable k-ε Delayed Detached Eddy Simulation (DDES) model was conducted in this study to numerically simulate the acoustic resonance problem. The model is shown to accurately capture the acoustic resonance phenomenon and self-excited vibration characteristics with low calculation cost. The pressure pulsation component of the acoustic resonance frequency is gradually amplified and transformed into a narrowband dominant frequency in the process of acoustic resonance excitation, forming a so-called “frequency lock-in phenomenon.” The gas is pressed into and out of the branch in sinusoidal mode during excitation. The first-order frequency, single vortex moves at the branch inlet following the same pattern. A quarter wavelength steady standing wave forms in the branch. The mechanism and characteristics presented in this paper may provide guidelines for developing new excitation suppression methods

Numerical Simulation of Acoustic Resonance Enhancement for Mean Flow Wind Energy Harvester as Well as Suppression for Pipeline

Acoustic resonance in closed side branches should be enhanced to improve the efficiency of wind energy harvesting equipment or thermo-acoustic engine. However, in gas pipeline transportation systems, this kind of acoustic resonance should be suppressed to avoid fatigue damage to the pipeline. Realizable k-ε delayed detached eddy simulations (DDES) were conducted to study the effect of different branch pipe shapes on acoustic resonance. At some flow velocities, the pressure amplitude of the simulation results is twice as large as that of the experimental results, but the simulation can accurately capture the flow velocity range where acoustic resonance occurs. The results prove the feasibility of the method of the equivalent diameter of the circular cross-section pipe and the square cross-section pipe to predict acoustic resonance. The pressure pulsation amplitude of acoustic resonance in a square cross-section pipe is significantly increased than that in a circular square cross-section pipe, indicating that the square cross-section branch configuration can be more conducive to improving the efficiency of wind energy harvesting. The influence of the angle between the branch and the main pipe on the acoustic resonance was studied for the first time, which has an obvious influence on the acoustic resonance. It is found that the design of a square wind energy harvester is better than that of a circular one; meanwhile, changing the branch angle can increase or suppress the acoustic resonance, which can improve the utilization efficiency of the acoustic resonance and provide a new method for suppressing the acoustic resonance

Clinical Value of Four-hole Unilateral Dissecting Lobectomy and Mediastinal Lymph Node Dissection in the Treatment of Early Non-small Cell Lung Cancer

Background and objective Thoracoscopic lobectomy combined with mediastinal lymph node dissection has been considered as one of the standard surgical procedures for early lung cancer. After 20 years of development, thoracoscopic lobectomy has reached a consensus on reliability and minimally invasive. At present, thoracoscopic lobectomy has a variety of incisions, which gradually evolve into four holes based on three holes, and two or one hole as the operative approach. The aim of this study was to evaluate the clinical value of four-hole unilateral dissecting lobectomy and mediastinal lymph node dissection in the treatment of non-small cell lung cancer (NSCLC). The aim of this study was to investigate the clinical value of anatomical lobectomy with mediastinal lymphadenectomy under four-hole completely video-assisted thoracoscopic surgery (C-VATS) in the treatment of non-small cell lung cancer. Methods The patients undergoing lobectomy with mediastinal lymphadenectomy for NSCLC were identified in the Department of Thoracic Surgery, Yangzhou First People's Hospital, Yangzhou University from March 2015 to July 2016. Preoperative clinical diagnosis of peripheral-type early NSCLC. The patients were randomly divided into four-hole monophasic group (experimental group) and three-hole group (control group) according to the number of hospitalization before surgery. According to inclusion and exclusion criteria, the 39 cases assign in experimental group and 34 cases in the control group, including 36 males and 37 females; aged 38 to 84 years. The mean operation time, average blood loss, lymph node dissection group, average drainage, average extubation time and postoperative complications were compared between the two groups for statistical analysis. Results The two groups of patients were successfully completed surgery, no death after surgery. Mean bleeding in the two groups, the number of lymph node dissection group, the average postoperative drainage, the average time of extubation, postoperative complications, with no significant difference. The average operation time of the four-hole unidirectional group was shorter than that of the three-hole group. The difference was statistically significant (P<0.05). Conclusion The safety and efficacy of a four-hole one-way operation under VATS are satisfactory. The operation is smooth during operation, which shortens the course of operation and deserves the clinical promotion

Prognostic nomogram for overall survival in upper urinary tract urothelial carcinoma (UTUC) patients treated with chemotherapy: a SEER-based retrospective cohort study

Abstract Objective To establish a prognostic nomogram among UTUC patients who received chemotherapy. Methods 1195 UTUC patients who received chemotherapy were extracted from the Surveillance, Epidemiology, and End Results (SEER) database for the period between 2004 and 2015. Patients were randomly divided into a training and a validation set. Nomogram was constructed to predict 1-, 3-, and 5-year overall survival (OS) in those patients. Receiver-operating characteristic curves (ROCs), calibration plots, and Decision curve analysis (DCA) were applied to assess and compare the discrimination, accuracy, and practicability of the nomogram with 8th American Joint Committee on Cancer (AJCC) tumor node metastasis (TNM) staging system. Results Six clinical parameters were identified as independent prognostic factors for UTUC patients’ OS, including age, marital status, TNM stage, and surgical methods of the primary site. The ROC curves showed a satisfactory discrimination capacity of the nomogram, with 1-, 3-, and 5-year area under curve (AUC) values of 0.789, 0.772, and 0.763 in the training set and 0.772, 0.822, and 0.814 in the validation set, respectively. Calibration curves indicated a good agreement between actual observation and nomogram prediction. ROC and DCA curves showed our nomograms exhibited larger benefits than the 8th AJCC-TNM staging system. Conclusions A prognostic nomogram was established and validated to present individual predictions of OS among chemotherapeutic UTUC patients. This nomogram may assist clinicians in accurate survival prognostication, treatment decision-making, and design of future clinical trials

Isolation and characterization of cinnamate 4-hydroxylase gene from cultivated ramie (Boehmeria nivea)

The present study aimed to describe the cDNA cloning of the cinnamate 4-hydroxylase (C4H) gene from ramie, predict the protein sequence and perform phylogenetic and structural analyses of this gene. C4H catalyses the hydroxylation of trans-cinnamic acid to p-coumaric acid, which plays a crucial role in lignin biosynthesis. In the present study, the gene encoding C4H was cloned by polymerase chain reaction (PCR) technology from cultivated ramie (Boehmeria nivea) and named BnGC4H. In addition, bioinformatics and tissue expression analyses were performed. The results showed that the cloned BnGC4H cDNA contained a 1518-bp open reading frame encoding a 505–amino acid protein. The sequence of BnGC4H is available from the GenBank database with accession number KY937946. The amino acid sequence and structural analysis revealed that BnGC4H shared conserved domains with other C4H forms, including cytochrome P450 domain and trans-cinnamate 4-monooxygenase domain. The phylogenetic analysis indicated that BnGC4H was closely related to Aquilaria sinensis C4H and Ruta graveolens C4H. Real-time quantitative reverse transcription–PCR and RNA in situ hybridization showed that BnGC4H was strongly expressed in the xylem during the maturity stage. The findings provided a theoretical basis for further exploring the function of BnGC4H in the lignin biosynthesis and regulation in ramie