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Polylatic acid (PLA) and PLA foams show a promising prospect for replacing the traditional petroleum-based polymers and foams. However, PLA shows poor ductility, thermal stability and foaming ability, and its application is significantly limited. Herein, silane-modified glass fibers (m-GF) were adopted to improve the mechanical properties, thermal stability, and foaming ability of PLA. PLA/m-GF composites with different GF contents were firstly prepared by twin-screw compounding. Microscopic morphology analysis showed that silane-modified GF has a good bonding with PLA matrix, and increasing GF content led to slight decreased of GF length. Mechanical testing showed that GF led to simultaneously enhanced strength, rigidness, and toughness. The higher the GF content is, the more obvious the reinforcement effect is. With 20 wt% GF, the PLA/m-GF composite shows almost 2-fold enhanced strength and rigidness, and more than 3-fold enhanced impact toughness than the pure PLA. The outstanding mechanical properties arises from the strengthening effect of the GF network skeleton that shows good bonding with PLA matrix. Thermal analysis showed that GF led to increased heat deflection temperature but reduced melt flow index of PLA. Foaming experiments showed that GF can dramatically improve the foaming ability by increasing expansion ratio and refining cellular morphology. Microcellular PLA/m-GF foam with an expansion ratio of up to 20-fold and cell sizes less than 10 μm was achieved. Thus, the strong PLA/m-GF composites and their foams show a promising future in preparing lightweight structural components used in many applications such as automotive and aircraft industries.

In this study, the effect of various organic solvents on enzyme activity and substrate enantiomeric excess ( ee s ) of the lipase from Burkholderia cenocepacia (BCL) was investigated in the enantioselective transesterification of 1-phenylethanol. Secondary structure analysis by Fourier transform-infrared spectroscopy (FT-IR) showed that the variations in secondary structure element content (α-helix, β-sheet, β-turn and random coil) were probably responsible for the changes in enzyme activity and ee s . Furthermore, the change in fluorescence intensity indicated, to some extent, the alteration in tertiary structure, which may also explain why organic solvents affect enzyme activity and ee s . Moreover, response surface methodology (RSM) was employed to optimize the reaction parameters. The optimized reaction conditions were: substrate molar ratio 4.7:1; reaction time 18.6 h, and reaction temperature 53.4 °C. Under the optimal reaction conditions, the ee s and ee p were respectively 99.22% and 98.74%, and the corresponding enzyme activity was 1392.2 U/min/g protein. Compared with other lipases, BCL exhibited better catalytic efficiency and has significant potential in industrial applications.

Rapid heat cycle molding (RHCM) is a recently developed innovative injection molding technology to enhance the surface quality of the plastic parts without extending the molding cycle. Most of the common defects that occur in the plastic parts produced by conventional injection molding (CIM), such as flow mark, silver mark, jetting mark, weld mark, exposed fibers, short shot, etc., can be well solved by RHCM. However, RHCM is not a nostrum for all the defects in injection molding. Sink mark and warpage are two major defects occurring in RHCM. The purpose of this study is to investigate and further solve the sink mark and warpage of the molded parts in RHCM. To solve the problem of sink mark, a new “bench form” structure for the screw stud on the product coupling with a lifter structure for the injection mold was proposed. The external gas assisted packing was also proposed to reduce the sink mark in RHCM. To solve the problem of warpage, design of experiments via Taguchi methods were performed to systematically investigate the effect of processing parameters including melt temperature, injection time, packing pressure, packing time and also cooling time on the warpage. Injection molding simulations based on Moldflow were conducted to acquire the warpages of the plastic parts produced under different processing conditions. A signal to noise analysis was conducted to analyze the effect of the factors, and the optimal processing parameters were also found out. ANOVA was also conducted to quantitatively analyze the percentage contributions of the processing parameters on the warpage. The verification results show that part warpage can be reduced effectively based on the optimal design results.

Rapid heat cycle molding (RHCM) is a recently developed injection molding technology to enhance surface esthetic of the parts. By rapid heating and cooling of mold cavity surfaces in molding process, it can greatly alleviate or even eliminate the surface defects such as flow mark, weld line, glass fiber rich surface, silver mark, jetting mark, and swirl mark, and also improve gloss finish and dimensional accuracy without prolonging the molding cycle. Besides surface esthetic, mechanical property is also a very import issue for the molded plastic part. The aim of this study is focusing on the effects of the cavity surface temperature just before filling, T cs , in RHCM on the mechanical strength of the specimen with and without weld line. Six kinds of typical plastics including polystyrene (PS), polypropylene (PP), acrylonitrile butadiene styrene (ABS), acrylonitrile butadiene styrene/polymethylmethacrylate (ABS/PMMA), ABS/PMMA/nano-C a CO 3 and glass fiber reinforced polypropylene (FRPP) are used in experiments. The specimens with and without a weld line are produced with the different T cs on the developed electric-heating RHCM system. Tensile tests and notched Izod impact tests are conducted to characterize the mechanical strength of the specimens molded with different cavity surface temperatures. Simulations, differential scanning calorimetry (DSC), scanning electron microscope (SEM) and optical microscope are implemented to explain the impact mechanism of T cs on mechanical properties.

The influences of the cavity surface temperature just before filling on part surface appearance and texture in rapid heat cycle moulding are investigated. It is observed that the cavity surface temperature just before filling has a very significant influence on part surface appearance. As the cavity surface temperature increases, aesthetic quality of the moulded part can be greatly improved by reducing surface roughness, increasing surface gloss and reducing weld mark. There is a critical cavity surface temperature just before filling for each plastic material. As the cavity surface temperature reaches the critical value, the part surface appearance will reach the optimal level with lowest roughness, highest gloss and without any weld mark. The critical cavity surface temperature on surface gloss and roughness is close to the Vicat softening point of the plastic material. The critical cavity surface temperature on weld mark is 10–20 °C higher than that on surface roughness and gloss. The mechanisms for generating the rough surface of the part moulded with a low cavity surface temperature and improving part surface appearance by increasing cavity surface temperature are disclosed.

The influences of the cavity surface temperature just before filling on surface appearance and texture of the moulded reinforced plastic parts in rapid heat cycle moulding (RHCM) are investigated. Two typical reinforced plastics including ABS/PMMA/nano-C a CO 3 and 20% fibre reinforced polypropylene (FRPP) are tested in experiments. The roughness, gloss and morphology of the part surface are characterized with white light interferometer, gloss meter, and optical microscope, respectively. It is observed that the cavity surface temperature just before filling has a significant influence on part surface appearance. With the increase of the cavity surface temperature just before filling, aesthetic quality of the moulded part can be greatly improved. There is a critical value of the cavity surface temperature just before filling for each plastic. As the cavity surface temperature reaches the critical value, part surface appearance will reach the optimal level with low roughness and high gloss. The weld mark for ABS/PMMA/nano-C a CO 3 has a V-shaped structure while that for FRPP has a hump-shaped structure. With the increase of the cavity surface temperature just before filling, the width of the V-shaped weld mark reduces gradually until it disappears completely while the height of the hump-shaped weld mark decreases firstly and then increases. The mechanisms for the improvement of surface appearance by increasing cavity surface temperature just before filling and the generation of the V-shaped and hump-shaped weld mark are disclosed.

The present study aimed to examine the mechanism of triptolide in the treatment of ankylosing spondylitis (AS) through the anti‑ossification effect of bone morphogenetic protein (BMP)/small mothers against decapentaplegic (Smad) pathway. Male rats were randomly divided into five groups: Normal rat group; model group; triptolide low dose group (10 mg/kg); triptolide middle dose group (20 mg/kg); triptolide high dose group (40 mg/kg). The spinal joint capsules of each group of rats were collected to perform primary cell culture to determine the levels of cell proliferation. Western blot and reverse transcription‑polymerase chain reaction analyses, and ELISA were used to detect the mRNA and protein expression levels of core‑binding factor α1 (Cbfal), BMP receptor type II (BMPRII), Smad1, Smad4, Smad5 and Smad6, the protein expression of phosphorylation indicators, including phosphorylated (p)Smad1 and pSmad5, the mRNA expression of tumor necrosis factor‑α (TNF‑α), interleukin (IL)‑1β and IL‑6 in rat plasma, and the mRNA expression of BMP/Smads in fibroblasts induced by recombinant human (rh)BMP‑2. The effects on AS in the rats were also examined. The results revealed that, following intervention with triptolide, inflammation was suppressed, and the mRNA expression levels of TNF‑α, IL‑1β and IL‑6 were reduced. The expression levels of Cbfal, BMPRII, Smad1, Smad4 and Smad5 were also reduced, whereas the expression of Smad6 was increased. Following induction by rhBMP‑2, the effects of triptolide weakened, with the most marked effects observed at the highest concentration, suggesting that triptolide functions through the BMP/Smad signaling pathway. Taken together, the results suggested that triptolide may be used to treat AS, the mechanism of which may be through the BMP/Smad pathway.

Cross-linking of enzyme aggregates from recombinant Geotrichum sp. lipase based on polyethylenimine (PEI) was applied to hydrolyze fish oil for enrichment of polyunsaturated fatty acids successfully. Through acetone precipitation and cross-linking of physical aggregates using glutaraldehyde in the presence of PEI, firmly cross-linked enzyme aggregates (PEI-CLEAs) were prepared. They could maintain more than 65% of relative hydrolysis degree after incubation in the range of 50-55 °C for 4 h and maintain more than 85% of relative hydrolysis degree after being treated by acetone, tert-butyl alcohol and octane for 4 h. PEI-CLEAs increased hydrolysis degree to 42% from 12% by free lipase. After five batch reactions, PEI-CLEAs still maintained 72% of relative hydrolysis degree. Hydrolysis of fish oil by PEI-CLEAs produced glycerides containing concentrated EPA and DHA in good yield. PEI-CLEAs had advantages over general CLEAs and free lipase in initial reaction rate, hydrolysis degree, thermostability, organic solvent tolerance and reusability.

Novel modification methods for lipase biocatalysts effective in hydrolysis of fish oil for enrichment of polyunsaturated fatty acids (PUFAs) were described. Based on conventional immobilization in single aqueous medium, immobilization of lipase in two phase medium composed of buffer and octane was employed. Furthermore, immobilization (in single aqueous or in two phase medium) coupled to fish oil treatment was integrated. Among these, lipase immobilized in two phase medium coupled to fish oil treatment (IMLAOF) had advantages over other modified lipases in initial reaction rate and hydrolysis degree. The hydrolysis degree increased from 12% with the free lipase to 40% with IMLAOF. Strong polar and hydrophobic solvents had negative impact on immobilization-fish oil treatment lipases, while low polar solvents were helpful to maintain the modification effect of immobilization-fish oil treatment. After five cycles of usage, the immobilization-fish oil treatment lipases still maintained more than 80% of relative hydrolysis degree.

The layout of the heating/cooling channels is of great significance for rapid heat cycle molding (RHCM) mold with steam heating and coolant cooling because it not only affects heating/cooling efficiency, temperature uniformity of mold cavity surface, but also has a great influence on mold strength. Thermal, structural and fatigue analysis based on finite element method (FEM) is performed to investigate the effect of the heating/cooling channels layout on thermal response, structural strength and fatigue life of the RHCM mold. In order to obtain a reasonable layout of heating/cooling channels, this study focuses on the development of an effective methodology for the layout optimization of the heating/cooling channels by integrating response surface methodology (RSM) and multi-objective particle swarm optimization (MOPSO) algorithm. Three design variables describing the layout and scale of the heating channels are selected to do the design of Box-Behnken experiment with three factors and three levels. Thermal/structural analysis is carried out using ANSYS to obtain the corresponding values of three objective variables, including required heating time, maximum cavity surface temperature difference and maximum von-Mises stress due to thermal expansion, which are used to describe heating efficiency, temperature uniformity and mold strength, respectively, for different sets of design variables. RSM is utilized to analyze the effect of the design parameters and further construct mathematical models to quantitatively describe the relationship between design variables and objective variables via regression analysis. Analysis of variance (ANOVA) demonstrates that the developed quadratic models are highly effective and significant. Confirmation experiment is also conducted to verify the effectiveness and accuracy of the developed quadratic polynomial models. Based on these mathematical models, a MOPSO algorithm is then introduced to optimize the design variables by comprehensively considering thermal efficiency, temperature uniformity and structural strength of the RHCM mold. The optimum results show that thermal efficiency and temperature uniformity of the RHCM mold can be greatly improved with the optimum design variables for the layout of the heating/cooling channels. The following verification experiment demonstrates the validity of the optimum results.

The usage of rapid heat cycle molding (RHCM) has gained increasing attention in overcoming the limits of conventional injection molding (CIM) and improving the surface quality and mechanical properties of molded plastic products. In RHCM, the vario-thermal mold temperature control system is the key technique because it directly affects the molding cycle time and the final part quality. In this study, a new RHCM technology with electric heating and coolant cooling was studied in detail. Two different RHCM mold structures for a large LCD TV panel were proposed and designed. The numerical simulation method was used to analyze the thermal response of the mold cavity surface at the heating stage and the thermal response of the resin melt at the cooling stage. The heating/cooling efficiency of the proposed electric heating RHCM system was evaluated. The thermal expansion analysis of mold cavity was implemented and the fixation of the cavity in molds was also optimized. The results showed that the electric-heating mold with a separate cooling plate can efficiently enhance the heating efficiency. The thermal expansion of the cavity surface can be reduced by increasing the alleviating-gap between the cavity and the cavity-retainer plate. Then, the service lifetime of the electric-heating mold can be improved. A RHCM production line with electric heating for the large LCD TV panel was constructed. Both the simulation and test production results indicate that the proposed electric heating RHCM technique can realize high-temperature injection molding without increasing the molding cycle time. The surface appearance of the LCD TV panels was dramatically improved and the surface marks that usually occur in CIM process were eliminated completely. Copyright © 2009 John Wiley & Sons, Ltd.

A dual modification procedure composed of cross-linking and protein coating with K 2 SO 4 was employed to modify Geotrichum sp. lipase for catalyzing biodiesel production from waste cooking oil. Compared to single modification of protein coating with K 2 SO 4 , the dual modification of cross-linking and lipase coating improved catalytic properties in terms of thermostable stability, organic solvent tolerance, pH stability and operational stability in biodiesel production process, although biodiesel yield and initial reaction rate for CLPCMCs were not improved. After five successive batch reactions, CLPCMCs could still maintain 80% of relative biodiesel yield. CLPCMCs retained 64% of relative biodiesel yield after incubation in a pH range of 4–6 for 4 h, and 85% of relative biodiesel yield after incubation in a range of 45–50 °C for 4 h. CLPCMCs still maintained 83% of relative biodiesel yield after both treated in polar organic solvent and non-polar organic solvent for 4 h.

Rapid heat cycle molding (RHCM) is a novel injection molding technology, in which injection mold is rapidly heated to a high temperature, usually higher than the glass transition temperature of the polymer material, before melt-injection and rapidly cooled down to solidify the shaped polymer melt in mold cavity for ejection. Since the elevated mold temperature can eliminate the unwanted premature melt freezing during filling stage, the melt flow resistance is greatly reduced and the filling ability of the polymer melt is also significantly improved. As a result, plastic parts with excellent surface appearance can be obtained. In this study, a three-dimensional numerical model coupled with heat transfer analysis and melt-filling processes for RHCM with steam heating was established. The thermal response analysis for the heating stage of RHCM process was performed by solving heat conduction equations. The heat transfer analysis results right after the mold cavity surface is heated up to the required tempera...

Rapid heat cycle moulding (RHCM) is a newly developed moulding technique to improve the surface appearance of plastic parts and eliminate the polluting secondary operations such as primers and painting. In steam-assisted RHCM, the mould surface temperature should be thermally cycled by alternatively cycling the high temperature steam and cooling water in the heating/cooling channels of the mould. The mould design is of great importance for RHCM because it not only has a great effect on the heating/cooling efficiency and hence the productivity but also directly affects the mould surface temperature uniformity and accordingly the final part quality. Furthermore, the service life of the RHCM mould with steam heating is also very much dependent on the mould structure or the layout of the heating/cooling channels as the fatigue crack is likely to occur at the wall of the heating/cooling channels under combined thermal cycling and mechanical loading. In this study, an RHCM mould for a type of 52-inch LCD TV frame was designed. A three-dimensional (3D) transient thermal analysis was performed to determine the thermal response efficiency of the designed RHCM mould cavity and investigate the factors affecting the heating efficiency. Then, by using the results obtained from the heat transfer simulation, the thermal-structure coupling analysis comprehensively considering the cavity pressure and clamp force was conducted to analyse the stress distribution in the mould cavity, which is helpful to find the weak position in the mould cavity. We found that the spots where the maximum stresses occur are similar to the region where fatigue cracks come into being in the actual RHCM mould. Based on the simulation results, the mechanism of the cavity cracks formation on the cavity surface was proposed. Finally, the fatigue analysis was conducted to predict the fatigue life of the RHCM mould. The analysis results show that the regions at the top edges of the heating/cooling channels have the lowest fatigue life and safety factor. The discrepancy between the available life predicted by simulation and the actual service life of the RHCM mould is also discussed.

A new electric-heating rapid thermal response (RTR) mold with floating cavity/core for rapid heat cycle molding is investigated in this study. Process principles of Rapid heat cycle molding (RHCM) with such new electric-heating mold are discussed and presented. Response surface methodology (RSM) is employed to develop mathematical relationships between layout of the heating elements and heating efficiency, temperature uniformity and structural strength of the floating cavity. Three explanatory variables including half distance between two adjacent heating rods, spacing between heating rods and cavity surface, and the diameter of the heating rod are used to describe the layout and scale of the heating elements. The response variables involving required heating time, maximum cavity surface temperature, and maximum von-Mises stress are used to characterize heating efficiency, temperature uniformity, and structural strength of the floating cavity, respectively. Central composite design (CCD) method is used for factorial experiments. Finite element analyses are conducted for combination of explanatory parameters to acquire the corresponding values of the response variables. Three predictive models for the response variables are created by regression analysis. Analysis of variance (ANOVA) is used to check their accuracy. These response surface models are interfaced with an effective particle swarm algorithm for the optimum heating system design of the electric-heating RTR mold. The developed optimum method is then used for the design of the floating electric-heating cavity for an actual industrial product. The following heat transfer analysis results show that the temperature distribution uniformity of the cavity surface is greatly improved with the optimal cavity structure and layout of heating rods. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

This study evaluated the effect of pentazocine pretreatment on fentanyl-induced cough. With ethics committee approval, 277 ASA I-II patients, aged between 19 and 63 years, undergoing various elective surgeries during general anesthesia, were enrolled in this prospective, randomized, double-blind, placebo-controlled clinical trial. All patients were randomly assigned to one of three groups. Group I (n = 92) and Group II (n = 93) received normal saline, while Group III (n = 92) received pentazocine 0.5 mg·kg(-1) 5 min prior to receiving fentanyl, Patients belonging to Groups II and III were administered 2 μg/kg fentanyl intravenously over 2 s after the first injection; Group I served as a negative control for fentanyl. Physiologic indicators such as heart rate (HR), non-invasive blood pressure (NBP) and pulse oximetry oxygen saturation (SpO(2)) of patients were recorded before giving pentazocine or normal saline 1 minute after fentanyl injections. The incidence of cough was recorded and graded as mild (1-2), moderate (3-5) and severe (> 5), depending on the number of coughs observed [13]. The incidence of cough was 0%, 22.6% and 4.3% in Group I, Group II and Group III, respectively. There was no significant difference in SpO(2) for the duration of the trial among the three groups. Premedication with intravenous pentazocine can minimize the incidence of fentanyl-induced cough and has no influence on blood pressure, heart rate, and SpO(2) compared with Group II.

The dynamic mold temperature control system is the key of rapid heat cycle molding (RHCM) technology because it significantly affects the stability of the process, productivity and the quality of the final polymer part. For this reason, the approaches and techniques for dynamic mold temperature control were discussed in this study and two different dynamic mold temperature control methods, respectively, with steam heating and electric heating were found to be very feasible in mass production. The methods and principles of mold design for the two RHCM technologies were also discussed and then several different kinds of mold structures were designed. By constructing the corresponding thermal response analytical models for these RHCM molds, the temperature responses of the molding systems in the heating and cooling process of RHCM were simulated and studied. The effects of the mold design parameters such as the insulation layer between mold plate and mold inert, and mold material, on thermal response efficiency and temperature uniformity of the two RHCM processes were analyzed based on the simulation results. The results show that the insulation layer can increase the upper limit temperature of RHCM with steam heating and improve the heating speed of RHCM with electric heating. It can also greatly decrease the energy consumption of the two RHCM processes. The heating efficiency of RHCM with steam heating can be effectively improved by increasing the thermal conductivity of the cavity/core material, while the situation is diametrically opposite for RHCM with electric heating. Therefore, we acquired an optimized mold design principle and method for RHCM with steam heating and electric heating, respectively. Finally, a new electric heating mold with a cooling plate was proposed to enhance the cooling efficiency. The thermal response of this new electric heating mold was also simulated. The simulation results show that the cooling plate can significantly improve the cooling and heating efficiency.

The polymer injection products produced by using the current injection molding method usually have many defects, such as short shot, jetting, sink mark, flow mark, weld mark, and floating fibers. These defects have to be eliminated by using post-processing processes such as spraying and coating, which will cause environment pollution and waste in time, materials, energy and labor. These problems can be solved effectively by using a new injection method, named as variotherm injection molding or rapid heat cycle molding (RHCM). In this paper, a new type of dynamic mold temperature control system using steam as heating medium and cooling water as coolant was developed for variotherm injection molding. The injection mold is heated to a temperature higher than the glass transition temperature of the resin, and keeps this temperature in the polymer melt filling stage. To evaluate the efficiency of steam heating and coolant cooling, the mold surface temperature response during the heating stage and the polymer m...

In this study, combined strategies were employed to heterologously overexpress Candida rugosa lipase Lip1 (CRL1) in a Pichia pastoris system. The LIP1 gene was systematically codon-optimized and synthesized in vitro. The Lip1 activity of a recombinant strain harboring three copies of the codon-optimized LIP1 gene reached 1200 U/mL in a shake flask culture. Higher lipase activity, 1450 U/mL, was obtained using a five copy number construct. Co-expressing one copy of the ERO1p and BiP chaperones with Lip1p, the CRL1 lipase yield further reached 1758 U/mL, which was significantly higher than that achieved by expressing Lip1p alone or only co-expressing one molecular chaperone. When cultivated in a 3 L fermenter under optimal conditions, the recombinant strain GS115/87-ZA-ERO1p-BiP #7, expressing the molecular chaperones Ero1p and BiP, produced 13,490 U/mL of lipase activity at 130 h, which was greater than the 11,400 U/mL of activity for the recombinant strain GS115/pAO815-α-mCRL1 #87, which did not express a molecular chaperone. This study indicates that a strategy of combining codon optimization with co-expression of molecular chaperones has great potential for the industrial-scale production of pure CRL1.

This study investigated the biological effects of microRNA-126 overexpression in human MG63 osteosarcoma cells. A recombinant plasmid expressing microRNA-126, pcDNA6.2-microRNA-126, was constructed and transfected into MG63 cells. Using real-time fluorogenic quantitative polymerase chain reaction, the microRNA-126 expression was measured in microRNA-126-MG63 group, Ctrl-MG63 group, and blank group. Cell proliferation, cell cycle distribution, cell migration, and invasion were analyzed using methyl thiazolyl tetrazolium assay, flow cytometer, wound-healing assay, and transwell assay, respectively. As expected, microRNA-126 expression was higher in microRNA-126-MG63 group than in Ctrl-MG63 group and blank group (both P < .05). After 48/72 hours of transfection, cell proliferation in microRNA-126-MG63 group was significantly reduced compared to blank group (both P < .05). Compared to blank group, cell population in G0/G1 stage was significantly higher in microRNA-126-MG63 group, accompanied by lower cell numbers in the S and G2/M phases and decreased proliferation index (all P < .05). Wound-healing assay showed a wider scratch width in microRNA-126-MG63 group and reduced cell migration than blank group (both P < .05). Cells overexpressing microRNA-126 exhibited reduced ADAM9 expression levels compared to other 2 groups (all P < .05), suggesting ADAM9 is a target of microRNA-126. Cell proliferation, migration, and invasion rates were reduced in microRNA-126 group after 48/72 hours of transfection, compared with blank group (all P < .05). Cotransfection of pcDNA6.2-microRNA-126 and pMIR-ADAM9 into MG63 cells led to higher cell proliferation, invasion, and migration rates, compared with transfection of pcDNA6.2-microRNA-126 alone (all P < .05). In summary, our data show that microRNA-126 inhibits cell proliferation, migration, and invasion in human osteosarcoma cells by targeting ADAM9.

Mold temperature is one of the key factors affecting the morphology and quality of plastic parts. This article explores the melt flow phenomena in a vario-thermal mold cavity. A coupled numerical method, considering the conjugate heat transfer between the mold and melt, is developed for the melt flow simulation. Mold temperature variations and melt flow phenomena for short shot injection in an electrical heated mold cavity are numerically studied and verified by experiments. The results indicate that the melt flow length and cavity filling ratio increase significantly with the elongation of the preheating time before injection. Melt filling ratio increased nearly linearly with the increasing of electric heating time. The smaller the injection pressure is, the bigger the relative filling ratio increment is. Therefore, polymer melt can flow much longer or the mold cavity can be filled up with a smaller injection pressure when the cavity is preheated. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45193.

In this article, we studied the cell forming process of microcellular injection-molded parts. Using a modified injection molding machine equipped with a Mucell V R SCF delivery system, microcellular-foamed acrylonitrile-butadiene-styrene parts with dif- ferent shot sizes were molded. The cell structure on the fractured surfaces along the direction both vertical and parallel to melt flow in the molded parts was examined. The results showed that a regular spherical cells region and a distorted ellipsoidal cells region exist in the molded parts simultaneously. The length of the distorted cells region along the melt flow direction in the molded parts remained basically unchanged for different shot sizes and it is about 195 mm away from the flow front in this study's conditions. The cell formation mechanism was analyzed, two cell forming processes in microcellular injection molding, the "foam during filling" process and the "foam after filling" process, were proposed. It was also found that the melt pressure in the filling stage is the domi- nant factor affecting the cell forming process, and there is a critical melt pressure value in the filling stage, 20.9 MPa, as the dividing line of the two cell forming processes in this study. V C 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40365.

To study the clinical manifestations and identify causative mutations for a Chinese family affected with X-linked Charcot-Marie-Tooth disease.Clinical, electrophysiological and pathological features of the family were carefully analyzed by neurologists. Blood samples were obtained from the proband and other family members. Genomic DNA was extracted. Mutation analysis of GJB1 gene was analyzed with PCR and direct sequencing.The family has fit with X-linked inheritance, and the affected individuals have typical clinical manifestations. A c.614AG (p.Asn205Ser) mutation was detected in the GJB1 gene in all affected individuals in the family.A c.614AG (p.Asn205Ser) mutation of GJB1 gene is co-segregated with the disease phenotype in this family and probably underlies the disease.

The Nano-TiO 2 was modified by doping TiO 2 nanoparticles with W 6+ as catalyst, improving the photocatalytic activity and photocatalytic properties of nanometer TiO 2 . We have studied the tungsten doped TiO 2 nanoparticles’ photocatalytic degradation performance and viscosity reduction properties to the polymer by the degradation of polyacrylamide in oilfield sewage (PAM). Different catalysts, different amount of catalyst and PAM aqueous solution’s pH value effect the photocatalytic degradation rate. The results show that: tungsten doped nanometer TiO 2 has higher photocatalytic activity than the TiO 2 nanoparticles and its photocatalytic performance of viscosity reduction is very significant. The oil-field sewage degradation rate reached about 70% after 120min light reaction of 125 W high pressure mercury lamp as the light source with 3%tungsten doping amount and 1% photocatalyst dosage. TiO 2 nano-particles doped with tungsten had obvious viscosity reduction effect on the photolytic oxidation of oilfield wastewater containing PAM.

Rapid heat cycle molding (RHCM) is a newly developed injection molding technology in recent years. In this article, a new electric heating RHCM mold is developed for rapid heating and cooling of the cavity surface. A data acquisition system is constructed to evaluate thermal response of the cavity surfaces of the electric heating RHCM mold. Thermal cycling experiments are implemented to investigate cavity surface temperature responses with different heating time and cooling time. According to the experimental results, a mathematical model is developed by regression analysis to predict the highest temperature and the lowest temperature of the cavity surface during thermal cycling of the electric heating RHCM mold. The verification experiments show that the proposed model is very effective for accurate control of the cavity surface temperature. For a more comprehensive analysis of the thermal response and temperature distribution of the cavity surfaces, the numerical-method-based finite element analysis (FEA) is used to simulate thermal response of the electric heating RHCM mold during thermal cycling process. The simulated cavity surface temperature response shows a good agreement with the experimental results. Based on simulations, the influence of the power density of the cartridge heaters and the temperature of the cooling water on thermal response of the cavity surface is obtained. Finally, the effect of RHCM process on surface appearance and tensile strength of the part is studied. The results show that the high-cavity surface temperature during filling stage in RHCM can significantly improve the surface appearance by greatly improving the surface gloss and completely eliminating the weld line and jetting mark. RHCM process can also eliminate the exposing fibers on the part surface for the fiber-reinforced plastics. For the high-gloss acrylonitrile butadiene styrene/polymethyl methacrylate (ABS/PMMA) alloy, RHCM process reduces the tensile strength of the part either with or without weld mark. For the fiber-reinforced plastics of polypropylene (PP) + 20% glass fiber, RHCM process reduces the tensile strength of the part without weld mark but slightly increases the tensile strength of the part with weld mark. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

The tie-bolt fastened rotor which is assembled by rods distributed circumferentially is modeled and analyzed by finite element method with the consideration of elastic-plastic contact between discs. Based on elastic-plastic contact model between an elastic hemisphere and a rigid plane, the contact between discs is investigated by the statistical contact model of rough surfaces, and the contact stiffness is derived. The equivalent bending stiffness between discs is acquired. With the increase of the load between the two contact surfaces, the difference between the contact stiffness of purely elastic contact and elastic-plastic model is compared. With the obtained contact stiffness, the equation of motion for the tie-bolt fastened rotor system is formed and the critical speeds are calculated. It indicates that the contact stiffness between discs increases as the load increases. The contact stiffness of elastic-plastic contact model is lower than that of the elastic contact model, and the difference between the two models increases with load. With the stiffness of elastic-plastic contact, the critical speeds of tie-bolt fastened rotor are lower than that of the pure elastic contact situation.Copyright © 2011 by ASME

Rapid heating cycle molding (RHCM) is a novel injection molding technology. The mold cavity is heated up to a high temperature before the filling stage, usually higher than the glass transition temperature of the polymer. This new technology can be used to inject plastic parts with a shiny surface, no weld line?? and no flow mark??. A Rapid Heating Cycle Molding Simulation System (RHCM-S) was developed on the basis of an open software library OpenFOAM. The coupled velocity and pressure fields were solved using the PISO (Pressure Implicit with Splitting of Operations) algorithm. The VOF (volume of fluid) method was used to track the melt flow front. The filling process of polymer melt was simulated under various mold temperature. Mold temperature has significant influence on the flow field, temperature field, shear rate and injection pressure of the polymer melt. The results showed that the RHCM process with a relatively high mold temperature could improve the surface quality and performance of the plastic parts.

Based on the data obtained from laboratory and field experiments, this paper established the morphological and behavioral indices for phase solitaria (S) and phase gregaria (G) of oriental migratory locust Locusta migratoria manilensis. S-females and S-males jumped 1.4 times x min(-1), and the frequency of turning was 1.3 times x min(-1) for S-females and 1.4 times x min(-1) for S-males. G-females and G-males jumped 1.6 times x min(-1), and the frequency of turning was 1.6 times x min(-1) for G-females and 1.5 times x min(-1) for G-males. Both jumping and turning behaviours were significantly greater (P0.05) for gregaria locusts than for solitairia locusts. These behavioral parameters of the frequency of locust jumping and turning can be used as "the behavioral indices for phase transformation". The F/C ratio and the E/F ratio might be used as the morphological indices for phase transformation of the gregaria and solitaria of Locusta migratoria manilensis. The F/C ratio goes up as the locust grows, but the F/C ratio of females from the 4th instar to adult is less than that of the male of the same instar and phase. Comparing with the F/C and E/F ratio of the male, those of the female exhibited significant difference in the same phase. The F/C ratio of the fourth instar, fifth instar and adults were 2.5, 2.8 and 3.3 for S-females, and 2.6, 2.9 and 3.5 for S-males. As for G-females and and G-males, the F/C ratio of the fourth instar, fifth instar and adults were 2.5, 2.8, 3.3 and 2.5, 2.7, 3.1, respectively. The E/F ratios of adults can be used as "the morphological phase indices for phase transformation".

The nanoporous Co 3 O 4 thin films were prepared on indium tin oxide (ITO) glasses by an electrodeposition method. The surface morphology and composition of the nanoporous Co 3 O 4 films were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the as-deposited nanoporous Co 3 O 4 film is constructed by many interconnected nanoflakes with thickness of about 40 nm. The cyclic voltammetry (CV) measurement indicates that the nanoporous Co 3 O 4 films exhibit remarkable electrocatalytic activities for the hydrogen peroxide ( H 2 O 2) reduction which shows that it is a good candidate to be employed as electrode materials for electrochemical sensing of H 2 O 2. Further analysis indicated that the detection sensitivity of the sensor was 1.357 mA mM-1 cm-2 and the detection limit was estimated to be about 0.2 mM.