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Rhizopus stolonifer is one of the main pathogens in postharvest storage logistics of more than 100 kinds of fruit, such as strawberries, tomatoes and melons. In this paper, the research on the morphology and detection, pathogenicity and infection mechanism of Rhizopus stolonifer was reviewed. The control methods of Rhizopus stolonifer in recent years was summarized from three dimensions of physics, chemistry and biology, including the nanomaterials, biological metabolites, light control bacteria, etc. Future direction of postharvest Rhizopus stolonifer infection control was analyzed from two aspects of pathogenic mechanism research and new composite technology. The information provided in this review will help researchers and technicians to deepen their understanding of the pathogenicity of Rhizopus stolonifer, and develop more effective control methods in the future.

Abstract The objective of this study was to provide formulation of a new multilayer antibacterial film and to investigate the optimal use concentration of chitosan and carboxymethyl cellulose in the range from 0.5% to 2%, as well as its application for controlling postharvest disease in temperate fruit (apple, pear, and peach). The multilayer antibacterial film used chitosan (CS) and carboxymethyl cellulose (CMC) as polysaccharide macromolecule, lemon essential oil (LEO) as active agent, and ε‐polylysine (ε‐PL) as the main antibacterial ingredient. The results showed that the physical properties of the self‐assembled film were adjusted by the electrostatic layer‐by‐layer (LbL) deposition. Fourier transform infrared (FT‐IR) analysis and thermogravimetric (TGA) revealed that hydrogen bonds were generated during the self‐assembly of CS‐LEO/CMC‐ε‐PL film, resulting in changes in intermolecular interactions and thermal stability. Furthermore, compared with CS‐LEO single‐layer film, the multilayer film exhibited higher retention rate of LEO. In vivo test, the self‐assembled film significantly inhibited the infection of postharvest pathogenic fungi including Penicillium expansum (P. expansum) and Alternaria alternata (A. alternata) on fruit. To summarize, the CS‐LEO/CMC‐ε‐PL LbL self‐assembly coating notably controlled postharvest pathogen rot on fruit, and reduced the loss of fruit during storage and transportation. Our results suggest that the polysaccharide‐based edible coating prepared in this work may offer an alternative to synthetic waxes.

This study used Dutch potatoes at the end of dormancy as a material to explore the impact of menthol (0.2 and 0.5 g/kg based on potato mass) treatment on sprouting inhibition and potato quality. The findings revealed that a menthol concentration of 0.5 g/kg effectively inhibited potato tuber sprouting and significantly reduced glucoside alkaloid production. After a storage period of 15 days, the sprouting percentage and glucoside alkaloid content of potatoes treated with 0.5 g/kg menthol were observed to be significantly lower at 4.17% and 68.63 mg/kg, respectively, compared to the control group which exhibited values of 100% and 282.01 mg/kg, respectively (p < 0.05). Throughout the storage period, 0.5 g/kg of menthol promoted respiration, reduced malondialdehyde production in potatoes, inhibited polyphenol oxidase activity, and slowed down tissue browning. Additionally, it mitigated the decline in starch and soluble protein content, inhibiting the accumulation of reducing sugars.

Speleothem δ13C in monsoonal China differs from speleothem δ18O, which is widely used as a climatic proxy for several complex control reasons. Nevertheless, δ13C records have the potential to reveal the implications of hydroclimatic changes. This study reports a speleothem δ13C record from Didonghe (DDH) Cave in central China spanning 34 to 13 kyr BP. After we investigated the factors that influence speleothem δ13C, we found that the δ13C record showed that DDH Cave can prompt directional shifts via local hydroclimatic changes, such as in vegetation types, biomass, and rock–water interaction processes, suggesting that δ13C is mainly controlled by the local hydroclimate. Ensemble empirical mode decomposition (EEMD) results revealed a coupling relationship between δ18O and δ13C on multiple timescales, which suggested that changes in precipitation caused by large-scale monsoonal circulation are controlled by regional hydrological conditions to a great extent. However, the hydrological conditions of the cave were relatively mild and humid during the last glacial maximum (LGM), which revealed the impact of evaporation on changes in the region’s hydrological conditions. We also found that the δ18O and δ13C profiles decoupled when δ13C changed with a shift in the location of the westerly during HS1. The δ13C record correlates well with other paleoclimate records, suggesting that regional hydrological conditions are also modulated by the Earth’s internal and external driving factors.

Background: Pancreatic fistula (PF) and biliary fistula (BF) are two major leakage complications after pancreatoduodenectomy (PD). The aim of this study is to investigate the risk factors of PF and BF after laparoscopic PD (LPD). Materials and Methods: We conducted a retrospective analysis of 500 patients who underwent LPD from 1 April 2015 to 31 March 2020. Clinical data from patients were analysed using multivariate logistic regression analysis. Results: PF occurred in 86 (17.2%) patients. Univariate and multivariate analysis indicated that the soft texture of the pancreas (P = 0.001) was the independent risk factor for PF. BF occurred in 32 (6.4%) patients. Univariate and multivariate analysis indicated that history of cardiovascular disease (P < 0.001), surgical time (P = 0.005), pre-operative CA125 (P = 0.036) and pre-operative total bilirubin (P = 0.044) were independent risk factors for BF. Conclusion: The texture of the pancreas was an independent risk factor for PF after LPD, which was consistent with the literatures. In addition, history of cardiovascular disease, surgical time, pre-operative CA125 and pre-operative total bilirubin were new independent risk factors for BF after LPD. Therefore, patients with high-risk factors of BF should be informed that they are at a high risk for this complication.

Chilling injury (CI) in peach fruit (Prunus persica cv. Yuhualu) is generally caused by long-time low temperature (5 °C or 0 °C) storage. However, peach fruit stored at near-freezing temperature (NFT in this research is −1 °C), defined as within 0.5 °C above the biological freezing point of biological tissue, does not exhibit CI symptoms. The effect of NFT on the CI, proline metabolism, and antioxidant capability of peach fruit during storage was studied and compared with 5 °C and 0 °C storage as controls. The results exhibit that NFT completely inhibited the occurrence of CI in peach fruit. NFT significantly (p < 0.05) enhanced the activities of superoxide dismutase, catalase, ascorbate peroxidase, and 1,1-diphenyl-2-picrylhydrazyl scavenging capacity. Moreover, the increase of malondialdehyde, ion leakage, and H2O2 accumulation were inhibited remarkably by NFT, and decreases in the contents of phenolics and ascorbic acid were slowed significantly in peach fruit stored at NFT (p < 0.05). Additionally, NFT storage enhanced proline accumulation by modulating the activity of proline metabolizing enzymes. In conclusion, the above results suggest that NFT storage can improve the chilling tolerance of peach fruit by regulating the antioxidant defense and proline metabolism, which might represent a potential novel method to store fruits and vegetables for longer storage times.

As a commercial potato sprout suppressant, ethylene (Eth) is usually used under a low temperature for long-term storage of potato tubers. However, in many cases, potato tubers are usually transferred from a refrigeration house and sold at room temperature. In the present research, Eth’s inhibitory effects on tuber sprouting at room temperature were investigated. The potential molecular mechanisms of Eth-induced sprout suppression were revealed by phytohormone and transcriptome analyses. Results showed that exogenous Eth significantly suppressed sprout growth in potato tubers during two weeks of storage. The endogenous plant hormone levels of abscisic acid (ABA) and auxin (Aux) were markedly reduced by Eth treatment. Transcriptomic analysis revealed that more transcriptional changes occurred in the early stage of sprouting. The differentially expressed genes (DEGs) assigned to the pathways of plant hormone signal transduction, photosynthesis, starch and sucrose metabolism and phenylpropanoid biosynthesis, which were closely associated with sprouting, were extensively down-regulated by Eth treatment. In addition, the heat map of six hormone signal transduction pathways showed that the expression of most DEGs annotated into the Aux signal transduction pathway was suppressed by Eth treatment, while the expression of many DEGs annotated as ETR (Eth receptor) and ERF1/2 (Eth-responsive transcription factor 1 and 2) in the Eth signal transduction pathway was enhanced by Eth treatment. Taken together, our results indicated that Eth-induced sprout inhibition might be closely related to the suppression of internal Aux production and signal transduction and the activation of Eth signal transduction.

In order to improve the nutritional and functional value of the mixed congee products, and to improve its stability, the experiment was carried out to prepare mixed congee powders through pulverisation treatments including general (3000 r/min, 1600 W) and superfine grinding (−20 ℃, 960 r/min, 1100 W). The effects of superfine grinding on the particle size distribution, color parameters, hydration properties, filling properties, fluidity properties，micro structure，antioxidant activity, the dissolutions of flavonoids and total polyphenols were investigated, which would provide reference for the application and promotion of superfine grinding in mixed congee processing industry. The results showed that superfine grinding had a significant effect on the physicochemical and functional properties of mixed congee powder (P

The reconstruction of Asian summer monsoon (ASM) changes during the last glacial period is of great significance for better understanding monsoon dynamics. The phase relationship between the Indian summer monsoon (ISM) and East Asian summer monsoon (EASM) subsystems on different timescales is still unclear. The comparative analysis of speleothem records in the ISM region, EASM region, and central China helps to clarify the relationship between the ISM and EASM. Based on the well-dated isotope records of stalagmite DDH-B15 from the Didonghe (DDH) Cave in Hanzhong, Shaanxi, we reconstructed ASM changes during the past 34–13 thousand years before the present (kyr BP). The small average error (61 years) of 18 uranium-series ages enables a precise comparison of the stalagmite δ18O record with other well-dated records from the orbital to the millennial timescales. The δ18O signal of the DDH-B15 stalagmite is controlled by changes of the low latitude northern hemisphere summer insolation (NHSI) on the orbital timescale. It records cold Heinrich Stadial (HS) and Dansgaard–Oeschger (DO) cycles which are originated from the northern high latitude on the millennial time scale. The δ18O changes of stalagmites from the three regions are similar on the millennial and centennial timescales. But on the orbital-suborbital timescale, stalagmite δ18O changes during the last glacial cycle have different characteristics. The stalagmite δ18O values in eastern China became gradually negative, and the stalagmite δ18O values in the Indian monsoon domain showed a increasing trend, but the stalagmite δ18O values in Central China adopted an intermediate state between the EASM and ISM. Then we argued that the δ18O value of stalagmites in Central China is a mixed signal of the ISM and EASM, which indicates a change of the water vapor source as an important influence on the Chinese stalagmite δ18O record.

Therapeutic payload delivery to the central nervous system (CNS) remains a major challenge in gene therapy. Recent studies using function-driven evolution of adeno-associated virus (AAV) vectors have successfully identified engineered capsids with improved blood-brain barrier (BBB) penetration and CNS tropism in mouse. However, these strategies require transgenic animals and thus are limited to rodents. To address this issue, we developed a directed evolution approach based on recovery of capsid library RNA transcribed from CNS-restricted promoters. This RNA-driven screen platform, termed TRACER (Tropism Redirection of AAV by Cell-type-specific Expression of RNA), was tested in the mouse with AAV9 peptide display libraries and showed rapid emergence of dominant sequences. Ten individual variants were characterized and showed up to 400-fold higher brain transduction over AAV9 following systemic administration. Our results demonstrate that the TRACER platform allows rapid selection of AAV capsids with robust BBB penetration and CNS tropism in non-transgenic animals.

Objective. To assess if the addition of fentanyl to brachial plexus block has an impact on anesthetic outcomes and complication rates in patients undergoing upper extremity surgeries. Methods. We explore the PubMed, Embase, ScienceDirect, CENTRAL, and Google Scholar databases for all randomized controlled trials (RCTs) comparing adjuvant fentanyl with placebo/no drug for patients undergoing upper extremity surgery under brachial plexus block. Outcomes assessed were onset, duration of sensory and motor anesthesia, complications, and postoperative analgesia scores. Meta-analysis was conducted utilizing a random-effects model. The risk of bias was assessed using the Cochrane Collaboration’s risk of bias assessment tool 2. Certainty of evidence was assessed using GRADE. Subgroup analysis was conducted depending upon the approach of brachial plexus block and type of local anesthetic. Results. Twelve RCTs with 660 patients were included. Addition of fentanyl had no effect on onset of sensory anesthesia (11 studies; MD: 0.48; 95% CI: −1.81, 0.85; I2 = 96%; p=0.48) but significantly shortened onset of motor anesthesia (8 studies; MD: −2.36; 95% CI: −3.99, −0.74; I2 = 96%; p=0.48). Duration of sensory anesthesia (9 studies; MD: 82.81; 95% CI: 41.81, 123.81; I2 = 99%; p

The surface quality of an aluminum foam sandwich panel (AFSP) is very important for its appearance and application. This paper mainly studies the surface quality of AFSP after plastic forming. Combined with three-dimensional (3D) scanning technology, the normal deviation between the experimental AFSP and the target surface was obtained, and the surface quality parameters Sq, Sz and dmax were calculated to evaluate surface quality. The AFSP models with cubic-spherical (CS) and tetrakaidecahedral (TKD) as foam structures were established respectively. A series of numerical simulations of multi-point forming (MPF) were then carried out. Equivalent strain and deformation characteristics of spherical and saddle-shaped AFSP were discussed. The main surface defects produced by AFSP in plastic forming, such as surface wrinkle, the local straight face effect and surface dimpling were analyzed. Finally, MPF experiments were carried out, and it was found that the numerical simulation results were significantly corresponded to the experimental AFSP in terms of the degree and distribution of normal deviation and surface quality evaluation parameters. The TKD model was more consistent with the experimental results than the CS model. Moreover, the results show that the surface quality can be improved by thicker face sheets and smaller core cell sizes.

Potato tuber sprout results in nutrient loss and solanine production. Essential oils have been mentioned to reduce sprouting; however, they can easily evaporate and decompose, thus restricting their application. In this paper, the inhibition effect of methyl salicylate (MeSA) as the main component of wintergreen essential oil on tuber sprouting was evaluated, and MeSA hydrogel was prepared by using the ionic gel method to improve the sprout inhibition efficiency. Based on SEM, FTIR, XRD, and DSC images, MeSA was encapsulated successfully in calcium alginate hydrogel, and the thermal stability of hydrogel was improved. MeSA direct fumigation released sharply on the first day, while MeSA in hydrogel released slowly and steadily; the release of MeSA content was 0.0085 mg mL−1 on the 7th day. The optimized formulations of MeSA hydrogel were as follows: 1.9% of sodium alginate, 2.2% of CaCl2, 1.9:1 of core–wall ratio, and 0.15% of Tween-80. The inhibition effect of MeSA hydrogel was better than that of pure MeSA at 18 days, the sprouting rates of the MeSA and MeSA hydrogel were 42.50% and 13.33%, and the corresponding sprouting indexes were 8.57% and 2.86%, respectively. MeSA was found to inhibit potato tuber sprouting for the first time in this paper; MeSA hydrogel can enhance the inhibitory effect of MeSA on potato sprouting.

This paper studies the plastic forming of sandwich panels and proposes a universal elastoplastic equivalent method suitable for sandwich panels. To verify the generality of the equivalent method, according to the different core structures, the cores of bi-directional trapezoidal sandwich (BTS) panels and aluminum foam sandwich (AFS) panels are equated to orthotropic and isotropic (special orthotropic) single-layer panels respectively. Through the finite element (FE) numerical simulation of the mesoscopic model of the sandwich panel, the elastoplastic constitutive relationship of the equivalent core model is established, and then the macroscopic equivalent model of the sandwich panel is established. The FE numerical simulation of plastic forming was carried out for the mesoscopic model and equivalent model of BTS panel and AFS panel, and plastic forming experiments were conducted for the sandwich panel through a multi-point forming (MPF) test machine. The results show that the relative errors of the section average stress at the same position of the equivalent model and the mesoscopic model of sandwich panels are all within 4%; compared with the experimental results, the equivalent model of the sandwich panel has high forming accuracy and small shape error, which verifies the high accuracy and generality of the equivalent method. Moreover, using the sandwich panel equivalent model effectively reduces the calculation time of the numerical simulation.

This paper presents a numerical investigation on the plastic forming of doubly curved surfaces of aluminum foam sandwich panel (AFSP). A mesoscopic 3D Voronoi model that can describe the structure of closed-cell aluminum foam relatively realistically was established, and a series of numerical simulations using the model of the sandwich panel with a Voronoi foam core were conducted on the plastic forming of two typical doubly curved surfaces including spherical and saddle-shaped surfaces of AFSPs to analyze the deformation behaviors and the forming defects in detail. Multi-point forming experiments of spherical and saddle-shaped AFSPs with different target radii were implemented and the doubly curved panels with good forming quality were obtained. The simulated results of the surface illumination maps, the face sheet profiles, and the maximum strain differences in selected areas of the face sheet and the experimental results indicated that the Voronoi AFSP model can reflect the actual defects occurred in the plastic forming of doubly curved sandwich panels, and the high forming accuracy of the sandwich panel model was also demonstrated in terms of the shape error and the thickness variation.

One possible treatment for Huntington's disease involves direct infusion of a small, interfering RNA (siRNA) designed to reduce huntingtin expression into brain tissue from a chronically implanted programmable pump. Here, we studied the suppression of huntingtin mRNA achievable with short infusion times, and investigated how long suppression may persist after infusion ceases. Rhesus monkeys received 3 days of infusion of Magnevist into the putamen to confirm catheter patency and fluid distribution. After a 1-week washout period, monkeys received radiolabeled siRNA targeting huntingtin. After 1 or 3 days of siRNA delivery, monkeys were either terminated, or their pumps were shut off and they were terminated 10 or 24 days later. Results indicate that the onset of huntingtin mRNA suppression in the rhesus putamen occurs rapidly, achieving a plateau throughout the putamen within 4 days. Conversely, loss of huntingtin suppression progresses slowly, persisting an estimated 27–39 days in the putamen and surrounding white matter. These findings indicate the rapid onset and durability of siRNA-mediated target gene suppression observed in other organs also occurs in the brain, and support the use of episodic delivery of siRNA into the brain for treatment of Huntington's disease and possibly other neurodegenerative diseases.

Although surface-enhanced Raman spectroscopy (SERS) substrates have achieved high sensitivity, it is still difficult to apply these SERS protocols to the on-site detection of real samples due to the SERS substrate being fabrication-complexed, unstable, reproducible, or unable to be applied in batch production. Here, a large-scale ordered two-dimensional array of Au nano-hemispheres was developed through electron beam vaporization of Au onto the easy-available commercialized anodic aluminum oxide (AAO) template with two-layer nanostructures of different diameters. The uniform Au nano-hemisphere is reliable for SERS detection of malachite green (MG) due to the relative standard deviation (RSD) of the SERS intensities at different locations less than 10%. With the optimized excitation wavelength, solvent effect and pH environment, the linear range of MG detection spans from 10–10 to 10–6 mol/L with a limit of detection (LOD) of 4×10–10 mol/L. The enhancement factor can reach 1.2×106. After extraction with acetonitrile and dichloromethane, MG in the spiked tilapia was detected with satisfactory recovery. The results indicate that the Au nano-hemisphere array can be expected to greatly facilitate SERS practical applications in detecting harmful food additives and chemicals due to the advantages of chemical inertness, physical robustness, simple fabrication, controllability, large-area uniformity, and large-batch production. [ABSTRACT FROM AUTHOR]

Based on the perspective of career construction, the paper aims to explore the role of trust as a mediating variable in the process of occupational adaptability (OA) affecting individual career success. To this end, a survey was conducted on 352 senior crew members, and the questionnaire data were analysed. The research results show that the OA has a significant positive impact on career success; trust plays some mediating role between the OA and career success. [ABSTRACT FROM AUTHOR]

This study was designed to investigate the regulatory role of the peroxisome proliferator-activated receptor γ (PPARγ) in the growth of hepatocellular carcinoma cells under the hypothesis that the levels of the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) mRNA and the phosphorylated Akt (pAkt) protein would be affected by the presence of different receptor ligand concentrations. SMMC-7721 hepatocellular carcinoma cells were cultured in the presence of different concentrations of either 15-deoxyprostaglandin J2 (15-d-PGJ2) or pioglitazone and experiments were conducted in order to determine cell growth changes and measure levels of PTEN mRNA and pAkt protein. Our results after treatment with MTT showed the addition of ligands to the cultured cells inhibited their proliferation in a time- and dose-dependent manner. Also, flow cytometry after PI treatment showed the presence of ligands in the growth media could increase the proportion of G0/G1 phase cells, and decrease the proportion of S phase cells. Finally, the same cells exhibited increased levels of the PTEN mRNA by RT-PCR and pAkt protein by western blot analysis. Taken together, our results support the notion that PPARγ ligands can inhibit the proliferation of hepatocellular carcinoma cells in a time- and dose-dependent manner, and that this is at least in part due to the resulting upregulation of PTEN expression. [ABSTRACT FROM AUTHOR]

In this work, investigations were made on the mechanical properties, stress-strain behavior during compression, swelling and compression set properties of polysulfide sealants at different carbon black and silicon dioxide loadings, and dynamic mechanical thermal analysis was also presented. The results reveal that carbon black filler indeed has significant effects on reinforcing mechanical properties of polysulfide sealants. Increasing carbon black loading improves the tensile strength of sealants promptly, but compression performance increases slowly. The simultaneous use of carbon black and silicon dioxide filler in polysulfide sealants hardly changes the tensile strength of sealants, whereas the ultimate elongation and compression performance of sealants are enhanced remarkably. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

In this article, modified polyoxypropylene diamines were synthesized and used as a new flexible curing agent for epoxy resins. The purpose of modification is to introduce urea group into epoxy resins. The reaction rate, mechanical properties, glass transition temperature Tg, and fracture surface morphology of these toughened epoxy resins were investigated. Because of urea groups, the reactivity between polyoxypropylene diamines and epoxy resins was significantly enhanced. At the same time, the urea groups resulted in strong intersegmental hydrogen bonding between modified polyoxypropylene chain, which reduced the compatibility of polyoxypropylene with epoxy resins and resulted in higher Tgof toughened epoxy. The modified sample had tensile strength of 15.8 MPa and ultimate elongation of 118 at room temperature, whereas the unmodified sample only had 6.2 MPa and 70. The scanning electron microscope analysis showed that the modified system displayed tough fracture feature, whereas the unmodified system showed typical brittle fracture. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [ABSTRACT FROM AUTHOR]

Abstract  Based on the mass transfer theory, a new mass transfer model of ion-exchange process on zeolite under liquid film diffusion control is established, and the kinetic curves and the mass transfer coefficients of $${\rm NH}_{4}^{}$$ –K ion-exchange under different conditions were systemically determined using the shallow-bed experimental method. The results showed that the $${\rm NH}_{4}^{}$$ –K ion-exchange rates and transfer coefficients are directly proportional to solution flow rate and temperature, and inversely proportional to solution viscosity and the size of zeolite granules. It also showed that the transfer coefficient is not influenced by the ion concentrations. For a large ranges of operational conditions including temperatures (10 − 75°C), flow rates (0.031 m s−1 −0.26 m s−1), liquid viscosities (1.002 ×  10−3 N s m−2 − 4.44 ×  10−3 N s m−2), and zeolite granular sizes (0.2 − 1.45 mm), the average mass transfer coefficients calculated by the model agree with the experimental results very well. [ABSTRACT FROM AUTHOR]

With a small amount of isocyanate‐terminated polysulfide (NCO‐PSF‐NCO) as additive, the commercial polysulfide‐based sealant had significant improvement in mechanical properties. The test results showed that 5% of NCO‐PSF‐NCO could help to rise 50% in the tensile strength and 27% in the ultimate elongation of the polysulfide sealant. The adhesive strength to substrates such as steel, epoxy‐coated or polyurethane‐coated surface also increased significantly. Dynamic mechanical thermal analysis and differential scanning calorimetry analysis revealed that formed polysulfide polythio‐urethane‐urea (polysulfide‐urea) contributed to a slight increase in the Tg of the polysulfide sealant. It might be due to the domains of polysulfide‐urea, which had effects of physical crosslinking and chain‐extending on the polysulfide sealant. However, the introduction of polysulfide‐urea structures had no appreciable influence on oil resistance of the polysulfide sealant. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 [ABSTRACT FROM AUTHOR]

Summary  A new 4-vinyl benzyl tetra-coordinate silicate (VBTCS) was synthesized from a promising highly reactive penta-coordinate potassium glycolato silicate compound through a facile and one-step reaction. FT-IR, 1H NMR, 13C NMR and elemental analysis identified the structure of the 4-vinyl benzyl tetra-coordinate silicate. This new monomer was homopolymerized and copolymerized with styrene and butylmethacrylate, respectively. FT-IR, TG, DSC and GPC characterized polymers. [ABSTRACT FROM AUTHOR]

The distribution of pores and the mechanical properties of materials are the key factors in preparing satisfactory low‐k films. In the present study, a kind of silsesquioxane‐polyethylene glycol (SSQ‐PEG) was synthesized and used as a template to make the distribution of pores more even in the low‐k films. The crosslinking density of films could be adjusted by the sol‐gel of tetramethoxysilane/dimethoxydimethylsilane with various proportions. The porosity of films could also be adjusted with different proportions of pendant PEG chains introduced. A dielectric constant as low as 2.1 had been achieved for nanoporous polyorganosilicate films with good tenacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1238–1243, 2007 [ABSTRACT FROM AUTHOR]

Experiments on the interactions between a single vortex/co-rotating vortices and the ground were conducted in a water channel using particle image velocimetry (PIV) measurements. Both the single vortex (SNV) and co-rotating vortex pair (CVP) were generated by using NACA0012 vortex generators to simulate the main flow features behind one side of the wings at the farfield and near field. The ground effect was achieved by allocating a flat plate downstream of the vortex generators. It has been found that the lower initial vortex height led to greater vortex rebound and lateral drift in both the SNV and CVP cases, whereas the development of a secondary vortex was also promoted with lower initial vortex height. In the CVP cases, the mutual rotation of the primary vortices led to variation of the close-to-wall velocity distribution. This effect added the disturbances to the formation and evolution of the secondary vortical structure, which eventually affected the height of the secondary vorticity and the rebound of the primary vortices. [ABSTRACT FROM AUTHOR]