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The abuse and improper disposal of antibiotics including metronidazole (MNZ) result in serious contamination in aquatic environments. In this study, pyrite, which was not reactive for MNZ removal, was simply mixed with zero valent iron (ZVI) to efficiently remove MNZ in anaerobic aqueous solutions. A dual ZVI/pyrite system consisting of ZVI (1.0 g/L) and pyrite (4.0 g/L) removed MNZ completely in 360 min within a broad pH0 range (5.0–9.0), and it still maintained a high removal efficiency (~80%) even at a high pH0 of 10.0. By contrast, single ZVI (1.0 g/L) showed much lower efficiency (4.8%–22.0%) within the same pH0 range (5.0–10.0). On investigating the mechanism of MNZ removal, the cooperation between ZVI and pyrite enhanced the surface corrosion of ZVI and facilitated the redox cycle of Fe(III)/Fe(II) to generate more sorbed Fe(II), which was a dominant reactive species for MNZ removal. Pyrite also activated the ZVI surface to form FeS@Fe in situ, accelerating the electron transfer from Fe0 core to the surface-enriched MNZ, and stimulated the formation of green rust sulfate on the ZVI surface to further promote MNZ removal. LC-MS analysis confirmed ZVI/pyrite reductively transformed MNZ into readily biodegradable products by denitration and cleavage of hydroxyethyl.

A 12-year field experiment was conducted to assess straw mulch effects on soil organic carbon fractions, the carbon pool management index (CPMI) at different depths, and crop yield under a no-till rice-wheat rotation system on the Chengdu Plain, southwestern China. There were two treatments in the experiment: no-till without straw mulch (CK) and no-till with straw mulch (SM). The soil was sampled at 0–5, 5–10, 10–20, and 20–30-cm depths. Soil total organic carbon (TOC), the labile organic carbon fractions, including particulate organic carbon (POC), dissolved organic carbon (DOC), microbial biomass carbon (MBC), and permanganate-oxidizable carbon (KMnO4-C), and the CPMI were analyzed. The crop grains were measured between September 2013 and May 2018. Between 2013 and 2018, rice and wheat grain yields under SM were comparable to CK, except there were higher rice yields in 2016 and higher wheat yields in 2017 under SM. The soil organic carbon decreased as soil depth increased in both treatments. Soil TOC, POC, and KMnO4-C concentrations at 0–5 and 5–10 cm, CPMI at 0–5 and 5–10 cm, and DOC at 0–5, 5–10, and 10–20-cm soil depths were significantly greater under SM than under CK, whereas the MBC at 0–5 and 5–10 cm under SM was lower than CK. The POC/TOC, KMnO4-C/TOC, and DOC/TOC ratios were greater under SM in the 0–5 and 5–10 cm, 0–5 cm, and 5–10 and 10–20-cm layers than CK, respectively, whereas the MBC/TOC ratio decreased under SM at 0–5, 5–10, and 10–20-cm depths. The results showed that straw mulching should be adopted when a no-till rice-wheat cropping system is used in southwestern China because it leads to effective improvements in SOC sequestration while still maintaining normal crop yields.

In this study, the solvent extraction experiment was investigated to probe the desorption behaviors and desorption mechanism of oily sludge with n-heptane as solvent. Desorption isotherms were analyzed and fitted by Langmuir, Freundlich and Redlich-Peterson equations at different temperatures. Then, the thermodynamics parameters such as standard free energy (ΔG°), standard enthalpy (ΔH°) and standard entropy (ΔS°) were calculated. Based on thermodynamics analysis and calculation, oil was proved to exist in the form of the colloidal dispersion system. In addition, the kinetics was fitted by the pseudo-first-order kinetic model and the pseudo-second-order kinetic model. Kinetic studies showed that desorption process of asphaltenes was restrained severely due to strong interactions between sludge and asphaltenes, and resins played a crucial role in asphaltenes desorption. The desorption mechanism was discussed based on experimental results and further analysis. The solvent effect and carry-over effect were deemed to be crucial to oil desorption. The carry-over effect is generated from electrostatic interactions, hydrogen bonds, electron donor-acceptor and π-π interactions, which was also the essence of asphaltenes desorption.

Downconverter plays a unique role in radio frequency (RF) receiving systems, which converts the RF signal to the intermediate frequency (IF) signal. This paper proposes a design of a miniaturized 2–18 GHz downconverter with a 1 GHz processing bandwidth. The key electrical parameters of the designed downconverter are the noise figure ( 70dB), and the spurious signal level (

A new platform for triptolide (TP) delivery was prepared by conjugating TP to a carboxylmethyl chitosan (CMCS). Compared with the natural TP, the TP-conjugate (TP-CMCS) containing TP of ~5 wt% exhibited excellent aqueous solubility (&gt, 5 mg/mL). Results of in vitro experiments showed that TP-CMCS could relieve TP-induced inhibition on RAW264.7 cells and apoptosis, respectively. Compared with the TP group, TP-CMCS could effectively alleviate the toxicity injury of TP and decreased the mortality rate of the mice (p &lt, 0.05). TP-CMCS did not cause much damage to the liver (AST and ALT) and kidney (BUN and CRE) (p &lt, 0.05). After administration, the levels of IL-6, IL-1&beta, and TNF-&alpha, decreased, and the arthritis detumescence percentages increased significantly, and the bony erosion degree was distinctly decreased in the TP-CMCS groups and TP group. Our results suggested that TP-CMCS was a useful carrier for the treatment of RA, which enhanced aqueous solubility of free TP and reduced drug toxicity in vitro and in vivo.

Healing of an anterior cruciate ligament graft in bone tunnel yields weaker fibrous scar tissue, which may prolong an already prolonged healing process within the tendon&ndash, bone interface. In this study, gelatin molecules were added to thermosensitive chitosan/&beta, glycerol phosphate disodium salt hydrogels to form chitosan/gelatin/&beta, glycerol phosphate (C/G/GP) hydrogels, which were applied to 0.1 mg/mL collagenase carrier in the tendon&ndash, bone junction. New Zealand white rabbit&rsquo, s long digital extensor tendon was detached and translated into a 2.5-mm diameter tibial plateau tunnel. Thirty-six rabbits underwent bilateral surgery and hydrogel injection treatment with and without collagenase. Histological analyses revealed early healing and more bone formation at the tendon&ndash, bone interface after collagenase partial digestion. The area of metachromasia significantly increased in both 4-week and 8-week groups after collagenase treatment (p &lt, 0.01). Micro computed tomography showed a significant increase in total bone volume and bone volume/tissue volume in the 8 weeks after collagenase treatment, compared with the control group. Load-to-failure was significantly higher in the treated group at 8 weeks (23.8 &plusmn, 8.13 N vs 14.3 &plusmn, 3.9 N, p = 0.008). Treatment with collagenase digestion resulted in a 66% increase in pull-out strength. In conclusion, injection of C/G/GP hydrogel with collagenase improves tendon-to-bone healing in a rabbit model.

An unexpected regioselective I2/TBHP-mediated 1,2-iodo­oxygenation of alkenes with N-hydroxylamines is described. The reaction proceeds through a radical coupling mechanism or a iodonium mechanism, which is controlled by the structures of both N-hydroxylamines and alkenes, to form vicinal iodo-substituted N-alkoxyamines regioselectively. Both the iodo and alkoxyamine group of the resulting products offer rich possibilities of synthetic manipulations.

This study evaluated the biocompatibility and biological performance of novel additive-manufactured bioabsorbable iron-based porous suture anchors (iron_SAs). Two types of bioabsorbable iron_SAs, with double- and triple-helical structures (iron_SA_2_helix and iron_SA_3_helix, respectively), were compared with the synthetic polymer-based bioabsorbable suture anchor (polymer_SAs). An in vitro mechanical test, MTT assay, and scanning electron microscope (SEM) analysis were performed. An in vivo animal study was also performed. The three types of suture anchors were randomly implanted in the outer cortex of the lateral femoral condyle. The ultimate in vitro pullout strength of the iron_SA_3_helix group was significantly higher than the iron_SA_2_helix and polymer_SA groups. The MTT assay findings demonstrated no significant cytotoxicity, and the SEM analysis showed cells attachment on implant surface. The ultimate failure load of the iron_SA_3_helix group was significantly higher than that of the polymer_SA group. The micro-CT analysis indicated the iron_SA_3_helix group showed a higher bone volume fraction (BV/TV) after surgery. Moreover, both iron SAs underwent degradation with time. Iron_SAs with triple-helical threads and a porous structure demonstrated better mechanical strength and high biocompatibility after short-term implantation. The combined advantages of the mechanical superiority of the iron metal and the possibility of absorption after implantation make the iron_SA a suitable candidate for further development.

Radioactive spent extraction solvent was treated by supercritical water oxidation. In this work, influences of reaction conditions on total organic carbon (TOC) removal, the volume percentage of CO2 yielded, and the distributions of radionuclides in gas, liquid and solid phase have been investigated. The results show that the TOC removal and the volume percentage of CO2 would be increased up to above 99% under optimal conditions. More than 88% of thorium and 67% of uranium were precipitated in solid phase, the rest remained in the liquid effluent, and no thorium and uranium were detected in gas phase.

Purpose. Prostate cancer (PC) is a common malignant tumor and a leading cause of cancer-related death in men worldwide. In order to design new therapeutic interventions for PC, an understanding of the molecular events underlying PC tumorigenesis is required. Bloom syndrome protein (BLM) is a RecQ-like helicase, which helps maintain genetic stability. BLM dysfunction has been implicated in tumor development, most recently during PC tumorigenesis. However, the molecular basis for BLM-induced PC progression remains poorly characterized. In this study, we investigated whether BLM modulates the phosphorylation of an array of prooncogenic signaling pathways to promote PC progression. Methods. We analyzed differentially expressed proteins (DEPs) using iTRAQ technology. Site-directed knockout of BLM in PC-3 prostate cancer cells was performed using CRISPR/Cas9-mediated homologous recombination gene editing to confirm the effects of BLM on DEPs. PathScan® Antibody Array Kits were used to analyze the phosphorylation of nodal proteins in PC tissue. Immunohistochemistry and automated western blot (WES) analyses were used to validate these findings. Results. We found that silencing BLM in PC-3 cells significantly reduced their proliferative capacity. In addition, BLM downregulation significantly reduced levels of phosphorylated protein kinase B (AKT (Ser473)) and proline-rich AKT substrate of 40 kDa (PRAS40 (Thr246)), and this was accompanied by enhanced ROS (reactive oxygen species) levels. In addition, we found that AKT and PRAS40 inhibition reduced BLM, increased ROS levels, and induced PC cell apoptosis. Conclusions. We demonstrated that BLM activates AKT and PRAS40 to promote PC cell proliferation and survival. We further propose that ROS act in concert with BLM to facilitate PC oncogenesis, potentially via further enhancing AKT signaling and downregulating PTEN expression. Importantly, inhibiting the BLM-AKT-PRAS40 axis induced PC cell apoptosis. Thus, we highlight new avenues for novel anti-PC treatments.

Celastrol is a promising drug candidate for treating diet-induced obesity, but the cytotoxicity and poor water solubility limit its clinical application. We prepared a novel celastrol conjugate (Cel-CMCS) with excellent water solubility (33.94 mg/mL), and then investigated its anti-obesity and toxic activities in diet-induced obese mice. Just as the parent celastrol, Cel-CMCS reduced body weight and body fat mass in an equally effective manner, but with lower toxicity. Collectively, Cel-CMCS provides a possible solution for the treatment of obesity in humans. In addition, the present study provided a practical experience of the development of carboxymethyl chitosan-based delivery system for poorly water-soluble drugs.

Multilayered MoO3/Cu thin films were prepared by thermal evaporation in combination with the thermal treatments. As-deposited multilayers are amorphous structure. With the increase of temperature, Mo4O11 phase forms in the thin films without copper while MoO2 phase with the weak reduced molybdenum oxide appears in the copper-containing thin films. After annealing at the temperature higher than 450 °C predominant MoO2 appears in the multilayered MoO3/Cu thin films. Meanwhile, CuO and Cu2O are also present in the thin films. The formation mechanism of reduced molybdenum suboxide can be explained by the oxygen-vacancy generation reaction or the reduction of MoO3 to MoO3-x via the inter-diffusion at the MoO3/Cu interfaces. The band gaps and conductivity activation energies of multilayered MoO3/Cu thin films decrease as the annealing temperature increases, in which the smallest band gap of ~2.05 eV and activation energy of ~0.02 eV for the MoO2 thin films are found. Our results open a new road to broaden the application of reduced molybdenum suboxides as a back contact material for CdTe solar cells.

A convenient synthetic approach to β-iodonitro alkenes based on the iodonitration of alkynes with t BuONO and I2 is described. No acid or oxidant is required in this reaction.

Silicone rubber composite materials are widely used in the external insulation equipment of power systems, and the tracking resistance grade is one of the indicators used for evaluating the performance of silicone rubber. It is of great significance to quickly detect the tracking resistance of insulator materials on site. The existing tracking resistance tests are all laboratory tests performed after sample preparation, and there is a lack of on-site detection methods. The laser-induced breakdown spectroscopy (LIBS) method was used to establish the linear relationship between the amount of ablation due to tracking and the background radiation intensity of the experimental LIBS spectrum, and the influence of silica and alumina trihydrate (ATH) fillers on the material’s tracking resistance was studied. This study showed that the LIBS technology can be used to detect the tracking resistance of silicone rubber materials.

In this study, a new synthetic route was developed to prepare UV-cured titanium hybrid optical materials. Transparent high refractive index titanium hybrid optical materials were prepared by means of non-hydrolyzed sol-gel and UV curing. The experimental results show: titanium was successfully introduced into the silicone chain in the form of Ti-O-Si chemical bonds. The materials have high light transmittance (>95%) in the visible light region, high thermal stability and tunable refractive index (1.6533–1.8145) at 486 nm. Our study provides a new ideal for preparing high refractive index UV-cured titanium hybrid optical materials for potential optical applications.

In this study, a new synthetic route was developed to prepare ZrO2 nano-hybrid materials. Polymer matrix containing S and Br elements was prepared by means of thiol-epoxy click chemistry. Transparent high refractive index ZrO2 nano-hybrid materials were prepared by means of sol-gel preparation and segmental heat curing. The experimental results show: ZrO2 particles were successfully synthesized and homogeneously dispersed at the nanometer scale into the polymer matrix, the materials had high light transmittance (>85%) in the visible light region, high thermal stability and tunable refractive index (1.6494–1.7021) at 486 nm. Our study provides a new ideal for preparing high refractive index ZrO2 nano-hybrid materials for potential optical applications.

The synthesis method of lysine aspirin was improved, and the new method was applied to the synthesis of similar new drugs. Aspirin is reacted with an aqueous solution of sodium hydrogen carbonate to prepare its sodium salt, and lysine was reacted with a sodium salt thereof in water to prepare lysine aspirin. The product was identified by melting point, infrared spectroscopy and high performance liquid chromatography; the cysteine salts of aspirin was prepared by this method, and the product was identified by micro melting point apparatus and infrared spectroscopy. Lysine aspirin was synthesized by the reaction of sodium acetylsalicylate with lysine. The author measured the melting point and infrared absorption spectrum of the cysteine salt sample of aspirin, which was initially determined to be possible. The new method offers the possibility to expand the production route of lysine aspirin, and also provides new ideas for the preparation of similar new drugs.

Background Although huge fetal hepatic hemangiomas are rare, they can cause fatal complications. The purpose of this study is to describe the imaging features and prognosis of these tumors. Methods Imaging data were collected for 6 patients with huge fetal hepatic hemangiomas treated at our hospital. Imaging modalities included prenatal magnetic resonance imaging and ultrasound and postnatal color Doppler ultrasound and contrast-enhanced computed tomography (CT). Results Among the 93,562 fetuses of 92,126 pregnant women examined at our hospital, 6 had huge hepatic hemangiomas (incidence rate, 0.64/10,000), as confirmed via postnatal color Doppler imaging and contrast-enhanced CT. Five fetuses had solitary lesions, whereas 1 (fetus 2) had multiple lesions. Four fetuses had lesions in the right liver lobe and 1 had a lesion in the left liver lobe, and 1 (fetus 2) had lesions in both lobes. All lesions showed centripetal enhancement on postnatal contrast-enhanced CT, which was more intense peripherally. Following postnatal treatment with oral propranolol, with or without dexamethasone or interventional therapy with the medical sclerosant pingyangmycin, all lesions decreased in size, with calcification plaques appearing 6 months after treatment. Conclusions Huge hepatic hemangiomas have typical ultrasonographic features and can be diagnosed prenatally. Treatment with propranolol, with or without dexamethasone, may result in a favorable prognosis. Electronic supplementary material The online version of this article (10.1186/s12884-017-1635-7) contains supplementary material, which is available to authorized users.

In the molten salt reactor (MSR), the fuel salt can be discharged out of the core to avoid a more serious consequence in the accident. In this paper, a special core fuel salt release system (CFSRS) is described. Its equipment reliability and human reliability are evaluated subsequently to identify the key failure factors and provide suggestions for the design, by means of the fault tree analysis and the human reliability analysis (HRA) respectively. Results show that the human error is a dominant factor of CFSRS failure in the accident scenario. A good operator training or a sufficient diagnosis time can greatly improve the CFSRS human reliability. Regardless of the human error, to obtain a balanced design and a low equipment failure probability of less than 2E−5, the redundant design of CFSRS including the pipe heating subsystem is necessary.

Seeds are one of the most significant innovations in the land plant lineage, critical to the diversification and adaptation of plants to terrestrial environments. From perspective of seed evo-devo, the most crucial developmental stage in this innovation is seed maturation, which includes accumulation of storage reserves, acquisition of desiccation tolerance, and induction of dormancy. Based on previous studies of seed development in the model plant Arabidopsis thaliana, seed maturation is mainly controlled by the LAFL regulatory network, which includes LEAFY COTYLEDON1 (LEC1) and LEC1-LIKE (L1L) of the NF-YB gene family, and ABSCISIC ACID INSENSITIVE3 (ABI3), FUSCA3 (FUS3), and LEC2 (LEAFY COTYLEDON2) of the B3-AFL gene family. In the present study, molecular evolution of these LAFL genes was analyzed, using representative species from across the major plant lineages. Additionally, to elucidate the molecular mechanisms of the seed maturation program, co-expression pattern analyses of LAFL genes were conducted across vascular plants. The results show that the origin of AFL gene family dates back to a common ancestor of bryophytes and vascular plants, while LEC1-type genes are only found in vascular plants. LAFL genes of vascular plants likely specify their co-expression in two different developmental phrases, spore and seed maturation, respectively, and expression patterns vary slightly across the major vascular plants lineages. All the information presented in this study will provide insights into the origin and diversification of seed plants.

Based on magnetron hollow cathode discharge, the magnetic condition of glow plasma generation in high vacuum, including both direction and magnitude of the applied magnetic field, is theoretically derived and experimentally evaluated in this paper. Single particle orbital theory is introduced to discuss the possibilities to generate glow plasma at gas pressure under 10−2 Pa when the magnetic field direction is parallel or perpendicular or oblique to the electric field direction. A quantitative estimation criterion of magnetic induction intensity is also proposed in theory. The comparison with experiments suggests that glow plasma in high vacuum will form more easily in oblique magnetic field condition and that the criterion is accurate enough to estimate magnetic induction intensity at a certain gas pressure.

Pure and Au nanoparticles loaded WO3 nanoflowers are synthesized by the hydrothermal method.The structures and morphologies of the as-prepared products are characterized by X-ray diffraction (XRD),scanning electron microswcope (SEM), and transmission electron microscope (TEM). The gas sensing performance of the Au/WO3 sensor to xylene is investigated. The Au content and the operating temperature are first optimized. It is found that WO3 with 0.4 μL Au nanoparticles shows the highest sensitivity at an operating temperature of 250 ℃. Compared with pure WO3, Au(0.4)/WO3 possesses fast response/recovery speed and high target gas selectivity. Its sensitivity to 100 ppm xylene is 29.5. Meanwhile, the practical detection limitation is as low as 0.5 ppm. Finally, the mechanism of Au/WO3 gas sensing is also proposed and discussed. Au nanoparticles loaded WO3 nanoflowers are considered to be a promising sensing material for detecting xylene pollutants.

Room-temperature deposited amorphous silicon nitride (a-SiNx:H) films exhibit intense green light emission after post-treated by plasma oxidation, thermal oxidation and natural oxidation, respectively. All the photolumines-cence (PL) spectra are peaked at around 500 nm, independent of oxidation method and excitation wavelength. Compared with the PL results from oxidized a-Si:H and as-deposited a-SiNx :H samples, it is indicated that not only oxygen but also nitrogen is of an important role in enhancing light emission from the oxidized a-SiNx:H. Combining the PL results with the analyses of the bonding configurations as well as chemical compositions of the films, the strong green light emission is suggested to be from radiative recombination in luminescent centres related to N–Si–O bonds.

An a-SiNx/nanocrystalline silicon [(nc-Si)/a-SiNx] sandwiched structure is fabricated in a plasma enhanced chemical vapour deposition (PECVD) system at low temperature (250° C). The nc-Si layer is fabricated from a hydrogen-diluted silane mixture gas by using a layer-by-layer deposition technique. Atom force microscopy measurement shows that the density of nc-Si is about 2 × 1011 cm−2. By the pretreatment of plasma nitridation, low density of interface states and high-quality interface between the Si substrate and a-SiNx insulator layer are obtained. The density of interface state at the midgap is calculated to be 1 × 1010 cm−2eV−1 from the quasistatic and high frequency C – V data. The charging and discharging property of nc-Si quantum dots is studied by capacitance-voltage (C – V) measurement at room temperature. An ultra-large hysteresis is observed in the C – V characteristics, which is attributed to storage of the electrons and holes into the nc-Si dots. The long-term charge-loss process is studied and ascribed to low density of interface states at SiNx/Si substrate.

Nanocrystalline Si/SiO2 multilayers are prepared by thermally annealing amorphous Si/SiO2 stacked structures. The photoluminescence intensity is obviously enhanced after hydrogen passivation at various temperatures. It is suggested that the hydrogen trapping and detrapping processes at different temperatures strongly influence the passivation effect. Direct experimental evidence is given by electron spin resonance spectra that hydrogen effectively reduces the nonradiative defect states existing in the Si nanocrystas/SiO2 system which enhances the radiative recombination probability. The luminescence characteristic shows its stability after hydrogen passivation even after aging eight months.

We investigate the properties of light emission from amorphous-Si:H/SiO2 and nc-Si/SiO2 multilayers (MLs). The size dependence of light emission is well exhibited when the a-Si:H sublayer thickness is thinner than 4 nm and the interface states are well passivated by hydrogen. For the nc-Si/SiO2 MLs, the oxygen modified interface states and nanocrystalline silicon play a predominant role in the properties of light emission. It is found that the light emission from nc-Si/SiO2 is in agreement with the model of interface state combining with quantum confinement when the size of nc-Si is smaller than 4 nm. The role of hydrogen and oxygen is discussed in detail.

Enhanced photoluminescence (PL) at room temperature from thermally annealed a-Si:H/SiO2 multilayers is observed through the step-by-step thermal post-treatment. The correlation between the PL and the crystallization process is studied using temperature-dependent PL, Raman, cross section high-resolution transmission electron microscopy (X-HRTEM) and x-ray diffraction (XRD) techniques. An intensified PL band around 820 nm is discovered from the sample annealed near the crystallization onset temperature, which is composed of two peaks centred at 773 nm and 863 nm, respectively. It is found that the PL band centred at 863 nm is related to the pseudo nanocrystal (p-nc-Si) silicon, and the PL band centred at 773 nm is attributed to Si = O bonds stabilized in the p-nc-Si surface.

Wet cleaning is very critical for technology nodes below 40&28nm in ULSI manufacturing. Better clean efficiency and less film damage becomes the main challenge for WET clean processes in advanced technology development. New chemicals were used in this article to study BEOL post Etch WET cleaning for 40nm node and beyond. We compared the cleaning performance of chemcial A and chemical B through CD enlargement, kink profile, Cu loss, inline defect and WAT. Experimental results indicated that the copper loss and kink performance of chemical A were better than that of chemical B, even though inline defect, CD enlargement and WAT were comparable.

Structures of nanocrystalline-Si (nc-Si) sandwiched between two asymmetric ultrathin SiO2 layers were fabricated. The nc-Si (dot density of 1011 cm−2) was formed by decomposition of hydrogen-diluted silane and the ultrathin SiO2 layers (about 2 nm) were prepared by plasma oxidation at a lower temperature (250 degrees C). The whole fabrication processes were completed in situ in a plasma-enhanced chemical vapour deposition system. By using the capacitance–voltage (C–V) and conductance–voltage (G–V) spectroscopy, we studied the electronic properties of the annealed samples. The experimental results show that there are distinct capacitance peaks and conductance plateau or peaks for annealed samples at room temperature, which can be explained by direct tunnelling of electrons into the nc-Si. At the same time, Coulomb blockade plays an important role in the electronic transport in the nc-Si. The effect of thermal annealing in N2 ambient on the electronic properties was studied and the results indicate that high temperature (1000 degrees C) annealing can improve the size uniformity of the nc-Si prepared by decomposition of hydrogen-diluted silane.

The surface tension driven convection, together with the rotating crystal growth process of potassium tantalate niobate (KTa1-xNbxO3, KTN) crystals from unstirred melt has been carried out in a high temperature in-situ observation system. The streamline of the stable convection is found to be in the form of a double loop axially symmetric vortices, which causes the rotation during KTN crystals growth process. The effect of surface tension convection on interfacial heat, mass and momentum transfer are investigated experimentally. The dimensionless parameters of the three transports are calculated. For KTN crystals, velocity and temperature boundary layers are pointless. Solute transfer is the main form of interface transport during crystal growth process. The effect of Nb content x on boundary layer thickness is discussed. There is a critical Marangoni Number Mac∼60. When Ma>Mac, the concentration boundary layer becomes thinner with the increase of x as a result of weakened segregation effect. When Ma>Mac, a thicker boundary layer emerges due to slower growth velocity under higher Nb contents. When Ma∼Mac, the influence of the two is comparable and the boundary layer can maintain a relatively steady value under different components.

Graphene-based polyaniline (PANI/RGO), used as conductive filler, was synthesized through a new one-pot emulsion polymerization technology. Graphene dispersion (RGO) was obtained by ultrasonically reducing graphene oxide (GO) in a hot sodium hydroxide solution in the absence of any toxic reductant, such as hydrazine hydrate. Sodium dodecyl benzene sulfonate (SDBS), in which RGO sheets were dispersed, was synthesized using dodecyl benzenesulfonic acid (DBSA) and NaOH. In this RGO/SDBS mixture, polyaniline (PANI), doped with multiple acids (HCl-DBSA), was then uniformly polymerized on the surface of the RGO sheets. The experimental results showed that this reaction improved the dispersion of the RGO in the PANI system, and increased the homogeneous distribution of the formed PANI particles on the RGO surface. The synthesized composite material (PANI/RGO) had good thermal stability, electrical conductivity (about 11.71[Formula: see text]S[Formula: see text][Formula: see text][Formula: see text]cm[Formula: see text] and water dispersibility. Based on its excellent properties, the PANI/RGO was combined with waterborne epoxy resin to prepare anticorrosion coatings. The corrosion resistance of these coatings was studied using Tafel plots, along with other critical properties tested by the national standards. The results suggested that the surface resistivity of the coatings could be as high as 2.48[Formula: see text][Formula: see text][Formula: see text]10[Formula: see text] with the addition around 3[Formula: see text]wt.% of the PANI/RGO meeting good antistatic standards. In addition, the antistatic coatings had outstanding corrosion resistance, as well as tremendous physical and chemical properties.

Steam explosion pressure, holding time and initial moisture content of red beans were used as variables for the experimental design, according to BBD (Box-Behnken) central composite model. Red beans were processed in steam explosion and the changes of protein, fat, cellulose and other nutritive contents of red beans, changes of hardness, springiness, chewiness and other texture properties, and changes of puffing ratio and cooking properties after the steam explosion processing were determined to analyze the effects of steam explosion processing on quality of red beans. After the processing, the content of crude protein, crude fat and crude cellulose decreased by 0.84%, 0.02% and 0.33% respectively, while the content of starch increased by 0.58%, but no significant effect of steam explosion processing on nutritive contents of red beans was identified (P>0.05); after the steam explosion processing, the average springiness and chewiness increased by 0.15mm, 1.07mJ respectively, but no significant difference with that before such processing was identified (P>0.05). However, the hardness reduced by 22.0N with a very significant change (P

Thermooxidative decomposition and its kinetics on chlorinated natural rubber (CNR) from latex are studied by thermal gravimetry (TG) analysis and TG coupled with FTIR spectroscopy. The thermooxidative decomposition of CNR is a two-step reaction. The first step is the reaction of dehydrochlorination of which the reaction order (n) is 1.1; the reaction activation energy (E) increases linearly with the increment of the heating rate (B), and the apparent activation energy (E0) is 101.7 kJ/mol. The initial temperature of weight loss (T0) is 1.29B + 248.7, the final temperature of weight loss (Tf) is 0.86B + 312.4, and the temperature at the maximum weight loss ratio (Tp) is 1.05B + 286.2. The decomposition ratio at Tp(Cp) is not affected by B, and its average value is 38%. The decomposition ratio at Tf(Cf) is also not affected by B, and its average value is 60%. The second step is an oxidative decomposition reaction of the molecular main chain. The value of n is 1.1, E increases linearly with the increment of B, E0 is 125.0 kJ/mol, the relation between B and T is similar to that of the first step, and Cf approaches 100%. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1305–1309, 2001

Clay was modified by using a polymeric coating agent, a silicane coupling agent, and a titanate coupling agent together with the antioxidant for preparing the clay–rubber masterbatch. After the thermooxidative, photooxidative, and ozone aging, the properties of the masterbatch were also determined. The results indicate that, under the synergistic actions of the polymeric coating agent, antioxidant, and coupling agent, the thermooxidative and photooxidative aging resistances of the masterbatch were greatly improved. The properties of ozone aging resistance of the masterbatch can be increased by 50% under the combined action of a new kind of amine antioxidant with a titanate coupling agent. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 338–342, 2001

A three-dimensional (3D) biomimetic SERS substrate with hierarchical nanogaps was formed on the bioscaffold arrays of cicada wings by one-step and reagents-free ion-sputtering techniques. This approach requires a minimal fabrication effort and cost and offers Ag nanoislands and Ag nanoflowers with four types of nanogaps (

A series of hydrogenated amorphous silicon carbide films (a-SiC:H) were prepared by rf plasma-enhanced chemical vapor deposition method. The optical band gap(Egopt) of the films can be extended to 2.6 eV. The as-deposited films were then irradiated by a KrF excimer laser. During the irradiation process, hydrogen escaped out of the films, and the structure of the films was changed from an amorphous phase to mixed phases of nanocrystallites of silicon and amorphous silicon carbide. The room-temperature dark conductivity of the laser irradiated films is 6-7 orders of magnitude larger than that of the as-deposited films, which was attributed to the modification of the conductivity mechanism resulting from the structural change.

Understanding the interactions of dendrimers as delivery vectors with biomembranes is important for functional optimization. Here, coarse-grained molecular dynamics simulations are employed to study the interactions between a surface-modified dendrimer with short peptides and lipid bilayers under physiological and low pH conditions. The peptide consists of three histidines (H) with the pH-sensitive property and an arginine (R). It is found that the peptide-dendrimer conjugate either adheres to or penetrates through the negatively charged, asymmetrical bilayer, dependent on the pH value. Calculation of the potential of mean force shows that the penetration is energy favorable at low pH. The conjugate can lead to membrane thinning with enhanced permeability. Inspired by the results, a possible route is proposed for gene delivery using the non-specific electrostatic interaction adjusted by the pH environment.

Four kinds of a-Si:H films deposited in the PECVD system with different Ts are studied by 1H NMR technique. Direct evidence is given to confirm hydrogen atoms in the diluted and clustered phases. The local bonding configurations for hydrogen and the density of dangling bonds are analyzed by ESR and infrared absorption spectroscopy. The behaviour of hydrogen in a-Si:H films is discussed.

We have applied the layer-by-layer deposition technique to the growth of nano-crystalline silicon films by varying the hydrogen plasma exposure time. The tailoring effect of hydrogen plasma has been studied. The novel optical and electronic properties of these films have also been reported.

ZnS quantum dots (QDs) synthesized in water and ethanol solutions were coated with polystyrene (PS) and SiO2 shells, respectively. The band edge emission was enhanced by nearly five times after PS coating and by about thirteen times after SiO2 coating, because the surface trap states were removed. From the photoluminescence properties of ZnS QDs coated with PS and SiO2 shells we have detected the improvement of thermal stability. This is due to the fact that the surface passivation can prevent the further growth of the ZnS QDs and the diffusion of oxygen on the surface of ZnS QDs during thermal oxidation.

In view of the difficult separation problem of powder bentonite from solution in water treatment, the development of new type magnetic bentonite composite materials was studied. The adsorption performance of natural bentonite was improved by organic modification. The bentonite was magnetic modified by nano Fe 3 O 4 which was prepared by coprecipitation method. This magnetite composite materials which combined by bentonite and Fe 3 O 4 not only has a better adsorptive capacity for COD and a better separate effect, but also has a simple preparation technology and reaction conditions. This composite materials have been characterized by powder X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results revealed that interlamellar spacing of bentonite was increased through organic modification and Fe 3 O 4 particles occured on the surface of bentonite particles and formed magnetic aggregation. These nano-magnetic modified materials with super performances would be used to treat coke wastewater.

Highly hydrogen-diluted silane plasma is used to fabricate microcrystalline silicon films in a plasma-enhanced chemical vapour deposition system. X-ray diffraction and micro-Raman scattering spectroscopy are utilized to characterize their microstructure properties. Dark conductivity and drift mobility are measured by the travelling wave method. With the decreasing gas flow ratio of silane-to-hydrogen from 2% to 0.2%, the crystalline volume fraction and the drift mobility increase at room temperature. Meanwhile, the dark conductivity increases initially and then decreases. The relationship between the microstructures and transport properties is discussed.