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Fluoride, iron and manganese simultaneous exceedance of standard can be observed in groundwater in northeastern China. This work aims to apply a highly efficient method combining adsorption and oxidation for the synchronous removal of the inorganic ions. An innovative adsorbent (manganese-supported activated alumina) was synthesized by the impregnation method and showed a significant adsorption capacity better than that of fresh activated alumina. The characterization (scanning electron microscope; Brunauer, Emmett and Teller; X-ray diffraction and Fourier transform infrared spectroscopy) results verified the successful introduction of MnOOH and MnO2, and the improvement of surface microstructure enhanced the removal ability. The effect of single factors, such as pH value, reaction time or dosage on the removal performance has been verified. The maximum removal efficiencies of fluoride, iron and manganese were optimized via Response surface methodology considering the independent factors in the range of MO@AA dosage (5–9 g/L), pH (4–6) and contact time (4–12 h). Noted that compared with control, MO@AA exhibited 59.4% of improved fluoride performance. At pH of 5.79, contacting time of 12 h and 8.21 g/L of MO@AA, fluoride, iron and manganese removal were found to be 91, 100 and 23%, respectively. Herein, MO@AA was distinguished as good applicability for the treatment of fluoride-, iron- and manganese-containing groundwater. HIGHLIGHTS The modified activated alumina were prepared by impregnation method.; Response surface methodology model is used in this research to find out the relationships among the factors.; The modified activated alumina can be applied for the removal of fluoride, manganese and iron.

Boron dipyrromethenes (BODIPYs) are versatile dyes with diverse structures and associated optoelectronic properties. Their integration into soft materials (polymers) has enabled a myriad of applications from biological/environmental (e.g., imaging, sensing, and therapy) to organic electronic devices and synthesis/degradation. The story herein is meant to guide the reader from the bottom-up, starting with general syntheses of BODIPYs, followed by a discussion of photophysical and electrochemical properties as they relate to structure. These structure–property relationships are then connected to three light driven transformations that are central to the utility of BODIPYs in materials science: (1) electron/energy transfer; (2) triplet formation, and (3) photolysis. Next, the synthetic integration of BODIPYs as structural motifs in both π-conjugated and non-π-conjugated polymers is described, along with prescribed methods to tailor their optoelectronic properties. These properties are then correlated to recent utility of BODIPYs within polymer science, both fundamental – examination of polymer dynamics and self-assembly – and applied – biomedicine, optoelectronics, chemosensors, small molecule photoredox catalysis, and photo-polymerization and -degradation. The end of this review provides a summary of the rich history and outlook on the exciting future opportunities for this burgeoning field of BODIPYs in polymer chemistry.

The driving of rapid polymerizations with visible to near-infrared light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. The improvement of efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to far-red light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (

To automatically detect and classify the lesions of diabetic retinopathy (DR) in fundus fluorescein angiography (FFA) images using deep learning algorithm through comparing 3 convolutional neural networks (CNNs). A total of 4067 FFA images from Eye Center at the Second Affiliated Hospital of Zhejiang University School of Medicine were annotated with 4 kinds of lesions of DR, including non-perfusion regions (NP), microaneurysms, leakages, and laser scars. Three CNNs including DenseNet, ResNet50, and VGG16 were trained to achieve multi-label classification, which means the algorithms could identify 4 retinal lesions above at the same time. The area under the curve (AUC) of DenseNet reached 0.8703, 0.9435, 0.9647, and 0.9653 for detecting NP, microaneurysms, leakages, and laser scars, respectively. For ResNet50, AUC was 0.8140 for NP, 0.9097 for microaneurysms, 0.9585 for leakages, and 0.9115 for laser scars. And for VGG16, AUC was 0.7125 for NP, 0.5569 for microaneurysms, 0.9177 for leakages, and 0.8537 for laser scars. Experimental results demonstrate that DenseNet is a suitable model to automatically detect and distinguish retinal lesions in the FFA images with multi-label classification, which lies the foundation of automatic analysis for FFA images and comprehensive diagnosis and treatment decision-making for DR.

Excessive application of nitrogen fertilizer has caused the reduction of nitrogen fertilizer utilization efficiency, resource waste and environmental problems in our country. There are disadvantages of long sampling and heavy workload using the traditional methods of acid absorption and box method for farmland ammonia volatilization measurement. In order to meet the application needs for on-line automatic measurement of ammonia volatilization in farmland, an in-situ automatic measurement device for ammonia volatilization was designed combined with laser spectroscopy technology. The main body of the measurement device is an integrated sampling box, with the advantages of long optical path measurement, heat resistance and corrosion resistance. The control circuit of the sampling box used ARM as the main controller for environmental data monitoring, automatic opening and closing of the cover and lens temperature controlling. The ammonia volatilization results were analyzed by the data acquisition and processing system after the laser passed through the sampling box to obtain ammonia spectroscopy signal. The device was used for observation at Fengqiu Ecological Station, CAS. The results showed that the ammonia volatilization rose rapidly after 90 minutes for nitrogen fertilizer applying, and it decreased gradually to a low value after 270 minutes. According to the experimental results, the continuous measurement time for cover closing can be set to 3 minutes, and the cover opening time can be set to 3 to 5 minutes. The working performance of the automatic measurement device was verified through these experiments, with the advantages of low power consumption, high measurement sensitivity, and no gas sampling. It realizes insitu automatic measurement for ammonia volatilization in farmland with the natural respiration condition of the soil.

The large-scale loach (Paramisgurnus dabryanus) is one of the most commercially important cultured species. Ammonia nitrogen accumulation is one of the key issue which limited production and animal health in aquaculture, but few of information is available on the molecular mechanisms of ammonia detoxification. We performed transcriptomic analyses of the gill and liver of large-scale loach subjected to 48 h of aerial and ammonia exposure. We obtained 47,473,424 to 56,791,496 clean reads from the aerial exposure, ammonia exposure and control groups, assembled and clustered a total of 92,658 unigenes with an average length of 909 bp and N50 of 1787 bp. Totals of 489/145 and 424/140 differentially expressed genes (DEGs) were detected in gill/liver of large-scale loach after aerial and ammonia exposure through comparative transcriptome analyses, respectively. In addition, totals of 43 gene ontology (GO) terms and 266 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were identified. After aerial and ammonia exposure, amino acid metabolism pathways in liver of large-scale loach were significantly enriched, suggesting that large-scale loach responded to high exogenous and endogenous ammonia stress by enhancing amino acid metabolism. Besides, the expression of several ammonia transporters (i.e., Rhesus glycoproteins and Aquaporins) in gill of large-scale loach were markedly changed after 48 h of aerial exposure, suggesting that large-scale loach responded to high endogenous ammonia stress by regulating the expression of Rh glycoproteins and Aqps related genes in gill. The results provide valuable information on the molecular mechanism of ammonia detoxification of large-scale loach to endogenous and environmental ammonia loading, will facilitate the molecular assisted breeding of ammonia resistant varieties, and will offer beneficial efforts for establishing an environmental-friendly and sustainable aquaculture industry.

Aggregation behavior of an amphiphilic diblock copolymer poly(lauryl acrylate)-block-poly(N-isopropylacrylamide) (PLA-b-PNIPAM) on neutral aqueous subphases with different salt species and salt concentrations, as well as the structures of its Langmuir-Blodgett (LB) films, were systematically studied. The presence of NaCl or Na2SO4 in subphases makes PNIPAM chains shrink on the water surface and reduce their solubility underwater. On the contrary, the presence of NaNO3 or NaSCN makes PNIPAM chains more stretched on water and increase their solubility underwater, whose stretch degree and solubility both increase with the increase of salt concentration. Solubility of PNIPAM chains in the above subphase solutions is ranked as NaSCN ≫ NaNO3 > pure H2O > NaCl ≈ Na2SO4, which is almost consistent with the Hofmeister series except for the latter two close cases. All the initial LB films of PLA-b-PNIPAM exhibit tiny isolated circular micelles. Upon compression, the LB films in the case of pure H2O exhibit the dense mixed structures of circular micelles and wormlike aggregates. The formation of wormlike aggregates is due to connection of some adjoining cores, which is less possible in other subphase cases because of the conformation difference of PNIPAM chains.

Aggregation behavior of an amphiphilic diblock polyelectrolyte poly(n-butylacrylate)-b-poly(acrylic acid) (PnBA-b-PAA) at the air/water interface and its Langmuir−Blodgett (LB) films were respectively characterized by the Langmuir film balance technique and atomic force microscopy. Effects of spreading solution concentration and volume, and subphase temperature and ionic strength on the interfacial aggregation behavior of PnBA-b-PAA under alkaline condition were systematically studied. With the increase of spreading concentration, surface pressure−molecular area isotherms shift to small molecular areas at the corresponding spreading volumes. With the rise in subphase temperature, the isotherms shift to small molecular areas due to the decreased pKa value and increased solubility of PAA blocks. With the increase of subphase ionic strength, the isotherms shift to large molecular areas because of the predominant salting out effect. The LB films transferred from alkaline subphase with different ionic strengths are more likely to exhibit isolated circular micelles. With the increase of spreading concentration, diameters of micelle cores first decrease and then increase, a behavior which is attributed to the gradually increased chain entanglements and surface polymer concentration, respectively. For small spreading volume, core diameters in the LB films first decrease and then increase with the rise in subphase temperature. For large spreading volume, however, core diameters increase with temperature due to the higher mobility and weaker entanglements of PAA blocks underwater. With the increase of subphase ionic strength, furthermore, core diameters first increase and then decrease, which is attributed to the predominant electrostatic shielding and salting out effects, respectively.

Effects of subphase pH and temperature on the aggregation behavior of a thermosensitive amphiphilic diblock copolymer poly(lauryl acrylate)-block-poly(N-isopropylacrylamide) (PLA-b-PNIPAM) at the a...

The development of high-performance, bio-energy-harvesting and green energy production materials remains a major objective. Perovskite quantum dots have been recently emerging as a potentially relevant material because of their outstanding optoelectronic properties; however, some issues regarding instability and environmental impact remains as stumbling blocks. This research presents a promising and facile method for incorporating lead toxicity reduced inorganic perovskite quantum dots (IPQDs; CsPb0.25Zn0.75I3) with eco-friendly cellulose nanocrystal (CNC) ligands into polyvinylidene fluoride (PVDF) electrospun nanofibers (PPNG) forming potential piezoelectric and pyroelectric applications. Applying distinct pressures through finger tapping, air pressure, hand bending, fist beating, and foot striking generates intriguing self-powered energy harvesting sensory performances. PPNG produces stable and sensitive signals with highest open-circuit voltage of 20.3 V, short circuit current of 1.2 μA cm−2, and power density of 29.0 μW cm−3. Furthermore, the material was found to be successful in pyrocatalytic decay of Rhodamine-B dye; the maximum dye decay was 91% and it exhibits five reusable cycles with ultra-low lead leakages (

Driving rapid polymerizations with visible to near-infrared (NIR) light will enable nascent technologies in the emerging fields of bio- and composite-printing. However, current photopolymerization strategies are limited by long reaction times, high light intensities, and/or large catalyst loadings. Improving efficiency remains elusive without a comprehensive, mechanistic evaluation of photocatalysis to better understand how composition relates to polymerization metrics. With this objective in mind, a series of methine- and aza-bridged boron dipyrromethene (BODIPY) derivatives were synthesized and systematically characterized to elucidate key structure-property relationships that facilitate efficient photopolymerization driven by visible to NIR light. For both BODIPY scaffolds, halogenation was shown as a general method to increase polymerization rate, quantitatively characterized using a custom real-time infrared spectroscopy setup. Furthermore, a combination of steady-state emission quenching experiments, electronic structure calculations, and ultrafast transient absorption revealed that efficient intersystem crossing to the lowest excited triplet state upon halogenation was a key mechanistic step to achieving rapid photopolymerization reactions. Unprecedented polymerization rates were achieved with extremely low light intensities (< 1 mW/cm2) and catalyst loadings (< 50 μM), exemplified by reaction completion within 60 seconds of irradiation using green, red, and NIR light-emitting diodes.

Ultraviolet (UV) spectroscopy is widely applied in real-time environmental monitoring, especially in diesel vehicle nitrogen monoxide (NO) emissions. However, in field experiments, UV absorption spectrum may exist for different degrees of drifts. Spectral jitters may exist for various reasons such as optical power variation, electrical signal drift, and the refractive index jitters of the optical path for an extended period of time, which causes the detection system to be calibrated. And the pulse xenon lamps as the UV source are characterized by specific emission lines that interfere in spectral analysis directly. For these problems, we proposed the spectral structure matching method based on principal component analysis (PCA), which was compared with the conventional polynomial fitting method to observe feasibility and variability. Further, the UV derivative spectrum was applied to the system appropriately, due to the variation of the absorption peak, and was only related to the target gas by using the above method. We validated our method experimentally by performing the NO UV detection system with the calibration and the comparison test. The results suggested that the calibration relative error was less than 9% and the measurement relative error was less than 6% for this wide range by the proposed processes, which optimized the interference of spectral structures and fluctuation to the system and therefore provided better monitoring. This study may provide an alternative spectral analysis method that is unaffected on the specific emission lines of lamps and is not limited to the spectral region and the target gas.

Inflammatory cytokine storm is one of the main pathogenesis of acute liver injury, and accumulating evidence suggests that the E3 ubiquitin ligase ring finger protein 31 (RNF31) plays an important regulatory role in the activation of inflammatory pathways. We found that RNF31 expression was up-regulated in lipopolysaccharide (LPS)-treated HL-7702 cells. Western blotting results showed decreased expression of RNF31 and total ubiquitinated proteins after transfection of si-RNF31. The results of MTT assay indicated that cell viability was enhanced. Flow cytometry analysis showed that cell apoptosis and ROS content was decreased, and ELISA assay results exhibited that the inflammatory factors secretion was reduced. Interestingly, A20 protein expression was inhibited as RNF31 expression was upregulated. On this basis, we performed co-immunoprecipitation assays and found that RNF31 could interact with A20. Actinomycin tracing and proteasome inhibition experiments showed that RNF31 degrades A20 through the proteasome pathway. Furthermore, overexpression of A20 enhanced cell viability, reduced apoptosis, and inhibited ROS generation and inflammatory factor secretion. Mechanistic studies revealed that RNF31 was able to degrade A20, which affected the inflammatory response and hepatocyte apoptosis mediated by the toll like receptor 4 (TLR4)/myeloid differentiation factor88 (MyD88)/nuclear transcription factor-κB (NF-κB) signaling pathway. Moreover, knockdown of RNF31 attenuated the inflammatory response induced by d-Gal/LPS in mice with acute liver injury. In conclusion, RNF31 degrades A20 by ubiquitination and activates the TLR4/MyD88/NF-κB signaling pathway to aggravate acute liver injury.

A family of cyanide-bridged heterometallic aggregates has been constructed of the chromophoric cycloplatinated metalloligands and coordinatively unsaturated d10 fragments {M(PPh3)n}. The tetranuclear complexes of general composition [Pt(C^N)(CN)2M(PPh3)2]2 [C^N = ppy, M = Cu (1), Ag (2); C^N = tolpy (Htolpy = 2-(4-tolyl)-pyridine), M = Cu (4), Ag (5); C^N = F2ppy (HF2ppy = 2-(4, 6-difluorophenyl)-pyridine), M = Cu (7), Ag (8)] demonstrate a squarelike arrangement of the molecular frameworks, which is achieved due to favorable coordination geometries of the bridging ligands and the metal ions. Variation of the amount of the ancillary phosphine (for M = Ag) afforded compounds [Pt(C^N)(CN)2Ag(PPh3)]2 (C^N = ppy, 3; C^N = tolpy, 6); for the latter one an alternative cluster topology, stabilized by the Pt–Ag metallophilic and η1-Cipso(C^N)–Ag bonding, was observed. The solid-state structures of all of the title species 1–8 were determined crystallographically. The complexes exhibit moderately strong room-tempe...

Fluoride pollution frequently occurs in many underground drinking water sources due to discrepancies in the geological environment. To address this problem, a manganese-supported activated alumina (MnOOH-supported AA) adsorbent was proposed in the present study. The adsorbent was prepared with an impregnation method, then the morphology and microstructure were systematically characterized. Further, the adsorption kinetics and thermodynamics were systematically explored through static experiments to confirm the adsorption mechanism. The results showed that MnOOH was successfully loaded on the activated alumina (AA), and irregular and convex spinous structures were formed on the surface of particles. Compared with the AA, MnOOH-supported AA exhibited a significantly higher defluoridation rate, which has been doubled. The kinetic behavior of fluoride adsorption on MnOOH-supported AA was governed by the quasi-second-order kinetics model with regression coefficients of 0.9862, 0.9978 and 0.9956, respectively. The adsorption rate was mainly ascribed to the intra-particle diffusion. Additionally, the Freundlich isotherm equation fitted the adsorption thermodynamic process reasonably well compared with the Langmuir adsorption model. Specifically, the correlation coefficients were 0.9614, 0.9383 and 0.9852 at 25 °C, 35 °C and 45 °C, respectively. The adsorption–desorption isotherm plot was similar to the Type V isotherm. The whole fluoride adsorption was a spontaneous endothermic reaction, and controlled by chemical adsorption. These results demonstrated that MnOOH-supported AA as an alternative to the conventional AA showed promising potential for defluoridation in drinking water treatment.

Various functional polymers as electrode binders with enhanced lithium ion conductivity have been proposed recently to improve the overall performance of high-power lithium ion battery (LIB). To identify the critical features of polymer binders, we utilized molecular dynamics (MD) simulations to systematically examine and compare the molecular effects of poly(vinylidene fluoride) (PVDF), poly(ethylene oxide) (PEO), polyacrylonitrile (PAN), poly(N-vinylformamide) (PNVF), and poly(styrene sulfonate) (PSS) binders on lithium ion transports at liquid electrolyte/LiFePO4 (LFP) cathode interface. Compared with conventional PVDF, all tested functional polymers have higher Li+ affinity and can disrupt the electric double layer structure. As a binder, PEO can form stable coordination complex with Li+ to effectively lower the free energy of Li+ at interface, resulting in a significantly reduction of interfacial impedance R int . Both PAN and PNVF have polar side-chains where the PNVF formamide groups has higher Li+ affinity than PAN nitrile. PNVF can further enhance the Li+ mobility near the LFP surface and lower the total R int . In contrast, rigid PAN has minor effects on Li+ free energy at interface, giving little impacts toward the total R int . Finally, the negatively charged PSS can significantly reduce the surface electric potential and lower the Li+ free energy over a wide range near the interface, which greatly reduces the total R int . The combined results suggest that improving the Li+ affinity and the local mobility at interface are important factors for a good binder, where the free energy variations play more dominant effects. The presented molecular mechanisms of various functional polymer binders provide valuable insights for novel binder design.

Influenced by geological environment, both fluoride ion and iron ion exceed the standard in underground drinking water sources in some areas. Aiming at this problem, the experiment was designed by Response Surface Methodologyology(RSM). With the goal that fluoride ion in the effluent meets the Standards for Drinking Water quality (GB 5749-2006) and the concentration of iron ion in the effluent drops significantly, the adsorption time, pH value and temperature were taken as independent variables, and the primary and secondary relationship of influencing factors on fluoride and iron reduction of manganese-loaded activated alumina was explored, then the process parameters were optimized. The remarkable relationships are AF(adsorption time)>BF(pH value)>CF(temperature), BFe(pH value) > CFe(temperature)>AFe(adsorption time).Under the conditions of adsorption time 8h, pH value 4 and temperature 25°C, when the mass concentrations of iron and fluorine in raw water are 2mg/L, the removal rates of fluoride and iron can reach 68% and 59.5%, and the mass concentrations of effluent are 0.61mg/L and 0.81mg/L, respectively.

In this paper, a CMOS multichannel transceiver (TRX) is proposed for angular identification in automotive car radar applications. Two transmitters (TXs) and six receivers (RXs) are placed on the same die using 65-nm CMOS technology with chip size $3.5 \times 3$ mm2. To generate a millimeter-wave (MMW) frequency-modulated continuous-wave signal, an injection-lock frequency sextupler cascaded a 1-to-8 Wilkinson power dividing network with wideband isolation is designed as the LO-chain to convert external source from 12.5–13.7 to 75–82.2 GHz for both the TXs and RXs. Each TX achieves above 11-dBm output power and the RXs achieve 30-dB conversion gain from 75 to 82 GHz, and the total power dissipation of whole chip is 1.43 W. Compared with other published multichannel TRXs in silicon germanium (SiGe) process, this paper demonstrates compatible performances and the potential of multichannel TRX using CMOS for MMW automotive car radar application.

A family of new branched phosphine derivatives {Ph2N-(C6H4)n-}3P → E (E = O 1-3, n = 1-3; E = S 4-6, n = 1-3; E = Se 7-9, n = 1-3; E = AuC6F5 4-6, n = 1-3), which are the donor-acceptor type molecules, exhibit efficient deep blue room temperature fluorescence (λem = 403-483 nm in CH2Cl2 solution, λem = 400-469 nm in the solid state). Fine tuning the emission characteristics can be achieved varying the length of aromatic oligophenylene bridge -(C6H4)n-. The pyramidal geometry of central R3P → E fragment on the one hand disrupts π-conjugation between the branches to preserve blue luminescence and high triplet energy, while on the other hand provides amorphous materials to prevent excimer formation and fluorescence self-quenching. Hence, compounds 2, 3, 5, and 12 were used as emitters to fabricate nondoped and doped electroluminescent devices. The luminophore 2 (E = O, n = 2) demonstrates excellently balanced bipolar charge transport and good nondoped device performance with a maximum external quantum efficiency (EQEmax) of 3.3% at 250 cd/m(2) and Commission International de L'Eclairage (CIE) coordinates of (0.15, 0.08). The doped device of 3 (E = O, n = 3) shows higher efficiency (EQEmax of 6.5, 6.0 at 100 cd/m(2)) and high color purity with CIE (0.15, 0.06) that matches the HDTV standard blue. The time-resolved electroluminescence measurement indicates that high efficiency of the device can be attributed to the triplet-triplet annihilation to enhance generation of singlet excitons.

Inorganic perovskite quantum dots (IPQDs) such as cesium lead halide (CsPbX3, X = Cl, Br and I) quantum dots have attracted much attention for developing cadmium-free quantum light-emitting displays (QLEDs) based on outstanding light emission properties including narrow full width at half maximum (FWHM), tunable bandgap and ultrahigh (>90%) photoluminescence quantum yield (PLQY). Nevertheless, their poor stability under ambient conditions, at high temperature or under continuous light irradiation is the main problem for practical applications. In this study, a new method is proposed to effectively stabilize CsPbBr3 IPQDs by synthesizing them with sulfate-functionalized cellulose nanocrystals (CNCs) at room temperature without using traditional quantum dot stabilizers such as oleylamine (OLA) and oleic acid (OA). The as-prepared CsPbBr3 IPQD/CNC hybrid paper-like films are highly stable and the relative photoluminescence (PL) intensity can be maintained at 92% under continuous UV light (306 nm, 15 W) illumination for 130 h, >99% at high temperature (100 °C) for 130 h, and >99% in ambient conditions for 15 d. Additionally, the PLQY and FWHM of IPQD/CNC are 45.69% and 22 nm, respectively. The ultrahigh stability and narrow FWHM characteristics proposed here for IPQD/CNC hybrid films can provide new possibilities for practical applications in the future development of IPQD-related devices.

We once studied the dewetting behaviors of spin-coated and Langmuir−Blodgett (LB) films of polystyrene-b-poly(methyl methacrylate) (PS-b-PMMA) induced by solvent vapor annealing (SVA), and revealed the different contact degrees between hydrophilic PMMA blocks and the substrate in the above two kinds of films. In this work, the dewetting behavior of self-assembled films of PS-b-PMMA induced by SVA was studied for the first time. Effects of copolymer composition, solution concentration, and SVA time were systematically considered. With the increase of SVA time, continuous flat self-assembled films undergo complicated progresses including the formation of bicontinuous or holed structures, the formation of droplets, and the periodic increase and decrease of droplet sizes. The periodic evolutions of droplet sizes in the self-assembled films are similar to those in our previous LB films but different from their single evolutions in the spin-coated films. It indicates that the former two kinds of films have good contact degrees between PMMA blocks and the substrate. Furthermore, the contact degrees in the self-assembled films are better than those in the LB films. In our current minds, the contact degrees are mainly related to the length of hydrophilic blocks and their parallel/vertical segment ratio to the substrate.

Aggregation behavior of an amphiphilic diblock polyelectrolyte poly(n-butylacrylate)-b-poly(acrylic acid) (PnBA-b-PAA) at the air/water interface and morphologies of its LB films were characterized by the Langmuir monolayer technique and atomic force microscopy (AFM), respectively. Effects of subphase pH, temperature and ionic strength on the isotherms and hysteresis curves of the PnBA-b-PAA monolayers and the morphologies of its LB films were systematically studied. With the increase of subphase pH, the isotherms shift negatively and the quasi-plateaus disappear under neutral and alkaline conditions. Hysteresis phenomena of the PnBA-b-PAA monolayers on acidic and neutral subphases are quite obvious and similar, while the compression and expansion isotherms under alkaline condition are almost overlapped. The LB films of PnBA-b-PAA transferred from acidic subphase exhibit isolated circular micelles with large size, while those from alkaline subphase exhibit condensed ones with small size. With the rise in subphase temperature, PnBA blocks on the water surface are more likely to aggregate into large cores due to the higher molecular mobility. Furthermore, the totally ringlike nanostructures prepared from alkaline subphase with medium ionic strength are observed for the first time in LB films of block copolymers.

Hierarchical porous graphene-based carbons (HPGCs) have been prepared by a simple carbon dioxide activation of graphite oxide. The effects of activation temperature on the structural and textural properties as well as gas adsorption capacities of the resultant carbons have been investigated. The HPGCs showed hierarchically micro-meso-macroporous structures, high specific surface areas of up to 532 m 2 g −1 , and large pore volumes of up to 1.67 cm 3 g −1 . Moreover, the HPGC materials were demonstrated to be efficient for CO 2 and H 2 adsorption. The HPGC-850, which was obtained after two hours of activation at 850 °C, exhibited the highest adsorption capacities of 7.74 wt% (1.76 mmol g −1 ) at 273 K and 1 bar for CO 2 and of 0.75 wt% (3.76 mmol g −1 ) at 77 K and 1 bar for H 2 .

Experimental study on the manganese sand, magnetite, quartz sand, ceramsite, volcanic rock in northeast China five different filter material of groundwater, and the effects of biological iron and manganese removal. Test results show that the effect of 4 kinds of filter material in addition to iron and manganese in turn is: manganese sand > magnetite > quartz sand > ceramsite.

A series of compounds containing 5-(2-aminobenzylidene)-2,3-dimethyl-3,5-dihydro-4H-imidazol-4-one (o-ABDI) as the core chromophore with a seven-membered-ring N-H-type intramolecular hydrogen bond have been synthesized and characterized. The acidity of the N-H proton and thus the hydrogen-bond strength can be fine-tuned by replacing one of the amino hydrogen atoms by a substituent R, the acidity increasing with increasing electron-withdrawing strength of R, that is, in the order H

Recent studies showed that Madecassoside (MAD), a pentacyclic triterpene isolated from Centella asitica (L.), was used as a therapeutic agent in wound healing and also as an anti-inflammatory, anti-oxidative activities and anti-aging agent. However, its role in cancer has not been elucidated. In our present study, hepatocyte growth factor (HGF) induced the phosphorylation of its corresponding receptor cMET, increased expression of cyclo-oxygenase-2 (COX-2) and prostaglandin E2 (PGE2) in human hepatocellular carcinoma (HCC) cells lines (HepG2 and SMMC-77), and this effect was inhibited by MAD in a dose-dependent manner. In addition, MAD exhibited significant anti-proliferative and anti-invasive effect in HGF-induced HepG2 and SMMC-77 cells. Moreover, MAD inhibited the phosphorylation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and the protein kinase C (PKC) activity in HGF-induced HepG2 and SMMC-77 cells. This conclusion was consistent with the effect of selective COX-2 inhibitor (NS-398) and knockdown of COX-2 by siRNA on attenuating the proliferation and invasiveness potential, and over-expression of COX-2 on abolishing the effects of MAD on proliferation and invasiveness potential, and was also in parallel with the effect of PKC inhibitor (Bisindolylmaleimide) on inhibiting PKC activity, MEK/ERK1/2 inhibitor (PD98059) inhibited MEK/ERK1/2 pathways in HGF-induced HepG2 and SMMC-77 cells. Collectively, MAD could inhibit the HGF-activated proliferation and invasiveness of HCC cells via regulating the activation of cMET-PKC-ERK1/2-COX-2-PGE2 cascade, which indicated that MAD might help control HGF-linked HCC.

The inhibitory effect of DNA topoisomerase (Top I) by isoliquiritigenin(ISO) were investigated and their interaction mechanism was evaluated using methods including UV–vis absorption, fluorescence, coupled with molecular simulation, and using the MTT method of inhibition rate of HCC tumor cell SNU475 proliferation assay, finally, the interaction of ISO with calf thymus DNA was investigated by melting measurements and molecular docking studies. It was found that isoliquiritigenin reversibly inhibited DNA Top I in a competitive manner with the concentrations of ISO resulting in 50% activity lost (IC50) were estimated to be 0.178 ± 0.12 mM. Isoliquiritigenin exhibited a strong ability to quench the intrinsic fluorescence of Top I through a static quenching procedure. The positive values of enthalpy change and entropy change suggested that the binding of isoliquiritigenin to Top I was driven mainly by hydrophobic interactions. The molecular docking results revealed isoliquiritigenin actually interacted with the primary amino acid residues on the active site of Top I, and the detection results of fluorescence staining and the inhibitory effect on the growth of HCC SUN475 showed that isoliquiritigenin induced the apoptosis cells increased gradually. The interaction of ISO with DNA can cause the denaturation temperature to be increased, which indicated that the stabilization of the DNA helix was increased in the presence of ISO, which indicated that the results provide strong evidence for intercalative binding of ISO with DNA.

A new transmission-line concept, called the field-effect transistor (FET)-integrated coplanar waveguide (CPW), is proposed. This concept treats the passive two-finger FET as CPW and, thus, the scaling rule is more accurate than the previous model, especially in high frequency. The extraction approach of the parameters of the FET-integrated CPW is also included. With this concept, the design procedure of traveling-wave switches can be equivalent to a filter synthesis problem. Based on this design procedure, a single-pole single-throw and a single-pole double-throw traveling-wave switch have been realized and measured using 0.15-/spl mu/m high-linearity AlGaAs/InGaAs/GaAs pseudomorphic high electron-mobility transistors. Finally, the frequency limitation of the traveling-wave switches is also discussed. The results show the FET-integrated CPW is the most efficient way to overcome the frequency limitations of traveling-wave switches, achieving operation frequency to 135 GHz, the highest frequency reported to date.

Dimethyl carbonate (DMC) was synthesized by the ester exchange reaction of ethylene carbonate and methanol. K2 CO3 , KOH, LiOH and NaOH were used as catalysts for DMC synthesis and their catalytic abilities were compared in terms of kinetics. LiOH showed the best reaction rate among the catalysts. The rate constant was estimated to be 0.02538 (dm 3 /mol) 0.21 /min at 298 K.

PMMA homopolymer with CF3(CF2)2CF2- end group was prepared by the ATRP of MMA using CF3(CF2)2CF2-I as an initiator and copper(I) salts/bipy catalysts. This indicated the production of perfluorobutyl radicals by ATRP mechanism and successful polymerization by them. Di- and triblock copolymers were also prepared by the ATRP of MMA using iodine-terminated PVDF as (macro)initiators. The kinetic plots (ln[M]o/[M] vs. time) showed nearly first-order with respect to monomer concentration and the Mn,NMR of block copolymers increased linearly with conversion. However, iodine-terminated PVDF showed low initiator efficiency because propagating rate was much faster than initiating rate

A broadband balanced distributed frequency doubler fabricated by 0.35 mum SiGe BiCMOS technology is developed to operate from 4 to 18 GHz output frequency. This balanced doubler consists of an active balun and a distributed doubler. A sharing collector line is used in the balanced distributed doubler to reduce the chip size. This circuit exhibits a measured conversion loss of less than 8 dB and a fundamental rejection of better than 23 dB for the output frequency between 4 and 18 GHz. The chip size is 1.1times0.7 mm2.

Adsorption equilibria of chloropentafluoroethane (CF 3 CF 2 Cl, CFC-115) on Pd/activated carbon powder and on activated carbon powder were examined between 298.15 and 373.15 K. The adsorption equilibria of CFC-115 on the Pd/activated carbon powder and the activated carbon powder can be well represented by the BET equation. The isosteric heats of adsorption of CFC-115 on both adsorbents are of approximately the same order of magnitude as the heats of condensation. This means that the adsorption of CFC-115 on both adsorbents is primarily due to physical forces. By hydrodechlorination over the Pd/activated carbon powder, CFC-115 could be converted to pentafluoroethane (CF 3 CF 2 H, HFC-125) with more than 99% selectivity. It was found that the Pd/activated carbon powder can be used as an adsorbent for recovering CFC-115 and a catalyst for manufacturing HFC-125 from CFC-115.

An equilibrium study was conducted on the adsorption of chloropentafluoroethane (CFC-115, CF3CF2Cl) on activated carbon powder between 298.15 K and 373.15 K. Experimental data were fitted with several isotherm equations. Among the twoparameter equations, the BET equation showed the best results over the entire relative pressure range studied. When the pressure range was divided into two regions, a better result was obtained by applying the Langmuir equation in the lower pressure range and the BET equation in the higher relative pressure region. Among the threeparameter equations, the Langmuir-Freundlich equation gave better results than the RedrichPeterson equation. The isosteric heat of adsorption of CFC-115 on the activated carbon powder was estimated. It was found to have the same order of magnitude with the heat of condensation, which indicates that the adsorption was primarily due to physical forces.

Equilibrium studies on the adsorption of chloropentafluoroethane (R-115, CF3CF2Cl) and pentafluoroethane (CF3CF2H, R-125) on an activated carbon pellet were made between 298.2 K and 373.6 K. Equilibrium parameters based on the Langmuir−Freundlich equation are derived. The Langmuir−Freundlich isotherms for R-115 and R-125 fit the experimental results within 2%. The isosteric enthalpies of adsorption of R-115 and R-125 were estimated.

The deactivation behavior of Pd catalysts on different supports in the hydrodechlorination of chloropentafluoroethane (CF 3 CF 2 Cl) was investigated. Changes of the BET surface area and the metal percentage exposed, measured by a multipurpose in situ catalyst characterization system during the reaction, gave some information about the deactivation mechanism of the Pd catalysts. The deactivation of the Pd catalysts was mainly caused by sintering of Pd particles rather than by coking. The sintering of Pd particles on the catalyst surface was promoted by the reaction of hydrogen fluoride with the support of the catalysts.

A remarkable synergism was observed in the higher oxygenate formation from ethanol on Cu/ZnO catalysts compared to one component catalyst of Cu or ZnO. The reaction mechanism was examined by 13C labelling studies and selective feeding methods. A 13C NMR and a GC/MS were used to determine the structure of the labelled products. A mass spectrometer was used to trace the dynamic change of the product distribution. A comprehensive reaction mechanism for the carbon chain growth on Cu/ZnO catalysts was proposed. The synergism could be explained by different intrinsic characteristics of copper and ZnO in the dehydrogenation of ethanol. Nucleophiles are produced preferentially on ZnO and electrophiles are produced preferentially on copper, and they would associate to from dioxygenated C4 intermediates, which are converted to various higher chain products. A stabilization of ethoxy carbanion on ZnO was suggested, which would participate in the chain growing reaction.

The thermal degradation of polytetrafluoroethylene was studied in the helium flowing atmosphere and the temperature range 510–600°C. The products of the thermal degradation of polytetrafluoroethylene were analyzed by an on-line gas Chromatograph and the product distribution was obtained. The products consist of tetrafluoroethylene (TFE), perfluoropropene (PFP) and cyclic-perfluorobutane (c-PFB). Under most conditions the main product was TFE. The c-PFB was regarded as the secondary product formed from TFE because the formation of c-PFB strongly depended upon the degradation rate. However, the production of PFP was not related to the degradation rate, but it was influenced by diffusion limitation of gaseous product in the sample matrix. These phenomena were also verified with Curie-point pyrolyser. The results showed that the production of PFP reached a maximum point under diffusion limitation condition. The degradation mechanism of polytetrafluoroethylene was proposed in terms of unzipping mechanism and other mechanism like radical chain transfer reaction.

Triethylene glycol monomethyl ether and poly(ethylene glycol) monomethyl ether modified 2-(2'-aminophenyl)benzothiazoles, namely ABT-P3EG, ABT-P7EG and ABT-P12EG varied by different chain length of poly(ethylene glycol) at the amino site, were synthesized to probe their photophysical and bio-imaging properties. In polar, aprotic solvents such as CH2Cl2 ultrafast excited-state intramolecular proton transfer (ESIPT) takes place, resulting in a large Stokes shifted tautomer emission in the green-yellow (550 nm) region. In neutral water, ABT-P12EG forms micelles with diameters of 15 ± 3 nm under a critical micelle concentration (CMC) of ~80 μM, in which the tautomer emission is greatly enhanced free from water perturbation. Cytotoxicity experiments showed that all ABT-PnEGs have negligible cytotoxicity against HeLa cells even at doses as high as 1 mM. Live-cell imaging experiments were also performed, the results indicate that all ABT-PnEGs are able to enter HeLa cells. While the two-photon excitation emission of ABT-P3EG in cells cytoplasm shows concentration independence and is dominated by the anion blue fluorescence, ABT-P7EG and ABT-P12EG exhibit prominent green tautomer emission at > CMC and in part penetrate to the nuclei, adding an additional advantage for the cell imaging.

High nitrogen fertilizer input is the main manner to maintain the high-yield crops in farmland in China. The average application quantity of nitrogen fertilizer in China is significantly higher than some developed countries in the world. However, the nitrogen fertilizer utilization efficiency is very low. Thus, high sensitivity sensing and on-line monitoring ammonia concentration were needed to quickly acquire the soil nutrient information and to get the nitrogen fertilizer utilization efficiency. A high sensitivity ammonia concentration sensor used in farmland has been developed based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) technology, high frequency modulation technique and long optical path technique. TDLAS is a method to obtain the spectroscopy of gas molecule single absorption line in the characteristic absorption spectrum region as the characteristic of the distributed feed back (DFB) laser with narrow line width and tunability. A sensor array formed with three ammonia concentration sensors by distributed sensing technique was used for ammonia volatilization experiment in a wide range of farmland. It was verified that the performance consistency of the three ammonia sensors was good and the sensor array realized the regional ammonia concentration monitoring. Continuous measurement results showed that the ammonia concentration influenced by the volatile source location, wind direction, weather and other factors, and it was positively correlated with the ammonia volatilization rate. The ammonia sensor array is suitable for continuously ammonia volatilization monitoring in a wide range of farmland environment with its high sensitivity, rapid response time without gas sampling.

The selective alkylation of aniline with methanol was investigated over various metallosilicates synthesized in two different media: alkaline medium (NaOH) and fluorine medium (NH4F). Through the elemental analysis, XRD, and29Si MAS NMR, it was thought that all the metallosilicates had MFI zeolite structure and the metals were incorporated in metallosilicate framework successfully. Temperature programmed desorption (TPD) of NH3 and aniline alkylation suggested that the selectivity for N,N-dimethylaniline (NNDMA) is high when the metallosilicates have a large number of medium acid sites (567–673 K), which means that the medium acid sites play an important role in the production of NNDMA. It was also known that metallosilicates synthesized in fluorine medium have strong acid sites (> 773 K) and were deactivated more rapidly than those synthesized in alkaline medium.

HCFC-133a (l-chloro-2,2,2-trifluoroethane) was thermally chlorinated in an integral reactor under atmospheric pressure in a temperature range between 573 and 723 K. From the analysis of the data it was confirmed that the reaction was a two-step series-parallel reaction and each step was a second-order reaction. The ratio of the second-step rate constant to the first-step rate constant did not change with temperature and its value was 1.13. The activation energy was 106 kJ/g-mol. These results indicate that the product distribution is the sole function of conversion of HCFC-133a.

Direct evidence for the differing characteristics of Cu and ZnO in the dehydrogenation of ethanol were provided through the deuterium exchange reaction of ethanol and acetaldehyde. Deuterium was mainly exchanged at the α-carbon of ethanol and acetaldehyde on Cu catalyst. On the other hand, deuterium was mainly exchanged at the β-carbon on ZnO catalyst. More deuterium atoms were exchanged with D2 than with D2O on Cu catalyst, but the reverse results were obtained on ZnO catalyst. β-Elimination type reaction mechanisms are suggested for the dehydrogenation of ethanol, and a β-carbanionic intermediate was proposed for the dehydrogenation of acetaldehyde.

The simultaneous biological removal of iron, manganese and ammonia from simulated contaminated groundwater was studied by biological aerated filter using dual layer ceramsite as support material in the lab. The system was simultaneously inoculated with iron and manganese oxidizing bacteria, nitrifying bacteria and nitrification bacteria and a series of experiments was performed to investigate simultaneous removal performance of the filter. The influence of variation flow rate on simultaneous removal of manganese, iron and ammonia nitrogen was studied. At the mean time effluent concentration and removal ratio of manganese, iron and ammonia nitrogen along the filter depth were analysized. The results showed that the simultaneous removal of the aforementioned pollutants can be achieved by single-step filtration for high pollutants load (influent concentration 2.52~4.22mg/l, 1.22~3.97mg/l, 1.24~3.92 mg/l, respectively). Biofiltration ability to remove Mn for mixed bacteria on the filter can be improved by a sudden increase of flow rate(flow rate was 20l/h, 40l/h, 60l/h and 80l/h,respectively). But iron and ammonia removal were unaffected by a sudden increase of flow rate. Manganese was the rate-limiting pollutant.

This paper presents a 24-GHz high gain and wide gain control range in cascode device technique. The VGA is implemented in 0.15-µm GaAs PHEMT process. This VGA has 15.7 dB gain and 18.5% 3-dB bandwidth and over 20 dB gain control range at 24 GHz, with a low dc power of 13.5 mW. These results indicate that cascode technique is suitable for low power consumption and small chip size for high frequency amplifiers using GaAs pHEMT process.

A modified low-power and low-noise distributed amplifier for ultra-wideband (UWB) radio systems is first proposed to overcome the bottleneck of conventional DA. The UWB LNA achieves 10-dB gain with 5.4-mW power consumption, and 3-dB roll-off up to 10.6 GHz. The measured noise figures are lower than 5.5 dB from 3.1 to 10.6 GHz with 1.5 V supply. The output P/sub 1dB/ is -5.8 dBm and input IP3 is -4 dBm from 1.5-V supply. The MMIC occupies total chip size of only 0.47 mm/sup 2/ including all testing pads.

The reaction mechanism for the methylformate formation on Cu/ZnO catalysts from methanol and CO was investigated by the labeling study with13C methanol. It was found that methylformate could be formed through two parallel reaction routes, i.e., methanol-formaldehyde reaction and carbonylation of methanol depending upon the catalyst composition as well as the reaction conditions. The major reaction route on the high ZnO-contcnt catalyst (Cu/ZnO=30/70) was found to be the methanol-formaldehyde reaction, and changed to the carbonylation reaction with the increase ol CO partial pressure. On the other hand, the major reaction route on the high Cu-content catalyst (Cu/ZnO=80/20) remained as methanol-formaldehyde reaction even under the high CO pressure.

A V-Band MMIC single pole double throw (SPDT) switch using GaAs PHEMT process is designed, fabricated and tested. In contrast to the conventional resonant-type switch design method, this passive FET switch circuit utilizes impedance transformation to compensate the drain-source capacitance effect for the off-state in millimeter-wave frequency range. This SPDT switch has a measured isolation better than 30 dB for the off-state and 4 dB insertion loss for the on-state from 53 GHz to 61 GHz. The isolation performance of this design approach outmatches previously published FET switches in this frequency range.