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It is necessary to develop NO2 gas sensors as NO2 is a pollutant. While, different from the reducing gases, oxidizing gas NO2 will put up a complicated sensing process. Density functional theory (DFT) calculations are necessary to be performed to understand NO2-sensing mechanisms at the atomic level. In this study we introduce NO2 to SnO2 (110) surface with oxygen species pre-adsorbed. The results show that NO2 sensing mechanism of SnO2 surface strongly depends on the concentration of oxygen in the ambient atmosphere (usually, no effects of temperature and pressure are considered). The direct interactions between NO2 molecule and SnO2 sub-reduced surface (with two rows of fold-coordinated bridging oxygens removed) for very low oxygen concentrations show that, NO2 gas molecules interact directly with Sn instead of reacting with oxygen species, resulting in an increase in resistance of SnO2. We investigate gas-sensing processes of interaction between NO2 molecule and SnO2 surface with pre-adsorbed oxygen species for the case of considerable high oxygen concentrations. Adsorbed molecular oxygen ions compete with adsorbing NO2 molecules for available surface sites and electrons from the SnO2. As the availability of oxygen ions on the SnO2 surface increasing, the interaction between NO2 and adsorbed oxygen species give rise to a reducing interaction, which brings a decrease in resistance of SnO2.

Objective: To study the effect of butyl phthalide on serum cytokines, soluble apoptosis factors and antioxidant molecules in patients with vascular dementia. Methods: 86 patients with vascular dementia admitted in our hospital between January 2014 and January 2016 were selected for retrospective study and divided into observation group and control group (n=43) according to double-blind randomized control. Observation group received butyl phthalide capsule (0.2 g/time, 3 times/d) treatment on the basis of conventional treatment, control group received conventional treatment alone, and both lasted for 24 weeks. After 24 weeks of treatment, ELISA was used to determine serum levels of vascular repair factors and soluble apoptosis factors of two groups of patients, and radioimmunoassay was used to determine serum levels of antioxidant molecules. Results: After 24 weeks of treatment, serum vascular repair factors heme oxygenase-1 (HO-1), angiogenin I (AngI) and vascular endothelial growth factor (VEGF) levels of observation group were higher than those of control group, matrix metalloproteinase-9 (MMP-9) level was lower than that of control group, and differences between groups were statistically significant (P

Acetamide (C2), propionamide (C3), butyramide (C4), isobutyramide (i-C4), isovaleramide (i-C5) and trimethylacetamide (t-C5) groups each were introduced to the terminals of hyperbranched polyethylenimine (HPEI) through the amidation reaction between HPEI and the corresponding anhydride. Moreover, HPEIs terminated with two kinds of amides were also prepared. The first amide was fixed to be i-C4 with 52% degree of amidation (DA), and the second amide varied from C2, C3, C4, i-C5 to t-C5. All the polymers were characterized by 1H-NMR. Turbidimetry measurements were performed for these polymers in water at different temperatures. With respect to the polymers bearing only one kind of amide group, except C2, all the other amide groups could render thermoresponsive properties to HPEI. The specific ordering of these amide groups to reduce the cloud point temperature (Tcp) was as follows: i-C5 > t-C5 > C4 > i-C4 > C3. Moreover, the more branched i-C4 and t-C5 were better groups than their less branched isomers C4 and i-C5 in the Tcp range of 12–51 °C to render the sharper phase transition to the thermoresponsive polymers. As for the polymers bearing two kinds of amide groups, the further introduction of C2, C3, C4, i-C5 or t-C5 could effectively endow HPEI bearing 52% of i-C4 with thermoresponsive properties. The specific ordering of these second amide groups to reduce the Tcp was as follows: i-C5 > C4 > i-C4 > C3 > C2. C4, i-C5 and t-C5 were all effective second amide groups to prepare the thermoresponsive polymers with sharper phase transition.

Background Fluorouracil implants are widely used in peritoneal interstitial chemotherapy. Curative effects have been obtained, but implants have also caused some complications. Case presentation We performed an analysis of a 66-year-old male patient’s case history, as well as conventional pathological analysis and Raman spectroscopic detection of the diaphragmatic tumor. We also analyzed the underlying causes of this condition to prevent complications and reduce misdiagnoses in future cases. The patient had a history of peritoneal fluorouracil implantation. Pathological analysis of the diaphragmatic mass revealed foreign particles, and Raman detection showed that the mass contained fluorouracil. Conclusion Fluorouracil implants may persist due to the high concentrations of this drug used in peritoneal chemotherapy. This finding should provide guidance and improve the application of peritoneal implants. In clinical trials, and the diagnosis of liver metastasis should be based on pathological results.

The La1-xCaxFeO3 nanocrystalline powders were prepared by sol-gel method. These powders crystallized as perovskite orthorhombic structure. With an increase of Ca content, the resistance of La1-xCaxFeO3 sensors in air decreases at first, undergoes a minimum at x=0.3, and then increases again. La1-xCaxFeO3-based sensors show sensitive responses to CO. Among those La1-xCaxFeO3-based sensors, the sensor with x=0.2 shows the highest response to 200 ppm CO at operating temperatures below 325°C. The highest response S=(RCO-Rair)/RCO for the La0.8Ca0.2FeO3 based sensor to 200 ppm CO is 87% with response time 15 s and recovery time 60 s at an operating temperature of 100°C.

The nanocrystalline powders Nd1-xCaxFeO3 prepared by sol-gel method crystallized as perovskite orthorhombic structure. The mean grain size of Nd1-xCaxFeO3 powders were about 15~ 40 nm. The conductivity of the Ca doped samples was enhanced, compared to that of the undoped. The Nd0.9Ca0.1FeO3-based sensor showed good gas sensing properties to ethanol and acetone. The responses of the Nd0.9Ca0.1FeO3-based sensor to 600ppm ethanol and acetone were about 158.4 at 220°C and 61.7 at 240°C, respectively.

As started late, China's large exhibition venue industry lags behind the developed countries in the exhibition venue construction and management concepts, and lacks of integrated management over the full cycle of large exhibition venue projects, therefore, decision-making, implementation and operational phases are disjointed with each other and all sorts of drawbacks exist, meanwhile, the overall optimization of social, environmental and economic benefits and win-win situation between stakeholders are unable to be realized. This paper takes large exhibition venue project full cycle integrated management model as object of research and discusses the reason mechanism, connotation, organizational methods and information system of the integrated management. Focusing on large exhibition venue project operation, this paper makes a research and analysis on venue project full cycle integrated management information system demands, and proposes information integration transformation models (including integration relationship model, integration element model and integration mapping model) and comprehensively designs the system basic function framework, hierarchical framework and overall running framework, and also proposes key technologies used to realize the system.

Fe86.5Zr7B3Cu3.5 nanocrystalline ribbon can be directly fabricated by melt – spinning technique with an appropriate quenching speed without annealing processes. The average grain size of α-Fe for Fe86.5Zr7B3Cu3.5 as quenched ribbon prepared with a quenched speed V=40 m/s is about 10-13 nm estimated from X-ray diffraction and TEM observation. For Fe86.5Zr7B3Cu3.5 nanocrystalline as quenched ribbon (V=40m/s), the saturation magnetic induction Bs is 1.47 T, permeability μe at 1 kHz is 25600 and saturation magnetostriction λs is -2×10-6. The magnetoimpedance value Z/Z0 of the Fe86.5Zr7B3Cu3.5 nanocrystalline as quenched ribbon reaches –38.32 % under H=7162 A/m. Our present results reveal a novel route to fabricate the nanocrystaline ribbons with excellent soft magnetic properties and giant magnetoimpedance.

In this work the giant magnetoimpedance effect has been found in Fe89B4Hf7 nanocrystalline ribbons. There is an optimal annealing temperature about 650°C for obtaining a large magnetoimpedance. The magnetoimpedance can reach 208% for Fe89B4Hf7 annealed at 650°C for 20min. meanwhile, it has been found that the magnetoimpedance in FeHfB shows a good thermal- heating stability, which is useful for application.

In the present work, we investigated the hard magnetic properties of Nd-Fe-B magnets prepared by the decrepitation technique. The microstructure of (Nd0.935Dy0.065)14.5Fe79.4B6.1 HD - magnet was observed and the average grain size is about 6-15 µm. The HD alignment degree f is about 93%. Most rich-Nd phase can be found at grain boundaries of main phase, but a few rich – Nd phase occurs within main phase grains. The magnetizing field dependence of the hardmagnetic properties for the (Nd0.935Dy0.065)14.5Fe79.4B6.1 were investigated. The value of magnetizing field for the saturation coercivity is smaller than the value of the saturation coercivity, showing that the coercivity for the (Nd0.935Dy0.065)14.5Fe79.4B6.1 HD-magnet is controlled by the nucleation mechanism. Meanwhile, the temperature dependence of coercivity for HD magnet Nd14.5Fe79.4B6.1 was analyzed.

FeCuNbSiB and FeZrBCu nanocrystalline ribbons can be obtained directly through the melt- spinning technique without additional annealing processes. The giant magnetoimpedance can be observed in FeCuNbSiB and FeZrBCu as quenched ribbons. The addition of Cu improves the nano-crystallization of a-Fe(Si) or a-Fe phase and reduces the grain size in FeCuNbSiB and FeZrBCu as quenched ribbons, which enhances the magnetoimpedance via increasing the variation of permeability under fields. The present experimental results reveal a novel route to fabricate the Fe based nanocrystalline soft magnetic materials with giant magnetoimpedance effect.

A series of aqueous latexes with solid contents of 56%–59% were synthesized by binary emulsion copolymerization of vinylidene chloride (VDC) with an acrylate, namely methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), hexyl acrylate (HA), or 2-ethylhexyl acrylate (EHA). Differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy showed that the acrylate units with short ester side-chains, such as MA and EA, made the copolymers hard and the crystallization tendency of their PVDC segments was reduced. Hydrophobic acrylates with relatively long ester groups, such as HA and EHA, gave flexible copolymers, and favored the crystallization of their PVDC segments. BA endowed the copolymers with medium flexibility and crystallization tendency. As coating materials, the copolymers bearing MA and EA adhered poorly to the tinplate before or after 100 hr of salt-spray corrosion, whereas those bearing BA, HA, or EHA showed good adhesion to tinplate when they had little or no crystallinity. After 100 hr of salt-spray corrosion, only BA–VDC80, containing 80% VDC, retained both excellent adhesion to metal and excellent barrier performance. Further study demonstrated that BA–VDC80 could protect tinplate from rusting for at least 250 hr under harsh salt-spray corrosion. Scanning electron microscopy, FTIR-attenuated total reflectance spectroscopy and DSC were used to evaluate the corroded BA–VDC80 film. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40192.

In recent years, there has been much interest in the perovskite compounds R1−x Ax MnO3 (R=La, Pr and A= Pb, Ca, Sr, Ba) with a Mn3+/Mn4+ mixed valence [1–13]. In the doping range 0.2< x < 0.5, these manganites undergo a paramagnetic insulator to ferromagnetic metal phase transition upon cooling, leading to a sharp resistance peak near the Curie temperature TC. Application of an external magnetic field of few teslas suppresses the resistance greatly. Within the double– exchange interaction model the itinerant carriers in the substituted R1−x Ax MnO3 oxide provide the mechanism for ferromagnetic interaction between Mn3+ and Mn4+ ions. The ferromagnetic Curie temperature is related to the strength of the transfer intergral ti j between Mn3+ and Mn4+ ions which control the the electronic (hole) conductivity. The unusual temperature and magnetic field dependent resistance exhibited by these compounds reflects a novel interplay between magnetism and electronic transport. It has been shown recently that the substitution of Mn3+ by Co3+, Ni3+, Cr3+ in R0.5A0.5MnO3 destroys the charge–ordered state and renders the material ferromagnetic and metallic when the average size of A–site cation, 〈rA〉, is larger than 1.17 A [10–12]. In the present work, we report the effects of the Ni-doping on the perovskite compound La0.67Ca0.33MnO3. Samples La0.67Ca0.33Mn1−x Nix O3 (x = 0, 0.05, 0.1 and 0.2) were prepared using solid state reaction method. Mixed powders of La2O3, MnO2, Ni2O3 and CaCO3 were ground for 60 min, then ball-milled for 30 min and pressed into flats. The flats were first heated at 800 ◦C for 24 h and subsequently pulverized. After being milled for 30 min, they were pressed into flats again, then sintered at 1300 ◦C for 100 h, followed by furnace–cooling in the atmosphere. X-ray diffraction analysis by Cu-Kα radiation was used to confirm a single phase with perovskite structure. The thermal– magnetic analysis using a vibrating sample magnetometer (VSM) at a small field of 0.04 T was performed from 77 to 300 K. The resistance were measured by a standard four–terminal method. The magnetization curves and magnetoresistances at 5 K, and the temperature dependence of the resistance at both zero field and H = 6 T from 5 to 300 K were determined using a superconducting quantum interference device (SQUID) magnetometer.