Tungsten carbide-reduced graphene oxide intercalation compound as co-catalyst for methanol oxidation

Highly dispersed tungsten carbide（WC） nanoparticles（NPs） sandwiched between few-layer reduced graphene oxide（RGO） have been successfully synthesized by using thiourea as an anchoring and inducing reagent.The metatungstate ion,[H2W（12）O（40）]^6-,is assembled on thiourea-modified graphene oxide（GO） by an impregnation method.The WC NPs,with a mean diameter of 1.5 nm,are obtained through a process whereby ammonium metatungstate first turns to WS2,which then forms an intercalation compound with RGO before growing,in situ,to WC NPs.The Pt/WC-RGO electrocatalysts are fabricated by a microwave-assisted method.The intimate contacts between Pt,WC,and RGO are confirmed by X-ray diffraction,scanning electron microscope,transmission electron microscope,and Raman spectroscopy.For methanol oxidation,the Pt/WC-RGO electrocatalyst exhibited an electrochemical surface area value of 246.1 m^2/g Pt and a peak current density of1364.7 mA/mg Pt,which are,respectively,3.66 and 4.77 times greater than those of commercial Pt/C electrocatalyst（67.2 m^2/g Pt,286.0 mA/mg Pt）.The excellent CO-poisoning resistance and long-term stability of the electrocatalyst are also evidenced by CO stripping,chronoamperometry,and accelerated durability testing.Because Pt/WC-RGO has higher catalytic activity compared with that of commercial Pt/C,as a result of its intercalated structure and synergistic effect,less Pt will be required for the same performance,which in turn will reduce the cost of the fuel cell.The present method is facile,efficient,and scalable for mass production of the nanomaterials.

Corrosion resistance of 91W-6Ni-3Fe refractory metal,TiAl compound and iron based alloys in molten aluminum

The corrosion behaviors of 91W-6Ni-3Fe （91W） refractory alloy, TiAl intermetallic compound and two types of iron based alloys （QT700 and H13 tool steel） in a liquid aluminum were investigated. Corrosion experiments or static immersion-tests were carried out in pure molten aluminum at 750 ℃. The surface micro-topographies, corrosion interfaces and phase compositions of the immersed samples were investigated by 3D optical microscopy, SEM, EDS and XRD. The results show that 91W exhibits the best corrosion resistance, followed by QT700, H13 and TiAl alloy, consequently. The corrosion mass loss of the four metallic materials adheres to parabolic criterion, and the corrosion rate trends to be stable after initial acceleration. The diffusion-reaction mechanism is proposed for the dissolution of materials in molten aluminum, and the diffusion process is the rate-determining step during the dissolution of 91W in molten aluminum, while the low activation energy for the reaction between TiAl-（TiAl3）-Al couple results in poor corrosion resistance of TiAl alloy in molten aluminum.

Effects of Microencapsulated Compound Acidifier on Acidity and Development of Gastrointestinal Tract in Weaning Piglets

The effects of different types of compound acidifiers （encapsulated and non-encapsulated） in maize-soybean basic diets on acidity and development of the gastrointestinal tract in weaning piglets were investigated in this study. 64 28-day-old weaned Landrace x Yorkshire hybrid piglets with average weight of （7.00 ±0.10） kg were selected and grouped into four treatments with four pigs （ half boars and half sows） in each repeat of four repeats in each treatment based on single-factor test design principles, and the pre-test period was 3 days but the test period was 35 days. The results showed that compared with acid-free diet group, encapsulated compound acidifier could reduce pH of stomach and intestinal in weaning piglets significantly （P 〈 0.01 ）, while Test group 1 could also increase the relative weight of stomach and intestinal in piglets significantly （P 〈 0.05 ）. Compared with non-encapsulated acidifier, encapsulated compound acidifier could greatly decrease pH in jejunum and ileum of weaning piglets （ P 〈 0.05） or relative weight of stomach in piglets （ P〈0.05）, while Test group 1 could also enhance the relative weight of intestinal in piglets significantly （ P 〈0.01 ）. In addition, encapsulated compound acidifiers significantly increased the ratio between the villus height and crypt depth of jejunum （ P 〈0.01 ）. Accordingly, the microencapsulated compound acidifier in diets of weaning piglets can promote the development of gastrointestinal tracts for piglets by reducing pH of gastrointestinal tracts.

Ratio of Fe-Al compound at interface of steel-backed Al-graphite semi-solid bonding plate

The ratio of Fe-Al compound at the bonding interface of solid steel plate to Al-7graphite slurry was used to characterize the interracial structure of steel-Al-7graphite semi-solid bonding plate quantitatively. The relationship between the ratio of Fe-Al compound at interface and bonding parameters （such as preheat temperature of steel plate, solid fraction of Al-7graphite slurry and rolling speed） was established by artificial neural networks perfectly. The results show that when the bonding parameters are 516 ℃ for preheat temperature of steel plate, 32.5% for solid fraction of Al-7graphite slurry and 12 mm/s for rolling speed, the reasonable ratio of Fe-Al compound corresponding to the largest interfacial shear strength of bonding plate is obtained to be 70.1%. This reasonable ratio of Fe-Al compound is a quantitative criterion of interracial embrittlement, namely, when the ratio of Fe-Al compound at interface is larger than 70.1%, interfacial embrittlement will occur.

Clinical application of electrically evoked compound action potentials

ECAPs are the summary of multiple neurons’ spikes which could be recorded by a bidirectional stimulation-recording system via the cochlear implant,with the artifact elimination paradigms of forward-masking subtraction paradigm or alternating polarity paradigm.Three kinds of FDA approved cochlear implants support ECAP testing.This article is to summarize the clinical application of ECAP lest.ECAP test after insertion of electrode during implant operation has been widely used during cochlear implant surgery.In recent years.ECAP thresholds are also used to estimate the T levels and C levels helping programming.However,correlation between ECAP thresholds and psychophysical thresholds is affected by many factors.So far,ECAPs cannot yet be a good indicator of post-operative hearing and speech performance.

Effects of Compound Acidifier and Probiotics on Production Performance,Blood Biochemical Indexes,Antioxidant Indexes and Salmonella Infection of Laying Hens

This study evaluated the effects of compound acidifier and probiotics on production performance, blood biochemical indexes, antioxidant indexes and Salmonella infection of laying hens. A total of 600 50-week-old healthy laying hens with similar laying rate were randomly assigned to four groups, 10 repeats each group, and each repeat contained 15 chickens. The laying hens in control group were fed a basal diet, and in the other three experimental groups were fed basal di- ets supplemented with 300 g/t probiotics, 0. 1% compound acidifier in the drinking water every other day, and 300 g/t probiotics ＋ 0.1% compound aeidifier in the drinking water every other day, respectively. After the feeding of 16 weeks, a total of 60 laying hens from control group were divided into four treatments as the same above for a 13-day long Salmonella challenge （1.3×10^8 CFU） trial. The results were shown as follows： no significant effects were observed on production performance, hemoglobin content, the superoxide dismutase activity and total antioxidant capacity of reproductive organ in compound acidifier and probiotics groups （ P 〉 0.05 ）. Dirty egg rate was significantly decreased in compound acidifier group, probiotics group and combination group of both （P 〈 0.05 ）. Compared with the control group, white blood cell count in probiotics group was significantly decreased （P 〈0.05 ）, and the immunoglobulin content in probiotics group tended to be increased （P = 0.061 ）. The malondialdehyde （MDA） content in oviduct isthmus of hens in compound acidifier group and combination group was significantly decreased compared with the control group （ P 〈 0.05 ）. The Salmonella positive rate in oviduct of hens in compound acidifier group was significantly decreased at the 7th and 14^th days （ P 〈0.05 ）, but that in probiotics group and combination group was not significantly different compared with control group （ P 〉 0.05 ）. In conclusion, compound acidifier and probiotics can improve health status of laying hens through decreasing the dirty egg rate and increasing antioxidant capacity and immunity of them, thus reducing Salmonella infection of body and eggs.

Influence of New Compound Admixture on Shotcrete Performance

To analyze the influence of new compound admixture on shotcrete performance, the ordinary Portland cement pr425 was used as matrix components. The optimum proportion of admixture was obtained by analyzing the influence of content on cement setting time and compressive strength. The microstructure of cement test block and the mechanism of reducing dust of composite macromolecule admixture were analyzed by scanning electron microscopy and infrared spectroscopy. It was shown that the ratio of polyacrylic acid was 0.02%. The ratio of J85 accelerator was 5%. The ratio of bentonite was 4.5% in composite admixture. The most optimal content of admixture in the slurry was 7%. The compound coagulant formed by additive together with C3A, C4AF which provided nucleation for hydration and crystallization of C3S and C3S, and played an active role to promote the activity of the mineral admixture in cement, and increased the elastic modulus of C-S-H gel and accelerated the hydration process of portland cement. Bentonite and polyacrylic acid promote the wettability, cohesiveness and workability of cement paste in the process of hydration. The formation of cement test block gel was even. The interface between the matrix phase and the aggregate phase was not obvious which ensured the matching between the matrix and the aggregate phase. The addition of bentonite formed hydrogen bonds in cement paste and improved the cohesiveness of the system. The J-85 accelerator promoted the combination of aluminate and gypsum which hindered the formation of calcium carbide around the cement particles which made cement rapid condensation. Polyacrylic acid mainly changed the strength of hydroxyl absorption peak in cement paste to improve the initial strength of cement test block. The addition of new admixtures promoted the process of cement hydration to be more thorough and affected the later strength development of concrete by affecting the formation of calcium carbonate stone.

Bonding Characteristics of the Intermetallic Compound Al_3Ti+Cr

Based on our structural model and a tight-binding Hamiltonian the eIectronic structure has been calculated by use of a recursion method (RM) for two models of the tetragonal DO22 and the cubic Ll2 crystal structures in Al3Ti+Cr for contrast, from which bonding characteristics have been discussed. The results for the interaction energy (IE) show that Cr prefers to replacing Al site. Cr partly replacing Al can change the IE between the atoms and make the constriction of lattice constant c and the elongation of lattice constant a for the DO22 and thereby may induce the change of crystal structure from DO22 to L12. The results for bond order integral (BOI) and IE between the atoms also show that the strong (110) directional Cr-Ti bondings are existed.Thus, Al3Ti-base intermetallic compounds with addition of the Cr atom still remain brittle.

Improvement of AlN Thermal Conductivity Based on Reductive Compound Additives

AlN ceramics were prepared by plasma activation sintering(PAS)with compound additives yttrium acetylacetonate(Y(acac)_(3))and melamine(C_(3)H_(6)N_(6)).The effects of compound additives on the microstructure,density,and thermal properties of Al N ceramic were studied.Y(acac)3and C_(3)H_(6)N_(6)can form Y_(2)O_(3),residual organic carbon and reducing gas during the heating process,which improves the Al N sintering performance at a temperature of 1700℃and the bulk thermal conductivity.When the content of Y(acac)_(3)is 10 wt%and C_(3)H_(6)N_(6)is 3 wt%,the thermal conductivity of Al N ceramics is 105.6 W/(m·K),which is much higher than that of Al N ceramics with Y_(2)O_(3)under the same sintering conditions.This work provides theoretical reference for the preparation of high-performance Al N ceramic.

Clinical study of Qiming granule combined with compound anisodine injection in the treatment of diabetic retinopathy

Objective:To investigate the clinical study of Qiming granule combined with compound anisodine injection in the treatment of diabetic retinopathy.Methods:104 patients with nonproliferative diabetic retinopathy admitted to department of ophthalmology in Xishui Hospital Affiliated to Hubei University of science and technology from September 2016 to May 2018 were selected as the study subjects.According to the principle of treatment,they were divided into 52 cases in the control group and 52 cases in the treatment group,the clinical efficacy,blood sugar and lipid levels,hemorheological changes and adverse reactions were compared between the two groups.Results:The total effective rate difference between the treatment group(92.31%)and the control group(71.15%)was statistically significant(χ^(2)=7.792,P=0.005).After treatment,the two groups of fasting plasma glucose(FPG),hemoglobin A1c(HbA1c),total cholesterol(TC),low density lipoprotein-cholesterol(LDL-C),whole blood high-viscosity,whole blood cut viscosity,whole blood low-cut viscosity,plasma viscosity,number of microangioma and area of the hemorrhage were significantly lower than before treatment(P<0.05),and the levels of FPG,HbA1c,TC,LDL-C,whole blood highviscosity,whole blood cut viscosity,whole blood low-cut viscosity,plasma viscosity,number of microangioma and area of the hemorrhage in the treatment group were significantly lower than those in the control group(χ^(2)=0.122,P=0.727).Conclusions:Qiming granule combined with compound anisodine injection can effectively improve the clinical efficacy of patients with non-proliferative DR,and its mechanism may be related to improve blood sugar and blood lipid levels and correct blood rheology disorder,reduce microangioma and hemorrhage.It has clinical promotion significance.

Effects of Compound Acidifier on Growth Performance and Serum Biochemical Parameters of Heat-stressed Wenchang Chickens

[Objective]The paper was to investigate the effects of compound acidifier on growth performance and serum biochemical parameters of heat-stressed Wenchang chickens.[Method]A total of 28881-day-old Wenchang chickens with the same genetic background and similar initial weight(985.63±20.35 g)were randomly divided into four groups,four replicates per group and 18 chickens per replicate.Birds were fed the basal diet supplemented with 0 g/kg(control group),1 g/kg(groupⅠ),2 g/kg(groupⅡ)and 3 g/kg(groupⅢ)compound acidifier.The trial lasted 35 d.[Result]The daily gain of experimental groupⅠwas significantly higher than those of control group and groupⅢ(P<0.05),and the feed intake of experimental groupⅠwas also markedly higher than that of control group(P<0.05),but the feed gain ratio of experimental groupⅠwas significantly lower than that of groupⅢ(P<0.05).Compared with control group,the serum total protein and albumin levels of experimental groupⅠincreased(P>0.05),but the serum uric acid concentration decreased(P>0.05).[Conclusion]Supplementing 1 g/kg compound acidifier could improve the growth performance of heat-stressed Wenchang chickens.

Study on extracting alumina from fly ash by compound additive activation method

According to the chemical and mineral composition characteristics of the fly ash,alumina can be extracted from fly ash through the calcining method by using sodium carbonate and calcium carbonate additives.The effects on leaching rate of alumina have been investigated. The results showed that the fly ash can be activated effectively and the leaching rate of alumina can be improved to more than 92% through this method. The best process parameters were the ratio of raw materials,i. e. the material weight ratio of fly ash,calcium carbonate and sodium carbonate was 1. 0∶1. 2∶0. 9. The activating temperature was 850℃-900℃,activating time was 3 h. This process has a potential application prospect and improves the value of comprehensive utilization of fly ash.

A Study of Compound Action Potentials in Current-Coupled Tracts: the General Case

In this paper, the authors investigate compound action potentials formed when the underlying tract's axons have current-mediated coupling amongst themselves, and no field-mediated coupling. The key finding of the paper is that, for the case of biophysically inhomogeneous axon tracts, the compound action potential is governed by a Hodgkin-Huxley like equation itself in certain cases. The paper extends an earlier result for the identical axon case.

EFFECTS OF COMPOUND ACUPUNCTURE AND MEDICINE ANESTHESIA ON TNF AND INF-Γ CONTENTS IN THE PATIENT OF PNEUMONECTOMY

Objective To explore effects of acupuncture on senJm tumor necrosis factor （TNF） and ,γ-inter- feron （INF-γ） contents in the operative patient of lung cancer. Methods In the first stage, electroacupuncture （EA） stimulation was given to 25 cases of lung cancer before operation, once daily for 3 consecutive days, with continuous EA stimulation during operation; EA was given once each day from the 5^th-7^th days after operation. In the second stage, EA was added from the 8^th- 10^th days after operation in 30 cases, once daily. Serum TNF and INF-γ contents were compared before and after operation. Results Serum TNF content on the 8th day after operation in the first stage study was lower （P〈0.05） and on the 12th day after operation in the second stage study was higher （P〈0.05） in the compound anesthesia group than that in the general anesthesia group; serum INF-γ contents in the compound anesthesia group on the 8^th day after operation in the first stage and on the 12^th day after operation in the second stage were significantly higher than those in the general anesthesia group （P〈0.01, P〈0.05）. Conclusion Acupuncture can regulate serum TNF and INF-γ contents in the patient of operation of lung cancer, with dual-directional regulation on immunologic function.

Anesthetic Effect of Compound Artevacaine Hydrochloride in Patients Undergoing Oral Implantation

Objective:To investigate and analyze the anesthetic effect of compound artevacaine hydrochloride in patients undergoing oral implantation.Methods:In this study,60 patients receiving oral implant surgery in our hospital were selected as the research subjects,and the operation time was from July 2019 to March 2021.Patients were randomly selected and divided into groups for the study.30 patients receiving lidocaine hydrochloride anesthesia were used as the control group,and 30 patients receiving compound artevacaine hydrochloride anesthesia were used as the research group.The anesthetic effect and safety of the two groups were compared and analyzed.Results:The anesthetic effect of the study group was significantly better than that of the control group(P<0.05).The blood pressure and heart rate in the study group were significantly lower than those in the control group(P<0.05).There was no significant difference in blood pressure and heart rate between the two groups before anesthesia(P>0.05).There was no significant difference in the incidence of ADR between the two groups(P>0.05).Conclusions:For patients undergoing oral implant surgery,choosing compound artevacaine hydrochloride as anesthetic drug has obvious anesthetic effect and can stabilize patients'life indexes.The anesthetic effect is obvious,and there is no obvious adverse reaction,and the clinical value is obvious.

Polyphenolic Compound and the Degree of Browning in Processing Apple Varieties

Polyphenolic compound in processing apple （Malus domestica Borkh.） varieties and the relationship between polyphenol content and enzymatic browning were studied to provide reference for raw material selection and processing method optimization. The content of polyphenol compound in 10 processing apple varieties （4 cider and 6 juice varieties） were analyzed using the Folin-Ciocalteu method and HPLC. The degree of browning and the activities of polyphenol oxidase were also studied. The content and proportion of the polyphenol varied depending on the variety. Bitter varieties globally showed a higher polyphenol concentration than sweet or acid varieties. Proanthocyanidins, chlorogenic acid, （＋）-catechin, （-）-epicatechin were high-concentrated polyphenols in apple fruits. Phloridzin, the unique polyphenol of apple, was abundant in the bitter variety Frequin rouge fruit. Total polyphenols, proanthocyanidins, （＋）-catechin, and phloridzin had higher correlations with browning. The correlation was low between chlorogenic acid and browning. The polyphenolic profiles were correlated with the apple types. Cider apples contained more polyphenol than juice apple varieties. The content of flavan-3-ol has a close relationship with fruit browning.

Aroma Volatile Compound Analysis of SPME Headspace and Extract Samples from Crabapple (Malus sp.) Fruit Using GC-MS

Volatile compounds from the ripened crabapple fruit of six varieties （Red Splendor, Strawberry Parfait, Pink Spire, Radiant, Sparkler, and Flame） were analyzed by the use of the SPME/GC/MS method. The changes in the volatiles between the ripened and upon full maturity fruit states were studied in Red Splendor and Strawberry Parfait. An effort was made to summarize an effective method for searching and identifying new idioplasms containing a particular fruit aroma within Malus. A total of 37 compounds were identified from the sample. The main aroma volatiles of the six varieties of fruit were comprised of 2-hexenal, 3-hexenal, hexanal, 2,4-hexadienal, benzaldehyde, diethyl phtbalate. The main volatile compound of the crabapple fruit was 2-hexenal, but the relative content percentages were different （45.37, 21.98, 33.56, 32.21, 38.60, and 45.88%）. The aroma components accumulated differently as the fruits ripened. The relative content of aldehydes and esters decreased as alcohols increased after the Red Splendor and Strawberry Parfait fruit ripened. For Red Splendor, the main volatile was still 2-hexenal, but the relative content decreased to 42.89%, and the relative content of alcohols increased by 13.86% as aldehydes and esters declined by 12.16 and 7.18%, respectively. For Strawberry Parfait, the main volatile was changed to cyclohexanol, and the relative content increased to 46.43%, while the relative content of alcohols increased by 49.03% as aldehydes and esters declined by 23.74 and 9.34%, respectively.

Synthesis and Characterization of Poly(St-co-BA) Latex with an Organic-Inorganic Hybrid Compound as Emulsifier

A poly (St-co-BA) latex was successfully synthesized by using an organic-inorganic hybrid compound (OIHC), an aliphatic carboxylate sodium/nano-silica composite, as the emulsifier, and investigated by particle size analyzer, transmission electron microscope (TEM), optical contact angle measurement (OCA) and dynamic mechanical analyzer (DMA). It was found that the protective agent, sodium polyacrylate (PA),could obviously improve the polymerization stability and the functional monomer, glycidyl methacrylate (GMA), could enhance the store stability of the latex. The particle size of poly(St-co-BA) latex decreased and then leveled off as OIHC content increased. TEM shows that the prepared polymers were actually organic-inorganic nanocomposites, and these films have better waterproof property than those prepared by traditional poly(St-co-BA) latex or organic silicone modified poly(St-co-BA) latex. The nanocomposite polymer has much higher glass transition temperature than organic silicone modified poly(St-co-BA) polymer containing the same organic silicone content.

Formation of Bulk Intermetallic Compound AgaSn in Slowly-Cooled Lead-Free Sn-4.0 wt pct Ag Solders

Sn-Ag alloy system has been regarded as one of the most promising lead-free solder to substitute conventional Sn- Pb eutectic solder. But the formation of bulk Ag3Sn intermetallic compounds （IMCs） during reflow and post heat treatment significantly influences the performance of the solder joints. With an effort to clarify its microstructural evolution as a function of slow cooling rates, the fraction of bulk IMCs within the slowly solidified Sn-4.0 wt pct Ag solder was investigated by standard metallographic and compared with that detected by thermal analysis. It was found that the bulk IMCs fraction determined by thermal analysis corresponds quite well with the microstructure observation results. In accordance with the conventional solidification theory, the lower the applied cooling rate, the fewer the amount of bulk Ag3Sn IMCs formed in Sn-4.0 wt pct Ag alloy. In addition, Vickers hardness measurement results indicated that the relative coarse eutectic Ag3Sn IMCs distributing in the lamellar eutectic structure favored the improvement of the mechanical performance.