Greatly enhanced corrosion/wear resistances of epoxy coating for Mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.

Calculated and Experimental Research of Sheet Resistances of Laser-Doped Silicon Solar Cells

The calculated and experimental research of sheet resistances of crystalline silicon solar cells by dry laser doping is investigated. The nonlinear numerical model on laser melting of crystalline silicon and liquid-phase diffusion of phosphorus atoms by dry laser doping is analyzed by the finite difference method implemented in MATLAB. The melting period and melting depth of crystalline silicon as a function of laser energy density is achieved. The effective liquid-phase diffusion of phosphorus atoms in melting silicon by dry laser doping is confirmed by the rapid decrease of sheet resistances in experimental measurement. The plateau of sheet resistances is reached at around 15 Ω/. The calculated sheet resistances as a function of laser energy density is obtained and the calculated results are in good agreement with the corresponding experimental measurement. Due to the successful verification by comparison between experimental measurement and calculated results, the simulation results could be used to optimize the virtual laser doping parameters.

Effects of yield and resistances on rice by application of Si-fertilizer

According to the analysis of 654 soil samples collected from 45 counties in Zhejiang Provence, 73.7% of paddy field showed Si deficient. During 1991 and 1993, in Lishi, Longquang, Qingtian and Tonglu Counties, field experiments were conducted to test the effects of basal or additional Si-fertilizer on rice. Si-fertilizer was produced by Nanjing Inorganic Chemical Manufacture, containing 50% water solu

How antibiotic resistances could change Helicobacter pylori treatment:A matter of geography?

Therapeutic management of Helicobacter pylori(H.pylori)remains an unsolved issue.Indeed,no therapeutic regimen is able to cure the infection in all treated patients,and in many the infection persists despite the administration of several consecutive standard therapies.Although antibiotic resistance reports describe alarming results,the outcome of therapeutic regimens does not seem to parallel this scenario in most cases,since a successful performance is often reached in more than 80%of cases.However,the phenomenon of increasing antibiotic resistance is being closely studied,and the results show controversial aspects even in the same geographic area.For the continents of Europe,America,Asia,Africa,and Oceania,minimal and maximal values of resistance to the main antibiotics(clarithromycin,amoxicillin,metronidazole,and levofloxacin)feature wide ranges in different countries.The real enigma is therefore linked to the several different therapeutic regimens,which show results that often do not parallel the in vitro findings even in the same areas.A first aspect to be emphasized is that some regimens are limited by their use in very small geographic districts.Moreover,not all therapeutic trials have considered bacterial and host factors affecting the therapeutic outcome.The additional use of probiotics may help to reduce adverse events,but their therapeutic impact is doubtful.In conclusion,the"ideal therapy",paradoxically,appears to be a"utopia",despite the unprecedented volume of studies in the field and the real breakthrough in medical practice made by the discovery and treatment of H.pylori.The ample discrepancies observed in the different areas do not encourage the development of therapeutic guidelines that could be valid worldwide.On these bases,one of the main challenges for the future might be identifying a successful solution to overcome antibiotic resistances.In this context,geography must be considered a relevant matter.

Effects of material of metallic frame on the penetration resistances of ceramic-metal hybrid structures

The effects of metallic material on the penetration resistances of ceramic-metal hybrid structures against vertical long-rod tungsten projectiles were studied by artillery-launched experiments and numerical simulation.Hybrid structures with rectangular cores in transverse orthogonal arrangement and slidefitting ceramic inserts of zirconia toughened alumina prisms were fabricated with titanium alloy TC4(Ti6 Al4 V),AISI 4340 steel and 7075 aluminum alloy panels,respectively.The results showed that the hybrid structure of Ti6A14V exhibited the highest penetration resistance,followed by that of 7075 aluminum alloy with the same area density.The penetration resistance of the hybrid structure of AISI4340 steel was the lowest.The underlying mechanisms showed that the metallic material of a ceramicmetal hybrid structure can directly affect its energy absorption from the impact projectile,which further affects its penetration resistance.Different metallic frames exhibited different failure characteristics,resulting in different constraint conditions or support conditions for ceramic prisms.The high penetration resistance of the Ti6Al4V hybrid structure was due to its stronger back support to ceramic prisms as compared with that of AISI 4340 steel hybrid structure,and better constraint condition for ceramic prisms by metallic webs as compared with that of 7075 aluminum alloy hybrid structure.The results of mass efficiency and thickness efficiency showed that the Ti6Al4V hybrid structure has advantages in reducing both the thickness and the mass of protective structure.In addition,because the ceramic-metal hybrid structures in the present work were heterogeneous,impact position has slight influence on their penetration resistances.

Synthesis of a Novel Core-shell Type Acrylic-polyurethane Hybrid Emulsion Containing Siloxane and Fluorine as well as Water and the Oil Resistances of Cured Film

Siliconated polyurethane （Si-PU） was synthesized using isophorone diisocyanate （IPDI）, hydroxybutyl-terminated polydimethylsiloxane （PDMS）, polytetramethylene ether glycol （PTMG）, polypropylene glycol （PPG）, 1,6-hexanediol （HDO）, dimethylol propionic acid （DMPA） and triethylamine （TEA）. Based on butyl acrylate （BA）, 2, 2, 2-trifluoroethylmethacrylate （TFEMA） and Si-PU as a seed emulsion, a novel core-shell type acrylic-polyurethane hybrid emulsion, containing siloxane and fluorine （F-Si-PU）, was prepared by seeded emulsion polymerization. The contents of siloxane and fluorine were determined according to the feed ratio. Fourier transform infrared spectroscopy （FTIR） was used to identify the chain structures of Si-PU and F-Si-PU. Investigation of transmission electron microscopy （TEM） confirmed the core-shell structure of F-Si-PU emulsion. Measurement results of water contact angle and the swelling ratio in water and n-octane for cured film showed that the water and the oil resistances for F-Si-PU had been significantly improved at a suitable content of fluorine and siloxane.

Evaluation of chronic kidney disease in chronic heart failure: From biomarkers to arterial renal resistances

Chronic kidney disease and its worsening are recurring conditions in chronic heart failure(CHF) which are independently associated with poor patient outcome.The heart and kidney share many pathophysiological mechanisms which can determine dysfunction in each organ. Cardiorenal syndrome is the condition in which these two organs negatively affect each other, therefore an accurate evaluation of renal function in the clinical setting of CHF is essential. This review aims to revise the parameters currently used to evaluate renal dysfunction in CHF with particular reference to the usefulness and the limitations of biomarkers in evaluating glomerular dysfunction and tubular damage. Moreover, it is reported the possible utility of renal arterial resistance index(a parameter associated with abnormalities in renal vascular bed) for a better assesment of kidney disfunction.

Flexural-gravity wave resistances due to a surface-moving line source on a fluid covered by a thin elastic plate

Analytical solutions for the flexural-gravity wave resistances due to a line source steadily moving on the surface of an infinitely deep fluid are investigated within the framework of the linear po- tential theory. The homogenous fluid, covered by a thin elastic plate, is assumed to be incompressible and inviscid, and the motion to be irrotational. The solution in integral form for the wave resistance is obtained by means of the Fourier transform and the explicitly analytical solutions are derived with the aid of the residue theorem. The dispersion relation shows that there is a minimal phase speed cmin, a threshold for the existence of the wave resistance. No wave is generated when the moving speed of the source V is less than emin while the wave resistances firstly increase to their peak values and then decrease when V ~〉 Crnin. The effects of the flexural rigidity and the inertia of the plate are studied. @ 2013 The Chinese Society of Theoretical and Applied Mechanics. [doi：10.1063/2.1302202]

Enhanced Corrosion and Wear Resistances of Zr-based Alloy Induced by Amorphous/Nanocrystalline Coating

To improve corrosion and wear resistances of the Zirconium(Zr) based alloys which are widely applied in nuclear reactors and chemical corrosion-resistant equipment, a new surface modification scheme was designed to deposit a Zr75Cu25 coating on Zr substrate by using magnetron sputtering technique. The microstructure and the phase composition were characterized by scanning electron microscope, transmission electron microscope, and X-ray diffraction measurements. The tribological properties and the corrosion resistance were investigated by performing reciprocating tribo-tester and electrochemical tests, respectively.It is found that the Zr75Cu25 coating is made up of a mixture of amorphous and a-(Zr) nanocrystalline phases.The nanocrystalline particles with a size of 5-10 nm are homogenously dispersed in the amorphous matrix.The Zr75Cu25 coating shows excellent tribological properties, due to the dispersion strengthen caused by the homogeneous distribution of a-(Zr) nano-size particles among the amorphous matrix. In addition, it is revealed that the Zr75Cu25 coating makes the Zr substrate exhibit excellent corrosion resistance, due to the robust passive film with a compact structure of the amorphous/nanocrystalline mixture.

Thermal Shock Resistances of FeMnCr/Cr_3C_2 Coatings Deposited by Arc Spraying

Arc spraying with the cored wires was applied to deposit FeMnCr/Cr3C2 coatings on low carbon steel substrates, namely FM1, FM2 and FM3. Thermal shock resistances of the coatings were investigated to assess the influence of Cr3C2 content on thermal shock resistance. Characteristics of the coatings under thermal cycling test were studied by optical microscopy, field emission scanning electron microscope （FE-SEM） and energy dispersion spectrum （EDS）, X-ray diffraction （XRD）. The experimental results show that hardness of the coatings increases, bonding strength decreases slightly with increase of the Cr3C2 content of the coatings. As a result, FM2 coating possesses the best thermal shock resistance, attributing to its better thermal expansion matches and wettability than those of FM3 coating, less oxide rate than that of FM1 coating restraining from cracks formation and propagation in coatings.

Studies on Wear and Corrosion Resistances of Carbon Nitride Thin Films on Ti Alloy

CN x /SiCN composite films were prepared on titanium ( Ti ) alloy substrates by Radio Frequency Plasma Enhanced Chemical Vapor Deposition ( RF\|PECVD ). As a buffer layer, SiCN ensured the adhesion of the CN x thin films on Ti substrates. X\|ray diffraction ( XRD) measurement revealed that the composite films possessed α\|C 3 N 4 structure. The microhardness of the films was 48 to 50 GPa. In order to test the characteristics of wear and corrosion resistances, we prepared Ti alloy samples with and without CN x /SiCN composite films. Also for strengthening the effect of wear and corrosion, the wear tests were carried out under high load (12 MPa) and in 0.9% NaCl solution. Results of the wear tests and the corrosive electrochemical measurements showed that the samples coated with CN x films had excellent characteristics of wear and corrosion resistances compared with Ti alloy substrate samples.

Detection of Resistances of Different Corn Varieties to Corn Borer

In order to practice integrated management of corn insect pests effectively, a field experiment was made to study the resistances of 33 corn varieties to corn borer （ Ostrinia furnacalis） in the corn area to the north of the Huaihe River in Anhui Province. The results showed that there were evident differences in resistances of different corn varieties to corn borer and the resistant levels of the same corn variety to corn borer were also different in the whorl stage and the ear stage. In the whorl stage of corn, eight corn varieties, ＇ ‘Zhongnougda 311＇, ‘Zhongke 11＇, ‘ Denghai 3＇, ＇ Dongdan 80＇ , ‘ Liyu 16＇, ‘ Zhengdan 23＇, ‘ Jidan 8＇ and‘ Huayu 13＇ preformed relatively stronger resistance to corn borer. In the ear stage of corn, five corn varieties of ‘ Xundan 20＇, ‘ Qidan 1 ＇, ‘ Zhongke 4＇, ‘ Nongda 108＇ and ＇ Ludan 6018＇ showed relatively stronger resistance to corn borer. The comprehensive resistances of ten corn varieties to corn borer in the whorl stage and the ear stage successively were ‘Zhongnongda 311’ 〉 ‘Zbong, ke 4＇ 〉 ‘Jidan 8＇ 〉 ‘ Zhengdan 23＇ 〉‘Zhengdan 958＇ 〉 ‘ Qidan 1＇ 〉 ‘ Zhongdi 985＇ 〉 ‘Nongda108＇ 〉 ‘Liyu16＇ 〉‘Denghai3＇.

Impact of Parasitic Resistances on the Output Power of a Parallel Vertical Junction Silicon Solar Cell

This paper describes the theoretical model for calculating IV-curve of parallel vertical silicon solar cells (SCs) based on solving diffusion-recombination equation for such SC, which was suggested that two IV curve zones (those which are close to the short current and open circuit points) can be linearized. This linearalization allows obtaining the values of shunt (Rsh) and series (Rs) resistances. The evolution of the electric power based on these resistances was illustrated to show the values that shunt and series resistances must have to obtain a good efficiency.

Influence of Heat Exchange Coefficients on Both Optimized Thermal Contact (OTCR) and Critical (CTCR) Resistances at the Contact Interface of a Flat Concrete Slab and a Rice Straw Board

The study is carried out in imperfect contact with a concrete slab wall attached to a panel based on rice straw compressed in a dynamic frequency regime. We will propose the characterization of thermal insulation for thermal resistance of contact (x = 0.05 m). The impact of heat exchange coefficients on the front face (x = 0 m) and the rear face (x = 0.1 m) on these resistors is shown.

Resistances in “A White Heron”

"A White Heron"provided an alternative to a civilized world dominated by men and their values.Jewett has weaved several irreconcilable conflicts between the masculine world and an artificial women Utopian world.The conflicts between two competing sets of values are material and spiritual,industrial and rural,sophisticated and innocent,and masculine and feminine.Sylvia unconsciously finished her spiritual journey by choosing the latter ones over the formers.

Body composition and metabolic syndrome in patients with type 1 diabetes

BACKGROUND In recent years,the prevalence of obesity and metabolic syndrome in type 1 diabetes(T1DM)patients has gradually increased.Insulin resistance in T1DM deserves attention.It is necessary to clarify the relationship between body composition,metabolic syndrome and insulin resistance in T1DM to guide clinical treatment and intervention.AIM To assess body composition(BC)in T1DM patients and evaluate the relationship between BC,metabolic syndrome(MS),and insulin resistance in these indi-viduals.METHODS A total of 101 subjects with T1DM,aged 10 years or older,and with a disease duration of over 1 year were included.Bioelectrical impedance analysis using the Tsinghua-Tongfang BC Analyzer BCA-1B was employed to measure various BC parameters.Clinical and laboratory data were collected,and insulin resistance was calculated using the estimated glucose disposal rate(eGDR).RESULTS MS was diagnosed in 16/101 patients(15.84%),overweight in 16/101 patients(15.84%),obesity in 4/101(3.96%),hypertension in 34/101(33.66%%)and dyslip-idemia in 16/101 patients(15.84%).Visceral fat index(VFI)and trunk fat mass were significantly and negatively correlated with eGDR(both P<0.001).Female patients exhibited higher body fat percentage and visceral fat ratio compared to male patients.Binary logistic regression analysis revealed that significant factors for MS included eGDR[P=0.017,odds ratio(OR)=0.109],VFI(P=0.030,OR=3.529),and a family history of diabetes(P=0.004,OR=0.228).Significant factors for hypertension included eGDR(P<0.001,OR=0.488)and skeletal muscle mass(P=0.003,OR=1.111).Significant factors for dyslipidemia included trunk fat mass(P=0.033,OR=1.202)and eGDR(P=0.037,OR=0.708).CONCLUSION Visceral fat was found to be a superior predictor of MS compared to conventional measures such as body mass index and waist-to-hip ratio in Chinese individuals with T1DM.BC analysis,specifically identifying visceral fat(trunk fat),may play an important role in identifying the increased risk of MS in non-obese patients with T1DM.

The influence of resistance exercise training prescription variables on skeletal muscle mass,strength,and physical function in healthy adults:An umbrella review

Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.Methods:Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass(or its proxies),strength,and/or physical function in healthy adults aged>18 years.Results:We identified 44 systematic reviews that met our inclusion criteria.The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews;standardized effectiveness statements were generated.We found that RT was consistently a potent stimulus for increasing skeletal muscle mass(4/4 reviews provide some or sufficient evidence),strength(4/6 reviews provided some or sufficient evidence),and physical function(1/1 review provided some evidence).RT load(6/8 reviews provided some or sufficient evidence),weekly frequency(2/4 reviews provided some or sufficient evidence),volume(3/7 reviews provided some or sufficient evidence),and exercise order(1/1 review provided some evidence)impacted RT-induced increases in muscular strength.We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass,while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass.There was insufficient evidence to conclude that time of day,periodization,inter-set rest,set configuration,set end point,contraction velocity/time under tension,or exercise order(only pertaining to hypertrophy)influenced skeletal muscle adaptations.A paucity of data limited insights into the impact of RT prescription variables on physical function.Conclusion:Overall,RT increased muscle mass,strength,and physical function compared to no exercise.RT intensity(load)and weekly frequency impacted RT-induced increases in muscular strength but not muscle hypertrophy.RT volume(number of sets)influenced muscular strength and hypertrophy.

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials Science.SEN alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical properties.Their main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening effects.These enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in extrudability.Consequently,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

Alleviation of the plastic deformation of gel ink under strong stress through an esterification of xanthan gum reinforcing its double helix structure

As a natural organic polymer,xanthan gum(XG)can alleviate the plastic deformation of gel ink under strong stress and realize the reasonable regulation of the rheological properties of gel ink.However,as the double-helix structure connected by hydrogen bonds cannot resist the mechanical environment of strong stress,XG shows poor shear resistance.In this study,a polymer gel with interpenetrating polymer network structure was prepared by esterifying XG,taking polystyrene maleic anhydride(SMA)as the modifier.In addition to retaining the excellent rheological properties of XG,the generated polymer gel also exhibited high shear resistance.The optimal addition amount of the esterification reaction modifier was determined as mXG:mSMA=5:3 according to the gel ink standard.With this amount,the viscosity of the modified xanthan gum(SXG)gel increased to 1578.8 mPa·s and 100.7 mPa·s at shear rates of 4 s1 and 383 s1,respectively,and the shear resistance increased more than 2 times compared to the unmodified one.It is because of the ester bond formed by esterification that the reaction strengthens the interaction between molecular segments,enabling the new gel to resist to strong mechanical stress.The new polymer gel studied in this paper and the proposed mechanism of action provide new insights for the development of high-end gel ink and also provide theoretical support for the study of rheological properties of non-Newtonian fluids.

Functional assessment of cadherin as a shared mechanism for cross/dual resistance to Cry1Ac and Cry2Ab in Helicoverpa zea

Helicoverpa zea is a major target pest of pyramided transgenic crops expressing Cry1,Cry2 and/or Vip3Aa proteins from Bacillus thuringiensis(Bt)in the United States.Laboratory-selected Cry1Ac/Cry2Ab cross resistance and fieldevolved practical dual resistance of H.zea to these two toxins have been widely reported.Whether the widespread Cry1Ac/Cy2Ab dual resistance of H.zea has resulted from the selection of one shared or two independent resistance mechanisms by pyramided Bt crops remains unclear.Cadherin is a well-confirmed receptor of Cry1Ac and a suggested receptor of Cry2Ab in at least three Lepidopteran species.To test whether cadherin may serve as one shared mechanism for the cross and dual resistance of H.zea to Cry1Ac and Cry2Ab,we cloned H.zea cadherin(HzCadherin)cDNA and studied its functional roles in the mode of action of Cry1Ac and Cry2Ab by gain-and lossof-function analyses.Heterologous expression of HzCadherin in H.zea midgut,H.zea fat body and Sf9 cells made all three of these cell lines more susceptible to activated Cry1Ac but not activated Cry2Ab,whereas silencing HzCadherin of H.zea midgut and fat body cells significantly reduced the susceptibility to Cry1Ac but not Cry2Ab.Likewise,suppressing HzCadherin with siRNA made H.zea larvae resistant to Cry1Ac.These results clearly demonstrate that HzCadherin is not a receptor for Cry2Ab,and thus it is unlikely to serve as one shared mechanism for the cross and dual resistance of H.zea to Cry1Ac and Cry2Ab.