涂布机背涂水装置的设计

涂布纸张翘曲是一个长期困扰纸张涂布的问题。笔者根据多年的实践,设计出一种纸张涂布翘曲矫正装置,对解决纸张涂布中产生的翘曲问题有显著的效果。

Stable and reversible zinc metal anode with fluorinated graphite nanosheets surface coating

A highly stable zinc metal anode modified with a fluorinated graphite nanosheets(FGNSs)coating was designed.The porous structure of the coating layer effectively hinders lateral mass transfer of Zn ions and suppresses dendrite growth.Moreover,the high electronegativity exhibited by fluorine atoms creates an almost superhydrophobic solid-liquid interface,thereby reducing the interaction between solvent water and the zinc substrate.Consequently,this leads to a significant inhibition of hydrogen evolution corrosion and other side reactions.The modified anode demonstrates exceptional cycling stability,as symmetric cells exhibit sustained cycling for over 1400 h at a current density of 5 mA/cm^(2).Moreover,the full cells with NH_(4)V_(4)O_(10)cathode exhibit an impressive capacity retention rate of 92.2%after undergoing 1000 cycles.

Microstructural, wettability, and corrosion behaviour of TiO_(2) thin film sputtered on aluminium

The study investigated the application of radiofrequency(RF)-sputtered TiO2 coatings at various temperatures to enhance the hydrophobicity and corrosion resistance of Al6061 alloy.The research aimed to establish a correlation between the coating process and the resulting surface properties.Surface roughness and wettability were quantified with a surface profilometer and goniometer.Additionally,chemical boiling and salt spray corrosion tests were conducted to evaluate any topographical changes during these procedures.The analysis further involved the use of field-emission scanning electron microscopy(FESEM),energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD)techniques to characterize the deposited coatings.The findings indicated that the TiO2 coating applied at 500℃exhibited the highest water contact angle and superior corrosion resistance compared to other temperatures.Surface characterization confirmed that this specific TiO_(2) coating at 500℃ effectively delays corrosion due to its hydrophobic behavior,making it durable for industrial applications.

降雨融化层对电波散射与衰减特性的研究

提出了更为切合实际的融化粒子的涂水雪球模型 .应用涂层球的计算方法计算了不同大小和不同融化状态下的融化粒子的散射特性及反照率 ,结果表明频率在 6及 10GHz时 ,粒子的反照率较雨滴和冰球的大 .计算了不同降雨率 ,不同融化度状态下融化层的单位距离衰减及整个融化层的衰减和散射损耗 ,结果表明 ,用涂水雪球模型计算的融化层的衰减稍大于用Mie理论计算的等效雨区的衰减 ;在频率较低时 ,融化层的散射损耗大于等效雨区的散射损耗 ,随着频率的升高 ,散射损耗的相对差值变小 .这与雷达观测和文献中结果均相符 ,说明了这种融化粒子模型是正确可行的 ,较雨滴或冰球模型更切合实际 .

复配乳液聚合物水泥防水涂料防护效果研究

本文以丙烯酸酯乳液和氯丁橡胶乳液复配的方法制备聚合物水泥防水涂料,以解决单一聚合物乳液水泥防水涂料在应用过程中易开裂、柔性不足等问题。将其涂覆于水泥砂浆试块表面,探讨了涂层对氯盐侵蚀、硫酸盐侵蚀、冻融循环、自然环境侵蚀下水泥砂浆试块质量、抗压强度的影响,分析了涂层对试块的防护效果。结果显示涂层水泥砂浆试块均无开裂、剥落现象,试块的质量损失率、抗压强度损失率均较小。采用复配乳液并添加外加剂制得涂层对水泥砂浆试块的防护效果最优,试块在氯盐、硫酸盐侵蚀180天、冻融循环100次后的抗压强度损失率分别为9.45%、10.84%、12.16%,自然环境侵蚀120天后,试块抗压强度可保持为29.80MPa远高于无涂层试块。还以其中防护效果最优配方制备聚合物水泥防水涂料,探讨了涂层涂覆方法对自然环境侵蚀下涂层水泥砂浆试块抗压强度的影响。结果显示固定涂层厚度,分多次涂覆制得涂层更致密,交叉涂覆方法制得涂层厚度更均匀,沿十字交叉方向分三次涂覆制得涂层对水泥砂浆试块的防护效果更优。

Research on asphalt concrete pavement deicing technology

In order to reduce the cohesive force between pavement and ice, the approach of pavement surface coating with hydrophobic admixtures is investigated. The deicing effect of this approach is examined by the contact angle test and the shear test. The durability of the approach is examined by the accelerated abrasion test, and the skid resistance of the pavement with surface coating is examined by the British pendulum test and the surface texture depth test. In the contact angle test, the contact angle between hydrophobic admixture and water is 100.2°. In the shear test, the maximum shear stress is 0.06 MPa for the specimen coated with hydrophobic admixture, which is much lower than that of the specimen without hydrophobic admixture coating, 3.5 MPa. Furth- ermore, the ice and asphalt surface are completely separated for the coated specimen while not for the uncoated specimen. Based on the accelerated abrasion test, the residual hydro- phobic admixture in the veins of the pavement after abrasion still has a deicing effect. From the skid resistance tests, the British pendulum number （BPN） and the texture depth （TD） of the specimen coated with hydrophobic admixtures are larger than those of the standard requirements. The overall experi-mental observation indicates that the approach can effectively reduce close contact between asphalt pavement and ice; therefore, it can be a promising solution to road icing problems in winter.

Influence of Seawall Line Choice on Tide Lock Drainage in Tidal Flat Inning——Cangdongpian Inning Area on the west part of Tiaozini Sand as a case study

Most of the flood from the wide inner lowland plain discharges through tide locks on coast, and the influence of tidal flat inning projects on the tide lock drainage must be solved by seawall line choice. Taking the Cangdongpian inning area on the west side of Tiaozini Sand as a case study, the paper analyzed the compages and validity of ebb tide water to maintain the flood discharge creek below the tide lock for different projects of seawall line. Result indicates that a rational seawall line program has little influence on the flood discharge of lock during the mean tide or general spring tides, but has certain influences during a storm surge or an extreme spring tide in autumn. However it could be resolved by several times of artificial scour on the creek.

Application of ultra-smooth composite diamond film coated WC-Co drawing dies under water-lubricating conditions

A specific revised HFCVD apparatus and a novel process combining HFCVD and polishing technique were presented to deposit the micro-and nano-crystalline multilayered ultra-smooth diamond（USCD） film on the interior-hole surface of WC-Co drawing dies with aperture ranging from d1.0 mm to 60 mm.Characterization results indicate that the surface roughness values（Ra） in the entry zone,drawing zone and bearing zone of as-fabricated USCD coated drawing die were measured as low as 25.7,23.3 and 25.5 nm,respectively.Furthermore,the friction properties of USCD films were examined in both dry sliding and water-lubricating conditions,and the results show that the USCD film presents much superior friction properties.Its friction coefficients against ball-bearing steel,copper and silicon nitride balls（d4 mm）,is always lower than that of microcrystalline diamond（MCD） or WC-Co sample,regardless of the lubricating condition.Meanwhile,it still presents competitive wear resistance with the MCD films.Finally,the working lifetime and performance of as-fabricated USCD coated drawing dies were examined under producing low-carbon steel pipes in dry-sliding and water-lubricating conditions.Under the water-lubricating drawing condition,its production significantly increases by about 20 times compared with the conventional WC-Co drawing dies.

Preparation of CulnS2 Thin Film Using Sulfides Nanoparticle Precursor Ink

A low cost spin coating route of fabricating CuInS2 polycrystalline thin films by reactive sintering method was put forward. The ink for spin coating was optimized by pre-reducing the precursor powders in hydrogen, which turned the nanoparticle precursor powders from mixed sulfides into a mixture of CuInS2 and Cu-In metal alloys. The results of scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and Raman spectra showed that this optimization could highly improve the performance of CuInS2 polycrystalline thin films, including higher packing density, less impurity phases, and better quality. The energy gap of optimized CuInS2 thin film was determined to be about 1.45 eV by absorption spectroscopy measurement.

Heat Transfer Characteristics of Dropwise Condensation of Steam on Vertical Polymer Coated Plates

The plasma polymerization method and dynamic ion-beam mixed implantation method were employed to coat ultra-thin polymer films on copper plates. Experiments indicated that steady dropwise condensation of steam at atmospheric pressure occurred. The condensation heat transfer coefficients increased by approximately 3 and 5－7 times for the polytrimethylvinylsilane film and polytetrafluoroethylene film respectively, compared with the value for film condensation under the same experimental conditions. The temperatures on the condensing surface and inside the test block were found to be rapidly and randomly fluctuated. The properties of the coated films and advantages of the methods used in this investigation were discussed briefly.

Corrosion and wear behaviors of PVD CrN and CrSiN coatings in seawater

To improve the tribological performance of 316 L in seawater, the CrN and CrSiN coatings were deposited by multi-arc ion plating. The coatings were systematically characterized. Corrosion properties were evaluated by immersion test and anodic polarization measurement. The friction and wear properties of the CrN and CrSiN coatings were investigated by ball-on-disk tribometer in artificial seawater. The results show that the CrN coating has strong（111） and（200） preferred orientations and the intensity of the peaks decreases for the CrSiN coating. The hardness of the CrSiN coating is higher than that of the CrN coating. The CrSiN coating presents better corrosion resistance in seawater. The friction coefficient and wear rate of the CrSiN coating are lower than those of the CrN coating, indicating positive effect of Si addition on tribological performance in seawater. The coatings could significantly improve the wear resistance of the 316 L in seawater.

Preparation and corrosion resistance of superhydrophobic coatings on AZ31 magnesium alloy

In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy wereprepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. Theeffects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated.The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobictreated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. Theoptimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ～900 nm, thethickness of ～6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sampledecreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31substrate sample.

One-step electrodeposition to fabricate robust superhydrophobic silver/graphene coatings with excellent stability

A facile method was proposed to prepare stretchable silver-based composite coatings with excellent conductivity and stability for flexible electronics.Silver coating was firstly deposited on thermoplastic polyurethane(TPU)elastomer rubber surface via two-component spraying technique,then the superhydrophobic surface was obtained by one-step electrodeposition of cerium compounds(CeM)and graphene nanosheets(GNS)to produce Ag/CeM/GNS composite coatings.The obtained Ag/CeM/GNS composite coatings maintained high conductivity after experiencing bending cycles and stretching cycles.Furthermore,the as-prepared Ag/CeM/GNS composite coatings showed excellent self-cleaning and anti-fouling properties,and the corrosion resistance has improved significantly compared to the original Ag coating.In addition,the Ag/CeM/GNS composite coatings could drive the circuit normally in the states of tensile,bending and twisting deformation,showing excellent mechanical stability and applicability.As a result,it is believed that the prepared Ag/CeM/GNS composite coatings with excellent conductivity and stability have promising applications for flexible electronics in harsh conditions.

The role of graphene coating on cordierite-supported Pd monolithic catalysts for low-temperature combustion of toluene

In the present work,a Pd/graphene/cordierite(Pd/Gr/Cor)composite was prepared as a monolithic catalyst for low-temperature combustion of toluene.We mainly focused on understanding the role of graphene coating through investigation of catalytic performance and adsorption behavior of the composite.Compared with the traditional Pd/Cor catalyst without graphene coating,Pd/Gr/Cor catalyst delivered much higher activity and stability for toluene catalytic combustion in both dry and moist conditions.Transmission electron microscopy(TEM)and hydrophobic characterizations indicated that graphene coating can considerably improve the dispersity of Pd nanoparticles and enhance the hydrophobicity of the cordierite support.The adsorption behavior of the above two catalysts,including adsorption isothermal,adsorption kinetics,and adsorption thermodynamics were carefully investigated.The simulation results indicated that a large amount of toluene was adsorbed on graphene surface through relatively weak interaction,whereas only a relatively small amount of toluene was adsorbed on Pd surface with strong affinity.The adsorption thermal calculation indicated that the adsorption of toluene on graphene was a process with reduced entropy,indicating highly-ordered assembly of toluene molecular on graphene.It is the significant concentration and affinity gap between graphene and Pd that ensures a simultaneously and rapid transfer of toluene during the reaction process.

Microbiologically Induced Corrosion of Concrete and Protective Coatings in Gravity Sewers

Microbiologically induced corrosion of concrete （MICC） and its protective coatings has a high eco-nomic impact on sewer maintenance and rehabilitation. A better understanding of the micro-organisms and the bio- genie acids that are generated in the sewer is essential in controlling the corrosion of concrete pipes and protective coatings. The role of succession of micro-organisms growth in the corrosion of concrete and protective coatings was evaluated in this study. Examination of various sewer pipe materials exhibiting various extents of degradation, including concrete, cement based and epoxy based coating revealed the presence of both organic and biogenic sulphuric acids. This reflects the activity of fungi and the thiobacilli strains. Organism growth and metabolism were strongly related to the substrate pH. Fungi were found to grow and metabolise organic acids at pH from 2.0-8.0. Whilst the thiobacilli strains grew and generated sulohuric acids at oH below 3.0. The successive growth of the organisms provides an impgrtant bearing in deyeloping improved strateegies.to better manage sewers.

Deterioration of Water Ballast Tank Coating Systems by Active Substances in Ballast Water Management Systems

Sodium hypochlorite and ozone are the principal active substances and usually employed in ballast water management systems. In the present study, the authors focus on the effect of these active substances to the maaix polymer of coating. In order to obtain such information, the authors investigated the penetration of active substances to the polymer from cross section of specimens introduced by SAICAS （surface and interracial cutting analysis system）, followed by FT-IR-ATR （Fourier transform infrared and attenuated total reflectance） spectroscopy analysis from Z direction of cross section. The corrosion test of coating panels by these active substances （control as artificial seawater） has been conducted for 120 days. The results show that the depth profile of each active substance is around few dozens of micrometers from coating surface. The criteria of corrosion test cannot be determined by these results due to lacking in actual corrosion data immersed for 15 years under active substances. However, the authors evaluated the effect on ballast tank coating systems by active substances using analytical methods of SAICAS and FT-IR-ATR spectroscopy.

Heat Transfer and Friction Characteristics of Wavy Fin with Hydrophilic Coating under Dehumidifying Conditions

An experimental study on the airside heat transfer and friction characteristics of seven hydrophilic-coated wavy finned tube heat exchangers is performed under dehumidifying conditions. The effects of fin pitch, number of tube rows and inlet air relative humidity on the airside characteristics are investigated. The airside heat transfer and friction characteristics are presented in the form of Colburn factor and friction factor, respectively. The test results indicate that the Colburn factor and friction factor increase with decreasing fin pitch. The Colburn factor of 2 tube row heat exchanger is higher than that of 3 row heat exchanger, while their friction factors are nearly equal. As the inlet relative humidity increases, the Colburn factor increases and the friction factor is almost unchanged. The airside heat transfer and friction correlations are proposed for the hydrophilic-coated wavy fin with mean deviations of 6.5% and 9.1%, respectively. They can be used to design or evaluate hydrophilic-coated wavy fin-and-tube heat exchangers.

Effects of CeO_2 coating on oxidation behavior of T91 steel in water vapor

Oxidation behaviors of blank and CeO2 coated T91 steel were investigated at 600 ℃ in water vapor for up to 150 h. Gold marker was used to define the mass transport direction. The oxide scales were studied with X-ray diffractometry （XRD）, scanning electron microscopy （SEM） and electron probe microanalyzer （EPMA）. The oxidation resistance of the steel is improved by CeO2 coating, though the improvement is not remarkable. Ce-rich oxide band is located at the interface of the inner equiaxed layer and the outer columnar layer after oxidation, which is not consistent with the original surface. The results show that outward iron transport is blocked by the Ce-rich band. A new oxide nucleating and growing site （reaction front） is induced at the inner surface of the Ce rich band.

Fluorinated Hyperbranched Poly(urea-urethane)s Containing Reactive Groups: Synthesis, Characterization and Application on Cotton Fabric

A series of hyperbranched poly(urea-urethane)s (HPUs) containing short fluoroalkyl chain and reactive groups (HPUFs) capable as hydrophobic and oleophobic coating materials were synthesized. The obtained polymers were characterized by FTIR(fouier transform-infrared spectroscopy), 1H NMR(nuclear magnetic resonance), 13C NMR, 19F NMR, GPC(gel permeation chromatography), TGA(thermogravimetric analyzer), and XPS(X-ray photoelectron spectroscopy) analyses. Highly hydrophobic and oleophobic cotton fabrics could be achieved from these fluorinated hyperbranched polymers by solution-immersion coating method. The static contact angles reached to 143°, 114°, and 92° for water, hexadecane, and decane, respectively. The water and oil repellency ratings were 90 and 6, respectively, and still kept 80 and 5, respectively, after 10 soaping cycles at 50℃.