164 research outputs found
One-step electrodeposition of a self-cleaning and corrosion resistant Ni/WS2 superhydrophobic surface
No full textSuperhydrophobic surfaces have been intensively investigated for applications requiring self-cleaning and corrosion resistance. The techniques used to fabricate such a coating tend to be costly, time and energy consuming; further surface modification steps are often needed. In this study, a superhydrophobic composite electrodeposit based on tungsten disulphide nanoparticles dispersed in nickel on a mild steel substrate was successfully developed. At room temperature, the deposit showed a water contact angle of 158.3 deg and a sliding angle of 7.7 deg. The effects of operational parameters on surface morphology and superhydrophobicity are discussed. Compared to the substrate, the robust surface of the as-prepared coatings exhibited good self-cleaning and corrosion resistance, providing potential for industrial applications
Robust Ni/WC superhydrophobic surfaces by electrodeposition
No full textSuperhydrophobic, water repellent surfaces have attracted much attention but poor surface mechanical properties have limited their wider practical application. Robust surfaces based on nickel-tungsten carbide composite coatings have been electrodeposited. The surfaces showed superhydrophobicity after being modified by stearic acid. The maximum contact angle of water was 164.3 degrees with a sliding angle close to zero degree. By controlling deposition conditions, versatile coatings have been produced and the effects of morphology on wettability are discussed. Coating texture has been analyzed by X-ray diffraction. The surfaces showed excellent abrasion resistance and water-repellence
Electroplating of non-fluorinated superhydrophobic Ni/WC/WS<sub>2</sub> composite coatings with high abrasive resistance
No full textWeak hierarchical rough structures on superhydrophobic surfaces hinder their practical industrial applications. This paper reports a strategy to fabricate robust nickel-based superhydrophobic coatings via the codeposition of nanosized WS2 and WC particles. The Ni/WC/WS2 composite coatings were synthesized on mild steel substrates by one-pot electroplating followed by the adsorption of stearic acid self-assembled monolayers to modify the surface wetting. The particle concentration in the bath was investigated and the maximum water contact angle of approx. 170° was achieved by optimizing the particle contained. Hardened by WC and lubricated by WS2 inclusions the superhydrophobic coatings showed remarkable abrasive resistance with a bearing capacity ≥10,000 mm abrasion length. The coatings also showed aerophilic behavior and good environmental stability over >6 months
Tetrahedrite-(Ni), Cu6(Cu4Ni2)Sb4S13, the first nickel member of tetrahedrite group mineral from Luobusa chromite deposits, Tibet, China
No full textTetrahedrite-(Ni) (IMA2021-031), ideally Cu-6(Cu4Ni2)Sb4S13, is the first natural Ni-member of tetrahedrite group mineral found in Luobusa chromite deposit, Tibet, China. The new species occurs as anhedral grains 2 to 20 mu m in size, associated with gersdorffite, vaesite, and chalcostibite, which are disseminated in a matrix of dolomite, magnesite, quartz, Cr-rich mica, and Cr-bearing clinochlore. Tetrahedrite-(Ni) is black in color with a reddish-black streak and metallic luster. It is brittle with uneven fractures and has a calculated density of 5.073 gcm(-3). The mean values of 9 electron micro-probe analyses (wt%) are Cu 39.83, Ni 5.67, Fe 1.45, Sb 21.69, As 5.45, S 25.39, total 99.48, and the empirical formula calculated on the basis of cation = 16 apfu is Cu-M(2)(6.00)M(1)[Cu-4.03(Ni1.55Fe0.42)(Sigma 1.97)](Sigma 6.00)(X(3))(Sb2.85As1.16)(Sigma 4.01)S-12.67. Tetrahedrite-(Ni) is cubic, with space group I43m, a = 10.3478(4) & Aring;, V = 1108.00(14) & Aring;(3), and Z = 2. Its crystal structure has been solved by X-ray single-crystal diffraction on the basis of 188 independent reflections, with a final R-1 = 0.0327. Tetrahedrite-(Ni) is isostructural with tetrahedrite group minerals. It represents the first natural tetrahedrite-group mineral with a Ni-dominated charge-compensating constituent. Tetrahedrite-(Ni) may be the product of late-serpentinization at moderately high-temperature conditions around 350 degrees C. In this case, tetrahedrite-(Ni) and its mineral paragenesis record an entire geological process of nickel enrichment, migration, activation, precipitation, and alteration from deep mantle to shallow crust
Insights from Evidence-Based Medicine Method for Building Security Systems Against Terrorist Attacks in Hospitals
No full textGuochen Chen, Gaofeng Jin School of Criminology, People’s Public Security University of China, Beijing, People’s Republic of ChinaCorrespondence: Guochen Chen, School of Criminology, People’s Public Security University of China, Beijing, People’s Republic of China, Email [email protected]: Hospitals have become soft targets for terrorism, with increasing terrorist attacks observed in the last two decades. Not only the counter-terrorism and law enforcement agencies but the hospitals also need to be actively involved and undertake the responsibility of safeguarding hospital security by establishing an effective security system. Evidence-based medicine emphasizes the significance of scientific evidence, and in practice, research methods for the generation, collection, and utilization of evidence may offer new insights to overcome the issue of terrorism. The present study discusses the potential application of methods in evidence-based medicine for developing security systems against terrorist attacks in hospitals. First, hospitals can use simulated scenarios of terrorist attacks to generate evidence. For example, combining virtual technology with virtual reality technology and selecting appropriate algorithms or models to generate evidence. Second, they can apply tabletop exercises to propose measures, as a means of collecting evidence. The collection of data can be obtained through questionnaires or interviews. Some biological methods, such as collecting salivary markers of acute stress (α-amylase and secretory immunoglobulin A), can also be used to assess emotional states. Third, they can use the collected evidence to practically test and refine the implemented measures. To verify the effectiveness and feasibility of the formulated solutions in real-life scenarios, simulations, models, drills, and similar methods can be used. This approach may provide new perspectives for the development of hospital security systems.Keywords: hospital security against terrorist attacks, security system development, evidence-based medicine metho
Research on Service Management Current Situation and Countermeasure of Chinese Large Retail Chains
No full textRecent development in the chemistry of transition metal-containing metallabenzenes and metallabenzynes
No full textTransition metal-containing metallabenzenes and metallabenzynes are organometallic compounds derived from formal replacement of a CH group or a C atom in benzene and benzyne by an isolobal transition metal fragment. The chemistry of these interesting metallaaromatics has received considerable attention in recent years. A number of such complexes have been obtained from various synthetic routes. Interesting chemical properties of these complexes have also been reported. This review summarizes recent progress in the synthesis and reactivity of metallabenzenes and metallabenzynes.</p
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