Search

The dimple of ball grid array (BGA) area with 70 mm × 70 mm size on load board for high performance integrated circuit final test is investigated by shadow moire at first, the dimple of BGA area decreases from 184.3 to 97.1 μm when six additional prepregs with 60 mm × 60 mm size are added at BGA area before hot lamination process. The micromorphology and stress/strain simulation are conducted to improve the coverage and reliability of copper metallization layer in through hole at that BGA area. The microcracks of electroless copper layer at the position of glass fiber and inner layer copper pad, which leads to serious crack after solder float, are well covered by subsequent electroplating copper layer. When the through holes at BGA area with 0.2 mm diameter and 7.0 mm depth are fabricated based on insulating dielectric material used for high-speed signal transmission, the simulation results point out that IT968 is better than M6G for the thermal shock reliability of through hole metallization layer. A load board vehicle with 126 layers and 8.3 mm thickness based on IT968 shows good interconnection structure reliability after 12 times 288°C solder float.

Solar-driven interfacial evaporation (SIE) faces challenges in practical applications due to low water transport rates and suboptimal light-to-heat conversion efficiency. To address these issues, innovative approaches are needed to enhance solar energy utilization and evaporator performance. This study presents a novel approach using the naturally structured fruit of Platanus acerifolia (PAF) combined with the fibrous crown hair of dandelions. The unique structure of PAF enhances solar light absorption and water transport, crucial for efficient SIE. We optimized PAF through a carbonization process after immersing it in transition metal solutions, leveraging its inherent structural properties to achieve a high carbon yield and improved thermal stability. The optimized material achieved a high evaporation rate of 2.17 kg m−2 h−1 and a light-to-heat energy conversion efficiency of 117.2%. These results demonstrate the potential of PAF as a highly efficient and easily produced material for solar water treatment applications. The facile production process and the natural abundance of PAF make it a promising and sustainable solution for SIE. [ABSTRACT FROM AUTHOR]

Frequent oil spills pose a serious threat to the ecological environment and to human health. Therefore, it is a global topic to develop adsorbents with photothermal and superhydrophobic properties for the effective absorption of a high-viscosity crude oil. Herein, for the first time, the multiwall carbon nanotubes (MWCNTs)-superlight clay (SLC) was prepared using a freeze-drying method. Then, it was modified with octadecyl trichlorosilane (OTS) to obtain a superhydrophobic adsorbent (OTS/MWCNTs-SLC). The surface temperature of OTS/MWCNTs-SLC reaches 70 °C quickly under 1 kW m–2 solar irradiation, which is essential to lower the viscosity of crude oil. Consequently, the adsorbent material demonstrated a crude oil absorption capacity of 19 ± 0.4 g/g and a light/heavy oil absorption capacity of 10–26 g/g. Additionally, the superhydrophobic photothermal OTS/MWCNTs-SLC exhibited mechanical and chemical stability and enabled continuous crude oil recovery. The prepared OTC/MWCNT-SLC broadens the application of SLC and provides a strategy for crude oil cleanup. [ABSTRACT FROM AUTHOR]

Photothermal soft actuators have become a hot research topic in recent years due to the unique light-to-heat conversion, mechanical deformation, contactless operation, and extended applications from bionic design to intelligent robots. Moreover, since superhydrophobic surfaces offer drag reduction, anticorrosive, and oil absorption properties, the synergistic effects expand their smartness in micro-robots, environmental remediation, bioengineering, transportation, wireless delivery, and oil spill recovery applications. In this review, we have provided an overview of soft actuators based on the photothermal effect. We begin with a comprehensive overview of the photothermal conversion mechanism and the photothermal actuation mechanism. It explores three different types of photothermal actuation, discussing their design and mechanisms. Furthermore, we focus on the latest advancements in photothermal soft actuators, categorizing them based on actuation mechanisms and addressing their significance and associated challenges. The photothermal soft actuators enable bionic-like soft movement in the horizontal and vertical directions through bending, contraction, and rotation in response to light-induced heat. Then, this review introduces various applications of photothermal soft actuators. Finally, we draw insightful conclusions and expose exciting new possibilities in the field of photothermal actuators to create innovative solutions for photothermal soft actuators that will eventually benefit society. [ABSTRACT FROM AUTHOR]

As a large number of photovoltaic power stations are built and put into operation, the total amount of photovoltaic power generation accounts for an increasing proportion of the total electricity. The inability to accurately predict solar energy output has brought great uncertainty to the grid. Therefore, predicting the future power of photovoltaic fields is of great significance. According to different time scales, predictions are divided into long-term, medium-term and ultra-short-term predictions. The main difficulty of ultra-short-term forecasting lies in the power fluctuations caused by sudden and drastic changes in environmental factors. The shading of clouds is directly related to the irradiance received on the surface of the photovoltaic panel, which has become the main factor affecting the fluctuation of photovoltaic power generation. Therefore, sky images captured by conventional cameras installed near solar panels can be used to analyze cloud characteristics and improve the accuracy of ultra-short-term predictions. This paper uses historical power information of photovoltaic power plants and cloud image data, combined with machine learning methods, to provide ultra-short-term predictions of the power generation of photovoltaic power plants. First, the random forest method is used to use historical power generation data to establish a single time series prediction model to predict ultra-short-term power generation. Compared with the continuous model, the root mean square (RMSE) error of prediction is reduced by 28.38%. Secondly, the Unet network is used to segment the cloud image, and the cloud amount information is analyzed and input into the random forest prediction model to obtain the bivariate prediction model. The experimental results prove that, based on the cloud amount information contained in the cloud chart, the bivariate prediction model has an 11.56% increase in prediction accuracy compared with the single time series prediction model, and an increase of 36.66% compared with the continuous model.

Wind power is developing rapidly in the context of sustainable development, and a series of problems such as wind curtailment and power curtailment have gradually emerged. The forecast of power generation output has become one of the hotspots of current research. This paper proposes a wind power plant output ultra-short-time prediction technology based on variational modal decomposition and particle swarm optimization least squares vector machine. Variational Modal Decomposition (VMD) method decomposes the historical output data of wind power plants at multiple levels. At the same time, it explores the impact of various decomposition methods such as EMD decomposition on the prediction accuracy, and uses the least squares support vector machine based on particle swarm optimization algorithm. Predictive summation is performed on each level of data separately to obtain a more accurate prediction effect, which has a certain improvement in prediction accuracy compared with traditional prediction algorithms.

In recent years, under the dual pressure of resource shortage and environmental pollution, the photovoltaic (PV) power generation industry has flourished. The irradiance forecasting technology of PV power plants is of great significance for output prediction, grid dispatching and safe operation. Cloud cover is always the key factor making the irradiance fluctuate. In this article, colorful ground-based cloud images are collected by the all-sky imager every minute as the research object. Based on the traditional threshold method, a hybrid entropy threshold method is proposed to identify cloud clusters. Using the correlation analysis, among many impact factors with high correlation, five are extracted as input parameters of a BP network optimized by genetic algorithm (GA-BP). Through verification and comparison analysis, it is concluded that the recognition accuracy of the hybrid entropy threshold method is higher, and the average relative error can be controlled at about 5%. Based on this, the irradiance prediction of GA-BP also achieved better results than other models. It can meet the application requirements of PV power plants.

Developing an efficient multi-functional electrocatalyst with high efficiency and low cost to replace noble metals is significantly crucial for the industrial water electrolysis process and for producing sustainable green hydrogen (H2) fuel. Herein, ultrathin CuCo2S4 nanosheets assembled into highly open three-dimensional (3D) nanospheres of CuCo2S4 (Cu/Co = 33:67) were prepared by a facile one-pot solvothermal approach and utilized as a bifunctional electrocatalyst for efficient overall water splitting. The as-prepared CuCo2S4 is characterized structurally and morphologically; the BET surface area of the CuCo2S4 (Cu/Co = 33:67) catalyst was found to have a larger specific surface area (21.783 m2g−1) than that of other catalysts with a Cu/Co ratio of 67:33, 50:50, and 20:80. Benefiting from a highly open structure and ultrathin nanosheets with excellent exposure to catalytically active sites, CuCo2S4 (Cu/Co = 33:67) is identified as an efficient catalyst for the proton reduction and oxygen evolution reactions in 1 M KOH with an overpotential of 182 and 274 mV at 10 mA cm−2, respectively. As expected, a low cell voltage of 1.68 V delivers a current density of 10 mA cm−2. Stability and durability are also greatly enhanced under harsh alkaline conditions. Therefore, this work provides a simple strategy for the rational design of spinel-based transition metal sulfide catalysts for electrocatalysis. [ABSTRACT FROM AUTHOR]

Ammonia is one of the most useful chemicals for the fertilizer industry and is also promising as an important energy carrier for fuel cell application, and is currently mostly produced by the traditional Haber–Bosch process under high temperature and pressure conditions. This energy-intensive process is detrimental to the environment due to the dependence on fossil fuels and the emission of significant greenhouse gases (such as CO2). Ammonia production via the electrochemical nitrogen reduction reaction (ENRR) has been recognized as a green sustainable alternative to the Haber–Bosch process in recent years. Current ENRR research mainly focuses on the catalyst for ammonia selective production and the enhancement of faradaic efficiency at high current density; however, these have not been explored well due to the unavailability of highly efficient and cheap catalysts. Herein, this review provides information on the ENRR process along with (i) theoretical background, (ii) experimental methodology of the electrocatalytic process and (iii) computational screening of promising catalysts. The impact of active sites and defects on the activity, selectivity, and stability of the catalysts is deeply understood. Furthermore, we demonstrate the mechanistic understanding of the ENRR process on the surface of catalysts, with the aim of boosting the improvement of the ENRR activities. The ammonia detection methods are also summarized along with thorough discussion of control experiments. Finally, this review highlights prevailing problems in existing ENRR methods of ammonia production along with technical advancements proposed to address these issues and concludes with comments on opportunities and future directions of the ENRR process. [ABSTRACT FROM AUTHOR]

A facile and inexpensive way have been developed to fabricate robust self‐cleaning superhydrophobic coating by depositing polymer layer on candle soot (CS) surface using dip coating method. The stability and robustness of the CS deposited superhydrophobic surface is much weaker due to weak interaction and nonchemical bonding with the substrate. We introduced a thin layer of polystyrene, polyethylene, polypropylene (PP), and polyvinylidene fluoride on CS surface in order to improve its mechanical properties. The fabricated surfaces with the use of respective polymers exhibited water contact angles of nearly 170, 174, 175, and 171° with sliding angles of 2, 1, 1, and 3°, respectively. Although, all the polymers used in this work exhibited excellent superhydrophobic and self‐cleaning surface property, we found that the PP deposited CS surface exhibit better stability against water jet hitting and water drop impact tests. The PP deposited CS surface almost maintained their surface properties even after 50 cycles of sandpaper abrasion and 20 cycles of adhesive tape peeling tests. The mechanical durability tests confirmed that PP is a better polymer to improve the long‐term durability of CS surface. Therefore, this simple, time saving, and inexpensive method for fabricating superhydrophobic coating can be used for potential industrial application. [ABSTRACT FROM AUTHOR]

Continuous oil–water separation is not only an important topic for scientific research but also for practical applications to clean oil from industrial oily wastewater and oil‐spill pollution. In this work, polyurethane sponges are coated by ZnO using dip coating technique. ZnO‐coated sponges are modified by stearic acid to achieve superhydrophobicity. The ZnO‐coated sponges exhibit water contact angle ≈165° and oil contact angle ≈0°. The prepared superhydrophobic sponge is sustained in oil–water separation and in separation of oil–hot water mixture. Also the wetting properties of the sponge are stable in mechanical test like cutting and twisting. Stearic acid modified ZnO‐coated sponge holds good promise for oil‐spill cleanup as well as oil/water separation from harsh environments. [ABSTRACT FROM AUTHOR]

In this study, the hydrophobic silica nanoparticles (NPs) are synthesized by simple sol–gel processing of polymethylhydrosiloxane (PMHS). The nanocomposite solution is prepared by adding hydrophobic silica NPs in polystyrene solution and applied on the skeleton of polyurethane sponge by simple immersion‐drying process. The as‐prepared sponges exhibited superhydrophobic property with water contact angle 161° and oil contact angle nearly 0° and can separate oil from oil–water and oil–muddy water mixture. The superhydrophobic sponge has sustainable anti‐wetting property under cross sectional cutting, pressing and twisting, and different pH environment. Such superhydrophobic sponge is suitable for practical application on a large scale. [ABSTRACT FROM AUTHOR]

A lotus leaf like self‐cleaning superhydrophobic coating has high demand in industrial applications. Such coatings are prepared by alternative dip and spray deposition techniques. A layer of polyvinyl chloride is applied on glass substrate by dip coating and then spray coated a suspension of hydrophobic silica nanoparticles at substrate temperature of 50 °C. This coating procedure is repeated for three times to achieve rough surface morphology which exhibits a water contact angle of 169 ± 2° and sliding angle of 6°. The superhydrophobic state of the coating is still preserved when water volume of 1.2 L is used to impact the water drops on coating surface. The stability of the wetting state of the coating is analyzed against the water jet, adhesive tape and sandpaper abrasion tests. The prepared superhydrophobic coating strongly repelled the muddy water suggesting its importance in self‐cleaning applications. [ABSTRACT FROM AUTHOR]

In the present research work, spray deposition technique is adopted for the fabrication of superhydrophobic coating on glass slide using TiO2 nanoparticles and polymethylhydrosyloxane (PMHS) composite. The prepared superhydrophobic coating revealed hierarchical surface morphology due to different micro and nanoscaled grains of TiO2 NPs/PMHS composite. The water drops hardly stay on the superhydrophobic coating and roll off the surface at sliding angle of 6° due to high water contact angle of 163 ± 2°. As a result, the prepared superhydrophobic coating revealed excellent self‐cleaning performance. To evaluate the mechanical durability the prepared superhydrophobic coating, the coating surface is exposed to water jet, water drop impact, adhesive tape peeling, and sandpaper abrasion tests. This coating approach can be applied to the substrates of any size and shape. [ABSTRACT FROM AUTHOR]

The preparation of superhydrophobic coating using cheap candle soot nanoparticles (CS NPs) collected from candle flame is a very novel research topic. A less than 30 nm sized candle soot particles are collected by passing through stainless steel mesh of pore size ̴30 nm. An optimum suspension of CS NPs and polydimethylsiloxane (PDMS) in chloroform is sprayed on clean glass substrate and dried at 100°C for 1 hour. The coating surface with water contact angle ̴173° and rolling angle ̴ 4° is achieved by spraying suspension of 100 mg CS NPs and 0.3 mL PDMS in chloroform. The stability of superhydrophobic coating is studied by finger‐wiping, water jet hitting, water dripping, adhesive tape, and sandpaper abrasion test. Result showed that the coatings prepared with an optimum 100 mg CS NPs in suspension are stable under water jet hitting and water dripping test. The superhydrophobicity is destroyed for four cycles of adhesive tape peeling and seven cycles of sandpaper abrasion tests. The coated substrate showed good self‐cleaning performance. The high water repellent and self‐cleaning property of the prepared coating can be adopted for industrial applications. [ABSTRACT FROM AUTHOR]

Electrochemical N2 reduction is an environmentally friendly and sustainable approach for NH3 synthesis under mild conditions, while an efficient electrocatalyst is crucial for the N2 reduction reaction (NRR). Herein, we report Ti3+ self-doped TiO2−x nanowires on Ti mesh (Ti3+–TiO2−x/TM) as an efficient non-noble-metal NRR electrocatalyst with excellent selectivity. In 0.1 M Na2SO4, the Ti3+–TiO2−x/TM achieves a high faradaic efficiency of 14.62% with a NH3 yield of 3.51 × 10−11 mol s−1 cm−2 at −0.55 V vs. the reversible hydrogen electrode. Density functional theory calculations further reveal that introducing Ti3+ decreases the reaction energy barrier and increases the number of active sites on the TiO2 surface for the NRR. [ABSTRACT FROM AUTHOR]

The synthesis of efficient, cost‐effective, and non‐toxic bifunctional electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is highly needed for renewable energy related processes (conversion and storage). In the present work, we report a simple and straightforward one‐step hydrothermal strategy to prepare Zn−Co−S colloidal nanocrystal clusters (CNCs) for total water splitting (OER and HER activity) for the first time. The Zn−Co−S CNCs consist of a large number of interconnected nanoparticles forming spherical structures, which is very helpful for the electrochemical activity. Under alkaline conditions, the Zn−Co−S electrocatalyst demonstrates an excellent electrocatalytic activity by driving 10 mA cm−2 at 157 mV HER and 320 mV OER overpotentials, respectively. The Zn−Co−S catalyst electrode maintained the catalytic activity for 12 h exhibiting a good electrochemical stability. Furthermore, as fabricated two‐electrode alkaline water‐splitting system of Zn−Co−S//Zn−Co−S affords 10 mA cm−2 at a voltage of 1.64 V. [ABSTRACT FROM AUTHOR]

Photocatalytic activity of monosized AuZnO composite nanoparticles with different compositions were synthesized by the one-pot polyol procedure, using the triblock copolymer poly(ethylene glycol)-block-poly(propylene glycol)-blockpoly(ethylene glycol) (PEO-PPO-PEO) as the surfactant. The structure and morphology of the composite nanoparticles were analyzed by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), selected area electron diffraction (SAED), a transmission electron microscope (TEM) and high resolution transmission electron microscopy (HRTEM). The characterization showed that the AuZnO composite nanoparticles were spherical, with narrow particle size distribution and high crystallinity. The Fourier transform infrared spectroscopy (FTIR) study confirms the PEO-PPO-PEO molecules on the surface of the composite nanoparticles. The investigations by ultraviolet-visible light absorbance spectrometer (UV-Vis) and photoluminescence spectrophotometer (PL) demonstrate well the dispersibility and excellent optical performance of the AuZnO composite nanoparticles. Photocatalytic activity and reusability of the AuZnO nanoparticles in UV and visible light regions was evaluated by the photocatalytic degradation of Rhodamine B (RhB). The experimental results show that the AuZnO composite nanoparticles with a suitable amount of Au loading have stability and improved photocatalytic activity. AuZnO composite nanoparticles are effective and stable for the degradation of organic pollutants in aqueous solution. [ABSTRACT FROM AUTHOR]

The key step in the fabrication of highly active electrochemical sensors is seeking multifunctional nanocomposites as electrode modified materials. In this study, the gold nanoparticle-decorated helical carbon nanotube nanocomposites (AuNPs-HCNTs) were fabricated for rutin detection because of its superior sensitivity, the chemical stability of AuNPs, and the superior conductivity and unique 3D-helical structure of helical carbon nanotubes. Results showed the prepared nanocomposites exhibited superior electrocatalytic activity towards rutin due to the synergetic effects of AuNPs and HCNTs. Under the optimized conditions, the developed sensor exhibited a linear response range from 0.1 to 31 μmol/L for rutin with a low detectable limit of 81 nmol/L. The proposed method might offer a possibility for electrochemical analysis of rutin in Chinese medical analysis or serum monitoring owing to its low cost, simplicity, high sensitivity, good stability, and few interferences against common coexisting ions in real samples. [ABSTRACT FROM AUTHOR]

Both surface morphology and surface energy of solid surface conclude its wettability, either in Wenzel’s hydrophobic or Cassie–Baxter’s superhydrophobic wetting state. The superhydrophobic silica coatings were prepared by spin deposition technique from a mixture of hydrophobically modified silica particles and polystyrene. To enhance the adherency of the coating on the substrate and also to improve the durability of the coating, polymer is especially utilized in the coating solution. The durability of the superhydrophobic coating was confirmed by resistency towards water jet impact. The consequence of number of spin deposited layers on the wettability of the coatings was precisely studied. The static and dynamic water contact angle of 158° and 9° were achieved on the coating surface. Freely rolling spherical water drops on the non-wettable solid surface are favourable for the self-cleaning effect and so the prepared superhydrophobic coatings revealed superior self-cleaning performance. An anti-corrosion performance of the superhydrophobic coating was also confirmed using electrochemical corrosion experiments in 3.5% NaCl solution with long immersion time. [ABSTRACT FROM AUTHOR]

Cu impregnation has been performed to improve electronic conductivity of La 0.75 Sr 0.25 Cr 0.5 Mn 0.5 O 3−δ (LSCM) material in reducing atmosphere, and solid oxide electrolysis cells (SOECs) with the configuration of LSCF|LSGM|LSCM–Cu are prepared and evaluated for high temperature steam and carbon dioxide co-electrolysis. Electrochemical impedance spectra (EIS) and voltage–current curves are carried out to characterize the cell performances. Compared with LSCF|LSGM|LSCM cell without Cu impregnation for steam electrolysis under the same conditions, EIS results show that LSCF|LSGM|LSCM–Cu cell not only displays lower ohmic resistance and better electrochemical performances, but also their resistance increases with the percentage of the fed CO 2 under open circuit voltage, in which the polarization resistance dominates. With the applied electrolysis voltage of 1.65 V and the operating temperature of 750 °C, the maximum consumed current density increases from 1.31 A cm −2 without CO 2 to 1.82 A cm −2 with 37.5% CO 2 . Although there is an increase of 2.0% in the applied electrolysis voltage, the cell has exhibited an excellent durability test for more than 50 h with the electrolysis current density of 0.33 A cm −2 and the gas mixture of 50% AH–25% H 2 –25% CO 2 at 750 °C. [ABSTRACT FROM AUTHOR]