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Objective: With the rapid development of networks in China, the Internet has become an important source of first aid information for scalds. As a country with the largest population, there are a large number of scald cases every year in China. The content analysis of websites aimed to assess the accuracy and quality of the information on scalds available on Chinese websites.Methods: Using keywords related to scald in the most popular Chinese search engines, 19 sites were eventually selected for evaluation based on the inclusion and exclusion criteria. These websites were assessed on quality and content accuracy by using HONcode, DISCERN, and Patient Education Materials Assessment Tool (PEMAT) evaluation scales, and a modified evaluation system based on the system developed by J.D. Burgess. The evaluation was completed by a 5-person evaluation team. The subjective items were reviewed by five independent reviewers. The objective items were recorded by one reviewer, then another checked the results.Results: Using "scald first aid," "scald treatment," and "scald blister" to search on Baidu, Sougou, and Haosou, a total of 180 websites were recorded. According to the inclusion and exclusion criteria, 19 websites were obtained for assessment. Among them, 17 websites (89%) were established by commercial companies. Of the remaining two websites, one was created by a government agency and the other was created by a non-profit organization. The mean total HONcode score, DISCERN score, PEMAT (understandability) score, PEMAT (actionability) score, content accuracy score, and website quality score were 5.19 ± 1.09 out of 8; 52.63 ± 3.69 out of 80; 68%; 56%; 5.05 ± 1.47 out of 8; and 6.11 out of 12, respectively. The scores of the government agency website are better than that of commercial websites.Conclusion: The websites established by government agencies and non-profit organizations are few, and most of the websites are established by commercial companies. Compared with the government agency website, these commercial websites contain many advertisements, and their website quality and accuracy need to be further improved. [ABSTRACT FROM AUTHOR]

This work produced V-doped NiMn-layered double hydroxide(V-NiMnLDH) composite positive electrode material directly on nickel foam using a simple one-step hydrothermal synthesis process. The composite's 3D nanoflower-like design increased spatial utilization, surface area, and active sites for Faradaic redox reactions. The composite material has a specific capacitance of 1551 F g−1 at 1 A g−1 and 85.6 % capacitance retention at 10 A g−1, demonstrating exceptional cycle stability. In addition, we combined V-NiMnLDH with commercial activated carbon to create an asymmetric supercapacitor (ASC) with 63.5 Wh kg−1 energy density and 975 W kg−1 power density. After 5000 charge-discharge cycles, the gadget preserved 89.7 % of its specific capacitance. This material outperforms similar electrode materials in certain performance evaluations. We also used density functional theory (DFT) computations to analyze each element in the V-NiMnLDH composite and explain their electronic density of states contributions. This theoretical framework explains how V doping improves capacitance. Band structure simulations also showed V-NiMnLDH's higher charge transfer and conductivity compared to intermediate products, explaining its extraordinary capacitance performance. Our work combines theoretical and experimental data to advance catalyst design and high-performance energy storage materials. [ABSTRACT FROM AUTHOR]

• Development of EC for an automatic on-line inspection of steel balls surface. • A FAECS is proposed to inspect the whole ball surface and sub-surface with high accuracy. • Simplify the mechanism of steel ball surface unfolding. In order to perform the rapid and efficient automatic on-line inspection of the surface quality of steel ball, a new spherical deployment method based on flexible array eddy current sensor (FAECS) is proposed. Full unfolding of the steel ball surface can be performed by combining the flexible array eddy current sensor with the one-dimensional orbital deployment. The inspection coil of array eddy current sensor is fabricated on flexible printed circuit board (FPCB), which is bent into a semicircle to fix on the top of one-dimensional track. When the steel ball rolls on the one-dimensional track, complete inspection of steel ball surface can be performed by the flexible array eddy current sensor. In this method, one-dimensional mechanical motion is used instead of the traditional two-dimensional deployment motion, which reduces the complexity and cost of deployment structure. Three typical defects include linear cracks (0.12 mm width × 0.5 mm depth), cross cracks (0.06 mm width × 0.9 mm depth) and arc cracks (0.05 mm width × 0.1 mm depth) are measured in the experiment to verify the effectiveness of the inspection system. Subsequently, same batch of steel balls are tested at speed of 4 pcs/s, results show that the inspection accuracy of surface defect of steel balls is 95.52%, and the false inspection rate is less than 0.7%, which proves this method efficiency. [ABSTRACT FROM AUTHOR]

Continuous silicon carbide fiber–reinforced silicon carbide matrix composites (SiC f /SiC) are promising candidate materials for nuclear applications. In this paper, three–dimensional SiC f /SiC composites were fabricated using polymer infiltration and pyrolysis method. Interface properties of SiC f /SiC composites that were irradiated with 3 MeV Si ions to 1 dpa and 5 dpa at room temperature were studied using single-fiber push–out test, Raman spectroscopy, and transmission electron microscopy. Results indicate that, after being irradiated with different doses of Si ions, SiC f /SiC composites have weaker interfacial shear strength compared to that of samples before irradiation. The greater that the ion irradiation damage is, the lower that the interfacial shear strength is. With an increase in ion irradiation dose, the strength of the disordered (D) and graphitic (G) characteristic peaks in Raman spectra of SiC f /SiC composite decreases, and full width at half–maximum broadens. TEM micrographs show that ion irradiation damaged the continuity of SiC f /SiC composites, and microcracks appeared at pyrocarbon interface between the fiber and matrix. The crystallinity of SiC was lowered, the grain size shrank, and the ordered C phase became amorphous noncrystalline structure. [ABSTRACT FROM AUTHOR]

A kind of coating nanostructure, Ag nanoparticles coated with multilayered reduced graphene oxide (RGO), is fabricated by employing a three-step reduction method in an orderly manner, which is significantly different from the conventional structures that are simply depositing or doping with Ag nanoparticles on RGO via chemical reduction. The as-prepared nanostructure is investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), selected-area electronic diffraction (SEAD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The results show that the obtained Ag/RGO nanostructure is observed to be a perfect coating structure with well dispersed Ag particles, which is responsible for the remarkable oxidation resistance. The results of XPS spectra indicate the content of metallic Ag is far greater than that of Ag oxides despite of prolonged exposure to the air, which fully demonstrate the excellent stability of thus coating nanostructure. [ABSTRACT FROM AUTHOR]

Continuous silicon carbide fiber–reinforced silicon carbide matrix (SiC f /SiC) composites have developed into a promising candidate for structural materials for high–temperature applications in aerospace engine systems. This is due to their advantageous properties, such as low density, high hardness and strength, and excellent high temperature and oxidation resistance. In this study, SiC f /SiC composites were fabricated via polymer infiltration and pyrolysis (PIP) with the lower–oxygen–content KD–II SiC fiber as the reinforcement; a mixture of 2,4,6,8–tetravinyl–2,4,6,8–tetramethylcyclotetrasiloxane (V4) and liquid polycarbosilane (LPCS), known as LPVCS, was used as the precursor; while pyrolytic carbon (PyC) was used as the interface. The effects of oxidation treatment at different temperatures on morphology, structure, composition, and mechanical properties of the KD–II SiC fibers, SiC matrix from LPVCS precursor conversion, and SiC f /SiC composites were comprehensively investigated. The results revealed that the oxidation treatment greatly impacted the mechanical properties of the SiC fiber, thereby significantly influencing the mechanical properties of the SiC f /SiC composite. After oxidation at 1300 °C for 1 h, the strength retention rates of the fiber and composite were 41% and 49%, respectively. In terms of the phase structure, oxidation treatment had little effect on the SiC fiber, while greatly influencing the SiC matrix. A weak peak corresponding to silica (SiO 2 ) appeared after high–temperature treatment of the fiber; however, oxidation treatment of the matrix led to the appearance of a very strong diffraction peak that corresponds to SiO 2 . The analysis of the morphology and composition indicated cracking of the fiber surface after oxidation treatment, which was increasingly obvious with the increase in the oxidation treatment temperature. The elemental composition of the fiber surface changed significantly, with drastically decreased carbon element content and sharply increased oxygen element content. [ABSTRACT FROM AUTHOR]

Abstract: The cSiO2/bY2O3/aSiO2/ZnS/aSiO2/bY2O3/cSiO2 system was fabricated to enhance the hardness and improve the transmittance of Zinc sulfide. The data of each thickness was obtained by the simulation of Filmstar package. 150nm SiO2 film was used to release the stress between ZnS and Y2O3 film as a buffer layer. Smooth SiO2 and crack-free Y2O3 films were successfully obtained. It was found that hardness of the multilayer system increased from 250 to 430Kg/mm2 and transmittance increased from 63% to 83% at 3–5μm. [Copyright &y& Elsevier]

Background: Diabetic nephropathy (DN) is a primary cause of end-stage renal disease. Increasing evidence indicates that microRNAs (miRNAs) are involved in DN pathogenesis. Trigonelline (TRL) has been shown to lower blood sugar and cholesterol levels, promote nerve regeneration, and exert anti-cancer and sedative properties.Method: The effect of TRL on human mesangial cell (HMC) growth was assessed using the MTT assay. Differentially expressed miRNAs were validated using real-time quantitative polymerase chain reaction (real-time PCR). Bioinformatics, cell transfection, and Western blot analyses were utilized to confirm the binding of miR-5189-5p to HIF1AN. The effects of miR-5189-5 expression on cell proliferation were also assessed. Western blot analysis was used to determine the activation of multiple signaling molecules including phosphorylated-(p)-AMPK, SIRT1, LC3B, p62, and Beclin-1 in the autophagy pathway.Results: TRL improved proliferation, increased the expression of miR-5189-5p, reduced HIF1AN, and restored the inhibition of autophagy in HMCs induced by high glucose. MiR-5189-5p mimics inhibited HIF1AN expression, and the miR-5189-5p inhibitor increased HIF1AN expression. MiR-5189-5p mimics significantly improved the proliferation of HMCs induced by high glucose, reduced the relative protein expression of p-AMPK, SIRT1, LC3B, and Beclin-1, and significantly increased the relative protein expression of p62.Conclusion: We showed that TRL up-regulated miR-5189-5p expression, activated the AMPK pathway, and activated autophagy in HMCs. Our study demonstrates that TRL could be a new treatment strategy to protect mesangial cells in response to high glucose. [ABSTRACT FROM AUTHOR]

Abstract: We investigate the polarization and dielectric properties of ferroelectric BaTiO3 thin film grown compositionally graded substrate by using first-principles method. Due to the spatial variation of the misfit strain between film and substrate, the polarization in the film decreases gradually along direction of the film. Moreover, localization of the polarization also results in large spatial variation of the dielectric constant in the ferroelectric thin film. Our results suggest that such interesting properties of ferroelectric thin films can be controlled by choosing appropriate compositionally graded substrates. [Copyright &y& Elsevier]

Netrin-4, recognized in neural and vascular development, is highly expressed by mature endothelial cells. The function of this netrin-4 in vascular biology after development has remained unclear. We found that the expression of netrin-4 is highly regulated in endothelial cells and is important for quiescent healthy endothelium. Netrin-4 expression is upregulated in endothelial cells cultured under laminar flow conditions, while endothelial cells stimulated with tumor necrosis factor alpha resulted in decreased netrin-4 expression. Targeted reduction of netrin-4 in endothelial cells resulted in increased expression of vascular cell adhesion molecule 1 and intercellular adhesion molecule 1. Besides, these endothelial cells were more prone to monocyte adhesion and showed impaired barrier function, measured with electric cell-substrate impedance sensing, as well as in an 'organ-on-a-chip' microfluidic system. Importantly, endothelial cells with reduced levels of netrin-4 showed increased expression of the senescence-associated markers cyclin-dependent kinase inhibitor-1 and -2A, an increased cell size and decreased ability to proliferate. Consistent with the gene expression profile, netrin-4 reduction was accompanied with more senescent associated β-galactosidase activity, which could be rescued by adding netrin-4 protein. Finally, using human decellularized kidney extracellular matrix scaffolds, we found that pre-treatment of the scaffolds with netrin-4 increased numbers of endothelial cells adhering to the matrix, showing a pro-survival effect of netrin-4. Taken together, netrin-4 acts as an anti-senescence and anti-inflammation factor in endothelial cell function and our results provide insights as to maintain endothelial homeostasis and supporting vascular health. [ABSTRACT FROM AUTHOR]

Long noncoding RNAs (LncRNAs) are involved in multiple processes of human malignancy, and emerge as crucial molecules in RNA biology. However, the function of lncRNAs has not been well illustrated in abdominal aortic aneurysm (AAA). In this research, the effects of dysregulated ladybird homeobox 2 antisense RNA 1 (LBX2-AS1) or ladybird homeobox 2 (LBX2) on vascular smooth muscle cell (VSMC) biological processes were surveyed via cell counting kit-8 (CCK-8), methyl thiazolyl tetrazolium (MTT), terminal-deoxynucleoitidyl transferase mediated nick end labeling (TUNEL) and caspase-3 activity assays. LBX2-AS1 and LBX2 both possessed pro-apoptosis and anti-proliferation functions in AAA. Mechanically, the regulation role of LBX2-AS1 on miR-4685-5p or that of miR-4685-5p on LBX2 was investigated by quantitative real-time polymerase chain reaction (qRT-PCR). Additionally, the competing endogenous RNA (ceRNA) network was confirmed by luciferase reporter, RNA pull-down, and RNA immunoprecipitation (RIP) assays. LBX2-AS1 sequestered miR-4685-5p to release LBX2 expression via ceRNA mechanism. Further, LBX2 could act as a transcriptional activator of LBX2-AS1. A positive feedback loop was formed by LBX2-AS1, miR-4685-5p and LBX2, deteriorating AAA formation and progression. To sum up, our data suggested that LBX2-AS1, miR-4685-5p and LBX2 constituted a positive feedback loop in promoting AAA development, implying a potential usage of LBX2-AS1/miR-4685-5p/LBX2 axis in AAA management. [ABSTRACT FROM AUTHOR]

Bearing steel ball is the basic part of rolling bearing, and its surface quality has a vital impact on the service performance, life and safety of rolling bearing. Therefore, the surface quality of bearing steel balls must be fully tested before leaving the factory. The unfolding mechanism and inspection sensor of steel ball surface are mainly described in this paper. First of all, the inspection methods of steel ball surface quality are analyzed in detail, including visual inspection, eddy current inspection, optical fiber sensor inspection, capacitance sensor inspection, ultrasonic sensor inspection, etc. Then, the methods of steel ball surface unfolding methods are introduced, including meridian unfolding method, one-dimensional orbit unfolding method, disk unfolding method, one-dimensional wheel unfolding method and rotating magnetic field unfolding method. Finally, the future development direction of steel ball detection technology is pointed out, which provides theoretical basis and technical reference for the realization of bearing steel ball surface micro-defect inspection system. [ABSTRACT FROM AUTHOR]

• A novel MnS/Ni 3 S 2 @Co(OH) 2 electrode was synthesized on nickel foam using cost effective three-step approaches. • The synergistic coupling of MnS/Ni 3 S 2 with Co(OH) 2 nanosheets enhanced electrochemical performance. • The constructed MnS/Ni 3 S 2 @Co(OH) 2 //AC ASC device showed a high energy density and remarkable cycle stability. The fabrication of electrode materials with a high specific capacitance is essential for the development of enhanced performance supercapacitors. A novel binder-free electrode material, composed of MnS/Ni 3 S 2 and Co(OH) 2 , was synthesized on nickel foam by hydrothermal, sulfuration, and electrodeposition techniques. The MnS/Ni 3 S 2 exhibited a unique flower-like structure, resulting in a high specific capacitance of 1780 F g−1 at 1 A/g. By optimizing the synthesis conditions through several characterization and electrochemical tests, the MnS/Ni 3 S 2 @Co(OH) 2 composite was obtained, which displayed an ultrahigh specific capacitance of 2495 F g−1 at 1 A/g and a capacitance retention rate of 86.1% after 5000 cycles at 10 A/g in three-electrode system. The synergistic coupling of MnS/Ni 3 S 2 and Co(OH) 2 , along with the conductive nickel foam substrate, donated towards the excellent electrochemical performance. Furthermore, the MnS/Ni 3 S 2 @Co(OH) 2 //AC asymmetric supercapacitor (ASC) device was constructed with MnS/Ni 3 S 2 @Co(OH) 2 as positive electrode, activated carbon (AC) as negative electrode and 1 M KOH solution as electrolyte, demonstrated a high energy density of 68.6 Wh kg−1 at 750 W kg−1 and excellent cycle stability with 91.2% capacitance retention after 10,000 cycles at 15 A/g. The outstanding electrochemical properties observed in both the pre-electrodeposition and post-electrodeposition samples indicate the effectiveness of reasonable design and construction of composite as a pathway for producing electrode materials with exceptional performance. [ABSTRACT FROM AUTHOR]

Copper nanowires (Cu NWs) encapsulated with polypyrrole (PPy) (Cu@PPy) have been fabricated by a facile liquid-phase reduction with copper (II) chloride as precursor. The as-synthesized Cu NWs grow along the crystal orientation of (1 1 0) and the encapsulated polypyrrole layer is also observed on the surface of Cu NWs. The Cu@PPy nanostructure is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). And the experimental results show that the synthesized Cu@PPy are uniform and cross each other with the average width of 160 nm. Additionally, the results of XRD and XPS indicate the Cu@PPy nanostructure has excellent oxidation resistance and temporal stability. [ABSTRACT FROM AUTHOR]

In order to improve the accuracy and stability of K-means algorithm and solve the problem of determining the most appropriate number K of clusters and best initial seeds, an improved K-means algorithm based on density Canopy is proposed. Firstly, the density of sample data sets, the average sample distance in clusters and the distance between clusters are calculated, choosing the density maximum sampling point as the first cluster center and removing the density cluster from the data sets. Defining the product of sample density, the reciprocal of the average distance between the samples in the cluster, and the distance between the clusters as weight product, the other initial seeds is determined by the maximum weight product in the remaining data sets until the data sets is empty. The density Canopy is used as the preprocessing procedure of K-means and its result is used as the cluster number and initial clustering center of K-means algorithm. Finally, the new algorithm is tested on some well-known data sets from UCI machine learning repository and on some simulated data sets with different proportions of noise samples. The simulation results show that the improved K-means algorithm based on density Canopy achieves better clustering results and is insensitive to noisy data compared to the traditional K-means algorithm, the Canopy-based K-means algorithm, Semi-supervised K-means++ algorithm and K-means-u* algorithm. The clustering accuracy of the proposed K-means algorithm based on density Canopy is improved by 30.7%, 6.1%, 5.3% and 3.7% on average on UCI data sets, and improved by 44.3%, 3.6%, 9.6% and 8.9% on the simulated data sets with noise signal respectively. With the increase of the noise ratio, the noise immunity of the new algorithm is more obvious, when the noise ratio reached 30%, the accuracy rate is improved 50% and 6% compared to the traditional K-means algorithm and the Canopy-based K-means algorithm. [ABSTRACT FROM AUTHOR]

Abstract: Sapphire (i.e., Al2O3 single crystal) window and dome are important sensor components. Large-sized sapphire crystal was prepared by an improved Kyropoulos method, and its machining technique of ultrasonic vibration was also reported. The quality and structure were evaluated by illumination of a He–Ne laser transmission electron microscopy (TEM), double crystal X-ray diffraction (DCXRD) and Raman spectroscopy. For practical window and dome application, its high-temperature mechanical strength and optical transmission were both measured, and a modification measure of sputtering Mg film on sapphire surface followed by annealing and subsequent quenching was demonstrated. Large-sized sapphire crystals with high quality and different profiles were successfully grown by adjustment of pulling velocity and crucible size, design of suitable temperature field. Moreover, a series of sapphire windows and domes were fabricated for different optical application. The biaxial flexure strength of sapphire crystal decreases with increasing temperature, and the infrared transmission is also slightly degraded at high temperature. In addition, it should be noted that there is sharp strength drop in the temperature range of 400° to 600°C which is related with twin formation in sapphire crystal. Submicron MgAl2O4 spinel precipitation can effectively harden sapphire crystal and do not induce large optical-scattering loss, which is a potential modification method for window and dome application of sapphire crystal. [Copyright &y& Elsevier]

• The rectangular probe is placed parallel to the specimen to produce more uniform eddy current. • The pulsed eddy current sensor is installed on the mobile car for weld defect detection. • Three subsurface defects of weld were detected. In order to solve the problems of low detection efficiency, high labor intensity and poor working environment of large pressure vessel cylinder, the pulsed eddy current (PEC) nondestructive testing technology is used to detect the defects in the welding seam of the cylinder. The PEC sensor composed of rectangular probe coil and Hall sensor is installed on the mobile inspection platform to test two simulated cylinder weld samples. Results show that the signal curve of sample 1 without defect is gentle and without mutation, while the signal of sample 2 with defect has three mutation signals. Then, the X-ray testing method is used to detect the sample, radiograph confirmed that there are no defects on sample 1 and three porosity defects in sample 2. Through the comparison and analysis of the above two kinds of detection results, the feasibility of the detection method for weld subsurface defects is verified. [ABSTRACT FROM AUTHOR]

Axially aligned fibrous monolithic ceramics present non-catastrophic fracture behavior via crack deflection and delamination along cell boundaries. However, severe in-plane anisotropy and time-consuming preparation procedures prevent their extensive promotion. The introduction of high content of weak phase components with poor oxidation resistance in weak interface destroys the excellent oxidation resistance of ceramic matrix. In this work, ZrB 2 -based short fibrous monolithic (SFM) ceramics with in-plane isotropic mechanical properties and excellent oxidation resistance were easily prepared by hot pressing randomly assembled short ceramic fibers. The microstructure and mechanical behavior of ZrB 2 -based SFM ceramics densified at various temperatures were systematically investigated. The mechanical properties of ZrB 2 -based SFM ceramics slightly improved with the increase of sintering temperature. ZrB 2 -based SFM ceramics exhibited excellent oxidation resistance and remained intact without macroscopic cracks after ablation for 615 s in oxyacetylene flame with maximum temperatures exceeding 2150 °C. The oxidation behavior was analyzed in detail. [ABSTRACT FROM AUTHOR]

Exogenous administration of melatonin has been demonstrated to down-regulate inflammatory responses and attenuate organ damage in various models. However, the salutary effect of melatonin against secondary intra-abdominal hypertension (IAH) remains unclear. This study sought to test the influence of melatonin on secondary IAH in a pathophysiological rat model and the underlying mechanisms involved. Before resuscitation, male rats underwent a combination of induced portal hypertension, applying an abdominal restraint device, and hemorrhaging to mean arterial pressure (MAP) of 40 mmHg for 2 h. After blood reinfusion, the rats were treated with lactated Ringer solution (LR) (30 mL/h), melatonin (50 mg/kg) +LR, and SB-203580 (10 μmol/kg)+LR. LR was continuously infused for 6 h. MAP, the inferior vena cava pressure and urine output were monitored. Histopathological examination, immunofluorescence of tight junction proteins, and transmission electron microscopy were administered. Intestinal permeability, myeloperoxidase activity, malondialdehyde, glutathione peroxidase, and levels of TNF-a, IL-2, and IL-6, were assessed. The expression of extracellular signal-regulated kinase, p38, c-Jun NH2-terminal kinase, translocation of nuclear factor kappa B subunit, signal transducers and activators of transcription and tight junction proteins were detected by Western blot. We found that melatonin inhibited the inflammatory responses, decreased expression of p38 MAPK, attenuated intestinal injury, and prevented secondary IAH. Moreover, administration of SB203580 abolished the increase in p38 MAPK and also attenuated intestinal injury. These data indicate that melatonin exerts a protective effect in intestine in secondary IAH primarily by attenuating the inflammatory responses which are in part attributable to p38 MAPK inhibition. [ABSTRACT FROM AUTHOR]

Abstract: The electronic structure of Cu2HgSnSe4 in stannite structure is studied by the first-principles calculations. This material is a direct band-gap compound. In addition, the dielectric function, absorption coefficient, reflectivity, and energy-loss function are studied using the density functional theory within the generalized gradient approximation. We discuss the optical transitions between the valence bands and the conduction bands in the spectra of the imaginary part of the dielectric function at length. High and wide optical absorption spectrum is obtained. There are several prominent peaks for Cu2HgSnSe4 in the reflectivity spectra. And a rapid decrease of reflectance corresponds to the prominent peak in the energy-loss spectrum. [Copyright &y& Elsevier]

Abstract: The electronic structure, dielectric function, absorption coefficient, and reflectivity of two polycrystalline semiconductors CuAlSe2 and CuAl5Se8 are studied using the density functional theory within the generalized gradient approximation. There are different peaks in the spectra of the imaginary part of the dielectric function. The transitions between the valence bands and conduction bands are discussed at length. In addition, we also notice that the reduced absorption coefficient and reflectivity near band-edge in Cu-poor CuAlSe2 are closely related to a reduction of the density of states near the valence band maximum. [Copyright &y& Elsevier]