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WMoTaNb refractory high entropy alloy (RHEA) coating was prepared successfully by laser cladding. The coating is a composite structure composed of BCC1 and BCC2 structural HEA with some tiny intermetallic compound (IMC). The surface EBSD results indicates that the BCC1 has a strong (0001) texture with the intensity of 63.96. BCC2 possesses higher content of solute atoms, such as Nb, Mo, Ta, W, than that in BCC1, resulting in the formation of higher KAM mean value in BCC2, which indicates BCC2 has greater stresses and strains than that of the BCC1. Large numbers of LAGBs and dislocation lines are found to exist in BCC2, while little LAGBs and dislocation can be seen in BCC1. The interfaces between BCC1/BCC2, BCC1/IMC- and coating/substrate were analyzed using TEM. By calculating the lattice mismatch of each phase interface, it can be seen that typical incoherent characteristics are presented in each interface and large stress-strain is existed within the RHEA coating by laser cladding. The microhardness value of the laser cladded WMoTaNb coating is 551 HV0.2, which is much higher than that of the substrate due to the dislocations interaction and solid solution strengthening in the coating. The friction coefficient of laser cladded WMoTaNb RHEA coating is in the range of 0.55–0.6 at room temperature, while the friction coefficient at 800 °C increases to the range of 0.8–1.3. The dissolution of Fe atoms deteriorates the wear performance of the coating at high temperature.

This study aimed to fabricate a new type of aluminum matrix composite exhibiting high strength, good magnetic property, and toughness to solve the issues on current magnetic materials, such as brittleness and high density. In this paper, the Nd2Fe14Bp/Al–Co composites with different cobalt (Co) contents (wt.%) are fabricated viamicrowave sintering. The effects of the Co content on the composite microstructures and properties are studied. The results indicate that at a 580 °C sintering temperature, 30 min sintering time, and 30 °C/min heating rate, with an increase in the Co content (0 → 1%→2.5%→5%→7.5%→10%), the compactness initially increases and then decreases and reaches the maximum of 94.5% for the 5%Co sample together with a smaller grain size. The composites mainly consist of Nd2Fe14B with various sizes, Co particles, and the Nd2(Fe,Co)14B phase. The interfacial deformation resistance of the 5%Co sample tested viananoindention is 22.8% higher than that of the Co-free sample, which can facilitate in the interfacial strengthening. The microhardness, yield strength, and tensile strength of the 5%Co samples are 107.4 HV, 210.84 MPa, and 139.8 MPa, respectively. The remanence Br, coercive force Hcj, and maximum magnetic energy product (BH)maxof the 5%Co sample are 0.37 T, 0.65 T, and 45.12 kJ/m3, respectively, which are 48.6%, 29.2%, and 63.9% higher than those of the Co-free sample. The significant increase in the magnetic properties is mainly attributed to the interactive coupling between the Co particle soft magnetic phase and Nd2Fe14B hard magnetic phase.

Humidification dehumidification processes have been extensively introduced to the field of desalination. In this paper, a water-heated humidification dehumidification desalination system (HDDS), with open-air and semi-closed seawater water configurations, is proposed to achieve the waste heat recovery. After establishing the energetic and entropic equations of the humidification dehumidification desalination system, the corresponding analysis is accomplished. Furthermore, the dependence of the desalination performance, including the water production and relevant thermal efficiency, to the effectiveness, and cycle ratio are focused. The simulation results show the peak values of water production and gained-output-ratio (GOR) emerge at the balance condition of the humidifier. Nevertheless, due to the acquisition of the negative entropy generation rate, the actual values of water production and GOR are found as 104.64 kg h–1and 1.98. Based on the parametric analysis, it is found that a lower humidification effectiveness is beneficial to raise the actual desalination performance, while the HDDS performance will be elevated after the increase of the dehumidification effectiveness. Furthermore, the improvement of energy conversion for the current configuration is also proved in response to recover partial brine into the feed seawater.

The high volatility and intermittency of power load pose significant challenges to achieving optimal operation of energy storage system (ESS), which ultimately affects the economic benefits of industrial parks. To address this issue, this paper proposes a random clustering and dynamic recognition-based operation strategy for ESS in industrial parks. Firstly, we propose an expected cost minimization-driven random clustering method to determine the optimal cluster number of load curves. We then develop optimal day-ahead self-operating strategies of ESS corresponding to each of the clustered load curves. The uncertainty of power load is described by linearized risk assessment indexes. Secondly, we present a dynamic recognition technology that consists of the characteristics of value range, slope similarity, power size similarity, and curve step similarity to recognize the cluster to which the intra-day load curve belongs. Finally, we select the optimal intra-day charging/discharging strategy of ESS according to the recognized cluster as the operation strategy of the industrial park. Numerical experiments on a real-life industrial park with photovoltaic and ESS validate that the proposed strategy can reduce operation costs as well as promote photovoltaic local accommodation.

Hydrogel was successfully synthesised by incorporating acrylic acid (AA) as copper ion (Cu2+) chelator into the thermo-responsive poly(N-isopropylacrylamide) (PNIPAM) via emulsion polymerisation. The stimuli-responsive properties and the Cu2+adsorption capacity of the cross-linked PNIPAM-co-AA hydrogels were evaluated. The hydrodynamic diameter of the PNIPAM-co-AA hydrogel particles was studied using dynamic light scattering (DLS) method. It was found that the volume phase transition temperature (VPTT) of hydrogels shifted from 32°C to 27°C after Cu2+adsorption and the hydrodynamic diameter decreased with increasing temperature. The size of the PNIPAM-co-AA hydrogel particles and the incorporation of AA functional group were confirmed by transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR), respectively. Equilibrium isotherms, kinetic and thermodynamic studies have also been evaluated for its copper ions adsorption. The adsorption capacity (qm) of PNIPAM-co-AA hydrogels for Cu2+was found to be 67.25mgg-1with best fit to Langmuir isotherm and the adsorption mechanism follows the pseudo-second-order model. Gibbs free energy analysis shows that the adsorption was spontaneous and it exhibited endothermic chemisorption properties. Adsorption of copper ions on PNIPAM-co-AA hydrogels was found to be more thermodynamically driven.

This work focused on the synthesis of source powder for SiC crystal growth. SiC powder was prepared using high purity silicon and carbon powder. Broad ranges of temperature and Ar pressure were studied on the property of the as-prepared powder. X-ray diffraction (XRD) results show that SiC polytypes were determined by synthesis temperature, while not related to the variation of Ar pressure. The lattice constant of SiC would expand when Ar pressure decreased. Raman results revealed that the variation of Ar pressure would influence SiC crystallization. It was found that the concentrations of free C, free Si and nitrogen all varied with the variation of temperature or Ar pressure.

With the increase of the difficulty and intensity on competitive movement, the rate of sport injury will happen in training and competing frequently. The metatarsal is one of the most prone to injury part in the human body. The incidence of metatarsal injuries is rising in recently years. In this study, Pedar-X plantar pressure measure system and Novel emed pressure distribution measure plate were used in order to get the dynamics data in normal landing and inverted landing. The research concluded that: metatarsal peak stress had been transferred from the first metatarsal to the fifth metatarsal with increasing of varus angle. When the foot was in inverted state, stress distribution of metatarsal changed significantly. Lateral metatarsal played a major role in supporting function. Also, forefoot pressure distribution changed a lot in different functional sports shoes. The purpose is to provide the reliable correlative theoretical basis for improving sport equipments and security protection recommendations for people to engage in sports.

Physical simulation was conducted on the process of upsetting cylinder between flat platens by using colorful plasticine. The results of the physical simulation are basically consistent with rigid-plastic finite element analysis, which supports the rigid-plastic mechanical model for the cylindrical billets whose height-diameter ratio are greater than 1. Further physical simulation is conducted on cylinders upsetting between platen and supporting ring. The experimental method provides a reference for physical simulation of large deformation.

By representing the uncertain parameters as interval numbers, the reliability index equations of bars structures were obtained. A modified matrix affine arithmetic polynomial evaluation method plus recursive derivative information was proposed in this paper, which keeps all powers of noise symbols without approximation. Based on the nature that affine forms and intervals variables could transform each other, affine forms of bounded uncertain variables and modified affine arithmetic including derivative information for interval univariate polynomial evaluation were introduced into modeling and calculating non-probabilistic reliability index. An extended beam example and a ten-bar truss structure example were provided to illustrate the validity and feasibility of the presented procedures.

Mg-doped (≤15at%) ZnO thin films were prepared on quartz glass substrates by sol-gel method using a spinning-techniques. The films were charactered by X-ray diffraction , UV Vis-NIR double beam spectrophotometer and a SHIMADZU fluorespectrometer. It was found that optimally crystallized when the Mg concentration is 9at% were obtained. A photoluminescence study at room temperature revealed a blue shift in the near band edge emission peak with increasing of Mg content , which is agreement with the observation from the optical transmittance measurement. The photoconductive UV detectors based on these films were investigated, and the result showed that highest response was obtained from the photodecters fabricated by films with 15at% Mg concentration.

This paper aims to study the uncertainty of the MDOF structural dynamic response, taking not only the interval characteristics of structural physical parameters and geometric dimension, but also the interval characteristics of applied load simultaneously . By means of the description of the interval parameters of uncertain structure with affine forms, the interval structural dynamic equation is studied, and an improved affine arithmetic based on interval division is presented, where correlations between the interval elements in eigenvalue and responses equations are considered, independent uncertain parameters are transformed to affine forms, and the solution of eigenvalue and response equations are transformed into the corresponding certain ones. With general affine arithmetic, the eigenvalue of each order and response bounds are determined by searching for the maximum and minimum in the solutions. Finally, some mathematical examples and a further engineering application confirm the feasibility and validity of this approach.

ZnO films with piezoelectric properties were deposited on polycrystalline diamond wafers for high frequency surface acoustic wave filter applications by dc reactive magnetron sputtering. The influences of different sputtering pressures and substrate temperatures on the properties of ZnO films were discussed. Highly c-axis oriented, fine-grain ZnO films with excellent surface flatness (average surface roughness of 5.3 nm) and high resistivities (6.3×107 *·cm) have been obtained. Then Al films for interdigital-transducer were deposited on ZnO/diamond by electron evaporation, a 2.48 GHz longitudinally- coupled double-mode surface acoustic wave filter has been fabricated using the Al/ZnO film on diamond wafer.

ZnO thin film, as a promising piezoelectric material, possesses unique electrical, acoustical, and optical properties. In this paper, Al/ZnO thin film was deposited on Si wafer by magnetron sputtering. Highly oriented, dense, and fine-grain polycrystalline ZnO films with excellent surface flatness and high resistivities have been obtained, when the sputtered gas pressure was 0.9 Pa, the temperature was 200 ºC and the Ar-to-O2 ratio was 1:3. A 780MHz surface acoustic wave filter (SAWF) has been successfully fabricated using the Al/ZnO film on silicon wafer.

Microarray analysis is a powerful tool to identify the biological effects of drugs or chemicals on cellular gene expression. In this study, we compare the relationships between traditional measures of genetic toxicology and mutagen-induced alterations in gene expression profiles. TK6 cells were incubated with 0.01, 0.1, or 1.0 μM ±anti-benzo(a)pyrene- trans -7,8-dihydrodiol-9,10-epoxide (BPDE) for 4 h and then cultured for an additional 20 h. Aliquots of the exposed cells were removed at 4 and 24 h in order to quantify DNA adduct levels by 32 P post-labeling and measure cell viability by cloning efficiency and flow cytometry. Gene expression profiles were developed by extracting total RNA from the control and exposed cells at 4 and 24 h, labeling with Cy3 or Cy5 and hybridizing to a human 350 gene array. Mutant frequencies in the Thymidine Kinase and Hypoxanthine Phosphoribosyl Transferase genes were also determined. The 10α-(deoxyguanosin- N -yl)-7α,8β,9β-trihydroxy-7,8,9,10-tetrahydrobenzo(a)pyrene (dG- N -BPDE) adduct increased as a function of dose and was the only adduct identified. A dose-related decrease in cell viability was evident at 24 h, but not at 4 h. Cell death occurred by apoptosis. At 4 h, analysis of the gene expression profiles revealed that Glutathione Peroxidase and Gadd45 were consistently upregulated (greater than 1.5-fold and significantly ( P<0.001 ) greater than the control in two experiments) in response to 1.0 μM BPDE exposure. Fifteen genes were consistently down-regulated (less than 0.67-fold and significantly ( P<0.001 ) lower than the control in two experiments) at 4 h in cultures exposed to 1.0 μM BPDE. Genes with altered expression at 4 h included genes important in the progression of the cell-cycle and those that inhibit apoptosis. At 24 h post-exposure, 16 genes, involved in cell-cycle control, detoxification, and apoptosis were consistently upregulated; 10 genes were repressed in cultures exposed to the high dose of BPDE. Real-time quantitative PCR confirmed the differential expression of selected genes. These data suggest that changes in gene expression will help to identify effects of drugs and chemicals on molecular pathways in cells, and will provide useful information about the molecular responses associated with DNA damage. Of the endpoints evaluated, DNA adduct formation was the most sensitive indicator of DNA damage. DNA adduct formation was clearly evident at low doses, but the number of genes with significantly altered expression ( P<0.001 ) was minimal. Alterations in gene expression were more robust at doses associated with cellular toxicity and induction of mutations.

Inputs from the visual, somatosensory and vestibular systems must be integrated efficiently to activate appropriate motor responses in maintaining optimal balance. This study examined the standing balance of 17 children (7 to 10 years old) and 17 young adults (19 to 23 years old) as a function of sensory organization, sensory system efficiency, and postural strategy adopted. Tests of standing balance were administered under six sensory conditions created by simultaneous alteration of the visual (full, occluded, or sway-referenced) and the somatosensory inputs (fixed-foot or compliant-foot support). The sway area and the sway amplitude of the center of pressure were measured and analyzed. Three findings are notable. The function of sensory organization for balance control was poorer for the children than the young adults. The functional efficiency of the somatosensory and the visual systems of children have developed to the young adult level, but that of the vestibular system has not. There was no difference between children and young adults in hip control, but there was in ankle control when the vestibular input was the only reliable source of sensory input. These results suggest that the functional efficiency of the vestibular system in children 7 to 10 years of age may still be developing. This may account for their poorer function of sensory organization and lower performance of standing balance.

The mechanism by which HIV causes depletion of CD4 lymphocytes remains unknown. Recent studies have demonstrated that HIV binding to resting CD4 lymphocytes causes them to home from the blood into lymph node, and during the homing process, they are induced into apoptosis only to secondary signals through the homing receptors. If this is the principal mechanism of CD4 cell depletion, it can explain many of the events known to occur in HIV-infected individual.

Effect of norepinephrine on the phosphorylation of nuclear proteins was examined in cultured rat cardiocytes. Differential effects of phorbol esters, endothelin and platelet activating factor on the phosphorylation of a nuclear acid soluble fraction were evaluated. A specific phosphorylated nuclear acid soluble protein was identified in response to norepinephrine. The increase in phosphorylation in the norepinephrine-treated cardiocytes is significantly greater than 8 fold (p <0.001) as compared to the control group. This nuclear acid soluble protein has a high content of serine (> 12%) as well as acidic amino acids (> 20%) which is distinctively different from the histones as analyzed by amino acid composition. The specific phosphorylation of this nuclear protein (Mr 31 Kda) can be induced by norepinephrine within 5 minutes, indicating of an early gene activation event which modulates nucleosomal structure by phosphorylation.Copyright 1993, 1999 Academic Press

The problem of constructing the value set of an m-dimensional box Q under a nonlinear differentiable mapping f : Rm → C is considered, where R and C denote the sets of real and complex numbers respectively. More precisely, the notions of principal points and generalised principal points are exploited to characterise the boundary of the value set f(Q) and to present an effective and noniterative procedure for obtaining the set of principal points P whose image covers the boundary of the value set f(Q). The value-set construction procedure involves using a simplicial algorithm to trace out the set of generalised principal points G, which is the superset of P. A theorem for explicitly identifying the set of principal points P from the set of generalised principal points G is presented. As an application, the proposed value-set construction procedure is applied to robust D-stability analysis of a family of polynomials whose coefficients depend nonlinearly on a set of perturbed parameters.

The setting of acceptable exposure levels for neurotoxicants has followed the traditional approach of dividing experimental no-observed-adverse-effect-levels (NOAELs) by safety/uncertainty factors. NOAELs are believed by many toxicologists to represent levels having zero or negligible risk, while uncertainty factors are used to account for a number of sources of variation. Although the use of NOAELs in this manner has been criticized because of their imprecise quantitative definition, NOAELs for nonquantal neurotoxic effects have not been replaced by more precisely defined quantities (e.g., benchmark doses), partly due to the absence of a generally accepted methodology for attaching specific risk levels to low exposures. The present paper describes a quantitative approach to modeling nonquantal neurotoxic effects for risk assessment, which can be used to obtain results similar to the familiar results obtained in risk assessment for carcinogenicity and developmental toxicity. The steps involved in implementing the process are discussed, with particular attention being given to the critical step of defining an adverse neurologic effect. An experimental data set is used to illustrate the methodology.

The effect of cyclical mechanical stretch on angiotensinogen gene expression was examined using a neonatal rat cardiocyte culture system. Cultured cardiocytes grown on a flexible membrane base were stretched by vacuum to 20% of maximum elongation, at 60 cycles/min. The angiotensinogen gene was activated 2 to 5 fold after stretch for 3 to 24 hr, as shown by quantitative reverse transcription polymerase chain reaction. The 5′-flanking region of the angiotensinogen promoter was activated after stretch for 24 hr. This gene expression could be completely suppressed by losartan, a specific antagonist of angiotensin II receptor. These results indicate that (1) cyclical mechanical stretching of cardiocytes is a good model for the study of cardiac hypertrophy-related gene expression; (2) cyclical stretch up-regulates expression of the angiotensinogen gene and (3) the increase in promoter activity may contribute to the induction of angiotensinogen mRNA by cyclical stretch.

We examined the effect of cyclical mechanical stretch on the regulation of cardiac myosin heavy chain genes using an isolated neonatal rat cardiocyte culture system. Cultured cardiocytes grown on a flexible membrane were deformed by vacuum to 20% of maximum elongation, at 60 cycles/min in a serum-free medium. Cyclical stretch did not cause myocyte damage as assessed by supernatant LDH measurement and trypan blue exclusion test. The levels of myosin heavy chain (MyHC) mRNA increased as early as 1 h after stretch, reaching 12-fold over the control in 24 h, as shown by Northern blot analysis. However, the proximal 5'-flanking regions of the α- and β-MyHC gene which were linked to chloramphenicol acetyltransferase (CAT) reporter gene did not exhibit enhanced CAT activity following cyclical stretch. Deletion of the chimeric constructs to shorten the 5'-flanking regions of the MyHC genes generated by polymerase chain reaction amplification did not enhance the CAT activity under cyclical stretch. This finding suggests that the stretch-reponse element of the α- and β-MyHC gene promoter is probably not present in the proximal region of either the α- or β-MyHC genes.Copyright 1995, 1999 Academic Press, Inc.

Basic fibroblast growth factor is a biologically active polypeptide with mitogenic, angiogenic and neurotrophic properties. In the present study, the temporal and spatial expressions of basic fibroblast growth factor in stroke-prone spontaneously hypertensive rats were compared to two related strains of rat: spontaneously hypertensive rats and normotensive Wistar Kyoto rats. Higher levels of total RNA concentration were found in cerebral cortex of four-week-old stroke-prone rats compared to spontaneously hypertensive rats and Wistar Kyoto rats. Northern blot analysis showed no changes in levels of basic fibroblast growth factor messenger RNA with increasing age in cerebral cortex of Wistar Kyoto and spontaneously hypertensive rats. However, significant increases were found in 26- and 38-week-old stroke-prone rats compared to four-week-old stroke-prone rats. Although messenger RNA increases were also found in subcortical and cerebellar regions, a significant difference in levels of basic fibroblast growth factor messenger RNA was observed only in cerebral cortices among these three strains. This age-related increase in basic fibroblast growth factor messenger RNA correlated with the increase incidence of stroke in stroke-prone rats. Immunohistochemical study further revealed a dramatic increase in levels of basic fibroblast growth factor immunoreactivity in cerebral cortex of 30-week-old stroke-prone rats as compared to young stroke-prone rats, as well as age-matched Wistar Kyoto and spontaneously hypertensive rats. This increase in basic fibroblast growth factor immunoreactivity therefore appears very specific to aged stroke-prone rats. However, immunoreactivity decreased once severe tissue damages were observed in the cerebral cortex. Basic fibroblast growth factor-positive cells were diffusely expressed in cerebral cortex; double staining with glial fibrillary acidic protein showed the majority of these basic fibroblast growth factor-positive cells to be astrocytes.

To evaluate the incidence of empty sella in patients with cerebral arteriovenous malformations we retrospectively evaluated the pituitary gland height (PGH) on midsagittal T1 -weighted images in 216 patients with cerebral AVM (37.5% female, 62.5% male, mean age 33.4). Complete empty sella was defined as PGH<2 mm and partial empty sella as PGH<3 mm. Empty sella in patients with cerebral AVMs was analysed on the basis of nidal size, nidal location and age. We compared our results with those found in a normal population.Mean PGH in our patient population was 3.96 mm (range 1–9 mm). 3.4 mm in males and 4.8 mm in females. The overall incidence of empty sella was 41.2% (89/216). Empty sella occurred in 32% (48/150) of patients less than 40 years old and 62% (41/66) of patients over 40. The distribution of mean PGH values in AVM patients grouped by age was lower than but parallel to the distribution in normal PGH values. A statistically significant increased incidence of empty sella was found with cortical AVM location (48%; 69/144, p<0.0001), and nidal size> 3 cm (60%; 75/125, p<0.0001). Our results indicate that empty sella occurs more frequently in patients with cerebral AVM especially with a cortical location or a nidus greater than 3 cm. We conjecture that this may be related to altered CSF flow dynamics in these patients. Further studies may explain the higher incidence of empty sella in patients with cerebral AVM.

Objectives: Recent evidence indicates that reactive oxygen species (ROS) may act as second messengers in receptor-mediated signaling pathways. The possible role of ROS during Et-1 stimulation in cardiomyocytes was therefore investigated. Methods: Intracellular ROS levels were measured with fluorescence probe 2,7-dichlorofluorescin diacetate by confocal microscopy in cultured neonatal rat cardiomyocytes. The ROS-inducible c-fos expression was analyzed by Northern blotting and promoter activity. Results: Et-1 applied to cardiomyocytes dose-dependently increased intracellular ROS levels. The increase of ROS levels was attenuated by pretreating cardiomyocytes with Et-A receptor antagonist-BQ485, but not with Et-B receptor antagonist. Cardiomyocytes pretreated with catalase or an antioxidant N-acetylcysteine (NAC) reduced Et-1-induced ROS levels. Et-1 or H₂O₂ treatment of cardiomyocytes rapidly induced the expression of an immediate early gene c-fos. Et-1-treated cardiomyocytes enhanced the c-fos gene expression as revealed by functional analysis using a reporter gene construct containing c-fos promoter region (–2.25 kb) and reporter gene chloramphenicol acetyltransferase. The induction of mRNA levels and the promoter activities of c-fos gene by Et-1 or H₂O₂ were abolished by pretreating cardiomyocytes with catalase or NAC. Cells transiently transfected with the dominant positive mutant of p21ras (RasL61) led to a significant increase in intracellular ROS. Concomitantly, the mRNA levels and the promoter activities of c-fos were also induced. In contrast, cells transfected with the dominant negative mutant of Ras (RasN17) inhibited Et-1-induced ROS. Consistently, the increase of c-fos mRNA levels and promoter activities by Et-1 were also inhibited. Conclusions: These findings clearly indicate that Et-1 treatment to cardiomyocytes can induce ROS via Ras pathway and the increased ROS are involved in the increase of c-fos expression. Our studies thus emphasize the importance of ROS as second messengers in Et-1-induced responses in cardiomyocytes.