The lifetime of G. biloba is very long, and its growth is relatively slow. However, little is known about growth-related genes in this species. We combined mRNA sequencing (RNA-Seq) with bulked segregant analysis (BSA...The lifetime of G. biloba is very long, and its growth is relatively slow. However, little is known about growth-related genes in this species. We combined mRNA sequencing (RNA-Seq) with bulked segregant analysis (BSA) to fine map significant agronomic trait genes by developing polymorphism molecular markers at the transcriptome level. In this study, transcriptome sequencing of high growth (GD) and low growth (BD) samples of G. biloba half-sib families was performed. After assembling the clean reads, 601 differential expression genes were detected and 513 of them were assigned functional annotations. Single nucleotide polymorphism (SNP) analysis identified SNPs associated with 119 genes in the GD and BD groups;58 of these genes were annotated. Two Homeobox-leucine zipper protein genes were up-regulated in the GD group compared with the BD group;therefore, these are very likely related to high growth of G. biloba. This study provides molecular level data that could be used for seed selection of high growth G. biloba half-sib families for future breeding programs.展开更多
Growth rate has a direct impact on the productivity of nitride LED production. Atmospheric pressure growth of GaN with a growth rate as high as 10/zm/h and also Alo.lGao.gN growth of 1μm/h by using 4 inch by 11 produ...Growth rate has a direct impact on the productivity of nitride LED production. Atmospheric pressure growth of GaN with a growth rate as high as 10/zm/h and also Alo.lGao.gN growth of 1μm/h by using 4 inch by 11 production scale MOVPE are described. XRD of (002) and (102) direction was 200 arcsec and 250 arcsec, respectively. Impact of the growth rate on productivity is discussed.展开更多
High lattice match growth of InAsSb based materials on GaSb substrates is demonstrated. The present results indicate that a stable substrate temperature and the optimal flux ratios are of critical importance in achiev...High lattice match growth of InAsSb based materials on GaSb substrates is demonstrated. The present results indicate that a stable substrate temperature and the optimal flux ratios are of critical importance in achieving a homogeneous InAsSb based material composition throughout the growth period. The quality of these epilayers is assessed using a high-resolution x-ray diffraction and atomic force microscope. The mismatch between the GaSb substrate and InAsSb alloy achieves almost zero, and the rms surface roughness of InAsSb alloy achieves around 1.7A over an area of 28μm × 28μm. At the same time, the mismatches between GaSb and InAs/InAs0.73Sb0.27 superlattices (SLs) achieve approximately 100 arcsec (75 periods) and zero (300 periods), with the surface rms roughnesses of InAs/InAs0.73Sb0.27 SLs around 1.8 A (75 periods) and 2.1A (300 periods) over an area of 20 μm×20 μm, respectively. After fabrication and characterization of the devices, the dynamic resistance of the n-barrier-n InAsSb photodetector near zero bias is of the order of 10^6Ω·cm^2. At 77K, the positive-intrinsic-negative photodetectors are demonstrated in InAsSb and InAs/InAsSb SL (75 periods) materials, exhibiting fifty-percent cutoff wavelengths of 3.8μm and 5.1μm, respectively.展开更多
The work was based on the relationship between the crystal structure and parameters of diamonds in the synthetic process, in which Ni Mn C powder catalyst was used. At first, the diamond crystals nucleated in a cubic ...The work was based on the relationship between the crystal structure and parameters of diamonds in the synthetic process, in which Ni Mn C powder catalyst was used. At first, the diamond crystals nucleated in a cubic octahedron morphology through controlling such synthetic parameters as temperature and pressure in a parameter region where cubic octahedron ctystals can be obtained. Then the diamond nuclei grew epitaxially into crystals with a perfect octahedron morphology through increasing the synthesis temperature and decreasing the synthesis pressure in a parameter region where octahedron crystals can be obtained.展开更多
AIM: To investigate the effects of high glucose levels and anti-vascular endothelial growth factor(VEGF) agents(bevacizumab,ranibizumab and aflibercept) on retinal pigment epithelium(RPE) cells.METHODS: ARPE-1...AIM: To investigate the effects of high glucose levels and anti-vascular endothelial growth factor(VEGF) agents(bevacizumab,ranibizumab and aflibercept) on retinal pigment epithelium(RPE) cells.METHODS: ARPE-19 cells were cultured at different glucose levels(5.5 mmol/L,25 mmol/L,and 75 mmol/L).Cell viability was evaluated by MTT assay at 3d after treatment with D-glucose.Cell migration ability was measured by wound healing assay at 3d.A cell death detection kit was used to assess apoptosis at 3 and 14 d.Cell proliferation was assessed by EdU assay at 3d.The culture medium was treated with anti-VEGF agents at clinically relevant concentrations.The experiment was then repeated at a different glucose level.RESULTS: The viability and migration of ARPE-19 cells were significantly decreased in the presence of 75 mmol/L as compared to 5.5 mmol/L glucose.The percentage of TUNEL-positive cells was significantly increased and the proliferative potential was decreased with 75 mmol/L compared to 5.5 mmol/L glucose.There were no significant differences in the results between 25 mmol/L and 5.5 mmol/L glucose.In the presence of 75 mmol/L glucose,the groups treated with anti-VEGF showed decreased cell viability and proliferation and increased apoptosis.However,there were no significant differences between the anti-VEGF groups.CONCLUSION: High glucose level decreases the viability,wound healing ability,and proliferation of RPE cells,while increasing apoptosis.Furthermore,anti-VEGF agents interfered with the physiological functions of RPE cells under high-glucose conditions,accompanied by decreases in cell viability and proliferation.展开更多
In the transition of China’s economy from high-speed growth to high-quality growth in the new era,economic practices are oriented to fostering new growth drivers,developing new industries,and forming new models.Based...In the transition of China’s economy from high-speed growth to high-quality growth in the new era,economic practices are oriented to fostering new growth drivers,developing new industries,and forming new models.Based on the data flow,big data effectively integrates technology,material,fund,and human resource flows and reveals new paths for the development of new growth drivers,new industries and new models.Adopting an analytical framework with"macro-meso-micro"levels,this paper elaborates on the theoretical mechanisms by which big data drives high-quality growth through efficiency improvements,upgrades of industrial structures,and business model innovations.It also explores the practical foundations for big data driven high-quality growth including technological advancements of big data,the development of big data industries,and the formulation of big data strategies.Finally,this paper proposes policy options for big data promoting high-quality growth in terms of developing digital economy,consolidating the infrastructure construction of big data,expediting convergence of big data and the real economy,advocating for a big data culture,and expanding financing options for big data.展开更多
The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and grow...The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration (Nd) is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.展开更多
High-temperature oxidation is an important property to evaluate thermal protection materials. However, since oxidation is a complex process involving microstructure evolution, its quantitative analysis has always been...High-temperature oxidation is an important property to evaluate thermal protection materials. However, since oxidation is a complex process involving microstructure evolution, its quantitative analysis has always been a challenge. In this work, a phase field method (PFM) based on the thermodynamics theory is developed to simulate the oxidation behavior and oxidation induced growth stress. It involves microstructure evolution and solves the problem of quantitatively computational analysis for the oxidation behavior and growth stress. Employing this method, the diffusion process, oxidation performance, and stress evolution axe predicted for Fe-Cr-A1-Y alloys. The numerical results agree well with the experimental data. The linear relationship between the maximum growth stress and the environment oxygen concentration is found. PFM provides a powerful tool to investigate high-temperature oxidation in complex environments.展开更多
A model is proposed to correlate the crack growth rate and stress ratio containing very high cycle fatigue regime.The model is verified by the experimental data in literature.Then a formula is derived for the effect o...A model is proposed to correlate the crack growth rate and stress ratio containing very high cycle fatigue regime.The model is verified by the experimental data in literature.Then a formula is derived for the effect of mean stress on fatigue strength,and it is used to estimate the fatigue strength of a bearing steel in very high cycle fatigue regime at different stress ratios.The estimated results are also compared with those by Goodman formula.展开更多
A self-made directional solidification setup was used to prepare high purity aluminum ingots of 100mm in diameter. The morphology of the growth interface was detected by SEM and AFM, and the grain lattice orientation ...A self-made directional solidification setup was used to prepare high purity aluminum ingots of 100mm in diameter. The morphology of the growth interface was detected by SEM and AFM, and the grain lattice orientation was detected by XRD. The results indicate that the grains suffer competitive growth under any conditions in experiments. The lattice orientation of the preferred grains is determined by the flow field above the solid-liquid interface. The horizontal lattice position does not change during the growth process. However, the lattice orientation in the growth direction varies with the growth velocity and approaches to [100] gradually during the growth process.展开更多
BACKGROUND: Many studies have evaluated the role of vascular endothelial growth factor (VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE: To observe the effects of VEGF expression on permeabil...BACKGROUND: Many studies have evaluated the role of vascular endothelial growth factor (VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE: To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure, and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure. DESIGN, TIME AND SETTING: The randomized, controlled, animal study was performed at the Tanggula Etape, Central Laboratory of Chengdu Medical College, and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA, China, from July 2003 to November 2004. MATERIALS: Quantitative RT-PCR kit (Sigma, USA), VEGF ELISA kit (Biosource, USA), and Evans blue (Jingchun, China) were acquired for this study. METHODS: A total of 180 Wistar rats were equally and randomly assigned to 15 groups: low-altitude (500 m), middle-altitude (2 880 m), high-altitude (4 200 m), super-high-altitude (5 000 m), 1,3, 5, 7, 9, 11, 13, 15, 17, 19, and 21 days of super high-altitude exposure. Wistar rats were exposed to various altitude gradients to establish a hypoxia model. MAIN OUTCOME MEASURES: Brain water content was calculated according to the wet-to-dry weight ratio. BBB permeability to Evans blue was determined by colorimetric method. VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA. RESULTS: Brain water content, BBB permeability to Evans blue, and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude. The greatest increase was determined on day 9 upon ascending 5 000 m. Simultaneously, VEGF expression positively correlated to BBB permeability of Evans blue and brain water content (r = 0.975, 0.917, P〈 0.01). CONCLUSION: Increased VEGF protein and mRNA expression was responsible for increased BBB permeability, which may be an important mechanism underlying brain edema during high-altitude exposure.展开更多
The study was undertaken to identify the suitable mulch paper for different high-value vegetables during the winter season of November 2019 to March 2020 at the Olericulture research field of Bangladesh Agricultural R...The study was undertaken to identify the suitable mulch paper for different high-value vegetables during the winter season of November 2019 to March 2020 at the Olericulture research field of Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. The study was a randomized complete block design with 3 replications. Four vegetable varieties viz., tomato, brinjal, capsicum and broccoli and 3 mulch treatments viz., T1 = Silver over black mulch;T2 = Black mulch;T3 = No mulch were included in this study. Different vegetables responded differently with the changes of mulches irrespective of different characters. it was clear that fruit number, average fruit weight, fruit length, fruit diameter were strongly related to soil moisture content. The effect of different plastic mulches on fruit weight per plant and yield (t/ha) was significant. Mulching produced higher fruit yield per plant and fruit yield per hectare than for the control, indicating that the mulch had a positive effect in generating increased fruit yield. Silver over black plastic mulch produced the highest fruit yield viz., 98.05 t/ha (tomato), 54.11 t/ha (brinjal), 34.33 t/ha (capsicum), 26.09 t/ha (broccoli) followed by black and no mulches, while the control plot produced the lowest fruit yield.展开更多
Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentr...Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentric dislocation loops were successfully examined by Moire images. The surface morphologies of growing and as-grown diamond single crystals were observed by scanning electron microscopy (SEM). The concentric dislocation loops formation process and their effect on the diamond crystal growth mode were analyzed. It should be noted that whatever the nature of the dislocation is, should the Burgers vector of dislocation has a component at the direction normal to the growth interface, the dislocation will make the face parallel to the growth interface grow into spiral face. The presence of consecutive spiral steps on the diamond crystal surface also provides a direct evidence of the dislocation mechanism of diamond crystal growth.展开更多
Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces...Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions.展开更多
The initial growth and microstructure feature of Ag films formation were investigated, which were prepared by using the very-high-frequency(VHF)(60 MHz) magnetron sputtering. Because of the moderate energy and ver...The initial growth and microstructure feature of Ag films formation were investigated, which were prepared by using the very-high-frequency(VHF)(60 MHz) magnetron sputtering. Because of the moderate energy and very low flux density of ions impinging on the substrate, the evolutions of initial growth for Ag films formation were well controlled by varying the sputtering power. It was found that the initial growth of Ag films followed the island(Volmer—Weber, VW) growth mode, but before the island nucleation, the adsorption of Ag nanoparticles and the formation of Ag clusters dominated the growth. Therefore, the whole initial stages of Ag films formation included the adsorption of nanoparticles, the formation of clusters, the nucleation by the nanoparticles and clusters simultaneously, the islands formation, and the coalescence of islands.展开更多
<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font...<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font-family:Verdana;">japonicus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">) is one of the important economic species in the pelagic light seine fishery in China, but few studies have been reported on the age, growth and management recommendations of Japanese mackerel in the high seas of the northwest Pacific Ocean. In this study, we fitted expressions for the relationship between fork length and body weight of Japanese mackerel based on fork length and body weight data of Japanese mackerel in the high seas of the Northwest Pacific Ocean from 2018 to 2019, and calculated growth parameters and growth characteristics of Japanese mackerel von Bertalanffy growth equation by identifying otolith age data combined with the least squares method. The results showed that the relationship between fork length and body weight of Japanese mackerel in the open sea of the Northwest Pacific Ocean was W = 2.0 × 10</span><sup><span style="font-family:Verdana;">-6</span></sup><span style="font-family:Verdana;"> L</span><sup><span style="font-family:Verdana;">3.289</span></sup><span style="font-family:Verdana;"> (r = 0.9764, n = 2833);the growth parameters were L = 447.61</span><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;">, K = 0.264, t = -1.06</span><sub><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"></span></span></span></sub><span style="font-family:Verdana;">;the growth rate reached the maximum when the bodyweight growth rate was 122 g/yr, at which the inflection point age was 3 years old, the inflection point body weight was 310 g, and the inflection point length was 309 mm. We recommend 2 years of age start fishing with a fork length of 250 mm (±10 mm). The growth parameters of Japanese mackerel in the open sea of the Northwest Pacific Ocean were not significantly different from those of the Japanese mackerel population on Japan’s coast (P > 0.05), Finally, based on the knowledge of biological research and resource evaluation, we suggest that the age of opening trap should be 2 years old and the length of fork should be 250 mm (±10 mm).</span>展开更多
文摘The lifetime of G. biloba is very long, and its growth is relatively slow. However, little is known about growth-related genes in this species. We combined mRNA sequencing (RNA-Seq) with bulked segregant analysis (BSA) to fine map significant agronomic trait genes by developing polymorphism molecular markers at the transcriptome level. In this study, transcriptome sequencing of high growth (GD) and low growth (BD) samples of G. biloba half-sib families was performed. After assembling the clean reads, 601 differential expression genes were detected and 513 of them were assigned functional annotations. Single nucleotide polymorphism (SNP) analysis identified SNPs associated with 119 genes in the GD and BD groups;58 of these genes were annotated. Two Homeobox-leucine zipper protein genes were up-regulated in the GD group compared with the BD group;therefore, these are very likely related to high growth of G. biloba. This study provides molecular level data that could be used for seed selection of high growth G. biloba half-sib families for future breeding programs.
文摘Growth rate has a direct impact on the productivity of nitride LED production. Atmospheric pressure growth of GaN with a growth rate as high as 10/zm/h and also Alo.lGao.gN growth of 1μm/h by using 4 inch by 11 production scale MOVPE are described. XRD of (002) and (102) direction was 200 arcsec and 250 arcsec, respectively. Impact of the growth rate on productivity is discussed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11474248,61176127,61006085,61274013 and 61306013the Key Program for International S&T Cooperation Projects of China under Grant No 2011DFA62380the Ph.D. Programs Foundation of the Ministry of Education of China under Grant No 20105303120002
文摘High lattice match growth of InAsSb based materials on GaSb substrates is demonstrated. The present results indicate that a stable substrate temperature and the optimal flux ratios are of critical importance in achieving a homogeneous InAsSb based material composition throughout the growth period. The quality of these epilayers is assessed using a high-resolution x-ray diffraction and atomic force microscope. The mismatch between the GaSb substrate and InAsSb alloy achieves almost zero, and the rms surface roughness of InAsSb alloy achieves around 1.7A over an area of 28μm × 28μm. At the same time, the mismatches between GaSb and InAs/InAs0.73Sb0.27 superlattices (SLs) achieve approximately 100 arcsec (75 periods) and zero (300 periods), with the surface rms roughnesses of InAs/InAs0.73Sb0.27 SLs around 1.8 A (75 periods) and 2.1A (300 periods) over an area of 20 μm×20 μm, respectively. After fabrication and characterization of the devices, the dynamic resistance of the n-barrier-n InAsSb photodetector near zero bias is of the order of 10^6Ω·cm^2. At 77K, the positive-intrinsic-negative photodetectors are demonstrated in InAsSb and InAs/InAsSb SL (75 periods) materials, exhibiting fifty-percent cutoff wavelengths of 3.8μm and 5.1μm, respectively.
文摘The work was based on the relationship between the crystal structure and parameters of diamonds in the synthetic process, in which Ni Mn C powder catalyst was used. At first, the diamond crystals nucleated in a cubic octahedron morphology through controlling such synthetic parameters as temperature and pressure in a parameter region where cubic octahedron ctystals can be obtained. Then the diamond nuclei grew epitaxially into crystals with a perfect octahedron morphology through increasing the synthesis temperature and decreasing the synthesis pressure in a parameter region where octahedron crystals can be obtained.
基金Supported by grants from Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the ministry of Education,Science,and Technology(No.2016R1A2B4008376Seoul,Republic of Korea)partially supported by the Soonchunhyang University Research Fund
文摘AIM: To investigate the effects of high glucose levels and anti-vascular endothelial growth factor(VEGF) agents(bevacizumab,ranibizumab and aflibercept) on retinal pigment epithelium(RPE) cells.METHODS: ARPE-19 cells were cultured at different glucose levels(5.5 mmol/L,25 mmol/L,and 75 mmol/L).Cell viability was evaluated by MTT assay at 3d after treatment with D-glucose.Cell migration ability was measured by wound healing assay at 3d.A cell death detection kit was used to assess apoptosis at 3 and 14 d.Cell proliferation was assessed by EdU assay at 3d.The culture medium was treated with anti-VEGF agents at clinically relevant concentrations.The experiment was then repeated at a different glucose level.RESULTS: The viability and migration of ARPE-19 cells were significantly decreased in the presence of 75 mmol/L as compared to 5.5 mmol/L glucose.The percentage of TUNEL-positive cells was significantly increased and the proliferative potential was decreased with 75 mmol/L compared to 5.5 mmol/L glucose.There were no significant differences in the results between 25 mmol/L and 5.5 mmol/L glucose.In the presence of 75 mmol/L glucose,the groups treated with anti-VEGF showed decreased cell viability and proliferation and increased apoptosis.However,there were no significant differences between the anti-VEGF groups.CONCLUSION: High glucose level decreases the viability,wound healing ability,and proliferation of RPE cells,while increasing apoptosis.Furthermore,anti-VEGF agents interfered with the physiological functions of RPE cells under high-glucose conditions,accompanied by decreases in cell viability and proliferation.
基金funded by the Program for “Sanqin Scholar Innovation Teams in Shanxi Province”(SZTZ [2018] No.34)“the Research on the Mechanism,Effect Evaluation,and Policy Support of Replacing Business Tax with VAT In Promoting the Industrial Structure Upgrade of China” funded by the Humanity and Social Science Youth Foundation of the Ministry of Education of China(18YJC790078)“the Evaluation and Study of the Effect of Promoting Industrial Transformation and Upgrade of Shaanxi by Replacing Business Tax with Value-added Tax” funded by the Social Science Foundation Project of Shanxi Province(2017D037)
文摘In the transition of China’s economy from high-speed growth to high-quality growth in the new era,economic practices are oriented to fostering new growth drivers,developing new industries,and forming new models.Based on the data flow,big data effectively integrates technology,material,fund,and human resource flows and reveals new paths for the development of new growth drivers,new industries and new models.Adopting an analytical framework with"macro-meso-micro"levels,this paper elaborates on the theoretical mechanisms by which big data drives high-quality growth through efficiency improvements,upgrades of industrial structures,and business model innovations.It also explores the practical foundations for big data driven high-quality growth including technological advancements of big data,the development of big data industries,and the formulation of big data strategies.Finally,this paper proposes policy options for big data promoting high-quality growth in terms of developing digital economy,consolidating the infrastructure construction of big data,expediting convergence of big data and the real economy,advocating for a big data culture,and expanding financing options for big data.
基金Supported by the National Natural Science Foundation of China under Grant No 61434006
文摘The InGaAs/InAIAs/InP high electron mobility transistor (HEM:F) structures with lattice-matched and pseudo- morphic channels are grown by gas source molecular beam epitaxy. Effects of Si ^-doping condition and growth interruption on the electrical properties are investigated by changing the Si-cell temperature, doping time and growth process. It is found that the optimal Si ^-doping concentration (Nd) is about 5.0 x 1012 cm-2 and the use of growth interruption has a dramatic effect on the improvement of electrical properties. The material structure and crystal interface are analyzed by secondary ion mass spectroscopy and high resolution transmission elec- tron microscopy. An InGaAs/InAiAs/InP HEMT device with a gate length of lOOnm is fabricated. The device presents good pinch-off characteristics and the kink-effect of the device is trifling. In addition, the device exhibits fT = 249 GHa and fmax 〉 400 GHz.
基金Project supported by the National Natural Science Foundation of China (Nos. 90505015 and10702035)
文摘High-temperature oxidation is an important property to evaluate thermal protection materials. However, since oxidation is a complex process involving microstructure evolution, its quantitative analysis has always been a challenge. In this work, a phase field method (PFM) based on the thermodynamics theory is developed to simulate the oxidation behavior and oxidation induced growth stress. It involves microstructure evolution and solves the problem of quantitatively computational analysis for the oxidation behavior and growth stress. Employing this method, the diffusion process, oxidation performance, and stress evolution axe predicted for Fe-Cr-A1-Y alloys. The numerical results agree well with the experimental data. The linear relationship between the maximum growth stress and the environment oxygen concentration is found. PFM provides a powerful tool to investigate high-temperature oxidation in complex environments.
基金supported by the National Natural Science Foundation of China(11172304 and 11021262)the National Basic Research Program of China (2012CB937500)
文摘A model is proposed to correlate the crack growth rate and stress ratio containing very high cycle fatigue regime.The model is verified by the experimental data in literature.Then a formula is derived for the effect of mean stress on fatigue strength,and it is used to estimate the fatigue strength of a bearing steel in very high cycle fatigue regime at different stress ratios.The estimated results are also compared with those by Goodman formula.
基金Project(2002AA336072) supported by the High-tech Research and Development Program of ChinaProject(03XD14009) supported by the Program of Shanghai Subject Chief Scientist
文摘A self-made directional solidification setup was used to prepare high purity aluminum ingots of 100mm in diameter. The morphology of the growth interface was detected by SEM and AFM, and the grain lattice orientation was detected by XRD. The results indicate that the grains suffer competitive growth under any conditions in experiments. The lattice orientation of the preferred grains is determined by the flow field above the solid-liquid interface. The horizontal lattice position does not change during the growth process. However, the lattice orientation in the growth direction varies with the growth velocity and approaches to [100] gradually during the growth process.
基金Supported by:the Tackle Key Problem in Science and Technology during the "11~(th) Five-Year Plan" Period of Chinese PLA,No.06G030
文摘BACKGROUND: Many studies have evaluated the role of vascular endothelial growth factor (VEGF) in traumatic brain edema and hemorrhagic brain edema. OBJECTIVE: To observe the effects of VEGF expression on permeability of the blood-brain barrier (BBB) during high-altitude and hypoxia exposure, and to investigate the correlation between VEGF expression and BBB permeability with regard to Evans blue staining and brain edema during high-altitude exposure. DESIGN, TIME AND SETTING: The randomized, controlled, animal study was performed at the Tanggula Etape, Central Laboratory of Chengdu Medical College, and Central Laboratory of General Hospital of Chengdu Military Area Command of Chinese PLA, China, from July 2003 to November 2004. MATERIALS: Quantitative RT-PCR kit (Sigma, USA), VEGF ELISA kit (Biosource, USA), and Evans blue (Jingchun, China) were acquired for this study. METHODS: A total of 180 Wistar rats were equally and randomly assigned to 15 groups: low-altitude (500 m), middle-altitude (2 880 m), high-altitude (4 200 m), super-high-altitude (5 000 m), 1,3, 5, 7, 9, 11, 13, 15, 17, 19, and 21 days of super high-altitude exposure. Wistar rats were exposed to various altitude gradients to establish a hypoxia model. MAIN OUTCOME MEASURES: Brain water content was calculated according to the wet-to-dry weight ratio. BBB permeability to Evans blue was determined by colorimetric method. VEGF mRNA and protein levels in brain tissues were detected using RT-PCR and double-antibody sandwich ELISA. RESULTS: Brain water content, BBB permeability to Evans blue, and VEGF mRNA and protein levels in brain tissues increased with increasing altitude and prolonged exposure to altitude. The greatest increase was determined on day 9 upon ascending 5 000 m. Simultaneously, VEGF expression positively correlated to BBB permeability of Evans blue and brain water content (r = 0.975, 0.917, P〈 0.01). CONCLUSION: Increased VEGF protein and mRNA expression was responsible for increased BBB permeability, which may be an important mechanism underlying brain edema during high-altitude exposure.
文摘The study was undertaken to identify the suitable mulch paper for different high-value vegetables during the winter season of November 2019 to March 2020 at the Olericulture research field of Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. The study was a randomized complete block design with 3 replications. Four vegetable varieties viz., tomato, brinjal, capsicum and broccoli and 3 mulch treatments viz., T1 = Silver over black mulch;T2 = Black mulch;T3 = No mulch were included in this study. Different vegetables responded differently with the changes of mulches irrespective of different characters. it was clear that fruit number, average fruit weight, fruit length, fruit diameter were strongly related to soil moisture content. The effect of different plastic mulches on fruit weight per plant and yield (t/ha) was significant. Mulching produced higher fruit yield per plant and fruit yield per hectare than for the control, indicating that the mulch had a positive effect in generating increased fruit yield. Silver over black plastic mulch produced the highest fruit yield viz., 98.05 t/ha (tomato), 54.11 t/ha (brinjal), 34.33 t/ha (capsicum), 26.09 t/ha (broccoli) followed by black and no mulches, while the control plot produced the lowest fruit yield.
基金Thi work was supported by the Nstional Natural ScienceFoundation of China (Grant. No 593T1027).
文摘Some dislocations, which are generated in the diamond single crystal during the diamond crystal growth from Fe-Ni-C system, may affect diamond crystal growth mode at high temperature-high pressure (HPHT). The concentric dislocation loops were successfully examined by Moire images. The surface morphologies of growing and as-grown diamond single crystals were observed by scanning electron microscopy (SEM). The concentric dislocation loops formation process and their effect on the diamond crystal growth mode were analyzed. It should be noted that whatever the nature of the dislocation is, should the Burgers vector of dislocation has a component at the direction normal to the growth interface, the dislocation will make the face parallel to the growth interface grow into spiral face. The presence of consecutive spiral steps on the diamond crystal surface also provides a direct evidence of the dislocation mechanism of diamond crystal growth.
基金Supported by the Yangtze Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT_17R81)the Technology Support Project of Tianjin(No.16YFZCNC00810)
文摘Biofloc technology has been applied successfully in the intensive aquaculture of several fish and shrimp species. The growth of heterotrophic microorganisms can be stimulated through adding extra carbon, which reduces the nitrogen level in the water and provides microbial protein to the animals. However, most of the studies and practical applications have been conducted in freshwater and marine environment. This paper focused on brine shrimp Artemia that lives in high salinity environment together with other halophilic or halotolerant microorganisms. The effect of carbon supplementation on Artemia growth, water quality, and microbial diversity of biofl ocs was studied in the closed culture condition without any water exchange. The salinity of the culture medium was 100. A 24-d culture trial was conducted through supplementing sucrose at carbon/nitrogen (C/N) ratio of 5, 15, and 30 (Su5, Su15, and Su30), respectively. The culture without adding sucrose was used as a control. Artemia was fed formulated feed at a feeding ration of 60% recommended feeding level. The results showed that sucrose supplementation at higher C/N ratio (15 and 30) signifi cantly improved the Artemia survival, growth and water quality ( P <0.05). Addition of sucrose at C/N ratio of 15 and 30 significantly increased biofloc volume (BFV)( P <0.05). The Illumina MiSeq sequencing analysis showed that supplementing carbon at C/N ratio of 15 had a better total bacterial diversity and richness, and shaped the microbial composition at genera level. This study should provide information for studying the mechanism of biofloc technology and its application in high salinity culture conditions.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11675118 and 11275136)
文摘The initial growth and microstructure feature of Ag films formation were investigated, which were prepared by using the very-high-frequency(VHF)(60 MHz) magnetron sputtering. Because of the moderate energy and very low flux density of ions impinging on the substrate, the evolutions of initial growth for Ag films formation were well controlled by varying the sputtering power. It was found that the initial growth of Ag films followed the island(Volmer—Weber, VW) growth mode, but before the island nucleation, the adsorption of Ag nanoparticles and the formation of Ag clusters dominated the growth. Therefore, the whole initial stages of Ag films formation included the adsorption of nanoparticles, the formation of clusters, the nucleation by the nanoparticles and clusters simultaneously, the islands formation, and the coalescence of islands.
文摘<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font-family:Verdana;">japonicus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">) is one of the important economic species in the pelagic light seine fishery in China, but few studies have been reported on the age, growth and management recommendations of Japanese mackerel in the high seas of the northwest Pacific Ocean. In this study, we fitted expressions for the relationship between fork length and body weight of Japanese mackerel based on fork length and body weight data of Japanese mackerel in the high seas of the Northwest Pacific Ocean from 2018 to 2019, and calculated growth parameters and growth characteristics of Japanese mackerel von Bertalanffy growth equation by identifying otolith age data combined with the least squares method. The results showed that the relationship between fork length and body weight of Japanese mackerel in the open sea of the Northwest Pacific Ocean was W = 2.0 × 10</span><sup><span style="font-family:Verdana;">-6</span></sup><span style="font-family:Verdana;"> L</span><sup><span style="font-family:Verdana;">3.289</span></sup><span style="font-family:Verdana;"> (r = 0.9764, n = 2833);the growth parameters were L = 447.61</span><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;">, K = 0.264, t = -1.06</span><sub><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"></span></span></span></sub><span style="font-family:Verdana;">;the growth rate reached the maximum when the bodyweight growth rate was 122 g/yr, at which the inflection point age was 3 years old, the inflection point body weight was 310 g, and the inflection point length was 309 mm. We recommend 2 years of age start fishing with a fork length of 250 mm (±10 mm). The growth parameters of Japanese mackerel in the open sea of the Northwest Pacific Ocean were not significantly different from those of the Japanese mackerel population on Japan’s coast (P > 0.05), Finally, based on the knowledge of biological research and resource evaluation, we suggest that the age of opening trap should be 2 years old and the length of fork should be 250 mm (±10 mm).</span>