[Objective] The aim was to research and analyze characters and related correlation of indica hybrid rice containing high amylose. [Method] In the research, major characters of 16 species of groups of {ndica hybrid ric...[Objective] The aim was to research and analyze characters and related correlation of indica hybrid rice containing high amylose. [Method] In the research, major characters of 16 species of groups of {ndica hybrid rice and the correlation were explored in rice belts in Sichuan in 2011. [Result] The variation of chalkiness degree was the highest at 26.8%, followed by rate of head rice at 22.89%; varia- tions of head rice rate and chalkiness degree were lower at 0.72% and 2.61%. In addition, rate of unpolished rice was of significantly negative correlation with chalki- ness degree; rate of chalky rice was of extremely positive correlation with chalkiness degree and gel consistency; chalkiness degree was of significantly positive correla- tion with gel consistency; gel consistency was of significantly negative correlation with protein content; amylose content was of insignificant correlation with gel consis- tency (r=0.166 9) of the 16 hybrid groups. These indicated that gel consistency would be still high as the content of amylose grows (AC≥25%). For example, when the content of anylose in Chuanxiang 29A/Luhui 37, Kangfeng AJ6684, and Lefeng A/SR536 exceeded 27%, the gel consistency was over 80 mm in the research. [Conclusion] The research provides references for improvement of amylose content in breeding hybrid rice.展开更多
A design of a linear and fully-balanced operational transconductanee amplifier (OTA) with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor (FET)...A design of a linear and fully-balanced operational transconductanee amplifier (OTA) with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor (FET) cas- cade and its DC I-V characteristics,the third-order coefficient g3 hasbeen well compensated with a parallel FET operated in the triode region, which has even-odd symmetries between the boundary of the saturation and triode region. Therefore,for high linearity,a simple solution is obtained to increase input signal amplitude in saturation for the application of OTA continuous-time filters. A negative resistance load (NRL) technique is used for the compensation of parasitic output resistance and an achievement of a high DC-gain of the OTA circuits without extra internal nodes. Additionally, derivations from the ideal -90° phase of the gm-C integrator mainly due to a finite DC gain and parasitic poles will be avoided in the frequency range of interest. HSPICE simulation shows that the total harmonic distortion at 1Vp-p is less than 1% from a single 3.3V supply. As an application of the VHF CMOS OTA,a second-order OTA-C bandpass filter is fabricated using a 0. 18μm CMOS process with two kinds of gate-oxide layers, which has achieved a center frequency of 20MHz,a 3dB-bandwidth of 180kHz,and a quality factor of 110.展开更多
Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) +...Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.展开更多
When a seismic wave propagates through subsurface viscoelastic media,the formation absorbs the high-frequency energy of the seismic wave more strongly than the low-frequency energy.As the depth and the off set increas...When a seismic wave propagates through subsurface viscoelastic media,the formation absorbs the high-frequency energy of the seismic wave more strongly than the low-frequency energy.As the depth and the off set increase,the diff erence between the logarithmic spectral areas with high and low frequencies gradually increases.Based on this seismic wave characteristic,we have developed a novel Q-estimation method based on logarithmic spectral area diff erence of high and low frequencies(referred to as the LSAD_LH method).In this paper,we derive the theoretical relationship between the Q value and difference of logarithmic spectral areas with high and low frequencies and prove the applicability of the LSAD_LH method using a single-layer medium numerical model.To verify the sensitivity of the LSAD_LH method to bandwidth selection and noise,we compare the LSAD_LH method with two credible methods—the logarithmic spectral ratio(LSR)and logarithmic spectral area diff erence(LSAD)methods using a synthetic model containing the random noise.The results demonstrate that the LSAD_LH method is not highly dependent on bandwidth,and in terms of noise immunity,it is signifi cantly better than the LSR method and has the same advantages as the LSAD method.To further highlight the advantages of the LSAD_LH method,we apply the LSAD_LH and LSAD methods to the vertical seismic profi ling(VSP)numerical simulation of the multilayer media and the fi eld zero-off set VSP data.The application of the two cases proves the applicability of the LSAD_LH method and the accuracy of the high Q-value estimation relative to the LSAD method.Moreover,via the transmission coeffi cient,the LSAD_LH method overcomes the weakness of the LSAD method.展开更多
Comparative test of 4 Ganoderma lucidum varieties from different sources showed that the mycelium of Chizhi 1 grew fast with thick and dense hyphae,round and solid cap,and high spore powder yield.Chizhi 1 was proved t...Comparative test of 4 Ganoderma lucidum varieties from different sources showed that the mycelium of Chizhi 1 grew fast with thick and dense hyphae,round and solid cap,and high spore powder yield.Chizhi 1 was proved to be an excellent variety because of its strong resistance and high spore powder yield.Different cultivation materials were chosen and combined to form 3 cultivation formulations.The results showed that Formulation(3),in which basswood was soaked in nutrient solution for 24 h,presented fast mycelial growth and high spore powder output,and therefore was proved to be a high-yield formulation of Ganoderma lucidum spore powder.展开更多
The new kiwifruit variety 'Fengyue' has bigger,avg.90g,max.127.8g fruit with beautiful appearance and good storage tolerance.The fruit is fine and tender in pulp texture with a thick sweet taste and rich refre...The new kiwifruit variety 'Fengyue' has bigger,avg.90g,max.127.8g fruit with beautiful appearance and good storage tolerance.The fruit is fine and tender in pulp texture with a thick sweet taste and rich refreshing aroma in addition to over 15% soluble solids content.This variety matures in September,Changsha,and has a high fruit setting percentage.Fruiters should pay great attention to fertilizer or water management,pruning,and flower or fruit thinning in cultivating'Fengyue展开更多
OBJECTIVE: To determine the effect of hypercholsterolemia induced by a high-lipid diet on glomerulosclerosis. METHODS: Twenty nephrotic syndrome (NS) Wistar rats administrated adriamycin (ADR) with a single intravenou...OBJECTIVE: To determine the effect of hypercholsterolemia induced by a high-lipid diet on glomerulosclerosis. METHODS: Twenty nephrotic syndrome (NS) Wistar rats administrated adriamycin (ADR) with a single intravenous dose of 5 mg/kg body weight, were divided into the standard and high-lipid chow groups. Another 20 weight-matched non-NS rats that received a vehicle alone were grouped as control. Urinary protein excretion and serum cholesterol were assayed; image analysis and techniques of pathology, immunohistochemistry, and molecular biology were used to determine morphological changes in glomeruli and the production of glomerular mesangial matrices in different groups. RESULTS: The serum total cholesterol level was significantly higher in rats with high-lipid chow in both non-NS [(2.2 +/- 0.3) g/L vs. (0.9 +/- 0.1) g/L, P展开更多
Twenty-eight sweet sorghum (Sorghum bicolor (L.) Moench) genotypes of the different ecological and geographic origins: Kazakhstan, Russia, India, Uzbekistan, and China were tested in the high latitude rainfed con...Twenty-eight sweet sorghum (Sorghum bicolor (L.) Moench) genotypes of the different ecological and geographic origins: Kazakhstan, Russia, India, Uzbekistan, and China were tested in the high latitude rainfed conditions of northern Kazakhstan. The genotypes demonstrated high biomass production (up to 100 t'ha1 and more). The genotypes ripening to full reproductive seeds were selected for seed production and introduction in the northern Kazakhstan. Lactic acid bacteria Lactobacillus plantarum S-1, Streptococcus thermophilus F-1 and Lactococcus lactis F-4 essentially enhance the fermentation process, suppressing undesirable microbiological processes, reducing the loss of nutrient compounds, accelerating in 2 times maturation ensilage process and providing higher quality of the feed product.展开更多
Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local o...Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local or global uncertainty by honouring spatial correlation structures.The sequential Gaussian conditional simulation was used to assess uncertainty of grade estimates and illustrate simulated models in Sivas gold deposit,Turkey.In situ variability and risk quantification of the gold grade were assessed by probabilistic approach based on the sequential Gaussian simulations to yield a series of conditional maps characterized by equally probable spatial distribution of the gold grade for the study area.The simulation results were validated by a number of tests such as descriptive statistics,histogram,variogram and contour map reproductions.The case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variable such as the gold grade variability and distribution.The simulated models can be incorporated into exploration,exploitation and scheduling of the gold deposit.展开更多
In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q, adaptive fuzzy control was studied with a self-fabricated ultrasonic plasti...In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q, adaptive fuzzy control was studied with a self-fabricated ultrasonic plastic welding machine. At first, relations between amplitude of vibration and frequency as well as main loop current and amplitude of vibration were analyzed. From this analysis, we deduced that frequency tracking process of the vibration system can be concluded as an optimizing problem of one dimensional fluctuant extremum of main loop current in vibration system. Then a method of self-optimizing fuzzy control, used for the realization of automatic frequency tracking in vibration system, is presented on the basis of serf-optimizing adaptive control approach and fuzzy control approach. The result of experiments shows that the fuzzy self-optimizing method can solve the problem of tracking frequency drift very well. Response time of tracking in the system is less than 50 ms, which basically meets the requirements of frequency tracking in ultrasonic plastic welding machine.展开更多
In order to reveal difference of phenolic substances and the content in the different varieties of pomegranate fruit and different mature period. The article uses 3 different fruit color phenotype (white, red, green...In order to reveal difference of phenolic substances and the content in the different varieties of pomegranate fruit and different mature period. The article uses 3 different fruit color phenotype (white, red, green) pomegranate cultivars as materials, the peel were determined by high performance liquid chromatography respectively (composition and content of phenolic compounds in the seeds and juice). Results shows that the varieties of pomegranate peel and seeds were detected in 13 kinds of phenols, juice was detected in 12 type, and which did not detect epicatechin. At the same time, there was a significant difference in different parts of different varieties of pomegranate phenolic content.展开更多
Agriculture is the basis of national economy. Through science and technology and the intensive utilization of land, great achievements have been made in agriculture. However, some agro-ecological and environmental pro...Agriculture is the basis of national economy. Through science and technology and the intensive utilization of land, great achievements have been made in agriculture. However, some agro-ecological and environmental problems are rising. Because of this, people have begun to reflect on agricultural developmental policy, patterns and technologies, and put forward new thoughts for agricultural development. In the late 20th century, China’s ecologists and agronomists co-sponsored the concept of ecological agriculture with Chinese characteristics. Its essence includes a series of concepts such as integration, coordination, circulation and regeneration within agroecosystems or within systems of agriculture production, processing and marketing. After nearly 30 years of practice and development, ecological agriculture in China has achieved remarkable outcomes. However, current eco-agriculture development is unsatisfactory due to the following two factors: (i) A lack of research and accounting across a variety of agro-ecosystem service functions; (ii) It is difficult to obtain remarkable economic benefits because of the lack of market-oriented guidance, scale management, specialized production and brand popularization for the traditional autarkic peasant economy. In order to further promote the development of ecological agriculture it is necessary to engage in serious reflection on ecological agriculture in China and arrive at new understandings about circular economy, multifunctional agriculture, high-quality agriculture, industrial development, integration of the traditional essence and modern technology, and finally, the sustainable development of rural areas.展开更多
We design a channel-drop filter(CDF)with a linear gradient microcavity in a two-dimensional(2D)photonic crystal(PC).The model of three-port CDF with reflector is used to achieve high quality factor(Q-factor)and 100%ch...We design a channel-drop filter(CDF)with a linear gradient microcavity in a two-dimensional(2D)photonic crystal(PC).The model of three-port CDF with reflector is used to achieve high quality factor(Q-factor)and 100%channel-drop efficiency.The research indicates that adjusting the distance between reference plane and reflector can simultaneously influence the Q-factor due to coupling to a bus waveguide and the phase retardation occurring in the round trip between a microcavity and a reflector.The calculation results of 2D finite-difference time-domain(FDTD)method show that the designed filter can achieve the drop efficiency of 96.7%and ultra-high Q-factor with an ultra-small modal volume.展开更多
High-throughput(HTP)experiments play key roles in accelerating the discovery of advanced materials,but the HTP preparation and characterization,especially for bulk samples,are extremely difficult.In this work,we devel...High-throughput(HTP)experiments play key roles in accelerating the discovery of advanced materials,but the HTP preparation and characterization,especially for bulk samples,are extremely difficult.In this work,we developed a novel and general strategy for HTP screening of high-performance bulk thermoelectric materials.The performed fullchain HTP experiments cover rapid synthesis of the bulk sample with quasi-continuous composition,microarea phase identification and structure analysis,and measurement of the spatial distribution of the sample composition,electrical and thermal transport properties.According to our experiments,bulk Bi_(2-x)Sb_(x)Te_(3)(x=1-2)and Bi_(2)Te_(3-x)Se_(x)(x=0-1.5)samples with quasi-continuous compositions have been rapidly fabricated by this HTP method.The target thermoelectric materials with the best Sb/Bi and Te/Se ratios are successfully screened out based on subsequent HTP characterization results,demonstrating that this HTP technique is effective in speeding up the exploration of novel high-performance thermoelectric materials.展开更多
Most economically important tungsten(W)deposits are of magmatic-hydrothermal origin.The species and partitioning of W during fluid exsolution,considered to be the controlling factors for the formation of ore deposits,...Most economically important tungsten(W)deposits are of magmatic-hydrothermal origin.The species and partitioning of W during fluid exsolution,considered to be the controlling factors for the formation of ore deposits,are thus of great significance to investigate.However,this issue has not been well addressed mainly due to the significant difference in reported partition coefficients(e.g.,from strongly incompatible to strongly compatible)between fluid and melt(D_(W)^(fluid/melt)).Here,we used an in situ Raman spectroscopic approach to describe the W speciation,and to quantitatively determine the Dfluid/melt of individual and total W species in granite melts and coexisting Na2WO4 solutions at elevated temperatures(T;700–800C)and pressures(P;0.35–1.08 GPa).Results show that WO_(4)^(2-)and HWO4are predominant W species,and the fractions of these two species are similar in melt and coexisting fluid.The partitioning behaviors of WO_(4)^(2-)and HWO4are comparable,exhibiting strong enrichment in the fluid.The total DW fluid/melt ranges from 8.6 to 37.1.Specifically,DW fluid/melt decreases with rising T–P,indicating that shallow exsolution favors enrichment of W in evolved fluids.Furthermore,Rayleigh fractionation modeling based on the obtained D_(W)^(fluid/melt)data was used to describe the fluid exsolution processes.Our results strongly support that fluid exsolution can serve as an important mechanism to generate W-rich oreforming fluids.This study also indicates that in situ approach can be used to further investigate the geochemical behavior of ore-forming elements during the magmatic-hydrothermal transition,especially for rare metals associated with granite and pegmatite.展开更多
基金Supported by Sichuan Financial Genetic Engineering Program of the 12th Five-year Plan(2011JYGC11-029)National Modern Agricultural and Industrial Technology System+1 种基金Sichuan Rice Breeding Key Program of the 12th Five-year Plan(2011NZ-0098-1)Luzhou Key Project for Science and Technology Development(2011-N-09)~~
文摘[Objective] The aim was to research and analyze characters and related correlation of indica hybrid rice containing high amylose. [Method] In the research, major characters of 16 species of groups of {ndica hybrid rice and the correlation were explored in rice belts in Sichuan in 2011. [Result] The variation of chalkiness degree was the highest at 26.8%, followed by rate of head rice at 22.89%; varia- tions of head rice rate and chalkiness degree were lower at 0.72% and 2.61%. In addition, rate of unpolished rice was of significantly negative correlation with chalki- ness degree; rate of chalky rice was of extremely positive correlation with chalkiness degree and gel consistency; chalkiness degree was of significantly positive correla- tion with gel consistency; gel consistency was of significantly negative correlation with protein content; amylose content was of insignificant correlation with gel consis- tency (r=0.166 9) of the 16 hybrid groups. These indicated that gel consistency would be still high as the content of amylose grows (AC≥25%). For example, when the content of anylose in Chuanxiang 29A/Luhui 37, Kangfeng AJ6684, and Lefeng A/SR536 exceeded 27%, the gel consistency was over 80 mm in the research. [Conclusion] The research provides references for improvement of amylose content in breeding hybrid rice.
文摘A design of a linear and fully-balanced operational transconductanee amplifier (OTA) with improved high DC gain and wide bandwidth is presented. Derivative from a single common-source field effect transistor (FET) cas- cade and its DC I-V characteristics,the third-order coefficient g3 hasbeen well compensated with a parallel FET operated in the triode region, which has even-odd symmetries between the boundary of the saturation and triode region. Therefore,for high linearity,a simple solution is obtained to increase input signal amplitude in saturation for the application of OTA continuous-time filters. A negative resistance load (NRL) technique is used for the compensation of parasitic output resistance and an achievement of a high DC-gain of the OTA circuits without extra internal nodes. Additionally, derivations from the ideal -90° phase of the gm-C integrator mainly due to a finite DC gain and parasitic poles will be avoided in the frequency range of interest. HSPICE simulation shows that the total harmonic distortion at 1Vp-p is less than 1% from a single 3.3V supply. As an application of the VHF CMOS OTA,a second-order OTA-C bandpass filter is fabricated using a 0. 18μm CMOS process with two kinds of gate-oxide layers, which has achieved a center frequency of 20MHz,a 3dB-bandwidth of 180kHz,and a quality factor of 110.
文摘Sweet cherries ( Prunus avium L. cv. Napoleon) were stored in controlled atmospheres (CA) of high O(2) (70% O(2) + 0% CO(2)) or high CO(2) (5% O(2) + 10% CO(2)), in modified atmosphere package (MAP, (13% - 18%) O(2) + (2% -4%) CO(2)) and in air (control) at 1 degreesC to investigate the effects of different O(2) and CO(2) concentrations on physiological properties, quality and storability of the fruits during storage. The results indicated that compared with other treatments, CA with high O(2) concentration decreased fruit decay and ethanol content, but increased the accumulation of malondialdehyde (MDA) and stimulated browning. CA with high CO(2) concentration inhibited polyphenol oxidase (PPO) activity, reduced MDA content, maintained vitamin C content and firmness, decreased fruit decay and browning. Soluble solids contents (SSC) were not significantly affected by different atmosphere treatments. 'Napoleon' fruits stored in 5% O(2) + 10% CO(2) for as long as 80 d were of good quality, but only 40, 20 and 30 d stored in MAP, 70% O(2) + 0% CO(2) and air, re-spectively.
基金National Nature Science Foundation of China(Grant No.U1562110)。
文摘When a seismic wave propagates through subsurface viscoelastic media,the formation absorbs the high-frequency energy of the seismic wave more strongly than the low-frequency energy.As the depth and the off set increase,the diff erence between the logarithmic spectral areas with high and low frequencies gradually increases.Based on this seismic wave characteristic,we have developed a novel Q-estimation method based on logarithmic spectral area diff erence of high and low frequencies(referred to as the LSAD_LH method).In this paper,we derive the theoretical relationship between the Q value and difference of logarithmic spectral areas with high and low frequencies and prove the applicability of the LSAD_LH method using a single-layer medium numerical model.To verify the sensitivity of the LSAD_LH method to bandwidth selection and noise,we compare the LSAD_LH method with two credible methods—the logarithmic spectral ratio(LSR)and logarithmic spectral area diff erence(LSAD)methods using a synthetic model containing the random noise.The results demonstrate that the LSAD_LH method is not highly dependent on bandwidth,and in terms of noise immunity,it is signifi cantly better than the LSR method and has the same advantages as the LSAD method.To further highlight the advantages of the LSAD_LH method,we apply the LSAD_LH and LSAD methods to the vertical seismic profi ling(VSP)numerical simulation of the multilayer media and the fi eld zero-off set VSP data.The application of the two cases proves the applicability of the LSAD_LH method and the accuracy of the high Q-value estimation relative to the LSAD method.Moreover,via the transmission coeffi cient,the LSAD_LH method overcomes the weakness of the LSAD method.
文摘Comparative test of 4 Ganoderma lucidum varieties from different sources showed that the mycelium of Chizhi 1 grew fast with thick and dense hyphae,round and solid cap,and high spore powder yield.Chizhi 1 was proved to be an excellent variety because of its strong resistance and high spore powder yield.Different cultivation materials were chosen and combined to form 3 cultivation formulations.The results showed that Formulation(3),in which basswood was soaked in nutrient solution for 24 h,presented fast mycelial growth and high spore powder output,and therefore was proved to be a high-yield formulation of Ganoderma lucidum spore powder.
文摘The new kiwifruit variety 'Fengyue' has bigger,avg.90g,max.127.8g fruit with beautiful appearance and good storage tolerance.The fruit is fine and tender in pulp texture with a thick sweet taste and rich refreshing aroma in addition to over 15% soluble solids content.This variety matures in September,Changsha,and has a high fruit setting percentage.Fruiters should pay great attention to fertilizer or water management,pruning,and flower or fruit thinning in cultivating'Fengyue
文摘OBJECTIVE: To determine the effect of hypercholsterolemia induced by a high-lipid diet on glomerulosclerosis. METHODS: Twenty nephrotic syndrome (NS) Wistar rats administrated adriamycin (ADR) with a single intravenous dose of 5 mg/kg body weight, were divided into the standard and high-lipid chow groups. Another 20 weight-matched non-NS rats that received a vehicle alone were grouped as control. Urinary protein excretion and serum cholesterol were assayed; image analysis and techniques of pathology, immunohistochemistry, and molecular biology were used to determine morphological changes in glomeruli and the production of glomerular mesangial matrices in different groups. RESULTS: The serum total cholesterol level was significantly higher in rats with high-lipid chow in both non-NS [(2.2 +/- 0.3) g/L vs. (0.9 +/- 0.1) g/L, P
文摘Twenty-eight sweet sorghum (Sorghum bicolor (L.) Moench) genotypes of the different ecological and geographic origins: Kazakhstan, Russia, India, Uzbekistan, and China were tested in the high latitude rainfed conditions of northern Kazakhstan. The genotypes demonstrated high biomass production (up to 100 t'ha1 and more). The genotypes ripening to full reproductive seeds were selected for seed production and introduction in the northern Kazakhstan. Lactic acid bacteria Lactobacillus plantarum S-1, Streptococcus thermophilus F-1 and Lactococcus lactis F-4 essentially enhance the fermentation process, suppressing undesirable microbiological processes, reducing the loss of nutrient compounds, accelerating in 2 times maturation ensilage process and providing higher quality of the feed product.
文摘Risk quantification in grade is critical for mine design and planning.Grade uncertainty is assessed using multiple grade realizations,from geostatistical conditional simulations,which are effective to evaluate local or global uncertainty by honouring spatial correlation structures.The sequential Gaussian conditional simulation was used to assess uncertainty of grade estimates and illustrate simulated models in Sivas gold deposit,Turkey.In situ variability and risk quantification of the gold grade were assessed by probabilistic approach based on the sequential Gaussian simulations to yield a series of conditional maps characterized by equally probable spatial distribution of the gold grade for the study area.The simulation results were validated by a number of tests such as descriptive statistics,histogram,variogram and contour map reproductions.The case study demonstrates the efficiency of the method in assessing risk associated with geological and engineering variable such as the gold grade variability and distribution.The simulated models can be incorporated into exploration,exploitation and scheduling of the gold deposit.
基金Sponsored by the Natural Science Foundation of Shanghai Education Committee(Grant No.05LZ13)Shanghai Leading Academic Discipline Project(Grant No. P1303)Shanghai Elitist Project(Grant No.04YQHB126)
文摘In order to realize automatic tracking drift of resonance frequency of ultrasonic vibration system with high power and high quality factor Q, adaptive fuzzy control was studied with a self-fabricated ultrasonic plastic welding machine. At first, relations between amplitude of vibration and frequency as well as main loop current and amplitude of vibration were analyzed. From this analysis, we deduced that frequency tracking process of the vibration system can be concluded as an optimizing problem of one dimensional fluctuant extremum of main loop current in vibration system. Then a method of self-optimizing fuzzy control, used for the realization of automatic frequency tracking in vibration system, is presented on the basis of serf-optimizing adaptive control approach and fuzzy control approach. The result of experiments shows that the fuzzy self-optimizing method can solve the problem of tracking frequency drift very well. Response time of tracking in the system is less than 50 ms, which basically meets the requirements of frequency tracking in ultrasonic plastic welding machine.
文摘In order to reveal difference of phenolic substances and the content in the different varieties of pomegranate fruit and different mature period. The article uses 3 different fruit color phenotype (white, red, green) pomegranate cultivars as materials, the peel were determined by high performance liquid chromatography respectively (composition and content of phenolic compounds in the seeds and juice). Results shows that the varieties of pomegranate peel and seeds were detected in 13 kinds of phenols, juice was detected in 12 type, and which did not detect epicatechin. At the same time, there was a significant difference in different parts of different varieties of pomegranate phenolic content.
基金National Public Benefit (Envrionmental) Research Foundation of China (201009020)Global Envrionment Facility (No. GCP/GLO/212/GEF)
文摘Agriculture is the basis of national economy. Through science and technology and the intensive utilization of land, great achievements have been made in agriculture. However, some agro-ecological and environmental problems are rising. Because of this, people have begun to reflect on agricultural developmental policy, patterns and technologies, and put forward new thoughts for agricultural development. In the late 20th century, China’s ecologists and agronomists co-sponsored the concept of ecological agriculture with Chinese characteristics. Its essence includes a series of concepts such as integration, coordination, circulation and regeneration within agroecosystems or within systems of agriculture production, processing and marketing. After nearly 30 years of practice and development, ecological agriculture in China has achieved remarkable outcomes. However, current eco-agriculture development is unsatisfactory due to the following two factors: (i) A lack of research and accounting across a variety of agro-ecosystem service functions; (ii) It is difficult to obtain remarkable economic benefits because of the lack of market-oriented guidance, scale management, specialized production and brand popularization for the traditional autarkic peasant economy. In order to further promote the development of ecological agriculture it is necessary to engage in serious reflection on ecological agriculture in China and arrive at new understandings about circular economy, multifunctional agriculture, high-quality agriculture, industrial development, integration of the traditional essence and modern technology, and finally, the sustainable development of rural areas.
基金supported by the Natural Science Foundation of the Higher Education Institutions of Guangxi Province in China(No.201202ZD010)
文摘We design a channel-drop filter(CDF)with a linear gradient microcavity in a two-dimensional(2D)photonic crystal(PC).The model of three-port CDF with reflector is used to achieve high quality factor(Q-factor)and 100%channel-drop efficiency.The research indicates that adjusting the distance between reference plane and reflector can simultaneously influence the Q-factor due to coupling to a bus waveguide and the phase retardation occurring in the round trip between a microcavity and a reflector.The calculation results of 2D finite-difference time-domain(FDTD)method show that the designed filter can achieve the drop efficiency of 96.7%and ultra-high Q-factor with an ultra-small modal volume.
基金supported by the National Key Research and Development Program of China(2018YFB0703600 and 2018YFA0702100)the National Natural Science Foundation of China(51772186,51632005 and 51371194)。
文摘High-throughput(HTP)experiments play key roles in accelerating the discovery of advanced materials,but the HTP preparation and characterization,especially for bulk samples,are extremely difficult.In this work,we developed a novel and general strategy for HTP screening of high-performance bulk thermoelectric materials.The performed fullchain HTP experiments cover rapid synthesis of the bulk sample with quasi-continuous composition,microarea phase identification and structure analysis,and measurement of the spatial distribution of the sample composition,electrical and thermal transport properties.According to our experiments,bulk Bi_(2-x)Sb_(x)Te_(3)(x=1-2)and Bi_(2)Te_(3-x)Se_(x)(x=0-1.5)samples with quasi-continuous compositions have been rapidly fabricated by this HTP method.The target thermoelectric materials with the best Sb/Bi and Te/Se ratios are successfully screened out based on subsequent HTP characterization results,demonstrating that this HTP technique is effective in speeding up the exploration of novel high-performance thermoelectric materials.
基金supported by the National Natural Science Foundation of China(41922023,41830428,42173038,41973055,and 42130109)the Research Funds for the Frontiers Science Center for Critical Earth Material Cycling(Nanjing University,China)the Fundamental Research Funds for the Central Universities,China(2022300192).
文摘Most economically important tungsten(W)deposits are of magmatic-hydrothermal origin.The species and partitioning of W during fluid exsolution,considered to be the controlling factors for the formation of ore deposits,are thus of great significance to investigate.However,this issue has not been well addressed mainly due to the significant difference in reported partition coefficients(e.g.,from strongly incompatible to strongly compatible)between fluid and melt(D_(W)^(fluid/melt)).Here,we used an in situ Raman spectroscopic approach to describe the W speciation,and to quantitatively determine the Dfluid/melt of individual and total W species in granite melts and coexisting Na2WO4 solutions at elevated temperatures(T;700–800C)and pressures(P;0.35–1.08 GPa).Results show that WO_(4)^(2-)and HWO4are predominant W species,and the fractions of these two species are similar in melt and coexisting fluid.The partitioning behaviors of WO_(4)^(2-)and HWO4are comparable,exhibiting strong enrichment in the fluid.The total DW fluid/melt ranges from 8.6 to 37.1.Specifically,DW fluid/melt decreases with rising T–P,indicating that shallow exsolution favors enrichment of W in evolved fluids.Furthermore,Rayleigh fractionation modeling based on the obtained D_(W)^(fluid/melt)data was used to describe the fluid exsolution processes.Our results strongly support that fluid exsolution can serve as an important mechanism to generate W-rich oreforming fluids.This study also indicates that in situ approach can be used to further investigate the geochemical behavior of ore-forming elements during the magmatic-hydrothermal transition,especially for rare metals associated with granite and pegmatite.