In order to solve the problems that the current synthetic aperture radar(SAR)image target detection method cannot adapt to targets of different sizes,and the complex image background leads to low detection accuracy,an...In order to solve the problems that the current synthetic aperture radar(SAR)image target detection method cannot adapt to targets of different sizes,and the complex image background leads to low detection accuracy,an improved SAR image small target detection method based on YOLOv7 was proposed in this study.The proposed method improved the feature extraction network by using Switchable Around Convolution(SAConv)in the backbone network to help the model capture target information at different scales,thus improving the feature extraction ability for small targets.Based on the attention mechanism,the DyHead module was embedded in the target detection head to reduce the impact of complex background,and better focus on the small targets.In addition,the NWD loss function was introduced and combined with CIoU loss.Compared to the CIoU loss function typically used in YOLOv7,the NWD loss function pays more attention to the processing of small targets,so as to further improve the detection ability of small targets.The experimental results on the HRSID dataset indicate that the proposed method achieved mAP@0.5 and mAP@0.95 scores of 93.5%and 71.5%,respectively.Compared to the baseline model,this represents an increase of 7.2%and 7.6%,respectively.The proposed method can effectively complete the task of SAR image small target detection.展开更多
Research progress of B. dorsalis and its species complex in Taiwan region and abroad was summarized from the aspects of classification, origin, transmission, distribution, host, biological characteristics and adaptabi...Research progress of B. dorsalis and its species complex in Taiwan region and abroad was summarized from the aspects of classification, origin, transmission, distribution, host, biological characteristics and adaptability to environmental conditions, in order to provide references and basis for researching B. dorsalis and its species complex in China.展开更多
[Objective]To study the effects of homologous chromosomes 7 (7A,7B and 7D) on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochem...[Objective]To study the effects of homologous chromosomes 7 (7A,7B and 7D) on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochemical means. [Method]The Triticum asetivum cultivar Chinese Spring wheat and nullisomic wheat (N7A,N7B and N7D) were planted in greenhouse. The photosynthetic indexes were determined at early filling stage. [Result]The photosynthetic rate (Pn),stomatal conductance (Gs),primary photochemical efficiency (Fv/Fm),actual chemical efficiency of photosystem II (ФPS II) and apparent electron transfer rate of photosystem II (ETR) were significantly lower in the N7A and N7B than in the Chinese Spring (P0.05). The photosynthetic rate and stomatal conductance was significantly lower in the N7D than in the Chinese Spring (P0.05). The Fv/Fm,ФPS II,ETR of N7D were higher than that of the Chinese Spring without significant difference. [Conclusion]The homologous chromosomes 7A and 7B have positive effects on photosynthetic rate and have relationship with stomatal conductance and photoreaction (chlorophyll fluorescence parameters). The homologous chromosome 7D has negative effects on photosynthetic rate,which is mainly related to stomatal conductance rather than photoreaction.展开更多
To develop a quick, accurate and antinoise automated image registration technique for infrared images, the wavelet analysis technique was used to extract the feature points in two images followed by the compensation f...To develop a quick, accurate and antinoise automated image registration technique for infrared images, the wavelet analysis technique was used to extract the feature points in two images followed by the compensation for input image with angle difference between them. A hi erarchical feature matching algorithm was adopted to get the final transform parameters between the two images. The simulation results for two infrared images show that the method can effectively, quickly and accurately register images and be antinoise to some extent.展开更多
Objective] This study aimed to investigate the al elopathy effect on the seed germination and seedling growth of different adzuki bean (Vigna angularis) vari-eties in wheat root aqueous extracts. [Method] Culture di...Objective] This study aimed to investigate the al elopathy effect on the seed germination and seedling growth of different adzuki bean (Vigna angularis) vari-eties in wheat root aqueous extracts. [Method] Culture dish method and pot experi-ment were carried out with the seeds and the seedling of 10 adzuki bean varieties, respectively, and seed germination rate and various indexes of the seedlings were measured. [Result] ① 30 g/L wheat root aqueous extracts very significantly im-proved the germination rate and sprouting index of B1789, Baihong 3, Baohong 947. ② The genotype differences of adzuki bean seedling was presented by the morphological index in wheat root aqueous extracts treatment; among al the mor-phological indexes, Baohong 947, Jinhong 3 presented a positive al elopathic effect, and their plant height, root length and leaf area were extremely significantly in-creased, while the fresh weights of both above-ground and underground parts were increased obviously, compared with the control. ③ According to the synthetical al-lelopathic indices, wheat root aqueous extracts had different degrees of promoting effects on the six adzuki bean varieties: Baohong 947〉Baihong 6〉B1789〉Zunhua-hong〉Jihong〉Jinhong 3〉Baohong 8824-17〉Baihong 3. ④ Treated by wheat root aqueous extract, the SOD activity, POD activity, MDA content, TTC activity and chlorophyl content in the seedlings of adzuki beans of different genotypes changed by a smal er range in al elopathic promotion varieties than in al elopathic inhibition varieties. [Conclusion] The results proved that Baohong 947 is the best summer-planting variety after wheat.展开更多
A new FM transmitter is reported. It adopts a fractional-N PLL synthesizer to realize the FM modulator. An extra offset current has also been applied to eliminate the effects of the mismatch in CP. The chip is fabrica...A new FM transmitter is reported. It adopts a fractional-N PLL synthesizer to realize the FM modulator. An extra offset current has also been applied to eliminate the effects of the mismatch in CP. The chip is fabricated with CSMC 0.5μm DPTM CMOS technology. Experiments show that it achieves THD≤0.08% and SNR≤ 82dB,and the maximum outband emission energy ≤ 90dBc/Hz. Furthermore,it also uses an auto frequency adjusting method to avoid tuning up the external inductances. All these merits are very suitable for FM transmission.展开更多
Soil erosion and nutrient loss due to erosion are world-wide problems. Similar to soil loss by erosion, soil nitrogen (N) loss by erosion in small catchments is affected by vegetation coverage. The practice of compreh...Soil erosion and nutrient loss due to erosion are world-wide problems. Similar to soil loss by erosion, soil nitrogen (N) loss by erosion in small catchments is affected by vegetation coverage. The practice of comprehensive management for catchments mainly by adjusting cropland, grassland and woodland areas was widely adopted to reduce soil and water loss in catchments of the Chinese Loess Plateau. Three experiments under natural and artificial rainfall conditions on N loss by erosion for a model catchment and for an actual catchment in Zhifanggou of Ansai County in China was performed to determine the relationships between comprehensive management and N loss by runoff in small catchments. The results for vegetation coverage of 60%, 40%, 20% and 0 show that runoff loss of ammonium, nitrate, and total N were 87.08, 44.31, 25.16, 13.71 kg/km(2); 85.50, 74.06, 63.95, 56.23 kg/km(2); and 0.18, 1.18, 1.98, 7.51 t/ km(2), respectively. Due to reduction in the size of cropped area on steeply sloping land, soil N loss by erosion in the catchments was decreased by 15.8% as compared with that in 1992, i.e., from 8 758.5 kg in 1992 to 7 562.2 kg in 1998. Whereas, catchments act as a filter for ammonium and nitrate in rain, the catchment filtering effects on nitrate is remarkably higher than that on ammonium. The enrichment of < 20 mum aggregate in sediment results in the enrichment of organic matter and total N in flood sediment. Greater vegetation coverage can effectively decrease soil erosion and total N loss. However, soil mineral N loss increased as vegetation coverage increased.展开更多
Microsatellites or SSRs as powerful genetic markers have widely been used in genetics and evolutionary biology in common wheat. Because of the high polymorphism, newly synthesized hexaploid wheat has been used in the ...Microsatellites or SSRs as powerful genetic markers have widely been used in genetics and evolutionary biology in common wheat. Because of the high polymorphism, newly synthesized hexaploid wheat has been used in the construction of genetic segregation population for SSR markers, However, data on the evolution of microsatellites during the polyploidization event of hexaploid wheat are limited. In this study, 66 pairs of specific to A/B genome SSR patterns among newly synthesized hexaploid wheat, the donor tetraploid wheat and Aegilops tauschii were compared. The results indicated that most SSR markers were conserved during the polyploidization events of newly synthetic hexaploid wheat, from Triticum turgidum and Ae. tauschii. Over 70% A/B genome specific SSR markers could amplify the SSR sequences from the D genome ofAe. tauschii. Most amplified fragments from Ae, tauschii were detected in synthetic hexaploid at corresponding positions with the same sizes and patterns as in its parental Ae. tauschii. This suggested that these SSR markers, specific for A/B genome in common wheat, could amplify SSR products of D genome besides A/B genome in the newly synthesized hexaploid wheat, that is, these SSR primers specific for A/B genome in common wheat were nonspecific for the A/B genome in the synthetic hexaploid wheat. In addition, one amplified Ae. tauschii product was not detected in the newly synthetic hexaploid wheat. An extra-amplified product was found in the newly synthetic hexaploid wheat. These results suggested that caution should be taken when using SSR marker to genotype newly synthetic hexaploid wheat.展开更多
The precipitation sequence of η(MgZn2) phase along low-angle grain boundaries in Al-Zn-Mg-Cu alloy was investigated by examining samples aged at 135 ℃ for various times from 5 min to 6 h. High resolution transmiss...The precipitation sequence of η(MgZn2) phase along low-angle grain boundaries in Al-Zn-Mg-Cu alloy was investigated by examining samples aged at 135 ℃ for various times from 5 min to 6 h. High resolution transmission electron microscopy (HRTEM) observations and energy dispersive X-ray spectroscopy (EDX) analysis indicate that the precipitation sequence of η phase along low-angle grain boundaries should be supersaturated solid solution (SSS)→vacancy-rich clusters (VRC)→GP Ⅱ zones→η'→η. Based on the theory of non-equilibrium grain boundary segregation (NGS) and non-equilibrium grain boundary co-segregation (NGCS), the excessive solute elements gradually segregate to the grain boundaries by the diffusion of the solute-vacancy complex during aging treatment. The grain boundary segregation plays an important role in the nucleation and growth of VRC, GP Ⅱ zones, η' phase as well as η phase.展开更多
An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coin...An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coincides with the physical characteristics of the fatigue life scatter. Two examples demonstrate the method. It is shown that the method has better accuracy and reasonableness compared with the usual least square method.展开更多
A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn(Ⅱ) and Co(Ⅱ), coexisting in t...A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn(Ⅱ) and Co(Ⅱ), coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares (NWLS). Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn(Ⅱ) and Co(Ⅱ).展开更多
To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor me...To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor measurements of the main strapdown inertial navigation system(M-SINS) and the slave strapdown inertial navigation system(S-SINS) are recorded for a few seconds and the integration of the data is calculated.Then,the possible maximum range of the delay value is defined and the points of the curve at different intervals are moved.The square of the differences between the corresponding points are calculated.Finally,the delay estimation can be acquired by the least-squares curve fitting of the M-SINS and the S-SINS.A delay compensation method by local data shifting is also presented.The simulation results demonstrate the effectiveness of delay estimation and indicate that the estimation accuracy is independent of the delay value.And the local data shifting compensation method can effectively reduce the errors of the transfer alignment caused by the reference information delay.展开更多
Aim To fuse the fluorescence image and transmission image of a cell into a single image containing more information than any of the individual image. Methods Image fusion technology was applied to biological cell imag...Aim To fuse the fluorescence image and transmission image of a cell into a single image containing more information than any of the individual image. Methods Image fusion technology was applied to biological cell imaging processing. It could match the images and improve the confidence and spatial resolution of the images. Using two algorithms, double thresholds algorithm and denoising algorithm based on wavelet transform,the fluorescence image and transmission image of a Cell were merged into a composite image. Results and Conclusion The position of fluorescence and the structure of cell can be displyed in the composite image. The signal-to-noise ratio of the exultant image is improved to a large extent. The algorithms are not only useful to investigate the fluorescence and transmission images, but also suitable to observing two or more fluoascent label proes in a single cell.展开更多
Infrared and visible light images can be obtained simultaneously by building fluorescence imaging system,which includes fluorescence excitation,images acquisition,mechanical part,image transmission and processing sect...Infrared and visible light images can be obtained simultaneously by building fluorescence imaging system,which includes fluorescence excitation,images acquisition,mechanical part,image transmission and processing section.This system studied the 2charge-coupled device(CCD)camera(AD-080CL)of the JAI company.Fusion algorithm of visible light and near infrared images was designed for the fluorescence imaging system with wavelet transform image fusion algorithm.In order to enhance the fluorescent moiety of the fusion image,the luminance value of the green component of the color image was changed.And using microsoft foundation classes(MFC)application architecture,the supporting software system was bulit in VS2010 environment.展开更多
TiC particles reinforced Ni-based alloy composite coatings were prepared on 7005 aluminum alloy by plasma spray. The effects of load, speed and temperature on the tribological behavior and mechanisms of the composite ...TiC particles reinforced Ni-based alloy composite coatings were prepared on 7005 aluminum alloy by plasma spray. The effects of load, speed and temperature on the tribological behavior and mechanisms of the composite coatings under dry friction were researched. The wear prediction model of the composite coatings was established based on the least square support vector machine (LS-SVM). The results show that the composite coatings exhibit smaller friction coefficients and wear losses than the Ni-based alloy coatings under different friction conditions. The predicting time of the LS-SVM model is only 12.93%of that of the BP-ANN model, and the predicting accuracies on friction coefficients and wear losses of the former are increased by 58.74%and 41.87%compared with the latter. The LS-SVM model can effectively predict the tribological behavior of the TiCP/Ni-base alloy composite coatings under dry friction.展开更多
文摘In order to solve the problems that the current synthetic aperture radar(SAR)image target detection method cannot adapt to targets of different sizes,and the complex image background leads to low detection accuracy,an improved SAR image small target detection method based on YOLOv7 was proposed in this study.The proposed method improved the feature extraction network by using Switchable Around Convolution(SAConv)in the backbone network to help the model capture target information at different scales,thus improving the feature extraction ability for small targets.Based on the attention mechanism,the DyHead module was embedded in the target detection head to reduce the impact of complex background,and better focus on the small targets.In addition,the NWD loss function was introduced and combined with CIoU loss.Compared to the CIoU loss function typically used in YOLOv7,the NWD loss function pays more attention to the processing of small targets,so as to further improve the detection ability of small targets.The experimental results on the HRSID dataset indicate that the proposed method achieved mAP@0.5 and mAP@0.95 scores of 93.5%and 71.5%,respectively.Compared to the baseline model,this represents an increase of 7.2%and 7.6%,respectively.The proposed method can effectively complete the task of SAR image small target detection.
基金Supported by Key Disciplinary Developing Project of Forest Protection and Zoology from Yunnan Province(Grant No.XKZ200905)Science and Technology Project of Jiangxi Provincial Department of Education(GJJ08471)~~
文摘Research progress of B. dorsalis and its species complex in Taiwan region and abroad was summarized from the aspects of classification, origin, transmission, distribution, host, biological characteristics and adaptability to environmental conditions, in order to provide references and basis for researching B. dorsalis and its species complex in China.
基金Supported by Excellent Young Academic Leaders Project of Shanxi Province~~
文摘[Objective]To study the effects of homologous chromosomes 7 (7A,7B and 7D) on wheat photosynthesis and provide theoretical basis for breeding high photosynthetic efficiency wheat by genetic,physiological and biochemical means. [Method]The Triticum asetivum cultivar Chinese Spring wheat and nullisomic wheat (N7A,N7B and N7D) were planted in greenhouse. The photosynthetic indexes were determined at early filling stage. [Result]The photosynthetic rate (Pn),stomatal conductance (Gs),primary photochemical efficiency (Fv/Fm),actual chemical efficiency of photosystem II (ФPS II) and apparent electron transfer rate of photosystem II (ETR) were significantly lower in the N7A and N7B than in the Chinese Spring (P0.05). The photosynthetic rate and stomatal conductance was significantly lower in the N7D than in the Chinese Spring (P0.05). The Fv/Fm,ФPS II,ETR of N7D were higher than that of the Chinese Spring without significant difference. [Conclusion]The homologous chromosomes 7A and 7B have positive effects on photosynthetic rate and have relationship with stomatal conductance and photoreaction (chlorophyll fluorescence parameters). The homologous chromosome 7D has negative effects on photosynthetic rate,which is mainly related to stomatal conductance rather than photoreaction.
文摘To develop a quick, accurate and antinoise automated image registration technique for infrared images, the wavelet analysis technique was used to extract the feature points in two images followed by the compensation for input image with angle difference between them. A hi erarchical feature matching algorithm was adopted to get the final transform parameters between the two images. The simulation results for two infrared images show that the method can effectively, quickly and accurately register images and be antinoise to some extent.
基金Supported by the Fund for Construction Program of Chemical Advantage and Key Discipline of Shanxi Province of China(912019)~~
文摘Objective] This study aimed to investigate the al elopathy effect on the seed germination and seedling growth of different adzuki bean (Vigna angularis) vari-eties in wheat root aqueous extracts. [Method] Culture dish method and pot experi-ment were carried out with the seeds and the seedling of 10 adzuki bean varieties, respectively, and seed germination rate and various indexes of the seedlings were measured. [Result] ① 30 g/L wheat root aqueous extracts very significantly im-proved the germination rate and sprouting index of B1789, Baihong 3, Baohong 947. ② The genotype differences of adzuki bean seedling was presented by the morphological index in wheat root aqueous extracts treatment; among al the mor-phological indexes, Baohong 947, Jinhong 3 presented a positive al elopathic effect, and their plant height, root length and leaf area were extremely significantly in-creased, while the fresh weights of both above-ground and underground parts were increased obviously, compared with the control. ③ According to the synthetical al-lelopathic indices, wheat root aqueous extracts had different degrees of promoting effects on the six adzuki bean varieties: Baohong 947〉Baihong 6〉B1789〉Zunhua-hong〉Jihong〉Jinhong 3〉Baohong 8824-17〉Baihong 3. ④ Treated by wheat root aqueous extract, the SOD activity, POD activity, MDA content, TTC activity and chlorophyl content in the seedlings of adzuki beans of different genotypes changed by a smal er range in al elopathic promotion varieties than in al elopathic inhibition varieties. [Conclusion] The results proved that Baohong 947 is the best summer-planting variety after wheat.
文摘A new FM transmitter is reported. It adopts a fractional-N PLL synthesizer to realize the FM modulator. An extra offset current has also been applied to eliminate the effects of the mismatch in CP. The chip is fabricated with CSMC 0.5μm DPTM CMOS technology. Experiments show that it achieves THD≤0.08% and SNR≤ 82dB,and the maximum outband emission energy ≤ 90dBc/Hz. Furthermore,it also uses an auto frequency adjusting method to avoid tuning up the external inductances. All these merits are very suitable for FM transmission.
文摘Soil erosion and nutrient loss due to erosion are world-wide problems. Similar to soil loss by erosion, soil nitrogen (N) loss by erosion in small catchments is affected by vegetation coverage. The practice of comprehensive management for catchments mainly by adjusting cropland, grassland and woodland areas was widely adopted to reduce soil and water loss in catchments of the Chinese Loess Plateau. Three experiments under natural and artificial rainfall conditions on N loss by erosion for a model catchment and for an actual catchment in Zhifanggou of Ansai County in China was performed to determine the relationships between comprehensive management and N loss by runoff in small catchments. The results for vegetation coverage of 60%, 40%, 20% and 0 show that runoff loss of ammonium, nitrate, and total N were 87.08, 44.31, 25.16, 13.71 kg/km(2); 85.50, 74.06, 63.95, 56.23 kg/km(2); and 0.18, 1.18, 1.98, 7.51 t/ km(2), respectively. Due to reduction in the size of cropped area on steeply sloping land, soil N loss by erosion in the catchments was decreased by 15.8% as compared with that in 1992, i.e., from 8 758.5 kg in 1992 to 7 562.2 kg in 1998. Whereas, catchments act as a filter for ammonium and nitrate in rain, the catchment filtering effects on nitrate is remarkably higher than that on ammonium. The enrichment of < 20 mum aggregate in sediment results in the enrichment of organic matter and total N in flood sediment. Greater vegetation coverage can effectively decrease soil erosion and total N loss. However, soil mineral N loss increased as vegetation coverage increased.
基金the project of Scientific Research Foundation for the Returned Overseas Chinese Scholars, New Century Excellent Talents in University (No. NCET-04-0908)Changjiang Scholars and Innovative Research Team in University (No. IRT0 453) of the Chinese Ministry of EducationNational Natural Science Foundation of China (No. 30270804), Education Department and Science and Technology Department of Sichuan Province.
文摘Microsatellites or SSRs as powerful genetic markers have widely been used in genetics and evolutionary biology in common wheat. Because of the high polymorphism, newly synthesized hexaploid wheat has been used in the construction of genetic segregation population for SSR markers, However, data on the evolution of microsatellites during the polyploidization event of hexaploid wheat are limited. In this study, 66 pairs of specific to A/B genome SSR patterns among newly synthesized hexaploid wheat, the donor tetraploid wheat and Aegilops tauschii were compared. The results indicated that most SSR markers were conserved during the polyploidization events of newly synthetic hexaploid wheat, from Triticum turgidum and Ae. tauschii. Over 70% A/B genome specific SSR markers could amplify the SSR sequences from the D genome ofAe. tauschii. Most amplified fragments from Ae, tauschii were detected in synthetic hexaploid at corresponding positions with the same sizes and patterns as in its parental Ae. tauschii. This suggested that these SSR markers, specific for A/B genome in common wheat, could amplify SSR products of D genome besides A/B genome in the newly synthesized hexaploid wheat, that is, these SSR primers specific for A/B genome in common wheat were nonspecific for the A/B genome in the synthetic hexaploid wheat. In addition, one amplified Ae. tauschii product was not detected in the newly synthetic hexaploid wheat. An extra-amplified product was found in the newly synthetic hexaploid wheat. These results suggested that caution should be taken when using SSR marker to genotype newly synthetic hexaploid wheat.
基金Project(51071122)supported by the National Natural Science Foundation of ChinaProject(B08040)supported by the Program of Introducing Talents of Discipline to Universities,China("111"Project)
文摘The precipitation sequence of η(MgZn2) phase along low-angle grain boundaries in Al-Zn-Mg-Cu alloy was investigated by examining samples aged at 135 ℃ for various times from 5 min to 6 h. High resolution transmission electron microscopy (HRTEM) observations and energy dispersive X-ray spectroscopy (EDX) analysis indicate that the precipitation sequence of η phase along low-angle grain boundaries should be supersaturated solid solution (SSS)→vacancy-rich clusters (VRC)→GP Ⅱ zones→η'→η. Based on the theory of non-equilibrium grain boundary segregation (NGS) and non-equilibrium grain boundary co-segregation (NGCS), the excessive solute elements gradually segregate to the grain boundaries by the diffusion of the solute-vacancy complex during aging treatment. The grain boundary segregation plays an important role in the nucleation and growth of VRC, GP Ⅱ zones, η' phase as well as η phase.
文摘An S-N curve fitting approach is proposed based on the weighted least square method, and the weights are inversely proportional to the length of mean confidence intervals of experimental data sets. The assumption coincides with the physical characteristics of the fatigue life scatter. Two examples demonstrate the method. It is shown that the method has better accuracy and reasonableness compared with the usual least square method.
基金Project(2012BAF03B05)supported by the National Key Technology R&D Program of ChinaProject(61025015)supported by the National Natural Science Foundation for Distinguished Young Scholars of China+1 种基金Project(61273185)supported by the National Natural Science Foundation of ChinaProject(2012CK4018)supported by the Science and Technology Project of Hunan Province,China
文摘A resolution method based on Gaussian-like distribution for overlapped linear sweep polarographic peaks was proposed to simultaneously detect the polymetallic components, such as Zn(Ⅱ) and Co(Ⅱ), coexisting in the leaching solution of zinc hydrometallurgy. A Gaussian-like distribution was constructed as the sub-model of overlapped peaks by analyzing the characteristics of linear sweep polarographic curve. Then, the abscissas of each peak and trough were pinpointed through multi-resolution wavelet decomposition, the curve and its derivative curves were fitted by using nonlinear weighted least squares (NWLS). Finally, overlapped peaks were resolved into independent sub-peaks based on fitted reconstruction parameters. The experimental results show that the relative error of half-wave potential pinpointed by multi-resolution wavelet decomposition is less than 1% and the accuracy of Ip fitted by NWLS is higher than 96%. The proposed resolution method is effective for overlapped linear sweep polarographic peaks of Zn(Ⅱ) and Co(Ⅱ).
基金The National Basic Research Program of China(973 Program) (No. 613121030201)the Fundamental Research of Commission of Science,Technology and Industry for National Defense (No. C1420080224)
文摘To reduce the error in transfer alignment caused by reference information delay,a time delay estimation method is developed based on least-squares curve fitting of the angular rate integration.First,the gyro sensor measurements of the main strapdown inertial navigation system(M-SINS) and the slave strapdown inertial navigation system(S-SINS) are recorded for a few seconds and the integration of the data is calculated.Then,the possible maximum range of the delay value is defined and the points of the curve at different intervals are moved.The square of the differences between the corresponding points are calculated.Finally,the delay estimation can be acquired by the least-squares curve fitting of the M-SINS and the S-SINS.A delay compensation method by local data shifting is also presented.The simulation results demonstrate the effectiveness of delay estimation and indicate that the estimation accuracy is independent of the delay value.And the local data shifting compensation method can effectively reduce the errors of the transfer alignment caused by the reference information delay.
文摘Aim To fuse the fluorescence image and transmission image of a cell into a single image containing more information than any of the individual image. Methods Image fusion technology was applied to biological cell imaging processing. It could match the images and improve the confidence and spatial resolution of the images. Using two algorithms, double thresholds algorithm and denoising algorithm based on wavelet transform,the fluorescence image and transmission image of a Cell were merged into a composite image. Results and Conclusion The position of fluorescence and the structure of cell can be displyed in the composite image. The signal-to-noise ratio of the exultant image is improved to a large extent. The algorithms are not only useful to investigate the fluorescence and transmission images, but also suitable to observing two or more fluoascent label proes in a single cell.
基金National Natural Science Foundation of China(No.61171177)National Major Scientific Equipment Development Projects of China(No.2013YQ240803)+1 种基金Natural Science Foundation for Young Scientists of Shanxi Province(No.2012021011-1)Scientific and Technological Project in Shanxi Province(No.20140321010-02)
文摘Infrared and visible light images can be obtained simultaneously by building fluorescence imaging system,which includes fluorescence excitation,images acquisition,mechanical part,image transmission and processing section.This system studied the 2charge-coupled device(CCD)camera(AD-080CL)of the JAI company.Fusion algorithm of visible light and near infrared images was designed for the fluorescence imaging system with wavelet transform image fusion algorithm.In order to enhance the fluorescent moiety of the fusion image,the luminance value of the green component of the color image was changed.And using microsoft foundation classes(MFC)application architecture,the supporting software system was bulit in VS2010 environment.
文摘TiC particles reinforced Ni-based alloy composite coatings were prepared on 7005 aluminum alloy by plasma spray. The effects of load, speed and temperature on the tribological behavior and mechanisms of the composite coatings under dry friction were researched. The wear prediction model of the composite coatings was established based on the least square support vector machine (LS-SVM). The results show that the composite coatings exhibit smaller friction coefficients and wear losses than the Ni-based alloy coatings under different friction conditions. The predicting time of the LS-SVM model is only 12.93%of that of the BP-ANN model, and the predicting accuracies on friction coefficients and wear losses of the former are increased by 58.74%and 41.87%compared with the latter. The LS-SVM model can effectively predict the tribological behavior of the TiCP/Ni-base alloy composite coatings under dry friction.