Flesh firmness(FF) is an important and complex trait for melon breeders and consumers. However, the genetic mechanism underlying FF is unclear. Here, a soft fruit melon(P5) and a hard fruit melon(P10) were crossed to ...Flesh firmness(FF) is an important and complex trait for melon breeders and consumers. However, the genetic mechanism underlying FF is unclear. Here, a soft fruit melon(P5) and a hard fruit melon(P10) were crossed to generate F2, and the FF and fruit-related traits were recorded for two years. By performing quantitative trait locus(QTL) specificlocus amplified fragment(SLAF)(QTL-SLAF) sequencing and molecular marker-linkage analysis, 112 844 SLAF markers were identified, and 5 919 SNPs were used to construct a genetic linkage map with a total genetic distance of1 356.49 cM. Ten FF-and fruit-related QTLs were identified. Consistent QTLs were detected for fruit length(FL) and fruit diameter(FD) in both years, and QTLs for single fruit weight(SFW) were detected on two separate chromosomes in both years. For FF, the consistent major locus(ff2.1) was located in a 0.17-Mb candidate region on chromosome 2. Using 429 F2individuals derived from a cross between P5 and P10, we refined the ff2.1 locus to a 28.3-kb region harboring three functional genes. These results provide not only a new candidate QTL for melon FF breeding but also a theoretical foundation for research on the mechanism underlying melon gene function.展开更多
Exit choice is one of the most important pedestrian behaviors during evacuation.Distance to the exit is a generally recognized factor influencing expected moving time to the exit.Visual range determines how much infor...Exit choice is one of the most important pedestrian behaviors during evacuation.Distance to the exit is a generally recognized factor influencing expected moving time to the exit.Visual range determines how much information a pedestrian can perceive,thus the number of pedestrians within the visual field can be used to estimate waiting time at the exit.Besides,the choice firmness that reflects the degree to which a pedestrian would persist in his/her previous choice of exit is proposed.By integrating game theory into a cellular automata simulation framework,the pedestrian exit choice mechanism is investigated and explicitly modeled in this paper.A systematic analysis of the key factors influencing pedestrian evacuation is conducted,including visual radius and choice firmness of a pedestrian,initial crowd distribution of the room,exit layout as well as exit width.It is found that low choice firmness level can lead to unnatural pedestrian behavior such as wandering,which is adverse to evacuation.The longer the pedestrian's visual radius,the earlier the pedestrian can determine his/her final selection of the exit.Compared with the scenario where the pedestrians are randomly distributed,pedestrians clustered together in a corner of the room lead to high crowd density and imbalanced use of exits.Furthermore,the exit layout and exit width also have a certain influence on pedestrian evacuation process.The results of this paper may be of benefit to the formulation of behavioral rules in other pedestrian simulation models.展开更多
Nowadays,many researches have been accomplished on the attributed quality assessment of agricultural products.Fruits have significantly contributed to these researches because of their high production and consumption,...Nowadays,many researches have been accomplished on the attributed quality assessment of agricultural products.Fruits have significantly contributed to these researches because of their high production and consumption,worldwide.In this paper,the nondestructive instrumental researches in the field of firmness assessment for apple fruit discussed.These researches are important for all production and distribution chain activists such as farmers,insurance companies,packaging and transportation companies,wholesalers and retailers.These studies can be used for examining texture quality,predicting the right time to harvest fruits and classifying them according to the level of ripeness and detecting the apparent and internal defects of the fruit.The apple flesh firmness measurement methods consist of acoustic and mechanical vibration methods,optical methods such as hyperspectral scattering imaging,near infrared,ultrasound and other methods.The destructive puncture test method commonly used as a reference method.Nondestructive methods are accurate and quick that is suitable for online applications.Recently,the use of artificial intelligence methods and data fusion techniques to increase the accuracy of quality measuring of the products has been considered that in the future we will see further development of these methods in measuring the firmness of the apples.展开更多
Firms are embedded in complex networks,where diverse ideas combine and generate new ideas.Shareholders of firms are of-ten seen as critical external resources that have significant influence on firm innovation.The cur...Firms are embedded in complex networks,where diverse ideas combine and generate new ideas.Shareholders of firms are of-ten seen as critical external resources that have significant influence on firm innovation.The current literature tends to focus on the rela-tionship between firms and their shareholders,while paying less attention to the connections between firms with the same shareholders.This article identifies two types of network spillover effects,intra-city network effect and inter-city network effect,by visualizing the co-ownership networks in China’s electric vehicle(EV)industry.We find that firms with the same shareholders,which are defined as co-owned EV firms,are more innovative than non-co-owned ones.Furthermore,there are two dominant types of firm co-ownership ties formed by corporate and financial institution shareholders.While corporate shareholders help exploiting local tacit knowledge,financial institutions are more active in bridging inter-city connections.The conclusion is confirmed at both firm and city levels.This paper theor-izes the firm co-ownership network as a new form of institutional proximity and tested the result empirically.For policy consideration,we have emphasized the importance of building formal or informal inter-firm network,and the government should further enhance the knowledge flow channel by institutional construction.展开更多
Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of ...Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of three varieties(‘Cuiguan’,‘Xueqing’and‘Xizilv’)was studied,both quantitatively and qualitatively.NIR models were established using partial least square(PLS)methods in the spectral range of 800 to 2500 nm.For quantitative analysis,the correlation coefficient r increased with more varieties involved in the model.Best results were obtained in the model for all three varieties:rcalwas 0.934,root mean square error of calibration(RMSEC)and root mean square error of prediction(RMSEP)were 2.06 N and 3.14 N,respectively.For qualitative analysis,the overall accuracies of discriminant PLS models for classifying pears into three firmness levels:low,medium and high firmness level were not so good,percentage of samples correctly classified ranged from 70.63%to 81.25%for calibration and from 56.25%to 74.38%for validation.The results indicate that NIR spectroscopy together with PLS chemometrics method is feasible for quantitative analysis of pear firmness,however,the classification accuracy is too low to put into practical application.展开更多
The objectives of this research were to compare the performance of each individual nondestructive sensor with the destructive sensor,and to apply sensor fusion technique to explore whether a combination of sensors wou...The objectives of this research were to compare the performance of each individual nondestructive sensor with the destructive sensor,and to apply sensor fusion technique to explore whether a combination of sensors would give better results than a single sensor for classification of peach firmness.Tests were carried out with four peach varieties namely Royal Glory,Caterina,Tirrenia and Suidring.In this research,the three nondestructive firmness sensors acoustic firmness,low-mass impact and micro-deformation impact were used to measure firmness.A Bayesian classifier was chosen to provide a classification into three categories,namely soft,intermediate and hard.High level fusion technique was performed by using identity declaration provided by each sensor.The data fusion system processed the information of the sensors to output the fused data.The result of the high level fusion was compared with the classification provided by an unsupervised algorithm based on destructive reference measurement.The fusion process of the nondestructive sensors provided some improvements in the firmness classification;the error rate varied from 25%to 19%for individual sensor.Furthermore,the results of fusion process by using three sensors decreased the error rate from 19%to 13%.This research demonstrated that the fused systems provided more complete and complementary information and,thus,were more effective than individual sensors in the firmness classification of peaches.展开更多
In order to achieve the non-destructive detection of the firmness of Korla fragrant pear during the ripening period,the characteristic variables integrating the parallel equivalent inductance(Lp),quality factor(Q),par...In order to achieve the non-destructive detection of the firmness of Korla fragrant pear during the ripening period,the characteristic variables integrating the parallel equivalent inductance(Lp),quality factor(Q),parallel equivalent capacitance(Cp),dissipation factor(D),parallel equivalent resistance(Rp)and impedance(Z)were formulated through principal component analysis(PCA).Further,based on the characteristic variables,the models were established for predicting the firmness of Korla fragrant pear by using the generalized regression neural network(GRNN)and back-propagation neural network(BPNN).The results showed that firmness has significant correlations with the six electrical parameters.The first two principal components(PCs)were selected as the characteristic variables of the electrical parameters.GRNN exhibited the best performance in predicting firmness(R2=0.9628,RMSE=0.383).The results could provide important references for non-destructive detection of the quality of Korla fragrant pear.展开更多
Firmness is one of the important indices to evaluate the internal quality of fruit.In this study,a noncontact loudspeaker-based detection system was developed to evaluate apple firmness.The structural parameters of th...Firmness is one of the important indices to evaluate the internal quality of fruit.In this study,a noncontact loudspeaker-based detection system was developed to evaluate apple firmness.The structural parameters of the excitation device were modified in the single-factor experiments,and the best combination of structural parameters was that the inner diameter of the gasket was 40 mm;the distance between fruit surface and loudspeaker was 95 mm.Besides,the proper posture style was that the apple was placed with its stem upward.After the modification of the Laser Doppler Vibrometer(LDV)method,the vibration response signals of 48 apples were measured to establish the firmness prediction model.The results showed that the better prediction performance of stiffness was obtained in multiple models.The Back Propagation Neural Network(BPNN)model had the best prediction performance by using parameters of elasticity index(EI),the peak value at the second resonance frequency f_(2)(A_(2)),and peak area S,with a correlation coefficient of prediction(r_(p))of 0.914;root mean square error of prediction(RMSEP)of 0.491 N/mm.Therefore,the proposed detection system is feasible to nondestructively detect apple firmness,which has the potential to be applied in online detection.展开更多
An important feature of China developing its aerospace industry is its insistence on self-reliance and independent innovation,because China firmly believes that aerospace is a hi-tech industry and high core technologi...An important feature of China developing its aerospace industry is its insistence on self-reliance and independent innovation,because China firmly believes that aerospace is a hi-tech industry and high core technologies cannot be bought.Only by mastering core technologies can China firmly grasp the initiative in development.展开更多
Fruit development and ripening is a complex procedure(Malus×domestica Borkh.)and can be caused by various factors such as cell structure,cell wall components,and cell wall hydrolytic enzymes.In our study,we focus...Fruit development and ripening is a complex procedure(Malus×domestica Borkh.)and can be caused by various factors such as cell structure,cell wall components,and cell wall hydrolytic enzymes.In our study,we focused on the variations in fruit firmness,cell wall morphology and components,the activity of cell wall hydrolytic enzymes and the expression patterns of associated genes during fruit development in two different types of apple cultivars,the hard-crisp cultivar and the loose-crisp cultivar.In this paper,the aim was to find out the causes of the texture variations between the different type cultivars.Cell wall materials(CWMs),hemicellulose and cellulose content were strongly associated with variations in fruit firmness during the fruit development.The content of water soluble pectin(WSP)and chelator soluble pectin(CSP)gradually increased,while the content of ionic soluble pectin(ISP)showed inconsistent trends in the four cultivars.The activities of polygalacturonase(PG),β-galactosidase(β-gal),cellulase(CEL),and pectate lyase(PL)gradually increased in four cultivars.And the activities of PG,β-gal,and CEL were higher in‘Fuji’and‘Honeycrisp’fruit with the fruit development,while the activity of PL of‘Fuji’and‘Honeycrisp’was lower than that of‘ENVY’and‘Modi’.Both four cultivars of fruit cells progressively became bigger as the fruit expanded,with looser cell arrangements and larger cell gaps.According to the qRT-PCR,the relative expression levels of MdACO and Mdβ-gal were notably enhanced.Our study showed that there were large differences in the content of ISP and hemicellulose,the activity of PL and the relative expression of Mdβ-gal between two different types of apple cultivars,and these differences might be responsible for the variations in the texture of the four cultivars.展开更多
奇异值分解(Singular value decomposition,SVD)作为一种有效的信号降噪方法广泛应用于旋转机械振动信号周期性瞬态冲击提取中。传统SVD以能量为导向,无法提取出能量较弱但含故障信息丰富的奇异分量(Singular Component,SC)。为此,提出...奇异值分解(Singular value decomposition,SVD)作为一种有效的信号降噪方法广泛应用于旋转机械振动信号周期性瞬态冲击提取中。传统SVD以能量为导向,无法提取出能量较弱但含故障信息丰富的奇异分量(Singular Component,SC)。为此,提出加权firm阈值奇异值分解(Weighted Firm Singular Value Decomposition,WFSVD)方法。该方法首先引入平方包络谱峭度(Squared Envelope Spectrum Kurtosis,SESK)作为量化故障敏感度的指标,以评估各个SC所含故障信息的丰富程度;其次,将SESK作为权重因子引入到基于firm阈值的SC去噪中,设计基于SESK的加权firm阈值SC去噪策略;最后,重构信号,实现信号降噪并有效提取故障特征。对于仿真信号与试验数据的分析验证了所提方法在周期性微弱瞬态冲击提取及旋转机械故障诊断中的有效性。展开更多
Increasing attention has been focused on the extent to which corporate political connections influence the growing pollution due to the rapid growth in the popularity of firm pollution in developing countries.We adopt...Increasing attention has been focused on the extent to which corporate political connections influence the growing pollution due to the rapid growth in the popularity of firm pollution in developing countries.We adopt a static threshold regression model to investigate the effects of heterogeneous environmental regulation on political connections and firm pollution based on the panel data from China’s A-share listed companies from 2012 to 2019.The empirical results show a non-linear relationship between the degree of political connection of listed company executives and the level of firm pollution.And the relationship between the two roughly presents a U-shaped relationship under the action of the marketincentive environmental regulation threshold.However,it roughly presents an inverted N-shaped relationship under the action of the command-control environmental regulation threshold.Additionally,the group test results show that the existence of regional and ownership heterogeneity causes certain differences in the environmental behaviour of politically connected enterprises.These findings indicate that diverse environmental regulations are needed to promote sustainable green development and to further expand the theoretical and practical exploration of political connections on firm pollution.展开更多
For this study of long-term spatial patterns and trends of active fires in southern hemispheric Africa and on Madagascar from 2001 to 2020,active fire data from the MODIS FIRMS global fire data products were analyzed....For this study of long-term spatial patterns and trends of active fires in southern hemispheric Africa and on Madagascar from 2001 to 2020,active fire data from the MODIS FIRMS global fire data products were analyzed.The annual center of fire concentration tended to migrate toward the preserved rainforests and nature conservation areas in the Congo Basin and the mountain forests on the northeastern coast of Madagascar.Fire frequency varied seasonally at both study areas.We used geo statistical analysis techniques,such as measures of dispersion and emerging hot spot analysis,to reveal long-term trends in spatial patterns of fire events.In southern hemispheric Africa,the observed active fires tended to drift northward toward the Zambia-DRC border in the Congo basin.This northward migration progressed toward humid rainforests,which were better suited to sustaining repeated fire events.On Madagascar,the observed active fires tended to migrate toward the east coast in protected mountain forests.The spatial patterns of long-term trends showed a concentration of fires in the tropical regions of southern hemispheric Africa.Moreover,smaller clusters of new hot spots were located over eastern South Africa,overlapping with undifferentiated woodlands.On Madagascar,both hot and cold spots were identified and were separated by the highland region in the center of the island.Most of the eastern island was characterized by cold spots that received less precipitation than did the rest of the island.The presence of increasing hots spots in the densely vegetated areas highlights the urgent need for fire prevention and management in this region.展开更多
This paper explores the relationship between resource constraints and innovation of new firms.Drawing upon the relevant literature,we incorporate resource constraints as the antecedent to the bricolage-innovation link...This paper explores the relationship between resource constraints and innovation of new firms.Drawing upon the relevant literature,we incorporate resource constraints as the antecedent to the bricolage-innovation link.Compared to prior studies that treated resource constraints as a one-dimensional variable,we operationalize it along two dimensions:knowledge constraints and financial constraints.Our argument posits that knowledge constraints and financial constraints act as catalysts for innovation in new firms,with bricolage serving as a mediating role.To test our hypotheses,we conducted a survey involving 183 entrepreneurs in the United States.The data analysis demonstrates that bricolage fully mediates the relationship between knowledge con‐straints and innovation and partially mediates the relationship between financial constraints and innovation.Theoretical and practical implications are discussed.展开更多
Innovation capitalization is a new concept in innovation geography research.Extant research on a city scale has proven that innovation is an important factor affecting housing prices and verified that innovation has a...Innovation capitalization is a new concept in innovation geography research.Extant research on a city scale has proven that innovation is an important factor affecting housing prices and verified that innovation has a capitalization effect.However,few studies investigate the spatial heterogeneity of innovation capitalization.Thus,case verification at the urban agglomeration scale is needed.Therefore,this study proposes a theoretical framework for the spatial heterogeneity of innovation capitalization at the urban agglomeration scale.Examining the Guangdong-Hong Kong-Macao Greater Bay Area(GHMGBA),China as a case study,the study investigated the spatial heterogeneity of the influence of high-tech firms,representing innovation,on housing prices.This work verified the spatial heterogeneity of innovation capitalization.The study constructed a data set influencing housing prices,comprising 11 factors in 5 categories(high-tech firms,convenience of living facilities,built environment,the natural environment,and the fundamentals of the districts)for 419 subdistricts in the GHMGBA.On the global scale,the study finds that high-tech firms have a significant and positive influence on housing prices,with the housing price increasing by 0.0156%when high-tech firm density increases by 1%.Furthermore,a semi-geographically weighted regression(SGWR)analysis shows that the influence of high-tech firms on housing prices has spatial heterogeneity.The areas where high-tech firms have a significant and positive influence on housing prices are mainly in the GuangzhouFoshan metropolitan area,western Shenzhen-Dongguan,north-central Zhongshan-Nansha district,and Guangzhou—all areas with densely distributed high-tech firms.These results confirm the spatial heterogeneity of innovation capitalization and the need for further discussion of its scale and spatial limitations.The study offers implications for relevant GHMGBA administrative authorities for spatially differentiated development strategies and housing policies that consider the role of innovation in successful urban development.展开更多
An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvestin...An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvesting. Bagged and non-bagged fruits were stored at 2℃ ± 1℃ and 90%-95% RH. Observations were recorded on color and fruit quality attributes such as total phenolics, AOX activity, fruit Ca contents, LOX activity, SSC and ascorbic acid contents at harvest and during storage. Our studies have revealed that bagged fruits have better color development (Hunter “a” = 52) than non-bagged fruits at harvest (Hunter “a” = 38), which declined slightly during storage. Similarly, at harvest, bagged fruits contained high amounts of Ca (5.38 mg/100g) and total phenolics (9.3 mg GAE/100gpulp) exhibited higher AOX activity (12.6 μmoles Trolox g-1), and had better SSC and ascorbic acid contents than non-bagged fruits, and there was a decline in all recorded parameters during storage. Bagged fruits exhibited lower LOX activity (1.38 μmoles min-1 g-1 FW) at harvest than non-bagged fruits (2.14 μmoles min-1 g-1 FW), indicating that non-bagged fruits were more senescent than bagged fruits. Further, LOX activity increased during storage both in bagged and non-bagged apples but increase in LOX activity was slower in bagged apples than in non-bagged apples.展开更多
Xylanase is a hemicellulase that can hydrolyses the complex polysaccharides.Hemicelluloses are main components of cell walls of cereal grains.Moreover,hemicelluloses are considered as potential sources of mono-and oli...Xylanase is a hemicellulase that can hydrolyses the complex polysaccharides.Hemicelluloses are main components of cell walls of cereal grains.Moreover,hemicelluloses are considered as potential sources of mono-and oligosaccharides.In this study,influence of xylanase on the physicochemical properties and sensory qualities of the whole wheat bread during storage was investigated.Studies of whole wheat bread on microstructure,texture,thermotics,Scanning Electron Microscopic(SEM),X-Ray Diffraction(XRD)were conducted at ambient temperature of 25 and 4◦C respectively.During storage at different temperatures,bread containing xylanase exhibited less firmness but larger volume with whiter crumb color and longer shelf life as compared to control bread.Results of firmness,enthalpy,Fourier Transformation Infra Red(FTIR)and X-Ray Diffraction(XRD)studies suggested a lower staling rate of bread containing xylanase as compared to control one.Bread containing xylanase showed a smoother surface and more uniform pore size than the control.Significant differences in microstructure of control and bread containing xylanase were observed which might be attributed due to the change in water starch gluten interaction.These differences were also found to be interrelated to the textural properties of bread.Better sensory features were achieved in bread containing xylanase.展开更多
The experiment shows that considerable influence on density rock properties are subjected by nival weathering conditions. The main parameter defining the rock suitability for solution various engineering and geologica...The experiment shows that considerable influence on density rock properties are subjected by nival weathering conditions. The main parameter defining the rock suitability for solution various engineering and geological problems is its firmness limit on single axis pressing.The firmness properties of sandstone being in absolutely dry condition for Kabakta suite at the beginning of investigation was 64.7 MPa, for Nerungri suite sandstones it was 48.7 MPa. The investigations showed how much the nival conditions of cryohypergenesis of rock sandstones in Kabakta and Nerungri suites have destructive influence in comparison with aquale and more over aerale conditions. In the aerale conditions sedimentary rock firmness of Kabakta suite decreased to 23.2 MPa, in aquale conditions to 16.5, and in the nivale conditions to 8.9 MPa. In Nerungri suite sandstones are according to 17.7 MPa, 11.1 MPa, and 6 MPa after 300 freezing and thawing cycles. The common sandstone firmness decrease of Kabakta suite was 25 %, of Nerungri suite it was 23.8%. Marlstone samples after 400 FTC decrease to 62% in the nivale conditions and to 33% in the aerale conditions. After 3～5 years of exploitation marlstone will destruct due to structural and textural inhomogenesis up to gruss, i.e. it will not meet the requirements of durability. Judging by the results of carried out experiment it should be concluded that by cryogenic weathering the sedimentary rocks (sandstones) and rocks with schistose lithogenic texture (marlstone) are subjected to disintegration. The primary rock samples firmness considerably influences on the disintegration rate.展开更多
The storage period of fleshy fruits greatly affects their quality and selection,and is largely controlled by genetic factors.Therefore,it is imperative to elucidate how genetic factors affect fruit ripening and its st...The storage period of fleshy fruits greatly affects their quality and selection,and is largely controlled by genetic factors.Therefore,it is imperative to elucidate how genetic factors affect fruit ripening and its storage.Here,we evaluated the postharvest storage properties of the basic helix-loop-helix(bHLH)transcription factor MdbHLH3-overexpressing transgenic Royal gala apple fruits.During storage,the contents of starch,malic acid,fructose,glucose,and sucrose in fruits of three MdbHLH3 transgenic lines were always higher than those of the wild-type(WT)control.Interestingly,the sugar-acid ratio also showed the same trend during fruit storage.Additionally,the fruit firmness decreased with increasing storage time,and the contents of cell wall components such as water-soluble pectin and cellulose in transgenic fruits were higher than those in control fruits,while the firmness of transgenic fruits was lower than that in WT control fruits.Though the ethylene release rate in both showed the same trend(firstly increasing,then decreasing,and finally peaking)in 90-day stored fruits,transgenic apples had higher ethylene levels than the WT control throughout storage.Furthermore,the activities of membrane peroxidase,antioxidant enzymes,and fruit ripening enzymes in all transgenic fruits were significantly higher than those in the WT control.Thus,our findings show how MdbHLH3 negatively regulates and reduces apple storage time.This may prove useful for not only developing biotechnological strategies,but also support traditional breeding programs,to help improve the storage time of fleshy fruits.展开更多
基金supported by the grants from the National Natural Science Foundation of China (31772330 and 32002043)the Natural Science Foundation of the Heilongjiang Province, China (LH2022C065)the Heilongjiang Bayi Agricultural University Support Program for SanHengSanZong, China (TDJH202004)。
文摘Flesh firmness(FF) is an important and complex trait for melon breeders and consumers. However, the genetic mechanism underlying FF is unclear. Here, a soft fruit melon(P5) and a hard fruit melon(P10) were crossed to generate F2, and the FF and fruit-related traits were recorded for two years. By performing quantitative trait locus(QTL) specificlocus amplified fragment(SLAF)(QTL-SLAF) sequencing and molecular marker-linkage analysis, 112 844 SLAF markers were identified, and 5 919 SNPs were used to construct a genetic linkage map with a total genetic distance of1 356.49 cM. Ten FF-and fruit-related QTLs were identified. Consistent QTLs were detected for fruit length(FL) and fruit diameter(FD) in both years, and QTLs for single fruit weight(SFW) were detected on two separate chromosomes in both years. For FF, the consistent major locus(ff2.1) was located in a 0.17-Mb candidate region on chromosome 2. Using 429 F2individuals derived from a cross between P5 and P10, we refined the ff2.1 locus to a 28.3-kb region harboring three functional genes. These results provide not only a new candidate QTL for melon FF breeding but also a theoretical foundation for research on the mechanism underlying melon gene function.
基金the National Natural Science Foundation of China(Grant No.71904116)the Fund from the Shanghai Municipal Commission of Science and Technology,China(Grant Nos.19DZ1209600 and 18DZ1201500)。
文摘Exit choice is one of the most important pedestrian behaviors during evacuation.Distance to the exit is a generally recognized factor influencing expected moving time to the exit.Visual range determines how much information a pedestrian can perceive,thus the number of pedestrians within the visual field can be used to estimate waiting time at the exit.Besides,the choice firmness that reflects the degree to which a pedestrian would persist in his/her previous choice of exit is proposed.By integrating game theory into a cellular automata simulation framework,the pedestrian exit choice mechanism is investigated and explicitly modeled in this paper.A systematic analysis of the key factors influencing pedestrian evacuation is conducted,including visual radius and choice firmness of a pedestrian,initial crowd distribution of the room,exit layout as well as exit width.It is found that low choice firmness level can lead to unnatural pedestrian behavior such as wandering,which is adverse to evacuation.The longer the pedestrian's visual radius,the earlier the pedestrian can determine his/her final selection of the exit.Compared with the scenario where the pedestrians are randomly distributed,pedestrians clustered together in a corner of the room lead to high crowd density and imbalanced use of exits.Furthermore,the exit layout and exit width also have a certain influence on pedestrian evacuation process.The results of this paper may be of benefit to the formulation of behavioral rules in other pedestrian simulation models.
文摘Nowadays,many researches have been accomplished on the attributed quality assessment of agricultural products.Fruits have significantly contributed to these researches because of their high production and consumption,worldwide.In this paper,the nondestructive instrumental researches in the field of firmness assessment for apple fruit discussed.These researches are important for all production and distribution chain activists such as farmers,insurance companies,packaging and transportation companies,wholesalers and retailers.These studies can be used for examining texture quality,predicting the right time to harvest fruits and classifying them according to the level of ripeness and detecting the apparent and internal defects of the fruit.The apple flesh firmness measurement methods consist of acoustic and mechanical vibration methods,optical methods such as hyperspectral scattering imaging,near infrared,ultrasound and other methods.The destructive puncture test method commonly used as a reference method.Nondestructive methods are accurate and quick that is suitable for online applications.Recently,the use of artificial intelligence methods and data fusion techniques to increase the accuracy of quality measuring of the products has been considered that in the future we will see further development of these methods in measuring the firmness of the apples.
基金Under the auspices of Natural Science Foundation of China(No.42122006,41971154)。
文摘Firms are embedded in complex networks,where diverse ideas combine and generate new ideas.Shareholders of firms are of-ten seen as critical external resources that have significant influence on firm innovation.The current literature tends to focus on the rela-tionship between firms and their shareholders,while paying less attention to the connections between firms with the same shareholders.This article identifies two types of network spillover effects,intra-city network effect and inter-city network effect,by visualizing the co-ownership networks in China’s electric vehicle(EV)industry.We find that firms with the same shareholders,which are defined as co-owned EV firms,are more innovative than non-co-owned ones.Furthermore,there are two dominant types of firm co-ownership ties formed by corporate and financial institution shareholders.While corporate shareholders help exploiting local tacit knowledge,financial institutions are more active in bridging inter-city connections.The conclusion is confirmed at both firm and city levels.This paper theor-izes the firm co-ownership network as a new form of institutional proximity and tested the result empirically.For policy consideration,we have emphasized the importance of building formal or informal inter-firm network,and the government should further enhance the knowledge flow channel by institutional construction.
基金The authors gratefully acknowledge the financial support provided by National Natural Science Foundation of China(No.30671197)the Program for New Century Excellent Talents in University(No.NCET-04-0524).
文摘Firmness is one of the most important characteristics to estimate fruit maturity and quality.The potential of near-infrared(NIR)diffuse reflectance spectroscopy as a nondestructive way for pear firmness evaluation of three varieties(‘Cuiguan’,‘Xueqing’and‘Xizilv’)was studied,both quantitatively and qualitatively.NIR models were established using partial least square(PLS)methods in the spectral range of 800 to 2500 nm.For quantitative analysis,the correlation coefficient r increased with more varieties involved in the model.Best results were obtained in the model for all three varieties:rcalwas 0.934,root mean square error of calibration(RMSEC)and root mean square error of prediction(RMSEP)were 2.06 N and 3.14 N,respectively.For qualitative analysis,the overall accuracies of discriminant PLS models for classifying pears into three firmness levels:low,medium and high firmness level were not so good,percentage of samples correctly classified ranged from 70.63%to 81.25%for calibration and from 56.25%to 74.38%for validation.The results indicate that NIR spectroscopy together with PLS chemometrics method is feasible for quantitative analysis of pear firmness,however,the classification accuracy is too low to put into practical application.
基金We express our appreciation to the head of department of Madrid Polytechnic University Physical Properties Laboratory(Technical University of Madrid LPF-TAGRALIA)for support to this studyThe authors Kubilay Kazim VURSAVUS and Yesim Benal YURTLU were also supported by a grant from The Council of Higher Education of Turkish Government for the present study.
文摘The objectives of this research were to compare the performance of each individual nondestructive sensor with the destructive sensor,and to apply sensor fusion technique to explore whether a combination of sensors would give better results than a single sensor for classification of peach firmness.Tests were carried out with four peach varieties namely Royal Glory,Caterina,Tirrenia and Suidring.In this research,the three nondestructive firmness sensors acoustic firmness,low-mass impact and micro-deformation impact were used to measure firmness.A Bayesian classifier was chosen to provide a classification into three categories,namely soft,intermediate and hard.High level fusion technique was performed by using identity declaration provided by each sensor.The data fusion system processed the information of the sensors to output the fused data.The result of the high level fusion was compared with the classification provided by an unsupervised algorithm based on destructive reference measurement.The fusion process of the nondestructive sensors provided some improvements in the firmness classification;the error rate varied from 25%to 19%for individual sensor.Furthermore,the results of fusion process by using three sensors decreased the error rate from 19%to 13%.This research demonstrated that the fused systems provided more complete and complementary information and,thus,were more effective than individual sensors in the firmness classification of peaches.
基金supported by the National Natural Science Foundation of China(Grant No.32202139,32260618)the Tarim University President Fund Project(Grant No.TDZKCQ201902,TDZKSS202109)+2 种基金the Innovation Research Team Project of President’s Fund of Tarim University(Grant No.TDZKCX202203)Xinjiang Production&Construction Group Key Laboratory of Agricultural Products Processing in Xinjiang South(Grant No.AP1905)the“Strong Youth”Key Talents of Scientific and Technological Innovation(Grant No.2021CB039)and the authors also acknowledge all of the persons who assisted in this writing.
文摘In order to achieve the non-destructive detection of the firmness of Korla fragrant pear during the ripening period,the characteristic variables integrating the parallel equivalent inductance(Lp),quality factor(Q),parallel equivalent capacitance(Cp),dissipation factor(D),parallel equivalent resistance(Rp)and impedance(Z)were formulated through principal component analysis(PCA).Further,based on the characteristic variables,the models were established for predicting the firmness of Korla fragrant pear by using the generalized regression neural network(GRNN)and back-propagation neural network(BPNN).The results showed that firmness has significant correlations with the six electrical parameters.The first two principal components(PCs)were selected as the characteristic variables of the electrical parameters.GRNN exhibited the best performance in predicting firmness(R2=0.9628,RMSE=0.383).The results could provide important references for non-destructive detection of the quality of Korla fragrant pear.
基金the China Agriculture Research System Project(CARS-30-4-01)the National Natural Science Foundation of China(Grant No.31571764).
文摘Firmness is one of the important indices to evaluate the internal quality of fruit.In this study,a noncontact loudspeaker-based detection system was developed to evaluate apple firmness.The structural parameters of the excitation device were modified in the single-factor experiments,and the best combination of structural parameters was that the inner diameter of the gasket was 40 mm;the distance between fruit surface and loudspeaker was 95 mm.Besides,the proper posture style was that the apple was placed with its stem upward.After the modification of the Laser Doppler Vibrometer(LDV)method,the vibration response signals of 48 apples were measured to establish the firmness prediction model.The results showed that the better prediction performance of stiffness was obtained in multiple models.The Back Propagation Neural Network(BPNN)model had the best prediction performance by using parameters of elasticity index(EI),the peak value at the second resonance frequency f_(2)(A_(2)),and peak area S,with a correlation coefficient of prediction(r_(p))of 0.914;root mean square error of prediction(RMSEP)of 0.491 N/mm.Therefore,the proposed detection system is feasible to nondestructively detect apple firmness,which has the potential to be applied in online detection.
文摘An important feature of China developing its aerospace industry is its insistence on self-reliance and independent innovation,because China firmly believes that aerospace is a hi-tech industry and high core technologies cannot be bought.Only by mastering core technologies can China firmly grasp the initiative in development.
基金supported by the China Agriculture Research System of MOF and MARA (CARS-27)
文摘Fruit development and ripening is a complex procedure(Malus×domestica Borkh.)and can be caused by various factors such as cell structure,cell wall components,and cell wall hydrolytic enzymes.In our study,we focused on the variations in fruit firmness,cell wall morphology and components,the activity of cell wall hydrolytic enzymes and the expression patterns of associated genes during fruit development in two different types of apple cultivars,the hard-crisp cultivar and the loose-crisp cultivar.In this paper,the aim was to find out the causes of the texture variations between the different type cultivars.Cell wall materials(CWMs),hemicellulose and cellulose content were strongly associated with variations in fruit firmness during the fruit development.The content of water soluble pectin(WSP)and chelator soluble pectin(CSP)gradually increased,while the content of ionic soluble pectin(ISP)showed inconsistent trends in the four cultivars.The activities of polygalacturonase(PG),β-galactosidase(β-gal),cellulase(CEL),and pectate lyase(PL)gradually increased in four cultivars.And the activities of PG,β-gal,and CEL were higher in‘Fuji’and‘Honeycrisp’fruit with the fruit development,while the activity of PL of‘Fuji’and‘Honeycrisp’was lower than that of‘ENVY’and‘Modi’.Both four cultivars of fruit cells progressively became bigger as the fruit expanded,with looser cell arrangements and larger cell gaps.According to the qRT-PCR,the relative expression levels of MdACO and Mdβ-gal were notably enhanced.Our study showed that there were large differences in the content of ISP and hemicellulose,the activity of PL and the relative expression of Mdβ-gal between two different types of apple cultivars,and these differences might be responsible for the variations in the texture of the four cultivars.
基金This work was supported by National Natural Science Foundation of China[No.72091515]the Natural Science Fund of Hunan Province(2022JJ40647).
文摘Increasing attention has been focused on the extent to which corporate political connections influence the growing pollution due to the rapid growth in the popularity of firm pollution in developing countries.We adopt a static threshold regression model to investigate the effects of heterogeneous environmental regulation on political connections and firm pollution based on the panel data from China’s A-share listed companies from 2012 to 2019.The empirical results show a non-linear relationship between the degree of political connection of listed company executives and the level of firm pollution.And the relationship between the two roughly presents a U-shaped relationship under the action of the marketincentive environmental regulation threshold.However,it roughly presents an inverted N-shaped relationship under the action of the command-control environmental regulation threshold.Additionally,the group test results show that the existence of regional and ownership heterogeneity causes certain differences in the environmental behaviour of politically connected enterprises.These findings indicate that diverse environmental regulations are needed to promote sustainable green development and to further expand the theoretical and practical exploration of political connections on firm pollution.
文摘For this study of long-term spatial patterns and trends of active fires in southern hemispheric Africa and on Madagascar from 2001 to 2020,active fire data from the MODIS FIRMS global fire data products were analyzed.The annual center of fire concentration tended to migrate toward the preserved rainforests and nature conservation areas in the Congo Basin and the mountain forests on the northeastern coast of Madagascar.Fire frequency varied seasonally at both study areas.We used geo statistical analysis techniques,such as measures of dispersion and emerging hot spot analysis,to reveal long-term trends in spatial patterns of fire events.In southern hemispheric Africa,the observed active fires tended to drift northward toward the Zambia-DRC border in the Congo basin.This northward migration progressed toward humid rainforests,which were better suited to sustaining repeated fire events.On Madagascar,the observed active fires tended to migrate toward the east coast in protected mountain forests.The spatial patterns of long-term trends showed a concentration of fires in the tropical regions of southern hemispheric Africa.Moreover,smaller clusters of new hot spots were located over eastern South Africa,overlapping with undifferentiated woodlands.On Madagascar,both hot and cold spots were identified and were separated by the highland region in the center of the island.Most of the eastern island was characterized by cold spots that received less precipitation than did the rest of the island.The presence of increasing hots spots in the densely vegetated areas highlights the urgent need for fire prevention and management in this region.
文摘This paper explores the relationship between resource constraints and innovation of new firms.Drawing upon the relevant literature,we incorporate resource constraints as the antecedent to the bricolage-innovation link.Compared to prior studies that treated resource constraints as a one-dimensional variable,we operationalize it along two dimensions:knowledge constraints and financial constraints.Our argument posits that knowledge constraints and financial constraints act as catalysts for innovation in new firms,with bricolage serving as a mediating role.To test our hypotheses,we conducted a survey involving 183 entrepreneurs in the United States.The data analysis demonstrates that bricolage fully mediates the relationship between knowledge con‐straints and innovation and partially mediates the relationship between financial constraints and innovation.Theoretical and practical implications are discussed.
基金Under the auspices of the National Natural Science Foundation of China (No.42101182,41871150)Guangdong Academy of Sciences (GDSA)Special Project of Science and Technology Development (No.2021GDASYL-20210103004,2020GDASYL-20200102002,2020GDASYL-20200104001)the Natural Science Foundation of Guangdong (No.2023A1515012399)。
文摘Innovation capitalization is a new concept in innovation geography research.Extant research on a city scale has proven that innovation is an important factor affecting housing prices and verified that innovation has a capitalization effect.However,few studies investigate the spatial heterogeneity of innovation capitalization.Thus,case verification at the urban agglomeration scale is needed.Therefore,this study proposes a theoretical framework for the spatial heterogeneity of innovation capitalization at the urban agglomeration scale.Examining the Guangdong-Hong Kong-Macao Greater Bay Area(GHMGBA),China as a case study,the study investigated the spatial heterogeneity of the influence of high-tech firms,representing innovation,on housing prices.This work verified the spatial heterogeneity of innovation capitalization.The study constructed a data set influencing housing prices,comprising 11 factors in 5 categories(high-tech firms,convenience of living facilities,built environment,the natural environment,and the fundamentals of the districts)for 419 subdistricts in the GHMGBA.On the global scale,the study finds that high-tech firms have a significant and positive influence on housing prices,with the housing price increasing by 0.0156%when high-tech firm density increases by 1%.Furthermore,a semi-geographically weighted regression(SGWR)analysis shows that the influence of high-tech firms on housing prices has spatial heterogeneity.The areas where high-tech firms have a significant and positive influence on housing prices are mainly in the GuangzhouFoshan metropolitan area,western Shenzhen-Dongguan,north-central Zhongshan-Nansha district,and Guangzhou—all areas with densely distributed high-tech firms.These results confirm the spatial heterogeneity of innovation capitalization and the need for further discussion of its scale and spatial limitations.The study offers implications for relevant GHMGBA administrative authorities for spatially differentiated development strategies and housing policies that consider the role of innovation in successful urban development.
文摘An attempt was made to observe the effect of pre-harvest bagging with spun-bound fabric bags on color and quality of Delicious apple. Bagging was done about a month before harvesting and removed 3-day before harvesting. Bagged and non-bagged fruits were stored at 2℃ ± 1℃ and 90%-95% RH. Observations were recorded on color and fruit quality attributes such as total phenolics, AOX activity, fruit Ca contents, LOX activity, SSC and ascorbic acid contents at harvest and during storage. Our studies have revealed that bagged fruits have better color development (Hunter “a” = 52) than non-bagged fruits at harvest (Hunter “a” = 38), which declined slightly during storage. Similarly, at harvest, bagged fruits contained high amounts of Ca (5.38 mg/100g) and total phenolics (9.3 mg GAE/100gpulp) exhibited higher AOX activity (12.6 μmoles Trolox g-1), and had better SSC and ascorbic acid contents than non-bagged fruits, and there was a decline in all recorded parameters during storage. Bagged fruits exhibited lower LOX activity (1.38 μmoles min-1 g-1 FW) at harvest than non-bagged fruits (2.14 μmoles min-1 g-1 FW), indicating that non-bagged fruits were more senescent than bagged fruits. Further, LOX activity increased during storage both in bagged and non-bagged apples but increase in LOX activity was slower in bagged apples than in non-bagged apples.
文摘Xylanase is a hemicellulase that can hydrolyses the complex polysaccharides.Hemicelluloses are main components of cell walls of cereal grains.Moreover,hemicelluloses are considered as potential sources of mono-and oligosaccharides.In this study,influence of xylanase on the physicochemical properties and sensory qualities of the whole wheat bread during storage was investigated.Studies of whole wheat bread on microstructure,texture,thermotics,Scanning Electron Microscopic(SEM),X-Ray Diffraction(XRD)were conducted at ambient temperature of 25 and 4◦C respectively.During storage at different temperatures,bread containing xylanase exhibited less firmness but larger volume with whiter crumb color and longer shelf life as compared to control bread.Results of firmness,enthalpy,Fourier Transformation Infra Red(FTIR)and X-Ray Diffraction(XRD)studies suggested a lower staling rate of bread containing xylanase as compared to control one.Bread containing xylanase showed a smoother surface and more uniform pore size than the control.Significant differences in microstructure of control and bread containing xylanase were observed which might be attributed due to the change in water starch gluten interaction.These differences were also found to be interrelated to the textural properties of bread.Better sensory features were achieved in bread containing xylanase.
文摘The experiment shows that considerable influence on density rock properties are subjected by nival weathering conditions. The main parameter defining the rock suitability for solution various engineering and geological problems is its firmness limit on single axis pressing.The firmness properties of sandstone being in absolutely dry condition for Kabakta suite at the beginning of investigation was 64.7 MPa, for Nerungri suite sandstones it was 48.7 MPa. The investigations showed how much the nival conditions of cryohypergenesis of rock sandstones in Kabakta and Nerungri suites have destructive influence in comparison with aquale and more over aerale conditions. In the aerale conditions sedimentary rock firmness of Kabakta suite decreased to 23.2 MPa, in aquale conditions to 16.5, and in the nivale conditions to 8.9 MPa. In Nerungri suite sandstones are according to 17.7 MPa, 11.1 MPa, and 6 MPa after 300 freezing and thawing cycles. The common sandstone firmness decrease of Kabakta suite was 25 %, of Nerungri suite it was 23.8%. Marlstone samples after 400 FTC decrease to 62% in the nivale conditions and to 33% in the aerale conditions. After 3～5 years of exploitation marlstone will destruct due to structural and textural inhomogenesis up to gruss, i.e. it will not meet the requirements of durability. Judging by the results of carried out experiment it should be concluded that by cryogenic weathering the sedimentary rocks (sandstones) and rocks with schistose lithogenic texture (marlstone) are subjected to disintegration. The primary rock samples firmness considerably influences on the disintegration rate.
基金supported by grants from the National Natural Science Foundation of China (Grant Nos.32122080,31972375)the National Key Research and Development Program of China (Grant No.2018YFD1000200)the Natural Science Foundation of Shandong Province (Grant No.ZR2020YQ25)。
文摘The storage period of fleshy fruits greatly affects their quality and selection,and is largely controlled by genetic factors.Therefore,it is imperative to elucidate how genetic factors affect fruit ripening and its storage.Here,we evaluated the postharvest storage properties of the basic helix-loop-helix(bHLH)transcription factor MdbHLH3-overexpressing transgenic Royal gala apple fruits.During storage,the contents of starch,malic acid,fructose,glucose,and sucrose in fruits of three MdbHLH3 transgenic lines were always higher than those of the wild-type(WT)control.Interestingly,the sugar-acid ratio also showed the same trend during fruit storage.Additionally,the fruit firmness decreased with increasing storage time,and the contents of cell wall components such as water-soluble pectin and cellulose in transgenic fruits were higher than those in control fruits,while the firmness of transgenic fruits was lower than that in WT control fruits.Though the ethylene release rate in both showed the same trend(firstly increasing,then decreasing,and finally peaking)in 90-day stored fruits,transgenic apples had higher ethylene levels than the WT control throughout storage.Furthermore,the activities of membrane peroxidase,antioxidant enzymes,and fruit ripening enzymes in all transgenic fruits were significantly higher than those in the WT control.Thus,our findings show how MdbHLH3 negatively regulates and reduces apple storage time.This may prove useful for not only developing biotechnological strategies,but also support traditional breeding programs,to help improve the storage time of fleshy fruits.
