To investigate the effects of drinking the soaking of Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China.It has been reported that longevity...To investigate the effects of drinking the soaking of Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China.It has been reported that longevity is closely related to metabolism and the gut microbiota.The 16S rRNA sequencing and liquid chromatography-mass spectrometry(LC-MS)were used to analysis fecal samples and explore the factors affecting longevity in the region.Interestingly,we discovered,that elderly individuals who had been drinking the soaking of M.domeri(Bois)Chev.leaves for a long time exhibited higher diversity of the gut microbiota than without drinking the soaking,notably.The proportions of Ruminococcaceae and Prevotella were decreased in those who did not drink this soaking.In addition,a total of 106 metabolites were characterized,and the people of long-lived people(>90 years old)and elderly people(<90 years old)who drinking soaking of M.domeri(Bois)Chev.leaves significantly altered the gut microbiota and upregulated levels of haplopine,farnesol,genipic acid,momordicinin,2-hydroxyestrone,hydroxyphenyllactic acid,caffeic acid,sophoraflavanone B,and soyasaponin I.We preliminarily determined that M.domeri(Bois)Chev.leaves consumption may be an important factor affecting longevity in this area.展开更多
Agriculture is the foundation of the national economy.The periodicity of agricultural product output and prices,the asymmetry of information between buyers and sellers,and the inherent characteristics of small scale,h...Agriculture is the foundation of the national economy.The periodicity of agricultural product output and prices,the asymmetry of information between buyers and sellers,and the inherent characteristics of small scale,high cost,and low profit have caused slow sales,which greatly hurt the enthusiasm of farmers to develop production and endanger social stability.Constructing an informationized and commercialized trading platform and an information sharing platform through e-commerce and establishing related systems and supervision mechanisms will help to promote the rapid growth of agricultural product sales.Research has shown that in the field of agricultural circulation,e-commerce has a significant effect on increasing the scale of agricultural trade.展开更多
To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to f...To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to form the interlayers.The multilayer structure contributes to the high permeability by reducing the coercivity and diminishing out-of-plane magnetization.The maximum imaginary permeability of[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer film reaches a large value of 800 at 0.52 GHz even though its overall thickness exceeds 1μm.Besides,the magnetic resonance frequency of the multilayer film can be modulated from 0.52 to 1.35 GHz by adjusting the sputtering power of Fe from 0 to 86 W,and its bandwidth for μ’’>200(Δf) is as large as 2.0 GHz.The desirable broad Δf of magnetic permeability,which can be well fitted by the Landau-Lifshitz-Gilbert equations,is due to dual magnetic resonances originated from double magnetic phases of Fe and FeNi that are of different saturation magnetization.The micron-thick multilayer films with high permeability in extended waveband are promising candidate for electromagnetic noise suppression application.展开更多
The frontogenetic processes of a submesoscale cold filament driven by the thermal convection turbulence are studied by a non-hydrostatic large eddy simulation.The results show that the periodic changes in the directio...The frontogenetic processes of a submesoscale cold filament driven by the thermal convection turbulence are studied by a non-hydrostatic large eddy simulation.The results show that the periodic changes in the direction of the cross-filament secondary circulations are induced by the inertial oscillation.The change in the direction of the secondary circulations induces the enhancement and reduction of the horizontal temperature gradient during the former and later inertial period,which indicates that the frontogenetical processes of the cold filament include both of frontogenesis and frontolysis.The structure of the cold filament may be broken and restored by frontogenesis and frontolysis,respectively.The magnitude of the down-filament currents has a periodic variation,while its direction is unchanged with time.The coupling effect of the turbulent mixing and the frontogenesis and frontolysis gradually weakens the temperature gradient of the cold filament with time,which reduces frontogenetical intensity and enlarges the width of cold filament.展开更多
Calcium carbonate,which is widely employed as a filler added into the polymer matrix,has large numbers of applications owing to the excellent properties such as low cost,non-toxicity,high natural reserves and biocompa...Calcium carbonate,which is widely employed as a filler added into the polymer matrix,has large numbers of applications owing to the excellent properties such as low cost,non-toxicity,high natural reserves and biocompatibility.Nevertheless,in order to obtain the good filling effect,calcium carbonate needs to be surface modified by organic molecules so as to enhance the dispersion and compatibility within the composites.This review paper systematically introduces the theory,methods,and applications progress of calcium carbonate with surface modification.Additionally,the key factors that affect the properties of the composites as well as the current difficulties and challenges are highlighted.The current research progress and potential application prospects of calcium carbonate in the fields of plastics,rubber,paper,medicine and environmental protection are discussed as well.Generally,this review can provide valuable reference for the modification and comprehensive utilization of calcium carbonate.展开更多
According to the problems of short life and low strength of TiB2 coating cathode for current technology in aluminium electrolysis industry,this work synthesized TiB2-TiB/Ti gradient composite with TiB2 coating and TiB...According to the problems of short life and low strength of TiB2 coating cathode for current technology in aluminium electrolysis industry,this work synthesized TiB2-TiB/Ti gradient composite with TiB2 coating and TiB whiskers in metallic Ti matrix by a electrolytic boronizing method based on similar density and thermal expansivity of the three materials.The phase composition and morphology of the cross-section were determined by X-ray diffraction(XRD),scanning electronic microscope(SEM)and X-ray energy dispersive spectrum(EDS).The results show that uniform TiB2 layer with a thickness of 8-10μm is continuously coated on the surface while the TiB whisker connected with TiB2 layer was embedded dispersedly into the matrix.The TiB crystal whisker has a maximum length of about 220μm.The growth rate of TiB2 and TiB is enhanced by the strong reduction of B4C.The novel gradient design of the composite helps to extend life and improve strength of the TiB2 cathode in aluminium electrolysis.展开更多
Rational fertilization is an important measure to increase crop yield and soil fertility. Through analysis,this paper aims to master the change characteristics of soil organic matter and rice yield under different fer...Rational fertilization is an important measure to increase crop yield and soil fertility. Through analysis,this paper aims to master the change characteristics of soil organic matter and rice yield under different fertilizer treatments,in order to provide an important reference for the sustainable use of soil and effective fertilization. Long-term( 19 years) rice crop rotation experiments in waterloggogenic paddy soil were conducted to investigate the change trend of crop grain yield and soil organic matter with time,reveal the dynamic characteristics and relationship between main fertility factors and crop yields using comparative analysis at three sites with conventional fertilization and non-fertilization in Guilin. The results showed that compared with previous years,the rice yield increased by 53% under the fertilization treatment and degreased by 66% under the control. Over the years,the average soil organic matter( SOM) content under fertilization treatment was 23% higher than under CK treatment. This indicates that chemical fertilizer and organic manure application can increase the rice yield and soil organic matter,and high rice yield can be attributed to the SOM increase.展开更多
Gross agricultural product is an important indication to measure the agricultural development level of a region. It would be affected by many factors,having the characteristics of non- linearity. For this reason,LM- B...Gross agricultural product is an important indication to measure the agricultural development level of a region. It would be affected by many factors,having the characteristics of non- linearity. For this reason,LM- BP neural network was put forward as the model and method for predicting gross agricultural product. Taking the indications of the sown area of crop,the output of grain,sugarcane,cassava,tea,meat,aquatic products,turpentine and camellia seed,etc. as inputs,during 2000 to 2012 in Guangxi,the gross agricultural product data from the analysis of simulation experiment show that the prediction of LM- BP neural network fits well with actual results.展开更多
With the rapid development of the economy, people’s living standards have been improved constantly. As people’s material life has been gradually improved, people pay more attention to the pursuit of high-quality spi...With the rapid development of the economy, people’s living standards have been improved constantly. As people’s material life has been gradually improved, people pay more attention to the pursuit of high-quality spiritual life, and the flourishing development of rural tourism just meets people’s pursuit about returning to nature that is far away from the hustle and bustle of the city, and about experiencing funny and quiet life in the countryside. The development of rural tourism relies on agricultural landscape resources, and the correct understanding and protection of the original value of agricultural landscape resources can effectively ensure the sustainable use of agricultural landscape resources. If land for agricultural landscape resource is occupied for developing blindly without reasonable planning and construction, it will lead to the distortion of the authentic value of agricultural landscape, which in turn affects the sustainable development of rural tourism.展开更多
Plant landscaping in courtyard design was studied from four perspectives of building, water, road, garden setting and plant landscaping. Landscape designs in Guangzhou Baiyun Hotel, the Humble Administrator's Gard...Plant landscaping in courtyard design was studied from four perspectives of building, water, road, garden setting and plant landscaping. Landscape designs in Guangzhou Baiyun Hotel, the Humble Administrator's Garden (Suzhou), and bamboo pathway of Small Yingzhou in the West Lake (Hangzhou) to improve scientific and artistic properties of plant landscaping, and develop economic, social and ecological effects of garden green spaces to the most.展开更多
[Objectives]This study was conducted to investigate the synergized preservation effect of different concentrations of prochloraz and chitosan on citrus Gonggan,so as to prolong the sales period of Gonggan.[Methods]&qu...[Objectives]This study was conducted to investigate the synergized preservation effect of different concentrations of prochloraz and chitosan on citrus Gonggan,so as to prolong the sales period of Gonggan.[Methods]"Zhongshan Gonggan" was used as a material.The Gonggan fruit was soaked with prochloraz (250,300 and 350 mg/L) and then coated with different concentrations of chitosan (1.0% and 1.5%),respectively.The good fruit rate,weight loss rate and titratable acid (TA),reducing sugar,total soluble solids (TSS) and Vc contents were used as evaluation indexes to investigate the preservation effect of Gonggan during cold storage.[Results]The treatment of prochloraz plus chitosan can significantly prolong the shelf life of Gonggan as it can inhibit the decline of good fruit rate,reduce the weight loss rate,and slow down the degradation and loss of titratable acid,reducing sugar,soluble solids and Vc.The 350 mg/L prochloraz+1.0% chitosan treatment was superior to other treatments.[Conclusions]This study provides a theoretical basis for better prolonging the storage period of Gonggan.展开更多
The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibil...The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.展开更多
Photo-induced intramolecular electron transfer (PIET) and intramolecular vibrational relaxation (IVR) dynamics of the excited state of rhodamine 6G (Rh6G+) in DMSO are investigated by multiplex transient gratin...Photo-induced intramolecular electron transfer (PIET) and intramolecular vibrational relaxation (IVR) dynamics of the excited state of rhodamine 6G (Rh6G+) in DMSO are investigated by multiplex transient grating. Two major compo- nents are resolved in the dynamics of Rh6G+. The first component, with a lifetime τTPIET = 140 fs-260 fs, is attributed to PIET from the phenyl ring to the xanthene plane. The IVR process occurring in the range ZIVR = 3.3 ps-5.2 ps is much slower than the first component. The PIET and IVR processes occurring in the excited state of Rh6G+ are quantitatively determined, and a better understanding of the relationship between these processes is obtained.展开更多
[Objectives]This study was conducted to discuss the change laws and relationships of the physiological indexes in green plums treated with nisin or 1-MCP in the cold storage process.[Methods]Different storage methods ...[Objectives]This study was conducted to discuss the change laws and relationships of the physiological indexes in green plums treated with nisin or 1-MCP in the cold storage process.[Methods]Different storage methods on the physiological and quality indexes of green plums were investigated through two kinds of different treatment methods(treatment 1:1-MCP+cold storage,treatment 2:nisin+cold storage),with rotten fruit rate,weight loss rate,yellow ripeness index,hardness,Vc content,titratable acid,soluble solids and peroxidase(POD)activity as the evaluation indexes.[Results]The storage method of treating green plums with 1-MCP combined with cold storage could delay the quality decline of green plums after harvest,while the effect of nisin treatment was slightly inferior.1-MCP treatment followed by cold storage could more effectively delay the senescence of green plums,delay the decrease of fruit hardness and soluble solid content to the greatest extent,and maintain the titratable acid and Vc contents at relatively good levels.It further reduced weight loss rate and rotten fruit rate,postponed the time of the peak of POD enzyme activity,and reduced the loss of nutrients in the fruit,thereby maintaining good commercial properties of the fruit.[Conclusions]This study plays an important role in the post-harvest storage,preservation and transportation,as well as the development of the green plum industry.展开更多
Soil temperature regime(STR)is important for soil classification and land use.Generally,STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm(MAST50)according to the Chinese Soil Taxonom...Soil temperature regime(STR)is important for soil classification and land use.Generally,STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm(MAST50)according to the Chinese Soil Taxonomy(CST).However,delineating the STR of China remains a challenge due to the difficulties in accurately estimating MAST50.The objectives of this study were to explore environmental factors that influence the spatial variation of MAST50 and generate an STR map for China.Soil temperature measurements at 40 and 80 cm depth were collected from 386 National Meteorological Stations in China during 1971–2000.The MAST50 was calculated as the average mean annual soil temperature(MAST)from 1971–2000 between 40 and 80 cm depths.In addition,2048 mean annual air temperature(MAAT)measurements from 1971 to 2000 were collected from the National Meteorological Stations across China.A zonal pedotransfer function(PTF)was developed based on the ensemble linear regression kriging model to predict the MAST50 in three topographic steps of China.The results showed that MAAT was the most important variable related to the variation of MAST50.The zonal PTF was evaluated with a 10%validation dataset with a mean absolute error(MAE)of 0.66°C and root mean square error(RMSE)of 0.78°C,which were smaller than the unified model with MAE of 0.83°C and RMSE of 0.96°C,respectively.This study demonstrated that the zonal PTF helped improve the accuracy of the predicted MAST50 map.Based on the prediction results,an STR map across China was generated to provide a consistent scientific base for the improvement and application of CST and land use support.展开更多
In this experiment,two-factor 7-level uniform design scheme was applied.Separate treatment of each factor was performed for single effect test.Then,it analyzed the effects of acid and aluminum stress under soilless cu...In this experiment,two-factor 7-level uniform design scheme was applied.Separate treatment of each factor was performed for single effect test.Then,it analyzed the effects of acid and aluminum stress under soilless culture on the water content of plant during the growth of Ginkgo biloba L.seedlings,so as to provide a theoretical basis for studying the connection between plant water and physiological stress.The results showed that the water content of G.biloba plants declined with the decrease of p H,but the water content of G.biloba plants declined with the increase in the concentration of aluminum treatment,indicating that the stronger the acid and aluminum stress,the lower the water content of the plants,affecting the normal absorption of water content of G.biloba plants,accordingly leading to lack of water.According to the analysis of the degree of influence on the water content,p H is the first factor influencing the growth of G.biloba plants.If p H is lower than 3.5,G.biloba plants will not growth,while p H is higher than 5.0,aluminum has no significant effect on the water content of G.biloba plants.In conclusion,the water content of G.biloba plants can be used as an essential indicator for acid and aluminum stress.展开更多
[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condit...[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condition of 4℃,a uniform design(U6*(64))experiment was carried out to optimize the compound preservative formula,and a better compound preservative formula was obtained using the regression equation.[Results]The compound preservative formula was:AA 0.25%,CA 0.5%,Nisin 0.09%,GSH 0.15%.The compound fresh-keeping liquid effectively delayed the browning of fresh-cut yam and the accumulation of MDA,maintained the content of TSS,inhibited the activity of PAL and delayed the appearance of the maximum activity of POD and POD.[Conclusions]This study provides technical support for the actual extension of the shelf life of fresh-cut yam.展开更多
Based on the basic principles of rain garden infrastructure, optimal species for rain facilities such as vegetated buffer strip, vegetated shallow groove, artificial wetland were selected, characteristics, configurati...Based on the basic principles of rain garden infrastructure, optimal species for rain facilities such as vegetated buffer strip, vegetated shallow groove, artificial wetland were selected, characteristics, configuration principles and methods were summarized.展开更多
Assessing the impact of plantation on microbial respiration (MR) is vitally important to understand the interactions between belowground metabolism and land use change. In this study, cumulative MR was determined by...Assessing the impact of plantation on microbial respiration (MR) is vitally important to understand the interactions between belowground metabolism and land use change. In this study, cumulative MR was determined by alkali absorption method in 1, 3, 7, 14, 21,28, 35, 42, 49, and 56 days from the soil in a representative plantations in the subtropical region of China. The treatment of plantations contained no plant (CK), orange trees (Citrus reticulata)+Bahia grass (Paspalum notatum) (GB), orange trees (C. reticulata)+Bahia grass (P. notatum)+soybean (Giycine max (L.) Merrill) (GBH). Results showed that plantation had significant effects on microbial respiration and the responses of microbial respiration to plantation from different soil layers and topographies were different: in 0-20 cm in uphill: GB〉GBH〉CK; in 20-40 cm in uphill: GBH〉CK〉GB; in 0-20 cm in downhill: GBH〉CK〉GB; in 20-40 cm in downhill: GB〉CK〉GBH. Furthermore, plantation also altered the relationships between MR and soil properties. In CK, microbial respiration was positively correlated with NH4+ and soil total N, and negatively correlated with soil moisture, pH, NO3-, and microbial biomass carbon (MBC). In GB, microbial respira- tion under GB significantly negatively correlated with dissolved organic carbon (DOC). In GBH, microbial respiration under GBH was positively correlated with NH4+, MBC, total soil carbon (TC), and total soil nitrogen (TN), and negatively correlated with soil moisture (SM), pH, NO-, and DOC. The underlying mechanisms could be attributed to soil heterogeneity and the effects of plantation on soil properties. Our results also showed that plantation significantly increased soil C storage, which suggested plantation is a key measure to enhance soil C sequestration and mitigate global CO2 emission, especially for the soil with low initial soil carbon content or bared soil.展开更多
This paper proposes a new full Nesterov-Todd(NT) step infeasible interior-point algorithm for semidefinite programming. Our algorithm uses a specific kernel function, which is adopted by Liu and Sun, to deduce the fea...This paper proposes a new full Nesterov-Todd(NT) step infeasible interior-point algorithm for semidefinite programming. Our algorithm uses a specific kernel function, which is adopted by Liu and Sun, to deduce the feasibility step. By using the step, it is remarkable that in each iteration of the algorithm it needs only one full-NT step, and can obtain an iterate approximate to the central path. Moreover, it is proved that the iterative bound corresponds with the known optimal one for semidefinite optimization problems.展开更多
基金supported by the National Natural Science Foundation of China (32072193)the Natural Science Foundation of Guangxi,China (2020GXNSFBA297083)。
文摘To investigate the effects of drinking the soaking of Malus domeri(Bois)Chev.leaves on gut microbiota and metabolites of long-living elderly individuals in Hezhou city,Guangxi,China.It has been reported that longevity is closely related to metabolism and the gut microbiota.The 16S rRNA sequencing and liquid chromatography-mass spectrometry(LC-MS)were used to analysis fecal samples and explore the factors affecting longevity in the region.Interestingly,we discovered,that elderly individuals who had been drinking the soaking of M.domeri(Bois)Chev.leaves for a long time exhibited higher diversity of the gut microbiota than without drinking the soaking,notably.The proportions of Ruminococcaceae and Prevotella were decreased in those who did not drink this soaking.In addition,a total of 106 metabolites were characterized,and the people of long-lived people(>90 years old)and elderly people(<90 years old)who drinking soaking of M.domeri(Bois)Chev.leaves significantly altered the gut microbiota and upregulated levels of haplopine,farnesol,genipic acid,momordicinin,2-hydroxyestrone,hydroxyphenyllactic acid,caffeic acid,sophoraflavanone B,and soyasaponin I.We preliminarily determined that M.domeri(Bois)Chev.leaves consumption may be an important factor affecting longevity in this area.
基金Supported by Guangxi Young and Middle-aged University Teachers’Scientific Research Ability Enhancement Project(2017KY0644).
文摘Agriculture is the foundation of the national economy.The periodicity of agricultural product output and prices,the asymmetry of information between buyers and sellers,and the inherent characteristics of small scale,high cost,and low profit have caused slow sales,which greatly hurt the enthusiasm of farmers to develop production and endanger social stability.Constructing an informationized and commercialized trading platform and an information sharing platform through e-commerce and establishing related systems and supervision mechanisms will help to promote the rapid growth of agricultural product sales.Research has shown that in the field of agricultural circulation,e-commerce has a significant effect on increasing the scale of agricultural trade.
基金Funded by the Young Top-notch Talent Cultivation Program of Hubei Provincethe Fundamental Research Funds for the Central Universities(WUT:2021IVA116 and WUT:2021CG015)。
文摘To achieve high microwave permeability in wide-band for the micron-thick magnetic films,[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer structure was proposed by co-sputtering Fe and FeNi to form the magnetic layers and Cr to form the interlayers.The multilayer structure contributes to the high permeability by reducing the coercivity and diminishing out-of-plane magnetization.The maximum imaginary permeability of[Fe-Fe_(20)Ni_(80)/Cr]_(n) multilayer film reaches a large value of 800 at 0.52 GHz even though its overall thickness exceeds 1μm.Besides,the magnetic resonance frequency of the multilayer film can be modulated from 0.52 to 1.35 GHz by adjusting the sputtering power of Fe from 0 to 86 W,and its bandwidth for μ’’>200(Δf) is as large as 2.0 GHz.The desirable broad Δf of magnetic permeability,which can be well fitted by the Landau-Lifshitz-Gilbert equations,is due to dual magnetic resonances originated from double magnetic phases of Fe and FeNi that are of different saturation magnetization.The micron-thick multilayer films with high permeability in extended waveband are promising candidate for electromagnetic noise suppression application.
基金The National Key Research and Development Program of China under contract No.2022YFC3103400the National Natural Science Foundation of China under contract Nos 42076019 and 42076026the Project supported by Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)under contract No.SML2023SP240.
文摘The frontogenetic processes of a submesoscale cold filament driven by the thermal convection turbulence are studied by a non-hydrostatic large eddy simulation.The results show that the periodic changes in the direction of the cross-filament secondary circulations are induced by the inertial oscillation.The change in the direction of the secondary circulations induces the enhancement and reduction of the horizontal temperature gradient during the former and later inertial period,which indicates that the frontogenetical processes of the cold filament include both of frontogenesis and frontolysis.The structure of the cold filament may be broken and restored by frontogenesis and frontolysis,respectively.The magnitude of the down-filament currents has a periodic variation,while its direction is unchanged with time.The coupling effect of the turbulent mixing and the frontogenesis and frontolysis gradually weakens the temperature gradient of the cold filament with time,which reduces frontogenetical intensity and enlarges the width of cold filament.
基金Project(AA18242008)supported by the Guangxi Science&Technology Major Project,ChinaProject(HZXYKFKT201904)supported by the Opening Project of Guangxi Key Laboratory of Calcium Carbonate Resources Comprehensive Utilization,China。
文摘Calcium carbonate,which is widely employed as a filler added into the polymer matrix,has large numbers of applications owing to the excellent properties such as low cost,non-toxicity,high natural reserves and biocompatibility.Nevertheless,in order to obtain the good filling effect,calcium carbonate needs to be surface modified by organic molecules so as to enhance the dispersion and compatibility within the composites.This review paper systematically introduces the theory,methods,and applications progress of calcium carbonate with surface modification.Additionally,the key factors that affect the properties of the composites as well as the current difficulties and challenges are highlighted.The current research progress and potential application prospects of calcium carbonate in the fields of plastics,rubber,paper,medicine and environmental protection are discussed as well.Generally,this review can provide valuable reference for the modification and comprehensive utilization of calcium carbonate.
基金Project(21473042) supported by the National Natural Science Foundation of ChinaProject(GUIKE-AD18126001) supported by the Guangxi Science and Technology Special Project on Bases and Talents,China
文摘According to the problems of short life and low strength of TiB2 coating cathode for current technology in aluminium electrolysis industry,this work synthesized TiB2-TiB/Ti gradient composite with TiB2 coating and TiB whiskers in metallic Ti matrix by a electrolytic boronizing method based on similar density and thermal expansivity of the three materials.The phase composition and morphology of the cross-section were determined by X-ray diffraction(XRD),scanning electronic microscope(SEM)and X-ray energy dispersive spectrum(EDS).The results show that uniform TiB2 layer with a thickness of 8-10μm is continuously coated on the surface while the TiB whisker connected with TiB2 layer was embedded dispersedly into the matrix.The TiB crystal whisker has a maximum length of about 220μm.The growth rate of TiB2 and TiB is enhanced by the strong reduction of B4C.The novel gradient design of the composite helps to extend life and improve strength of the TiB2 cathode in aluminium electrolysis.
基金Supported by National Natural Science Foundation of China(41361068)Key Science and Technology Research Funds for Guangxi Universities(2013ZD067)Guangxi Natural Science Foundation(2011GXNSFB-018056)
文摘Rational fertilization is an important measure to increase crop yield and soil fertility. Through analysis,this paper aims to master the change characteristics of soil organic matter and rice yield under different fertilizer treatments,in order to provide an important reference for the sustainable use of soil and effective fertilization. Long-term( 19 years) rice crop rotation experiments in waterloggogenic paddy soil were conducted to investigate the change trend of crop grain yield and soil organic matter with time,reveal the dynamic characteristics and relationship between main fertility factors and crop yields using comparative analysis at three sites with conventional fertilization and non-fertilization in Guilin. The results showed that compared with previous years,the rice yield increased by 53% under the fertilization treatment and degreased by 66% under the control. Over the years,the average soil organic matter( SOM) content under fertilization treatment was 23% higher than under CK treatment. This indicates that chemical fertilizer and organic manure application can increase the rice yield and soil organic matter,and high rice yield can be attributed to the SOM increase.
基金Supported by Science and Technology Research Project of Guangxi University(2013LX143)
文摘Gross agricultural product is an important indication to measure the agricultural development level of a region. It would be affected by many factors,having the characteristics of non- linearity. For this reason,LM- BP neural network was put forward as the model and method for predicting gross agricultural product. Taking the indications of the sown area of crop,the output of grain,sugarcane,cassava,tea,meat,aquatic products,turpentine and camellia seed,etc. as inputs,during 2000 to 2012 in Guangxi,the gross agricultural product data from the analysis of simulation experiment show that the prediction of LM- BP neural network fits well with actual results.
基金Sponsored by Youth Fund Project of Humanities and Social Sciences Research of the Ministry of Education(15YJCZH145)Guangxi Philosophy and Social Science Planning Project(18FJY007)
文摘With the rapid development of the economy, people’s living standards have been improved constantly. As people’s material life has been gradually improved, people pay more attention to the pursuit of high-quality spiritual life, and the flourishing development of rural tourism just meets people’s pursuit about returning to nature that is far away from the hustle and bustle of the city, and about experiencing funny and quiet life in the countryside. The development of rural tourism relies on agricultural landscape resources, and the correct understanding and protection of the original value of agricultural landscape resources can effectively ensure the sustainable use of agricultural landscape resources. If land for agricultural landscape resource is occupied for developing blindly without reasonable planning and construction, it will lead to the distortion of the authentic value of agricultural landscape, which in turn affects the sustainable development of rural tourism.
文摘Plant landscaping in courtyard design was studied from four perspectives of building, water, road, garden setting and plant landscaping. Landscape designs in Guangzhou Baiyun Hotel, the Humble Administrator's Garden (Suzhou), and bamboo pathway of Small Yingzhou in the West Lake (Hangzhou) to improve scientific and artistic properties of plant landscaping, and develop economic, social and ecological effects of garden green spaces to the most.
基金Supported by Natural Science Foundation of Guangxi(2017GXNSFAA198082)Hezhou Scientific Research and Technology Development Program of Guangxi(HKG1541005)
文摘[Objectives]This study was conducted to investigate the synergized preservation effect of different concentrations of prochloraz and chitosan on citrus Gonggan,so as to prolong the sales period of Gonggan.[Methods]"Zhongshan Gonggan" was used as a material.The Gonggan fruit was soaked with prochloraz (250,300 and 350 mg/L) and then coated with different concentrations of chitosan (1.0% and 1.5%),respectively.The good fruit rate,weight loss rate and titratable acid (TA),reducing sugar,total soluble solids (TSS) and Vc contents were used as evaluation indexes to investigate the preservation effect of Gonggan during cold storage.[Results]The treatment of prochloraz plus chitosan can significantly prolong the shelf life of Gonggan as it can inhibit the decline of good fruit rate,reduce the weight loss rate,and slow down the degradation and loss of titratable acid,reducing sugar,soluble solids and Vc.The 350 mg/L prochloraz+1.0% chitosan treatment was superior to other treatments.[Conclusions]This study provides a theoretical basis for better prolonging the storage period of Gonggan.
基金Supported by Scientific Research and Technology Development Program of Guangxi ProvinceConstruction of Science and Technology Service Platform in Hezhou Agricultural Science and Tech-nology Park(GKN 14258003)Scientific Research Project of Hezhou University(HZU-JS201617)
文摘The volatile oil of Artemisia argyi was extracted by ultrasonic assisted extraction, and the extraction rate of volatile oil was 0.68%. Thevolatile oil of A. argyi was emulsified with 1% Tween-80, and drug susceptibility test was conducted with avian Escherichia coli. The results showedthat the volatile oil of A. argyi had antibacterial effect against avian E. coli, and the minimal inhibitory concentration was 50 mg/mL. Taking sixcommon antibiotics as the control, drug susceptibility test was conducted with volatile oil of A. argyi. The results showed that 10 strains of E. coliwere sensitive to the volatile oil of A. argyi, three of which had different degrees of resistance and one had the tendency of resistance.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.21003033 and 21203047)the Guangxi Provincial Natural Science Foundation,China(Grant Nos.2012GXNSFBA053012 and 2014GXNSFAA118019)the Research Foundation of Education Bureau of Guangxi Zhuang Autonomous Region,China(Grant No.ZD2014127)
文摘Photo-induced intramolecular electron transfer (PIET) and intramolecular vibrational relaxation (IVR) dynamics of the excited state of rhodamine 6G (Rh6G+) in DMSO are investigated by multiplex transient grating. Two major compo- nents are resolved in the dynamics of Rh6G+. The first component, with a lifetime τTPIET = 140 fs-260 fs, is attributed to PIET from the phenyl ring to the xanthene plane. The IVR process occurring in the range ZIVR = 3.3 ps-5.2 ps is much slower than the first component. The PIET and IVR processes occurring in the excited state of Rh6G+ are quantitatively determined, and a better understanding of the relationship between these processes is obtained.
基金Supported by Scientific Research and Technology Development Project of Hezhou City,Guangxi(HKG 1541005)。
文摘[Objectives]This study was conducted to discuss the change laws and relationships of the physiological indexes in green plums treated with nisin or 1-MCP in the cold storage process.[Methods]Different storage methods on the physiological and quality indexes of green plums were investigated through two kinds of different treatment methods(treatment 1:1-MCP+cold storage,treatment 2:nisin+cold storage),with rotten fruit rate,weight loss rate,yellow ripeness index,hardness,Vc content,titratable acid,soluble solids and peroxidase(POD)activity as the evaluation indexes.[Results]The storage method of treating green plums with 1-MCP combined with cold storage could delay the quality decline of green plums after harvest,while the effect of nisin treatment was slightly inferior.1-MCP treatment followed by cold storage could more effectively delay the senescence of green plums,delay the decrease of fruit hardness and soluble solid content to the greatest extent,and maintain the titratable acid and Vc contents at relatively good levels.It further reduced weight loss rate and rotten fruit rate,postponed the time of the peak of POD enzyme activity,and reduced the loss of nutrients in the fruit,thereby maintaining good commercial properties of the fruit.[Conclusions]This study plays an important role in the post-harvest storage,preservation and transportation,as well as the development of the green plum industry.
基金funded by the National Key Basic Research Special Foundation of China(2021FY100405)the National Natural Science Foundation of China(U20A20114,42201069 and 42077002)the Fundamental Research Funds for Central Non-profit Scientific Institution,China(1610132018012).
文摘Soil temperature regime(STR)is important for soil classification and land use.Generally,STR is delineated by estimating the mean annual soil temperature at a depth of 50 cm(MAST50)according to the Chinese Soil Taxonomy(CST).However,delineating the STR of China remains a challenge due to the difficulties in accurately estimating MAST50.The objectives of this study were to explore environmental factors that influence the spatial variation of MAST50 and generate an STR map for China.Soil temperature measurements at 40 and 80 cm depth were collected from 386 National Meteorological Stations in China during 1971–2000.The MAST50 was calculated as the average mean annual soil temperature(MAST)from 1971–2000 between 40 and 80 cm depths.In addition,2048 mean annual air temperature(MAAT)measurements from 1971 to 2000 were collected from the National Meteorological Stations across China.A zonal pedotransfer function(PTF)was developed based on the ensemble linear regression kriging model to predict the MAST50 in three topographic steps of China.The results showed that MAAT was the most important variable related to the variation of MAST50.The zonal PTF was evaluated with a 10%validation dataset with a mean absolute error(MAE)of 0.66°C and root mean square error(RMSE)of 0.78°C,which were smaller than the unified model with MAE of 0.83°C and RMSE of 0.96°C,respectively.This study demonstrated that the zonal PTF helped improve the accuracy of the predicted MAST50 map.Based on the prediction results,an STR map across China was generated to provide a consistent scientific base for the improvement and application of CST and land use support.
基金Supported by Project of National Natural Science Foundation(41361068)Natural Science Foundation Project of Guangxi(2016GXNSFAA380183,2016GXNSFAA380160)Professor Startup Fund of Hezhou University(HZUJS201611)
文摘In this experiment,two-factor 7-level uniform design scheme was applied.Separate treatment of each factor was performed for single effect test.Then,it analyzed the effects of acid and aluminum stress under soilless culture on the water content of plant during the growth of Ginkgo biloba L.seedlings,so as to provide a theoretical basis for studying the connection between plant water and physiological stress.The results showed that the water content of G.biloba plants declined with the decrease of p H,but the water content of G.biloba plants declined with the increase in the concentration of aluminum treatment,indicating that the stronger the acid and aluminum stress,the lower the water content of the plants,affecting the normal absorption of water content of G.biloba plants,accordingly leading to lack of water.According to the analysis of the degree of influence on the water content,p H is the first factor influencing the growth of G.biloba plants.If p H is lower than 3.5,G.biloba plants will not growth,while p H is higher than 5.0,aluminum has no significant effect on the water content of G.biloba plants.In conclusion,the water content of G.biloba plants can be used as an essential indicator for acid and aluminum stress.
基金Natural Science Foundation of Guangxi(2017GXNSFAA198082)Guangxi Aquatic Vegetable Fresh-keeping and Processing Engineering Research Center Project(GXSSSCBXYJGZX1912)。
文摘[Objectives]This study was conducted to investigate the effect of compound fresh-keeping liquid on the browning and quality of fresh-cut yam during the cold chain process.[Methods]Under the simulated cold chain condition of 4℃,a uniform design(U6*(64))experiment was carried out to optimize the compound preservative formula,and a better compound preservative formula was obtained using the regression equation.[Results]The compound preservative formula was:AA 0.25%,CA 0.5%,Nisin 0.09%,GSH 0.15%.The compound fresh-keeping liquid effectively delayed the browning of fresh-cut yam and the accumulation of MDA,maintained the content of TSS,inhibited the activity of PAL and delayed the appearance of the maximum activity of POD and POD.[Conclusions]This study provides technical support for the actual extension of the shelf life of fresh-cut yam.
基金Sponsored by 2015 Undergraduates Innovation and Entrepreneurship Training Program(201511838074)
文摘Based on the basic principles of rain garden infrastructure, optimal species for rain facilities such as vegetated buffer strip, vegetated shallow groove, artificial wetland were selected, characteristics, configuration principles and methods were summarized.
基金funded by the National Natural Science Foundation of China (31360136, 31560168)the China Postdoctoral Science Foundation (2013M541080, 2014T70139)+2 种基金the Key Laboratory of Poyang Lake Wetland and Watershed Research, Ministry of Education, China (PK2014009)the Natural Science Foundation of Jiangxi Province, China (20151BAB204007)the Open Foundation of Jiangxi Province Key Lab of Protection and Utilization of Subtropical Plant Resources, China
文摘Assessing the impact of plantation on microbial respiration (MR) is vitally important to understand the interactions between belowground metabolism and land use change. In this study, cumulative MR was determined by alkali absorption method in 1, 3, 7, 14, 21,28, 35, 42, 49, and 56 days from the soil in a representative plantations in the subtropical region of China. The treatment of plantations contained no plant (CK), orange trees (Citrus reticulata)+Bahia grass (Paspalum notatum) (GB), orange trees (C. reticulata)+Bahia grass (P. notatum)+soybean (Giycine max (L.) Merrill) (GBH). Results showed that plantation had significant effects on microbial respiration and the responses of microbial respiration to plantation from different soil layers and topographies were different: in 0-20 cm in uphill: GB〉GBH〉CK; in 20-40 cm in uphill: GBH〉CK〉GB; in 0-20 cm in downhill: GBH〉CK〉GB; in 20-40 cm in downhill: GB〉CK〉GBH. Furthermore, plantation also altered the relationships between MR and soil properties. In CK, microbial respiration was positively correlated with NH4+ and soil total N, and negatively correlated with soil moisture, pH, NO3-, and microbial biomass carbon (MBC). In GB, microbial respira- tion under GB significantly negatively correlated with dissolved organic carbon (DOC). In GBH, microbial respiration under GBH was positively correlated with NH4+, MBC, total soil carbon (TC), and total soil nitrogen (TN), and negatively correlated with soil moisture (SM), pH, NO-, and DOC. The underlying mechanisms could be attributed to soil heterogeneity and the effects of plantation on soil properties. Our results also showed that plantation significantly increased soil C storage, which suggested plantation is a key measure to enhance soil C sequestration and mitigate global CO2 emission, especially for the soil with low initial soil carbon content or bared soil.
基金Sponsored by the National Natural Science Foundation of China(Grant No.11461021)the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2017JM1014)Scientific Research Project of Hezhou University(Grant Nos.2014YBZK06 and 2016HZXYSX03)
文摘This paper proposes a new full Nesterov-Todd(NT) step infeasible interior-point algorithm for semidefinite programming. Our algorithm uses a specific kernel function, which is adopted by Liu and Sun, to deduce the feasibility step. By using the step, it is remarkable that in each iteration of the algorithm it needs only one full-NT step, and can obtain an iterate approximate to the central path. Moreover, it is proved that the iterative bound corresponds with the known optimal one for semidefinite optimization problems.