In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic...In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.展开更多
Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint ...Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint with a5-m wavelength range, leaving a significant knowledge gap in this field.Design/methodology/approach – In this study, the authors used the well-established inertial referencemethod (IR-method), and the state-of-the-art multi-point chord reference method (MCR-method). Two methodshave been applied in different types of rail straightness measurement trollies, respectively. These instrumentswere tested in a high-speed rail section within a certain region of China. The test results were ultimatelyvalidated through using traditional straightedge and feeler gauge methods as reference data to evaluate the railweld joint straightness within the 5-m wavelength range.Findings – The research reveals that IR-method and MCR-method produce reasonably similar measurementresults for wavelengths below 1 m. However, MCR-method outperforms IR-method in terms of accuracy forwavelengths exceeding 3 m. Furthermore, it was observed that IR-method, while operating at a slower speed,carries the risk of derailing and is incapable of detecting rail weld joints and low joints within the track.Originality/value – The research compare two methods’ measurement effects in a longer wavelength rangeand demonstrate the superiority of MCR-method.展开更多
Environmental DNA(eDNA)has been used as an important tool for fish diversity analysis,which can greatly solve the problems in traditional survey methodology.However,little work has been done on the actual monitoring a...Environmental DNA(eDNA)has been used as an important tool for fish diversity analysis,which can greatly solve the problems in traditional survey methodology.However,little work has been done on the actual monitoring accuracy of eDNA.In this study,we analyzed the current status of fish resources in Erhai Lake in Yunnan,SW China,by dividing the lake into three sectors according to habitat differences,and compared the results of eDNA and traditional capture methods to investigate the shortcomings of the current analysis of eDNA results.A total of 27 fish species were detected by eDNA and traditional capture methods,including 20 and 19 fish species,respectively,and additional differences in fish composition between the two methods.The alpha diversity showed higher fish abundance and lower fish diversity by eDNA method compared to the traditional capture method,demonstrating that eDNA was not superior for use in fish diversity analysis.Fish community similarity analysis showed that community differences were generally significant for eDNA(P<0.05).RDA analysis indicated that environmental factors did not significantly affect fish communities monitored by the eDNA method.However,water temperature,aquatic plants,and water depth had significant(P<0.05)effects on fish communities in the traditional capture method,suggesting that eDNA results are insensitive to the effects of environmental factors.Our results illustrate the effectiveness of eDNA in fish identification and the issues in quantification compared to traditional capture methods.Therefore,combining eDNA with traditional methods is a more effective method for analyzing eDNA metabarcoding,following which the protocols of both quantitative methods can be designed to explore the regularity of eDNA quantification.展开更多
[Objectives]The paper was to screen new varieties of long cowpea that are suitable for autumn cultivation in Hunan,as well as to develop a comprehensive evaluation method to assess their adaptability and performance.[...[Objectives]The paper was to screen new varieties of long cowpea that are suitable for autumn cultivation in Hunan,as well as to develop a comprehensive evaluation method to assess their adaptability and performance.[Methods]A total of 48 long cowpea varieties were introduced,and a range of comprehensive evaluation methods was employed to assess these varieties through the collection and analysis of field data.[Results]The square Euclidean distance of 14 allowed for the classification of all varieties into eight distinct groups.Groups II,III,and V belong to the autumn dominant group within this region,while groups I and VIII belong to the intermediate group.Additionally,groups IV,VI,and VII belong to the autumn inferior group in this area.Through a comparative analysis of various comprehensive evaluation methods,it was determined that the common factor comprehensive evaluation,grey correlation method,and fuzzy evaluation method were appropriate for application in the selection of long cowpea varieties.Furthermore,the evaluation outcomes were largely consistent with the cluster pedigree diagram.[Conclusions]Through comprehensive index method,ten varieties demonstrating superior performance in autumn cultivation have been identified,including C20,C42,C29,C40,C3,C14,C18,C25,C15,and C47.The selected varieties exhibit several advantageous traits,such as a reduced growth duration,a lower position of initial flower nodes,a decreased number of branches,predominantly green young pods,elongated pod strips,thicker pod structures,an increased number of pods per plant,and higher overall yields.These characteristics render them particularly valuable for extensive cultivation.展开更多
We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of d...We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.展开更多
In this paper,experimental and numerical studies of heat transfer in a test local of side H=0.8 m heated from below are presented and compared.All the walls,the rest of the floor and the ceiling are made from plywood ...In this paper,experimental and numerical studies of heat transfer in a test local of side H=0.8 m heated from below are presented and compared.All the walls,the rest of the floor and the ceiling are made from plywood and polystyrene in sandwich form(3 mmplywood-3 cm polystyrene-3 mmplywood)just on one of the vertical walls contained a glazed door(2 H/3×0.15 m).This local is heated during two heating cycles by a square plate of iron the width L=0.6 H,which represents the heat source,its temperature Th is controlled.The plate is heated for two cycles by an adjustable set-point heat source placed just down the center of it.For each cycle,the heat source is switched“on”for 6 h and switched“off”for 6 h.The outdoor air temperature is kept constant at a low temperature Tc<Th.All measurements are carried out with k-type thermocouples and with flux meters.Results will be qualitatively presented for two cycles of heating in terms of temperatures and heat flux densitiesϕfor various positions of the test local.The temperature evolution of the center and the profile of the temperature along the vertical centerline are compared by two dimensions simulation using the lattice Boltzmann method.The comparison shows a good agreement with a difference that does not exceed±1℃.展开更多
There are a lot of methods in city water consumption short-term forecasting both inside and outside the country. But among these methods there exist many advantages and shortcomings in model establishing, solving and ...There are a lot of methods in city water consumption short-term forecasting both inside and outside the country. But among these methods there exist many advantages and shortcomings in model establishing, solving and predicting accuracy, speed, applicability. This article draws lessons from other realm mature methods after many years′ study. It′s systematically studied and compared to predict the water consumption in accuracy, speed, effect and applicability among the time series triangle function method, artificial neural network method, gray system theories method, wavelet analytical method.展开更多
[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasci...[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch.[Method] Leavies of Clematis fasciculiflora Franch were used as materials for comparing the purity and concentration of extracted DNA and extracting time among the four extraction methods of genomic DNA including improved CTAB method Ⅰ,improved CTAB method Ⅱ,improved CTAB method Ⅲ and improved SDS method.[Result] The four extraction methods could all be successfully used for extracting the genomic DNA from Clematis fasciculiflora Franch.The purity of genomic DNA was the highest using improved CTAB method Ⅰ,with the longest extracting time;while the concentration of genomic DNA was the maximum using the improved SDS method,with the shortest extracting time and relatively low purity;the extracting time of improved CTAB method Ⅲ was the shortest.[Conclusion] This study had established the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch and supported for the further research using molecular biological methods.展开更多
[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the ...[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the sugarcane RNA in stalks,and the quality of the extracted RNA was compared.[Result] RNA extracted by kit extraction method had a high-yield,the bands were clear and RNA had a good integrity,there was no significant degradation of RNA,and the OD260 nm/OD280 nm value was closed to 2.0.[Conclusion] Kit extraction method was the effectively method to extract sugarcane RNA,and this study had provided a theoretical basis for the molecular biology study of sugarcane.展开更多
[ Objective] The aim was to study method for extracting DNA from pteridophyta and provide basis for further study on genetic diversity and taxonomy. [ Method] By changing the dosage of reagent and operating method, CT...[ Objective] The aim was to study method for extracting DNA from pteridophyta and provide basis for further study on genetic diversity and taxonomy. [ Method] By changing the dosage of reagent and operating method, CTAB method for extracting DNA was improved. [ Result] The results showed that the improved CTAB method could extract high-quality DNA from pteridophyta. [ Conclusion] The study improved method for extracting DNA from pteridophyta.展开更多
To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues (leaves, stems and roots) of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS metho...To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues (leaves, stems and roots) of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS method and high- salt Iow-pH method, respectively. The quality and yield of extracted DNA was deter- mined using agarose gel electrophoresis and UV spectrophotometry. At the same time, the PCR-SSR and SSCP molecular detection was also performed. The results showed that the gel test strips, without obvious decomposition, of all the extraction methods were relatively obvious; the genomic DNA yield extracted by modified CTAB method was highest, followed by that by SDS method, and the genomic DNA extracted by high-salt Iow-pH method was lowest: the genomic DNA yields extracted by different methods from Chenopodium quinoa Wiltd leaves were all high- er than those from roots and stems; the quality of Chenopodium quinoa Willd ge- nomic DNA extracted by modified CTAB method and high-salt Iow-pH method was better, and polyphenols, polysaccharides and other impurities were removed more completely. The PCR-SSR and SSCP detection results showed that the genomic DNA extracted by different methods from different tissues of Chenopodium quinoa Willd all could be better amplified, and high-quality strips could be obtained. So the Chenopodium quinoa Willd genomic DNA extracted by the three methods all can be used for subsequent molecular biology research.展开更多
[Objective] This study aimed to identify the ultra-drying method most suitable for the storage of Chinese chive seeds through comparing different ultra-drying meth- ods. [Method] Through setting treatments including f...[Objective] This study aimed to identify the ultra-drying method most suitable for the storage of Chinese chive seeds through comparing different ultra-drying meth- ods. [Method] Through setting treatments including freezing, silica gel drying and heating drying at 50℃ as well as two controls, the effects of different drying methods for storing ultra-dried Chinese chive seeds were compared. [Result] There were no significant differences in the germination rate and seedling length between Chinese chive seeds treated with heating drying at 50℃ and those treated with either freezing or get drying at the initial stage of the storage. Storing of Chinese chive seeds previously treated with either heating drying at 50℃, or freezing or gel drying for 0-98 months at 20℃ hadn't caused any adverse effect on the germination rate of seeds. And the effect of different storage conditions on seedling length displayed earlier than that on the germination rate. There was no significant difference on seedling length between seeds treated with heating drying at 50℃ and those treated with freezing drying after stored for as long as 98 months, revealing similar efficacy on storing seeds. [Conclusion] Freezing drying requires huge investment and cost for perennial running, and silica gel drying is slow in drying and time-consuming. By contrast, heating drying at 50℃ is an economic and simple method, which can enable the Chinese chive seeds to sustain a longevity of eight years or more.展开更多
[Objective] This study aimed to investigate a reliable method for DNA ex- traction from Wusuli raccoon dog's hair. [Method] Several DNA extraction methods were used to extract DNA from Wusuli raccoon dog hair, includ...[Objective] This study aimed to investigate a reliable method for DNA ex- traction from Wusuli raccoon dog's hair. [Method] Several DNA extraction methods were used to extract DNA from Wusuli raccoon dog hair, including Chelex-100 method, PCR buffer method, organic phenol-chloroform method and centrifugal col- umn type kit method. The extracted DNA was analyzed by using PCR amplification and electrophoresis to compare these four DNA extraction methods. [Result] Accord- ing to the results of spectrophotometer detection and gel electrophoresis, nucleic acid extracted by Chetex-100 method had proteins and other impurities; nucleic acid ex- tracted by PCR buffer method was low in concentration; however, DNA extracted by organic phenol-chloroform method and centrifugal column type kit was high in con- centration with no impurity band. [Conclusion] This study had laid the strong founda- tion of scientific theory to further explore the efficient and simple method for extracting DNA from Wusuli raccoon dog hair follicle.展开更多
This paper is devoted to investigate the accuracy of the Pseudo spectral scheme with the Chebyshev tau method and Chebyshev collocation method. The computational results of the nonlinear disturbance development in p...This paper is devoted to investigate the accuracy of the Pseudo spectral scheme with the Chebyshev tau method and Chebyshev collocation method. The computational results of the nonlinear disturbance development in plane Poiseuille flow for both methods are presented and compared in detail. It is acknowledged that the Chebyshev collocation method has higher precision than the other one, especially for near netural situation.展开更多
In order to study the calculation methods of bending behavior of Chinese reinforced concrete beams from 1912 to 1949, tests on the mechanical performance of 66 rebars from different modem Chinese concrete buildings, t...In order to study the calculation methods of bending behavior of Chinese reinforced concrete beams from 1912 to 1949, tests on the mechanical performance of 66 rebars from different modem Chinese concrete buildings, the concrete compressive strength of 12 modem Chinese concrete buildings, and the concrete cover thickness of 9 modem Chinese concrete buildings are carried out; and the actual material properties and structural conformations of modem Chinese concrete buildings are obtained. Then, the comparison on calculation methods of bending behavior including the original Chinese calculation method, the present Chinese calculation method, the present American calculation method and the present European calculation method is studied. The results show that the original Chinese calculation method of bending behavior is based on the allowable stress calculation method, and the design safety factors are 3.55 to 4. 0. In term of the calculation area of longitudinal rebars of reinforced concrete beams, without considering earthquake action, the original Chinese structural calculation method is safer than the present Chinese structural calculation method, the present European structural calculation method, and the present American structural calculation method. The results can provide support for the structural safety assessments of modem Chinese reinforced concrete buildings.展开更多
In this paper, the many indices used in validation of crop models, such as RMSE (root mean square errors), Sd (standard error of absolute difference), da (mean absolute difference), dap (ratio of da to the mean...In this paper, the many indices used in validation of crop models, such as RMSE (root mean square errors), Sd (standard error of absolute difference), da (mean absolute difference), dap (ratio of da to the mean observation), r (correlation), and R2 (determination coefficient), are compared for the same rice architectural parameter model, and their advantages and disadvantages are analyzed. A new index for validation of crop models, dap between the observed and the simulated values, is proposed, with dap〈5% as the suggested standard for precision of crop models. The different kinds of validation methods in crop models should be combined in the following aspects:(1) calculating da and dap; (2) calculating the RMSE or Sd; (3) calculating r and R2, at the same time, plotting 1:1 diagram.展开更多
S The methane emission flux from rice paddies was simultaneously measured with automatic and manual methods in the suburban of Suzhou. Both methods were based on the static chamber/GC-FID techniques. Detail analysi...S The methane emission flux from rice paddies was simultaneously measured with automatic and manual methods in the suburban of Suzhou. Both methods were based on the static chamber/GC-FID techniques. Detail analysis of the experimental results indicates: a) The data of methane emission measured with the automatic method is reliable. b) About 11 or 19 o′clock of local time is recommended as the optimum sampling time for the manual spot measurement of methane emission from rice paddies. The methane emission fluxes measured by manual sampling at local time other than the optimum time have to be corrected. The correction coefficient may be determined by automatic and continuous measurement. c) In order to get a more accurate result, an empirical correction factor, such as 18%, is recommended to correct the seasonally total amount of measured methane emission by enlarging the automatically measured data or reducing the manually measured ones.展开更多
Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecula...Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology,quantitative genetics and genomics. Therefore,it is extremely necessary to select several versatile,low-cost,efficient and time-and labor-saving methods to develop a large panel of microsatellite markers. In this study,we used Zhikong scallop(Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency,while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time-and cost-saving,it is difficult to obtain a large number of microsatellite markers,mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study,we recommend two methods,microsatellite-enriched library construction method and FIASCO-colony hybridization method,for large-scale microsatellite marker development. Both methods were derived from the microsatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.展开更多
AIM:To investigate and compare efficacy and differences in the nutritional status evaluation of gastroenterology patients by application of two methods:subjective global assessment(SGA) and nutritional risk index(NRI)...AIM:To investigate and compare efficacy and differences in the nutritional status evaluation of gastroenterology patients by application of two methods:subjective global assessment(SGA) and nutritional risk index(NRI).METHODS:The investigation was performed on 299 hospitalized patients,aged 18-84 years(average life span 55.57 ± 12.84),with different gastrointe-stinal pathology,admitted to the Department of Gastroenterohepatology,Clinical and Hospital Center "Bezanijska Kosa" during a period of 180 d.All the patients,after being informed in detail about the study and signing a written consent,underwent nutritional status analysis,which included two different nutritional indices:SGA and NRI,anthropometric parameters,bioelectrical impedance analysis,and biochemical markers,within 24 h of admission.RESULTS:In our sample of 299 hospitalized patients,global malnutrition prevalence upon admission varied from 45.7% as assessed by the SGA to 63.9% by NRI.Two applied methods required different parameters for an adequate approach:glucose level(5.68 ± 1.06 mmol/L vs 4.83 ± 1.14 mmol/L,F = 10.63,P = 0.001);body mass index(26.03 ± 4.53 kg/m2 vs 18.17 ± 1.52 kg/m2,F = 58.36,P < 0.001);total body water(42.62 ± 7.98 kg vs 36.22 ± 9.32 kg,F = 7.95,P = 0.005);basal metabolic rate(1625.14 ± 304.91 kcal vs 1344.62 ± 219.08 kcal,F = 9.06,P = 0.003) were very important for SGA,and lymphocyte count was relevant for NRI:25.56% ± 8.94% vs 21.77% ± 10.08%,F = 11.55,P = 0.001.The number of malnourished patients rose with the length of hospital stay according to both nutritional indices.The discriminative function analysis(DFA) delineated the following parameters as important for prediction of nutritional status according to SGA assessment:concentration of albumins,level of proteins,SGA score and body weight.The DFA extracted MAMC,glucose level and NRI scores were variables of importance for the prediction of whether admitted patients would be classif ied as well or malnourished.CONCLUSION:SGA showed higher sensitivity to predictor factors.Assessment of nutritional status requires a multidimensional approach,which includes different clinical indices and various nutritional param eters.展开更多
To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(...To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(CR) as benefit, and the maximum modification compared to the original pairwise comparison matrix(PCM) as cost, then the improvement of consistency is transformed to a benefit/cost analysis problem. According to the maximal marginal effect principle, the elements of PCM are modified by a fixed increment(or decrement) step by step till the consistency ratio becomes acceptable, which can ensure minimum adjustment to the original PCM so that the decision makers’ judgment is preserved as much as possible. The correctness of the proposed method is proved mathematically by theorem. Firstly, the marginal benefit/cost ratio is calculated for each single element of the PCM when it has been modified by a fixed increment(or decrement).Then, modification to the element with the maximum marginal benefit/cost ratio is accepted. Next, the marginal benefit/cost ratio is calculated again upon the revised matrix, and followed by choosing the modification to the element with the maximum marginal benefit/cost ratio. The process of calculating marginal effect and choosing the best modified element is repeated for each revised matrix till acceptable consistency is reached, i.e., CR<0.1. Finally,illustrative examples show the proposed method is more effective and better in preserving the original comparison information than existing methods.展开更多
基金The Guangdong Basic and Applied Basic Research Foundation(2022A1515010730)National Natural Science Foundation of China(32001647)+2 种基金National Natural Science Foundation of China(31972022)Financial and moral assistance supported by the Guangdong Basic and Applied Basic Research Foundation(2019A1515011996)111 Project(B17018)。
文摘In this study,the structural characters,antioxidant activities and bile acid-binding ability of sea buckthorn polysaccharides(HRPs)obtained by the commonly used hot water(HRP-W),pressurized hot water(HRP-H),ultrasonic(HRP-U),acid(HRP-C)and alkali(HRP-A)assisted extraction methods were investigated.The results demonstrated that extraction methods had significant effects on extraction yield,monosaccharide composition,molecular weight,particle size,triple-helical structure,and surface morphology of HRPs except for the major linkage bands.Thermogravimetric analysis showed that HRP-U with filamentous reticular microstructure exhibited better thermal stability.The HRP-A with the lowest molecular weight and highest arabinose content possessed the best antioxidant activities.Moreover,the rheological analysis indicated that HRPs with higher galacturonic acid content and molecular weight showed higher viscosity and stronger crosslinking network(HRP-C,HRP-W and HRP-U),which exhibited stronger bile acid binding capacity.The present findings provide scientific evidence in the preparation technology of sea buckthorn polysaccharides with good antioxidant and bile acid binding capacity which are related to the structure affected by the extraction methods.
文摘Purpose – Straightness measurement of rail weld joint is of essential importance to railway maintenance. Dueto the lack of efficient measurement equipment, there has been limited in-depth research on rail weld joint with a5-m wavelength range, leaving a significant knowledge gap in this field.Design/methodology/approach – In this study, the authors used the well-established inertial referencemethod (IR-method), and the state-of-the-art multi-point chord reference method (MCR-method). Two methodshave been applied in different types of rail straightness measurement trollies, respectively. These instrumentswere tested in a high-speed rail section within a certain region of China. The test results were ultimatelyvalidated through using traditional straightedge and feeler gauge methods as reference data to evaluate the railweld joint straightness within the 5-m wavelength range.Findings – The research reveals that IR-method and MCR-method produce reasonably similar measurementresults for wavelengths below 1 m. However, MCR-method outperforms IR-method in terms of accuracy forwavelengths exceeding 3 m. Furthermore, it was observed that IR-method, while operating at a slower speed,carries the risk of derailing and is incapable of detecting rail weld joints and low joints within the track.Originality/value – The research compare two methods’ measurement effects in a longer wavelength rangeand demonstrate the superiority of MCR-method.
基金Supported by the Project of Basic Investigation on Ecological Environment Quality of Erhai Lake(No.TPDL-2021-C 265)the Ecological Effects,Population Regulation and Management Strategies of Invasion of Japanese Smelt(Hypomesus nipponensis)in Erhai Lake funded by the government of Dali City,Yunnan Province,China(No.[2018]447)。
文摘Environmental DNA(eDNA)has been used as an important tool for fish diversity analysis,which can greatly solve the problems in traditional survey methodology.However,little work has been done on the actual monitoring accuracy of eDNA.In this study,we analyzed the current status of fish resources in Erhai Lake in Yunnan,SW China,by dividing the lake into three sectors according to habitat differences,and compared the results of eDNA and traditional capture methods to investigate the shortcomings of the current analysis of eDNA results.A total of 27 fish species were detected by eDNA and traditional capture methods,including 20 and 19 fish species,respectively,and additional differences in fish composition between the two methods.The alpha diversity showed higher fish abundance and lower fish diversity by eDNA method compared to the traditional capture method,demonstrating that eDNA was not superior for use in fish diversity analysis.Fish community similarity analysis showed that community differences were generally significant for eDNA(P<0.05).RDA analysis indicated that environmental factors did not significantly affect fish communities monitored by the eDNA method.However,water temperature,aquatic plants,and water depth had significant(P<0.05)effects on fish communities in the traditional capture method,suggesting that eDNA results are insensitive to the effects of environmental factors.Our results illustrate the effectiveness of eDNA in fish identification and the issues in quantification compared to traditional capture methods.Therefore,combining eDNA with traditional methods is a more effective method for analyzing eDNA metabarcoding,following which the protocols of both quantitative methods can be designed to explore the regularity of eDNA quantification.
基金Supported by China Agricultural Industry Research System(CARS-23-G31)Technology Innovation Guidance Project of Changde City(CDKJJ20220265,CDKJJ2023YF33).
文摘[Objectives]The paper was to screen new varieties of long cowpea that are suitable for autumn cultivation in Hunan,as well as to develop a comprehensive evaluation method to assess their adaptability and performance.[Methods]A total of 48 long cowpea varieties were introduced,and a range of comprehensive evaluation methods was employed to assess these varieties through the collection and analysis of field data.[Results]The square Euclidean distance of 14 allowed for the classification of all varieties into eight distinct groups.Groups II,III,and V belong to the autumn dominant group within this region,while groups I and VIII belong to the intermediate group.Additionally,groups IV,VI,and VII belong to the autumn inferior group in this area.Through a comparative analysis of various comprehensive evaluation methods,it was determined that the common factor comprehensive evaluation,grey correlation method,and fuzzy evaluation method were appropriate for application in the selection of long cowpea varieties.Furthermore,the evaluation outcomes were largely consistent with the cluster pedigree diagram.[Conclusions]Through comprehensive index method,ten varieties demonstrating superior performance in autumn cultivation have been identified,including C20,C42,C29,C40,C3,C14,C18,C25,C15,and C47.The selected varieties exhibit several advantageous traits,such as a reduced growth duration,a lower position of initial flower nodes,a decreased number of branches,predominantly green young pods,elongated pod strips,thicker pod structures,an increased number of pods per plant,and higher overall yields.These characteristics render them particularly valuable for extensive cultivation.
文摘We analysed the photooxidation reaction in the electro-(1O2) and nucleophilic (O2•−) reaction of 2-pyridone azo derivatives. First, we calculated the energy (enthalpies) of tautomers formation, which is a measure of durability and the probability of their formation. We performed the light fastness calculations of the monoazopyridone dyes. Using the semi-empirical methods of quantum chemistry AM1 and PM3, the reactivity indicators of superdelocalisability (SrE(N)) and the electron density distribution in ground state on the highest occupied HOMO orbital and the lowest unoccupied excited state LUMO in 2-pyridone phenylazo derivatives were calculated. Superdelocalisability coefficients enable the stability to oxidising agents of various chemical molecules depending on the tautomeric forms in which they may occur. The results of the electron density calculations at the HOMO and LUMO boundary orbitals allow to determine the tendency to electrophilic attack with singlet oxygen 1O2 or nucleophilic attack of the superoxide anion O2•−on a specific atom in the molecule. The structure of the dyes was optimised with MM+, MD and AM1 or PM3 until a constant energy value was achieved with a convergence criterion of 0.01 kcal/mol.
文摘In this paper,experimental and numerical studies of heat transfer in a test local of side H=0.8 m heated from below are presented and compared.All the walls,the rest of the floor and the ceiling are made from plywood and polystyrene in sandwich form(3 mmplywood-3 cm polystyrene-3 mmplywood)just on one of the vertical walls contained a glazed door(2 H/3×0.15 m).This local is heated during two heating cycles by a square plate of iron the width L=0.6 H,which represents the heat source,its temperature Th is controlled.The plate is heated for two cycles by an adjustable set-point heat source placed just down the center of it.For each cycle,the heat source is switched“on”for 6 h and switched“off”for 6 h.The outdoor air temperature is kept constant at a low temperature Tc<Th.All measurements are carried out with k-type thermocouples and with flux meters.Results will be qualitatively presented for two cycles of heating in terms of temperatures and heat flux densitiesϕfor various positions of the test local.The temperature evolution of the center and the profile of the temperature along the vertical centerline are compared by two dimensions simulation using the lattice Boltzmann method.The comparison shows a good agreement with a difference that does not exceed±1℃.
文摘There are a lot of methods in city water consumption short-term forecasting both inside and outside the country. But among these methods there exist many advantages and shortcomings in model establishing, solving and predicting accuracy, speed, applicability. This article draws lessons from other realm mature methods after many years′ study. It′s systematically studied and compared to predict the water consumption in accuracy, speed, effect and applicability among the time series triangle function method, artificial neural network method, gray system theories method, wavelet analytical method.
基金Supported by Applied Basic Research Project of Yunnan Province(2010ZC089)the948Project of National Forestry Bureau(2008-4-11)+1 种基金Sharing Platform Project of Provincial and Ministerial Key Subject,Key Laboratory and School Laboratory of Provincial Colleges and Universities in Yunnan ProvinceScience and Technology Innovation Fund of Southwest Forestry University~~
文摘[Objective] This study aimed at comparing the four extraction methods of genomic DNA from Clematis fasciculiflora Franch and determining the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch.[Method] Leavies of Clematis fasciculiflora Franch were used as materials for comparing the purity and concentration of extracted DNA and extracting time among the four extraction methods of genomic DNA including improved CTAB method Ⅰ,improved CTAB method Ⅱ,improved CTAB method Ⅲ and improved SDS method.[Result] The four extraction methods could all be successfully used for extracting the genomic DNA from Clematis fasciculiflora Franch.The purity of genomic DNA was the highest using improved CTAB method Ⅰ,with the longest extracting time;while the concentration of genomic DNA was the maximum using the improved SDS method,with the shortest extracting time and relatively low purity;the extracting time of improved CTAB method Ⅲ was the shortest.[Conclusion] This study had established the optimal extraction method for extracting the genomic DNA from Clematis fasciculiflora Franch and supported for the further research using molecular biological methods.
基金Supported by Schools Fund of Hainan University(hd09xm62 )Higher Education Research Foundation Program of Hainan Provin-cial Education Department (Hjkj2010-17)Technology Foundation Program of South China Tropical Agricultural University(Rnd0710)~~
文摘[Objective] The study was to explore the most effective and feasible method for sugarcane stalks RNA extraction.[Method] SDS extraction method,kit extraction method and GHCL extraction method were used to extract the sugarcane RNA in stalks,and the quality of the extracted RNA was compared.[Result] RNA extracted by kit extraction method had a high-yield,the bands were clear and RNA had a good integrity,there was no significant degradation of RNA,and the OD260 nm/OD280 nm value was closed to 2.0.[Conclusion] Kit extraction method was the effectively method to extract sugarcane RNA,and this study had provided a theoretical basis for the molecular biology study of sugarcane.
基金Supported by Chongqing Natural Science Foundation~~
文摘[ Objective] The aim was to study method for extracting DNA from pteridophyta and provide basis for further study on genetic diversity and taxonomy. [ Method] By changing the dosage of reagent and operating method, CTAB method for extracting DNA was improved. [ Result] The results showed that the improved CTAB method could extract high-quality DNA from pteridophyta. [ Conclusion] The study improved method for extracting DNA from pteridophyta.
基金Supported by National Natural Science Foundation of China(31301372)Key Project of Science and Technology Plan of Zhejiang Province(2011C12030)Innovation Training Project of Zhejiang Agriculture and Forestry University(201301004)~~
文摘To rapidly obtain high-quality genomic DNA from Chenopodium quinoa Willd, the genomic DAN in different tissues (leaves, stems and roots) of Chenopodi- um quinoa Willd was extracted by modified CTAB method, SDS method and high- salt Iow-pH method, respectively. The quality and yield of extracted DNA was deter- mined using agarose gel electrophoresis and UV spectrophotometry. At the same time, the PCR-SSR and SSCP molecular detection was also performed. The results showed that the gel test strips, without obvious decomposition, of all the extraction methods were relatively obvious; the genomic DNA yield extracted by modified CTAB method was highest, followed by that by SDS method, and the genomic DNA extracted by high-salt Iow-pH method was lowest: the genomic DNA yields extracted by different methods from Chenopodium quinoa Wiltd leaves were all high- er than those from roots and stems; the quality of Chenopodium quinoa Willd ge- nomic DNA extracted by modified CTAB method and high-salt Iow-pH method was better, and polyphenols, polysaccharides and other impurities were removed more completely. The PCR-SSR and SSCP detection results showed that the genomic DNA extracted by different methods from different tissues of Chenopodium quinoa Willd all could be better amplified, and high-quality strips could be obtained. So the Chenopodium quinoa Willd genomic DNA extracted by the three methods all can be used for subsequent molecular biology research.
基金Supported by the Major Research Program of Beijing Municipal Commission of Science and Technology(D131100000413001)the Beijing Nova Program(2008B37)+1 种基金National Key Technologies R&D Program(2012BAK26B03)the Special Fund for Construction of Scientific and Technological Innovation Ability of Beijing Academy of Agriculture and Forestry Sciences~~
文摘[Objective] This study aimed to identify the ultra-drying method most suitable for the storage of Chinese chive seeds through comparing different ultra-drying meth- ods. [Method] Through setting treatments including freezing, silica gel drying and heating drying at 50℃ as well as two controls, the effects of different drying methods for storing ultra-dried Chinese chive seeds were compared. [Result] There were no significant differences in the germination rate and seedling length between Chinese chive seeds treated with heating drying at 50℃ and those treated with either freezing or get drying at the initial stage of the storage. Storing of Chinese chive seeds previously treated with either heating drying at 50℃, or freezing or gel drying for 0-98 months at 20℃ hadn't caused any adverse effect on the germination rate of seeds. And the effect of different storage conditions on seedling length displayed earlier than that on the germination rate. There was no significant difference on seedling length between seeds treated with heating drying at 50℃ and those treated with freezing drying after stored for as long as 98 months, revealing similar efficacy on storing seeds. [Conclusion] Freezing drying requires huge investment and cost for perennial running, and silica gel drying is slow in drying and time-consuming. By contrast, heating drying at 50℃ is an economic and simple method, which can enable the Chinese chive seeds to sustain a longevity of eight years or more.
基金Supported by National Natural Science Foundation of China (31072018)~~
文摘[Objective] This study aimed to investigate a reliable method for DNA ex- traction from Wusuli raccoon dog's hair. [Method] Several DNA extraction methods were used to extract DNA from Wusuli raccoon dog hair, including Chelex-100 method, PCR buffer method, organic phenol-chloroform method and centrifugal col- umn type kit method. The extracted DNA was analyzed by using PCR amplification and electrophoresis to compare these four DNA extraction methods. [Result] Accord- ing to the results of spectrophotometer detection and gel electrophoresis, nucleic acid extracted by Chetex-100 method had proteins and other impurities; nucleic acid ex- tracted by PCR buffer method was low in concentration; however, DNA extracted by organic phenol-chloroform method and centrifugal column type kit was high in con- centration with no impurity band. [Conclusion] This study had laid the strong founda- tion of scientific theory to further explore the efficient and simple method for extracting DNA from Wusuli raccoon dog hair follicle.
文摘This paper is devoted to investigate the accuracy of the Pseudo spectral scheme with the Chebyshev tau method and Chebyshev collocation method. The computational results of the nonlinear disturbance development in plane Poiseuille flow for both methods are presented and compared in detail. It is acknowledged that the Chebyshev collocation method has higher precision than the other one, especially for near netural situation.
基金The National Natural Science Foundation of China(No.51138002)the Foundation for the Author of National Excellent Doctoral Dissertation of PR China(No.201452)the Open Fund of Shanghai Key Laboratory of Engineering Structure Safety(No.2015-KF06)
文摘In order to study the calculation methods of bending behavior of Chinese reinforced concrete beams from 1912 to 1949, tests on the mechanical performance of 66 rebars from different modem Chinese concrete buildings, the concrete compressive strength of 12 modem Chinese concrete buildings, and the concrete cover thickness of 9 modem Chinese concrete buildings are carried out; and the actual material properties and structural conformations of modem Chinese concrete buildings are obtained. Then, the comparison on calculation methods of bending behavior including the original Chinese calculation method, the present Chinese calculation method, the present American calculation method and the present European calculation method is studied. The results show that the original Chinese calculation method of bending behavior is based on the allowable stress calculation method, and the design safety factors are 3.55 to 4. 0. In term of the calculation area of longitudinal rebars of reinforced concrete beams, without considering earthquake action, the original Chinese structural calculation method is safer than the present Chinese structural calculation method, the present European structural calculation method, and the present American structural calculation method. The results can provide support for the structural safety assessments of modem Chinese reinforced concrete buildings.
基金supported by the National High-Tech R&D Program (2006AA10Z230,2006AA10Z219-1)the National Natural Science Foundation of China (31171455)+3 种基金the Jiangsu Province Agricultural Scientific Technology Innovation Fund, China (CX(10)221, CX (11)2042)the Agricultural Scientific Technology Support Program, Jiangsu Province, China (BE2008397,BE2011342)the No-Profit Industry (Meteorology) Research Program, China (GYHY201006027, GYHY201106027)the Jiangsu Government Scholarship for Overseas Studies, China
文摘In this paper, the many indices used in validation of crop models, such as RMSE (root mean square errors), Sd (standard error of absolute difference), da (mean absolute difference), dap (ratio of da to the mean observation), r (correlation), and R2 (determination coefficient), are compared for the same rice architectural parameter model, and their advantages and disadvantages are analyzed. A new index for validation of crop models, dap between the observed and the simulated values, is proposed, with dap〈5% as the suggested standard for precision of crop models. The different kinds of validation methods in crop models should be combined in the following aspects:(1) calculating da and dap; (2) calculating the RMSE or Sd; (3) calculating r and R2, at the same time, plotting 1:1 diagram.
文摘S The methane emission flux from rice paddies was simultaneously measured with automatic and manual methods in the suburban of Suzhou. Both methods were based on the static chamber/GC-FID techniques. Detail analysis of the experimental results indicates: a) The data of methane emission measured with the automatic method is reliable. b) About 11 or 19 o′clock of local time is recommended as the optimum sampling time for the manual spot measurement of methane emission from rice paddies. The methane emission fluxes measured by manual sampling at local time other than the optimum time have to be corrected. The correction coefficient may be determined by automatic and continuous measurement. c) In order to get a more accurate result, an empirical correction factor, such as 18%, is recommended to correct the seasonally total amount of measured methane emission by enlarging the automatically measured data or reducing the manually measured ones.
基金supported by ‘863’ Program (2006AA10A408 and 2006AA10A411), NSFC30571417, NYHYZX07-047, 2005DKA30470, 2006BAD09A10 and NCET-06-0594.
文摘Microsatellite markers have become one kind of the most important molecular tools used in various researches. A large number of microsatellite markers are required for the whole genome survey in the fields of molecular ecology,quantitative genetics and genomics. Therefore,it is extremely necessary to select several versatile,low-cost,efficient and time-and labor-saving methods to develop a large panel of microsatellite markers. In this study,we used Zhikong scallop(Chlamys farreri) as the target species to compare the efficiency of the five methods derived from three strategies for microsatellite marker development. The results showed that the strategy of constructing small insert genomic DNA library resulted in poor efficiency,while the microsatellite-enriched strategy highly improved the isolation efficiency. Although the mining public database strategy is time-and cost-saving,it is difficult to obtain a large number of microsatellite markers,mainly due to the limited sequence data of non-model species deposited in public databases. Based on the results in this study,we recommend two methods,microsatellite-enriched library construction method and FIASCO-colony hybridization method,for large-scale microsatellite marker development. Both methods were derived from the microsatellite-enriched strategy. The experimental results obtained from Zhikong scallop also provide the reference for microsatellite marker development in other species with large genomes.
基金Supported by (in part) The Grant of Ministry of Science,Technology and Development of the Republic of Serbia,No. 156031
文摘AIM:To investigate and compare efficacy and differences in the nutritional status evaluation of gastroenterology patients by application of two methods:subjective global assessment(SGA) and nutritional risk index(NRI).METHODS:The investigation was performed on 299 hospitalized patients,aged 18-84 years(average life span 55.57 ± 12.84),with different gastrointe-stinal pathology,admitted to the Department of Gastroenterohepatology,Clinical and Hospital Center "Bezanijska Kosa" during a period of 180 d.All the patients,after being informed in detail about the study and signing a written consent,underwent nutritional status analysis,which included two different nutritional indices:SGA and NRI,anthropometric parameters,bioelectrical impedance analysis,and biochemical markers,within 24 h of admission.RESULTS:In our sample of 299 hospitalized patients,global malnutrition prevalence upon admission varied from 45.7% as assessed by the SGA to 63.9% by NRI.Two applied methods required different parameters for an adequate approach:glucose level(5.68 ± 1.06 mmol/L vs 4.83 ± 1.14 mmol/L,F = 10.63,P = 0.001);body mass index(26.03 ± 4.53 kg/m2 vs 18.17 ± 1.52 kg/m2,F = 58.36,P < 0.001);total body water(42.62 ± 7.98 kg vs 36.22 ± 9.32 kg,F = 7.95,P = 0.005);basal metabolic rate(1625.14 ± 304.91 kcal vs 1344.62 ± 219.08 kcal,F = 9.06,P = 0.003) were very important for SGA,and lymphocyte count was relevant for NRI:25.56% ± 8.94% vs 21.77% ± 10.08%,F = 11.55,P = 0.001.The number of malnourished patients rose with the length of hospital stay according to both nutritional indices.The discriminative function analysis(DFA) delineated the following parameters as important for prediction of nutritional status according to SGA assessment:concentration of albumins,level of proteins,SGA score and body weight.The DFA extracted MAMC,glucose level and NRI scores were variables of importance for the prediction of whether admitted patients would be classif ied as well or malnourished.CONCLUSION:SGA showed higher sensitivity to predictor factors.Assessment of nutritional status requires a multidimensional approach,which includes different clinical indices and various nutritional param eters.
基金supported by the National Natural Science Foundation of China(6160150161502521)
文摘To improve the inconsistency in the analytic hierarchy process(AHP), a new method based on marginal optimization theory is proposed. During the improving process, this paper regards the reduction of consistency ratio(CR) as benefit, and the maximum modification compared to the original pairwise comparison matrix(PCM) as cost, then the improvement of consistency is transformed to a benefit/cost analysis problem. According to the maximal marginal effect principle, the elements of PCM are modified by a fixed increment(or decrement) step by step till the consistency ratio becomes acceptable, which can ensure minimum adjustment to the original PCM so that the decision makers’ judgment is preserved as much as possible. The correctness of the proposed method is proved mathematically by theorem. Firstly, the marginal benefit/cost ratio is calculated for each single element of the PCM when it has been modified by a fixed increment(or decrement).Then, modification to the element with the maximum marginal benefit/cost ratio is accepted. Next, the marginal benefit/cost ratio is calculated again upon the revised matrix, and followed by choosing the modification to the element with the maximum marginal benefit/cost ratio. The process of calculating marginal effect and choosing the best modified element is repeated for each revised matrix till acceptable consistency is reached, i.e., CR<0.1. Finally,illustrative examples show the proposed method is more effective and better in preserving the original comparison information than existing methods.