With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attenti...With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated.展开更多
The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg...The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.展开更多
Objective: This study sought to investigate the content of the prescription rights and the prescription types of midwives under certain circumstances in China. Methods: The Delphi method was used to consult 18 nursi...Objective: This study sought to investigate the content of the prescription rights and the prescription types of midwives under certain circumstances in China. Methods: The Delphi method was used to consult 18 nursing experts and 14 medical experts, A total of 30 experts finished the consulting. The reliability of the expert opinions was analyzed to determine the specific situations in which midwives may write prescriptions, the content of the prescription rights and the prescription types. Results: In six specific circumstances (uterine contraction fatigue, uterine contractions that are too strong, postpartum hemorrhage, premature rupture of the membranes, normal delivery and neonatal asphyxia), midwives have the right to prescribe and administer medication, including 20 drugs and 13 auxiliary examinations. Of these drugs and examinations, 51.5% of the drugs and adjuvant examination prescriptions tend to be independent prescriptions, 30.3% tend to be protocol prescriptions, and 18.2% are similar to both types. Conclusions: The midwives should be granted some prescription rights to enhance their autonomy and the professionalism of midwifery.展开更多
<span style="font-family:Verdana;">Soil bulk density and moisture content are dynamic properties that vary with changes in soil and field conditions and have many agricultural, hydrological and environ...<span style="font-family:Verdana;">Soil bulk density and moisture content are dynamic properties that vary with changes in soil and field conditions and have many agricultural, hydrological and environmental implications. The main objective of this study was to compare between a soil core sampling method (core) and the CPN MC-3 Elite<span style="white-space:nowrap;"><sup>TM</sup></span> nuclear gauge method (radiation) for measuring bulk density (<span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span>) and volumetric moisture content (<span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span>) in a clay loam soil. Soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span> measurements were determined using the core and radiation methods at 0 - 10 and 10 - 20 cm soil depths. The mean values of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> obtained using the core method (1.454, 1.492 g<span style="color:#4F4F4F;font-family:" font-size:14px;white-space:normal;background-color:#f7f7f7;"="">·</span>cm<span style="white-space:nowrap;"><sup>−3</sup></span>) were greater than those obtained using the radiation method (1.343, 1.476 g<span style="color:#4F4F4F;font-family:" font-size:14px;white-space:normal;background-color:#f7f7f7;"="">·</span>cm<span style="white-space:nowrap;"><sup>−3</sup></span>) at the 0 - 10 and 10 - 20 cm depths, respectively. Mean <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span> values averaged across both depths (referred to as the 0 - 20 cm depth) measured by the core method were 4.47% and 22.74% greater, respectively, than those obtained by the radiation method. The coefficients of variation (CV) of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> values measured by the core method were lower than the CV values of those measured by the radiation method at both depths;however, the CV’s of <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> values for both methods were larger at the 0 - 10 cm depth than those measured at the 10 - 20 cm depth. Similarly, the CV values of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<sub>v</sub></i></span></span></i></span> values measured by the core method were lower than the CV values of those measured by the radiation method at both depths. There were significant differences between two methods in terms of <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<sub>v</sub></i></span></span></i></span>, with the core method generating greater values than the radiation method at the 0 - 20 cm depth. These discrepancies between the two methods could have resulted from soil compaction and soil disturbance caused by the core and radiation techniques, respectively, as well as by other sources of error. Nevertheless, the core sampling method is considered the most common one for measuring <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> for many agricultural, hydrological and environmental studies in most soils.</span>展开更多
The complex fluoride, KNiF3, with perovskite structure was synthesized by refluxing KF and Ni(NO3)2·6H20 in ethanediol. The samples were characterized by X-ray diffraction(XRD), transmission electron microsc...The complex fluoride, KNiF3, with perovskite structure was synthesized by refluxing KF and Ni(NO3)2·6H20 in ethanediol. The samples were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), X-ray photoelectron spectroscopy(XPS), and ultraviolet-visible diffuse reflectance speetroseopy(UV-Vis DRS). The results indicate that the mean diameter of KNiF3 particles is about 30-60 nm and the oxygen content in the samples is ≤5%. The prepared KNiF3 shows obvious absorption peaks at 400-830 nm.展开更多
For our research, a new hybrid experimental-computational method is presented. We applied a least squares fitting method (LSFM) to reconstruct the wood moisture content (WMC) from the data measured with a planar c...For our research, a new hybrid experimental-computational method is presented. We applied a least squares fitting method (LSFM) to reconstruct the wood moisture content (WMC) from the data measured with a planar capacitance sensor. A boundary element method (BEM) was used to compute the relationship between capacitance and the dielectric constant. A functional relationship between MC and the dielectric constant was identified by LSFM. The agreement of this final computation result with the experimental data indicates that this method can be used to estimate the WMC quickly and effectively with engineering analysis. Compared with popular statistical methods, a large number of experiments are avoided, some costs of testing are reduced and the efficiency of testing is enhanced.展开更多
The influence of coarse aggregate content on concrete properties was investigated.From the perspective of Frame Concrete Theory,six groups concrete were produced with the same proportion except for coarse aggregate co...The influence of coarse aggregate content on concrete properties was investigated.From the perspective of Frame Concrete Theory,six groups concrete were produced with the same proportion except for coarse aggregate content,with coarse aggregate content of 0%,40%,50%,60%,75%,and 80%,respectively.Slump,compressive and flexural tensile strengths,elastic modulus,and water penetration were tested to research the effect of coarse aggregate content on concrete.The experimental results reveal that slump reduces with increasing of coarse aggregate content,while compressive strength,elastic modulus and flexural tensile strength increase with the coarse aggregate content increasing,and water penetration reduces with coarse aggregate content increasing before 75% then increased.Workability,strength,durability and economical indexes system were established to optimize the coarse aggregate content in concrete based on efficacy coefficient method.The optimization results show that when coarse aggregate content is 60%,the system efficacy coefficient reaches to 0.89,and it expresses the better comprehensive performance.展开更多
Cellulose carbamates (CC) were synthesized with microcrystalline cellulose as raw materials. The Fourier transform infrared spectra of CC with different nitrogen content were recorded. The accurate results of the nitr...Cellulose carbamates (CC) were synthesized with microcrystalline cellulose as raw materials. The Fourier transform infrared spectra of CC with different nitrogen content were recorded. The accurate results of the nitrogen content for CC can be obtained by using the deconvolution method when the nitrogen content is less than 3.5%. The relationship between the nitrogen content and the absorption intensity ratio of the corresponding separated absorption peaks in FTIR spectra has been expressed bg an equation precisely.展开更多
Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has bee...Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has been widely used to measure protein content through the percentage of total nitrogen in the seed’s grounded powder. Near-Infrared Reflectance (NIR) has commonly been used to measure protein content in soybean seeds using whole grain without the need of seed grinding, which makes it possible to obtain fast results at a lower cost-per-analysis than the traditional combustion method. The specific objective of this study is to test a rapid method for measuring cowpea seed protein content by the NIR analyzer comparing to the traditional rapid N analyzer. A total of 240 cowpea genotypes were used in this study, including six seed coat colors, black, blackeye, browneye, cream, pinkeye, and red with 40 cowpea genotypes. The results showed that a linear relationship exists between the NIR analyzer and the Rapid N analyzer in the six different color groups. The correlation efficiency (r) between the seed protein contents from NIR and Rapid N was higher for pinkeye seed (r = 0.867), blackeye (0.771), cream (0.729), browneye (0.700), and red (0.623), respectively, but lower for black seeds, indicating that the NIR analyzer can be used to measure protein content for cowpea seeds with the five types of seed coat except black. Overview, the cowpea seed protein content measured from the NIR analyzer showed a little higher seed protein content. A series of regression models with different seed coat color have been built to adjust to protein content of colorful cowpea seeds from the NIR analyzer. But, it is not recommended to use for black color seeds due to a very low correlation efficiency (r) value with 0.184.展开更多
This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
This paper studied and compared the effects of three preservation methods( normal temperature 20℃,fresh-keeping box cold storage 4℃,and fresh-keeping box + fresh-keeping film cold storage 4℃) on six kinds of vegeta...This paper studied and compared the effects of three preservation methods( normal temperature 20℃,fresh-keeping box cold storage 4℃,and fresh-keeping box + fresh-keeping film cold storage 4℃) on six kinds of vegetables. The results showed that the content of vitamin C in the six vegetables was higher in cold storage than in normal temperature storage; the nitrate content was lower in cold storage than in normal temperature storage. In both the normal temperature storage and cold storage,the vitamin C in vegetables declined with the increase of the storage time,while the nitrate content increased with the increase of the storage time. Thus,cold storage has better fresh-keeping effect for vegetables. In cold storage conditions,the vitamin C content was higher in vegetables packaged by fresh-keeping box,and the nitrate content was lower,followed by the fresh-keeping film + fresh-keeping box cold storage. In conclusion,the best preservation method for vegetable is fresh-keeping box cold storage.展开更多
[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially availa...[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially available and homemade) by Folin-Ciocalteu method was inspected,and commercially available and homemade plum wine was evaluated by the method. [Results]The optimal determination conditions of total polyphenols content: sample dose of 1. 0 m L,Folin-Ciocalteu reagent of 1 m L,4% Na_2CO_3 solution of 4. 0 m L,reaction temperature of 50 ℃,reaction time of 1. 5 h,and determination wavelength of 756 nm. Absorbance showed good linear relationship with total polyphenols content within the range of 17. 73-59. 12 μg/m L( y = 14. 878 x + 0. 0739,R^2= 0. 9998). Recovery rate of adding standard sample was between 98. 8% and 103. 5%,and relative standard deviation was 2. 0%( n = 5). [Conclusions]The method had high precision degree and good stability,which was suitable for measuring total polyphenols content in plum wine( commercially available and homemade).展开更多
A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of...A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of a Cu deposit. Applications of the technique in Northeast China are presented.展开更多
The resin content in larch wood is usually determined by the traditionalBenzene-Alcohol Extract Method(BAEM).In order to meet the requirement of production prac-tice,the authors present two simple quick determination ...The resin content in larch wood is usually determined by the traditionalBenzene-Alcohol Extract Method(BAEM).In order to meet the requirement of production prac-tice,the authors present two simple quick determination methods,IR lamp method and hydrogenperoxide solution method.Compared with the results of traditional method,the results of newmethods are nearly the same as former,therefore,both two methods can reflect the change condi-tion of resin content in wood.展开更多
Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error...Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error of water content in crude oil proposed in this paper is based on switching measuring ranges of on-line water content analyzer automatically.Measuring precision on data collected from oil field and analyzed by in-field operators can be impressively improved by using back propogation (BP) neural network to predict water content in output crude oil.Application results show that the difficulty in accurately measuring water-oil content ratio can be solved effectively through this combination of on-line measuring range automatic switching and real time prediction,as this method has been tested repeatedly on-site in oil fields with satisfactory prediction results.展开更多
文摘With the increasing awareness of environmental protection, people’s concern of pollution issues arising. Vehicles, as the most important means of transportation, its exhaust emission has received considerable attention. The catalytic converter is able to purify harmful substances in exhaust gas. The absolute content of precious metals in the catalytic converter dominates the exhaust gas purification effect. Accurate detection of precious metal content is of great significance for controlling the cost of catalysts, ensuring catalytic performance and recovering precious metals from spent catalysts. We herein summarized several instruments for precious metals content exploration, such as X-ray fluorescence spectrometer (XRF), atomic absorption spectrometer (AAS), inductively coupled plasma emission spectrometer (ICP) and spectrophotometer. In this thesis, the feasibility of using various devices for characterizing precious metal content in catalytic converters is analyzed and their strengths or weaknesses are elaborated.
基金funded by the Special Funds for Industry System (CARS-03)Science and Technology Support Program (2012BAD04B07-03)
文摘The objective of this study was to evaluate the effects of wheat variety, food processing, and milling method on antioxidant properties. Black wheat variety Heibaoshi 1 had the highest total phenolic content(659.8 μg gallic acid equivalents g-1), total flavonoid content(319.3 μg rutin equivalents g-1), and antioxidant activity, whereas light purple wheat variety Shandongzimai 1 had the lowest total flavonoid content(236.2 μg rutin equivalents g-1) and antioxidant activity. Whole wheat flour and partially debranned grain flour had significantly higher total phenolic contents, total flavonoid contents, and antioxidant activity than refined flour(P < 0.05). Compared with flour, total phenolic contents, total flavonoid contents and antioxidant activity decreased in noodles and steamed bread, whereas noodles had slightly higher total phenolic and flavonoid content than steamed bread. Antioxidant activities(by ferric reducing ability of plasma assay) of steamed bread made from whole wheat flour, partially debranned grain flour, and refined flour were 23.5%, 21.1%, and 31.6% lower, respectively, than the corresponding values of flour. These results suggested that black whole wheat flour and partially debranned grain flour are beneficial to human health.
文摘Objective: This study sought to investigate the content of the prescription rights and the prescription types of midwives under certain circumstances in China. Methods: The Delphi method was used to consult 18 nursing experts and 14 medical experts, A total of 30 experts finished the consulting. The reliability of the expert opinions was analyzed to determine the specific situations in which midwives may write prescriptions, the content of the prescription rights and the prescription types. Results: In six specific circumstances (uterine contraction fatigue, uterine contractions that are too strong, postpartum hemorrhage, premature rupture of the membranes, normal delivery and neonatal asphyxia), midwives have the right to prescribe and administer medication, including 20 drugs and 13 auxiliary examinations. Of these drugs and examinations, 51.5% of the drugs and adjuvant examination prescriptions tend to be independent prescriptions, 30.3% tend to be protocol prescriptions, and 18.2% are similar to both types. Conclusions: The midwives should be granted some prescription rights to enhance their autonomy and the professionalism of midwifery.
文摘<span style="font-family:Verdana;">Soil bulk density and moisture content are dynamic properties that vary with changes in soil and field conditions and have many agricultural, hydrological and environmental implications. The main objective of this study was to compare between a soil core sampling method (core) and the CPN MC-3 Elite<span style="white-space:nowrap;"><sup>TM</sup></span> nuclear gauge method (radiation) for measuring bulk density (<span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span>) and volumetric moisture content (<span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span>) in a clay loam soil. Soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span> measurements were determined using the core and radiation methods at 0 - 10 and 10 - 20 cm soil depths. The mean values of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> obtained using the core method (1.454, 1.492 g<span style="color:#4F4F4F;font-family:" font-size:14px;white-space:normal;background-color:#f7f7f7;"="">·</span>cm<span style="white-space:nowrap;"><sup>−3</sup></span>) were greater than those obtained using the radiation method (1.343, 1.476 g<span style="color:#4F4F4F;font-family:" font-size:14px;white-space:normal;background-color:#f7f7f7;"="">·</span>cm<span style="white-space:nowrap;"><sup>−3</sup></span>) at the 0 - 10 and 10 - 20 cm depths, respectively. Mean <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<span style="font-size:10.9091px;">v</span></i></span></span></i></span> values averaged across both depths (referred to as the 0 - 20 cm depth) measured by the core method were 4.47% and 22.74% greater, respectively, than those obtained by the radiation method. The coefficients of variation (CV) of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"></span><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> values measured by the core method were lower than the CV values of those measured by the radiation method at both depths;however, the CV’s of <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> values for both methods were larger at the 0 - 10 cm depth than those measured at the 10 - 20 cm depth. Similarly, the CV values of soil <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<sub>v</sub></i></span></span></i></span> values measured by the core method were lower than the CV values of those measured by the radiation method at both depths. There were significant differences between two methods in terms of <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> and <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>θ<sub>v</sub></i></span></span></i></span>, with the core method generating greater values than the radiation method at the 0 - 20 cm depth. These discrepancies between the two methods could have resulted from soil compaction and soil disturbance caused by the core and radiation techniques, respectively, as well as by other sources of error. Nevertheless, the core sampling method is considered the most common one for measuring <span style="white-space:nowrap;"><i><span style="font-family:Verdana;white-space:normal;"><span style="white-space:nowrap;"><i>ρ<sub>B</sub></i></span></span></i></span> for many agricultural, hydrological and environmental studies in most soils.</span>
基金Supported by the National Natural Science Foundation of China(No.20671069)
文摘The complex fluoride, KNiF3, with perovskite structure was synthesized by refluxing KF and Ni(NO3)2·6H20 in ethanediol. The samples were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), X-ray photoelectron spectroscopy(XPS), and ultraviolet-visible diffuse reflectance speetroseopy(UV-Vis DRS). The results indicate that the mean diameter of KNiF3 particles is about 30-60 nm and the oxygen content in the samples is ≤5%. The prepared KNiF3 shows obvious absorption peaks at 400-830 nm.
基金supported by the Central University Basic Research Professional Expenses Special Foundation of Harbin Engineering University (Grant No. HEUCFL10101109)
文摘For our research, a new hybrid experimental-computational method is presented. We applied a least squares fitting method (LSFM) to reconstruct the wood moisture content (WMC) from the data measured with a planar capacitance sensor. A boundary element method (BEM) was used to compute the relationship between capacitance and the dielectric constant. A functional relationship between MC and the dielectric constant was identified by LSFM. The agreement of this final computation result with the experimental data indicates that this method can be used to estimate the WMC quickly and effectively with engineering analysis. Compared with popular statistical methods, a large number of experiments are avoided, some costs of testing are reduced and the efficiency of testing is enhanced.
基金Funded by the National Mega-project of Scientific & Technical Supporting Programs,Ministry of Science & Technology of China(No.2006BAJ04A04)the Education Department of Liaoning Province,China(No. 2008282)
文摘The influence of coarse aggregate content on concrete properties was investigated.From the perspective of Frame Concrete Theory,six groups concrete were produced with the same proportion except for coarse aggregate content,with coarse aggregate content of 0%,40%,50%,60%,75%,and 80%,respectively.Slump,compressive and flexural tensile strengths,elastic modulus,and water penetration were tested to research the effect of coarse aggregate content on concrete.The experimental results reveal that slump reduces with increasing of coarse aggregate content,while compressive strength,elastic modulus and flexural tensile strength increase with the coarse aggregate content increasing,and water penetration reduces with coarse aggregate content increasing before 75% then increased.Workability,strength,durability and economical indexes system were established to optimize the coarse aggregate content in concrete based on efficacy coefficient method.The optimization results show that when coarse aggregate content is 60%,the system efficacy coefficient reaches to 0.89,and it expresses the better comprehensive performance.
文摘Cellulose carbamates (CC) were synthesized with microcrystalline cellulose as raw materials. The Fourier transform infrared spectra of CC with different nitrogen content were recorded. The accurate results of the nitrogen content for CC can be obtained by using the deconvolution method when the nitrogen content is less than 3.5%. The relationship between the nitrogen content and the absorption intensity ratio of the corresponding separated absorption peaks in FTIR spectra has been expressed bg an equation precisely.
文摘Cowpea (Vigna unguiculata (L.) Walp), a legume crop that is grown in the worldwide, provides beneficial proteins for human consumption and animal feeding. In comparison, Rapid N analyzer as traditional method, has been widely used to measure protein content through the percentage of total nitrogen in the seed’s grounded powder. Near-Infrared Reflectance (NIR) has commonly been used to measure protein content in soybean seeds using whole grain without the need of seed grinding, which makes it possible to obtain fast results at a lower cost-per-analysis than the traditional combustion method. The specific objective of this study is to test a rapid method for measuring cowpea seed protein content by the NIR analyzer comparing to the traditional rapid N analyzer. A total of 240 cowpea genotypes were used in this study, including six seed coat colors, black, blackeye, browneye, cream, pinkeye, and red with 40 cowpea genotypes. The results showed that a linear relationship exists between the NIR analyzer and the Rapid N analyzer in the six different color groups. The correlation efficiency (r) between the seed protein contents from NIR and Rapid N was higher for pinkeye seed (r = 0.867), blackeye (0.771), cream (0.729), browneye (0.700), and red (0.623), respectively, but lower for black seeds, indicating that the NIR analyzer can be used to measure protein content for cowpea seeds with the five types of seed coat except black. Overview, the cowpea seed protein content measured from the NIR analyzer showed a little higher seed protein content. A series of regression models with different seed coat color have been built to adjust to protein content of colorful cowpea seeds from the NIR analyzer. But, it is not recommended to use for black color seeds due to a very low correlation efficiency (r) value with 0.184.
文摘This standard specifies the method summary, reagents, apparatus, sampling, procedure, test results calculation and permissible tolerance of the determination of magnesium oxide by CyDTA volumetric method.
文摘This paper studied and compared the effects of three preservation methods( normal temperature 20℃,fresh-keeping box cold storage 4℃,and fresh-keeping box + fresh-keeping film cold storage 4℃) on six kinds of vegetables. The results showed that the content of vitamin C in the six vegetables was higher in cold storage than in normal temperature storage; the nitrate content was lower in cold storage than in normal temperature storage. In both the normal temperature storage and cold storage,the vitamin C in vegetables declined with the increase of the storage time,while the nitrate content increased with the increase of the storage time. Thus,cold storage has better fresh-keeping effect for vegetables. In cold storage conditions,the vitamin C content was higher in vegetables packaged by fresh-keeping box,and the nitrate content was lower,followed by the fresh-keeping film + fresh-keeping box cold storage. In conclusion,the best preservation method for vegetable is fresh-keeping box cold storage.
基金Supported by Sichuan Science and Technology Support Plan(2015FZ0026)Postgraduate Innovation Project of Southwest University for Nationalities(CX2016SZ016)
文摘[Objectives] To study on colorimetric method and content determination of total phenol in homemade plum wine. [Methods]The optimal determination condition of total polyphenols content in plum wine( commercially available and homemade) by Folin-Ciocalteu method was inspected,and commercially available and homemade plum wine was evaluated by the method. [Results]The optimal determination conditions of total polyphenols content: sample dose of 1. 0 m L,Folin-Ciocalteu reagent of 1 m L,4% Na_2CO_3 solution of 4. 0 m L,reaction temperature of 50 ℃,reaction time of 1. 5 h,and determination wavelength of 756 nm. Absorbance showed good linear relationship with total polyphenols content within the range of 17. 73-59. 12 μg/m L( y = 14. 878 x + 0. 0739,R^2= 0. 9998). Recovery rate of adding standard sample was between 98. 8% and 103. 5%,and relative standard deviation was 2. 0%( n = 5). [Conclusions]The method had high precision degree and good stability,which was suitable for measuring total polyphenols content in plum wine( commercially available and homemade).
文摘A new method is proposed to prospect copper deposits with portable XRF analyzer. The method is based on the close relation between Cu and the chalcophile elements or some other elements in the geochemical anomalies of a Cu deposit. Applications of the technique in Northeast China are presented.
文摘The resin content in larch wood is usually determined by the traditionalBenzene-Alcohol Extract Method(BAEM).In order to meet the requirement of production prac-tice,the authors present two simple quick determination methods,IR lamp method and hydrogenperoxide solution method.Compared with the results of traditional method,the results of newmethods are nearly the same as former,therefore,both two methods can reflect the change condi-tion of resin content in wood.
基金Sponsored by the Basic Research Fundation of Beijing Institute of Technology (200705422009)
文摘Water content in output crude oil is hard to measure precisely because of wide range of dielectric coefficient of crude oil caused by injected dehydrating and demulsifying agents.The method to reduce measurement error of water content in crude oil proposed in this paper is based on switching measuring ranges of on-line water content analyzer automatically.Measuring precision on data collected from oil field and analyzed by in-field operators can be impressively improved by using back propogation (BP) neural network to predict water content in output crude oil.Application results show that the difficulty in accurately measuring water-oil content ratio can be solved effectively through this combination of on-line measuring range automatic switching and real time prediction,as this method has been tested repeatedly on-site in oil fields with satisfactory prediction results.