The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-...The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-cores samples were selected from the Wanniangou V–Ti–Fe mine tailings pond(Sichuan province,China)to investigate the mineralogicand geochemical characteristics in the tailings profile.The results reveal(1)the tailings pond profile consist of upper and lower layers.The upper layer is composed of carbonate weathering(1.4%),which was formed in the initial stages of tailings exposure and represented a minimal weathering degree.(2)The lower layer was primarily observed at the aquifer zone of the tailings pond,and was consistent with 0.45%carbonate weathering and 48.4%silicate weathering.(3)The weathering discrepancy in the tailings profile could be due to the sulfide oxidation and aerobic/flowing aquifer,which facilitate the water-tailings reactions.The tailings profile provides an analog to studying basalt weathering,as it spans both carbonate and silicate weathering.This research reinforces the idea that silicate weathering is predominant in basaltic areas and plays a crucial role in regulating atmospheric CO_(2)(carbon dioxide)levels on Earth.展开更多
In this paper, the changes of surface morphology, microstructure, hardness and corrosion resistance of industrial pure zirconium before and after surface modification by high current pulsed electron beam were discusse...In this paper, the changes of surface morphology, microstructure, hardness and corrosion resistance of industrial pure zirconium before and after surface modification by high current pulsed electron beam were discussed. The microstructure evolution and surface morphologies of the samples were characterized by using X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM). The experimental results show that sample by high current pulsed electron beam treatment surface melting, martensitic phase transformation occurred, and volcanic crater morphology and fine microstructure in the remelted layer surface;with the increase of number of pulses, after processing the microhardness of the samples also with the increase, 15-pulsed sample microhardness than the original sample increased by 30.9%. Corrosion resistance of samples was studied with the impedance diagram and polarization curve. The electrochemical results show that corrosion resistance of samples by high current pulsed electron beam treatment presents different degrees of change, the 5-pulsed sample in 1 mol HNO<sub>3</sub> solution corrosion of the best, and 15-pulsed sample corrosion resistance is even lower than the original sample. Grain refinement, martensite transformation, dislocation and deformation twins are the main reasons for improving the micro hardness and corrosion resistance of the samples.展开更多
目的:分析食管癌患者放疗期间预防性使用吡非尼酮对放射性肺炎的影响。方法:回顾性收集2017年11月至2020年1月于福建医科大学附属协和医院接受调强放疗(intensity-modulated radiation therapy,IMRT)的胸段食管癌患者资料,按是否使用吡...目的:分析食管癌患者放疗期间预防性使用吡非尼酮对放射性肺炎的影响。方法:回顾性收集2017年11月至2020年1月于福建医科大学附属协和医院接受调强放疗(intensity-modulated radiation therapy,IMRT)的胸段食管癌患者资料,按是否使用吡非尼酮将患者分为吡非尼酮组和对照组,通过逆概率处理加权法(inverse probability of treatment weighting,IPTW)将各协变量在两组人群进行加权处理,分析两组人群2级及3级以上放射性肺炎的发生率。结果:共纳入170例符合要求的病例,其中吡非尼酮组40例,对照组130例。中位随访时间22.6个月,通过对年龄、吡非尼酮用药史、放疗剂量、双肺V_(5)及V_(20)等可能影响放射性肺炎发生的临床因素及肺体积剂量参数等进行IPTW法加权分析,加权后两组基线特征标准化均值差值下降99.72%,两组2级以上、3级以上放射性肺炎发生率分别为3.92%vs.14.73%(P=0.0007)及3.92%vs.10.99%(P=0.0141),差异均有统计学意义。多因素Logistic回归分析发现吡非尼酮用药史(2级P=0.0017,3级P=0.0191)、年龄(2级P=0.0336,3级P=0.0028)、放疗剂量(2级P=0.0119,3级P=0.0031)均与2级和3级以上放射性肺炎相关。吡非尼酮组未发现明显的不良反应。结论:接受IMRT治疗食管癌患者,放疗期间同步使用吡非尼酮可有效降低2级及3级以上放射性肺炎的发生,安全性好,值得开展进一步临床研究证实。展开更多
A novel modulation recognition algorithm is proposed by introducing a Chen-Harker-Kanzow-Smale(CHKS) smooth function into the C-support vector machine deformation algorithm. A set of seven characteristic parameters is...A novel modulation recognition algorithm is proposed by introducing a Chen-Harker-Kanzow-Smale(CHKS) smooth function into the C-support vector machine deformation algorithm. A set of seven characteristic parameters is selected from a range of parameters of communication signals including instantaneous amplitude, phase, and frequency. And the Newton-Armijo algorithm is utilized to train the proposed algorithm, namely, smooth CHKS smooth support vector machine(SCHKS-SSVM). Compared with the existing algorithms, the proposed algorithm not only solves the non-differentiable problem of the second order objective function, but also reduces the recognition error. It significantly improves the training speed and also saves a large amount of storage space through large-scale sorting problems. The simulation results show that the recognition rate of the algorithm can batch training. Therefore, the proposed algorithm is suitable for solving the problem of high dimension and its recognition can exceed 95%when the signal-to-noise ratio is no less than 10 d B.展开更多
In this work,the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated.Filed emission scanning electron microscopy-energy dispersive X-ray spectrosc...In this work,the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated.Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEM) and X-ray diffraction(XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface,but rather penetrates into the bulk to form covellite crystal(synCuS),creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation.Additionally,as demonstrated by X-ray photoelectron spectroscopy(XPS) and time of flight secondary ion mass spectrometry(TOF-SIMS) analyses,a redox reaction occurred during this process,and Cu(Ⅱ) onto the mineral surface was reduced to Cu(Ⅰ).Correspondingly,reduced S^(2-) was oxidized to(S_(2))^(2-),(S_n)^(-2),and even to deeper oxidation state S~0,(S_(x)O_(y))^(n-) and SO_(4)^(2-).Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface,and provides enough raw material for crystal copper sulfide to grow,resulting in the formation of "flake-like" covellite with a better crystallinity.However,the floatability of azurite decreased dramatically under this condition,because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment,resulting in a decreased effective adsorption of collector onto azurite surfaces.展开更多
In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased...In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.展开更多
Polymer-supported hydrous iron oxides(HFOs) are promising for heavy metals removal from aqueous systems.The ubiquitous inorganic ligands, e.g., sulfate, are expected to exert considerable impacts on pollutants removal...Polymer-supported hydrous iron oxides(HFOs) are promising for heavy metals removal from aqueous systems.The ubiquitous inorganic ligands, e.g., sulfate, are expected to exert considerable impacts on pollutants removal by these hybrid sorbents. Herein, we obtained a hybrid sorbent HFO-PS by encapsulating nanosized HFO into macroporous polystyrene(PS) resin. Both batch and column sorption experiments of Cu(Ⅱ) by HFO-PS were carried out in the presence of sulfate. Obviously, the presence of sulfate is favorable for Cu(Ⅱ) sorption onto HFO-PS.The performances of column Cu(Ⅱ) removal were fitted and predicted with Adams–Bohart, Clark, Thomas and BDST models. Thomas model is suggested best-fit to predict the breakthrough curves. Besides, a linear correlation is observed between breakthrough time and column length based on BDST model, which might be useful for predicting the breakthrough time for Cu(Ⅱ) removal by HFO-PS.展开更多
Global navigation satellite system could provide accurate positioning results in signal complete condition. However, the performance is severe when signal denied, especially for the single-mode Bei Dou receiver. This ...Global navigation satellite system could provide accurate positioning results in signal complete condition. However, the performance is severe when signal denied, especially for the single-mode Bei Dou receiver. This paper proposes a dual-satellite positioning algorithm to promote the positioning performance in the satellite signal gap. The new algorithm utilizes the previous positioning data stored in complete condition to simplify the positioning equations. As the clock bias persists for a short period, this proposed method could work out accurate positioning results by only two visible satellites, without the need of computing the clock bias. Also, the Kalman filtering algorithm is used to smooth the trajectories, and improve the positioning results. During the incomplete period, only two satellites for 30 seconds and three satellites for 60 seconds, the preliminary experiment result shows that, the presented method could provide almost the same positioning results as in complete condition.展开更多
Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgradin...Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgrading traditional industry.This study aims to utilize SW as a substrate for the growth of probiotics and produce a SW based synbiotics.By a series of trials,the effect of the dietary supplementation with this fermented SW(FSW)was analyzed on ICR mice's body weight,metabolites,and intestinal microbiota in 4 weeks.The results showed that,when SW was concentrated 15 times,the count of viable Lactobacillus casei reached 3.4×10^(9) CFU/mL by liquid fermentation method,which was the highest viable cell count among all test strains.In this FSW,the protein,amino acid,total dietary fibre,soluble dietary fibre,and oligosaccharide were 2.10%,1.63%,0.52%,0.51% and 0.79%,respectively.Compared to two control group,the total yields of the short chain fatty acids(SCFAs)were significantly improved(75%-125% at average),while the SCFAs structure was also significantly changed(especially acetic acid and butyrate)in the faeces of mice fed FSW.Meanwhile,FSW dietary addition was associated with the diversity and richness of the intestinal microbiota.Obviously,with mice's body weight loss,Firmicutes/Bacteroides ratio reduced accordingly(<1.21),and the abundance of Akkermansia muciniphila was significantly increased(the maximum amount was about 0.013%).In summary,our results indicated that the dietary supplementation of FSW affected mice's intestinal microbiota and metabolism and improved their health profile.展开更多
Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market informat...Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market information, participants are risk neutral;under the situation of the manufacturers and wholesalers having twice pre-season decision-making opportunity, wholesalers can be replenished in the season;manufacturers join the lowest supply contract of commitment: manufacturers for exchanging the information that they cannot get directly from the market will promise wholesalers to have a season lowest supply in pre-season. According to this contract, we establish optimization models of manufacturers and wholesalers respectively, and get the optimal strategy of supply chain members by analyzing the supply chain system. Finally, by giving a numerical example and comparing the results with that under random circumstances, the result is reasonable.展开更多
Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a on...Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a one-size-fits-all approach cannot meet the goal(s) of these assessments. Probably even larger differences exist between individuals, research teams and departments.展开更多
The paper introduced the significance of risk control in food inspection organizations,expounded the risk points of food inspection organizations from the aspects of human,machine,material,law,environment and testing ...The paper introduced the significance of risk control in food inspection organizations,expounded the risk points of food inspection organizations from the aspects of human,machine,material,law,environment and testing of laboratory operation and gave corresponding risk management measures.This will help food inspection organizations' risk prevention and control to achieve effective management of inspection organizations.展开更多
[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theorie...[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theories such as Evaluation and expression of uncertainty in measurement,the uncertainty in the results of nitrofuran metabolites in chicken bone was analyzed and calculated combining with mathematical models. [Results] Under the addition amount of 1. 0 μg/kg,the uncertainty of the four nitrofuran metabolites was as follows: nitrofurazone metabolites C(SEM)= 0. 981 μg/kg,U = 0. 070 μg/kg,k = 2;furazolidone metabolites C(AOZ)= 1. 032 μg/kg,U = 0. 061 μg/kg,k = 2;furaltadone metabolites C(AMOZ)= 1. 068 μg/kg,U = 0. 076 μg/kg,k = 2;furadantin metabolites C(AHD)=1. 007 μg/kg,U = 0. 046 μg/kg,k = 2. [Conclusions]The uncertainty in the measurement process mainly comes from the purity of the standards,the preparation process,the sample weight,the number of repeated measurement and the recovery of spiked sample. The research results are of great significance for reducing uncertainty and improving data accuracy and reliability during actual operation.展开更多
Open access(OA)resources are becoming a main part of scholarly information.The paper summarizes the fast growth of OA journals and OA repositories,the outstanding OA journal impact increase,the rise of mega-OA journal...Open access(OA)resources are becoming a main part of scholarly information.The paper summarizes the fast growth of OA journals and OA repositories,the outstanding OA journal impact increase,the rise of mega-OA journals like PLoS ONE,the overwhelming support of research communities to open access of publicly funded research,and the quick building up of OA support structures.These forces work together to push scholarly communications toward a turning point where OA resources occupy a major and increasing share of scholarly research resources and when management of OA resources becomes a strategic,yet unfamiliar,and potentially disruptive task for research libraries.This paper is composed of two parts.The first part will focus on the development of OA resources,while the second part will analyze the challenges in management of OA resources and develop an OA resource strategy exemplified by some of NSL’s initiatives.展开更多
基金the financial support from the National Natural Science Foundation of China(51878332,21976084,and 21925602)the Fundamental Research Funds for the Central Universities.
基金financially supported by Sichuan Science and Technology Program(No.2023YFS0408)。
文摘The(ultra-)mafic mine tailings pond revealed a weathering discrepancy in the tailings profile,which provided a valuable analog to assess the role of carbonate and silicate weathering of the basalt.In this study,drill-cores samples were selected from the Wanniangou V–Ti–Fe mine tailings pond(Sichuan province,China)to investigate the mineralogicand geochemical characteristics in the tailings profile.The results reveal(1)the tailings pond profile consist of upper and lower layers.The upper layer is composed of carbonate weathering(1.4%),which was formed in the initial stages of tailings exposure and represented a minimal weathering degree.(2)The lower layer was primarily observed at the aquifer zone of the tailings pond,and was consistent with 0.45%carbonate weathering and 48.4%silicate weathering.(3)The weathering discrepancy in the tailings profile could be due to the sulfide oxidation and aerobic/flowing aquifer,which facilitate the water-tailings reactions.The tailings profile provides an analog to studying basalt weathering,as it spans both carbonate and silicate weathering.This research reinforces the idea that silicate weathering is predominant in basaltic areas and plays a crucial role in regulating atmospheric CO_(2)(carbon dioxide)levels on Earth.
文摘In this paper, the changes of surface morphology, microstructure, hardness and corrosion resistance of industrial pure zirconium before and after surface modification by high current pulsed electron beam were discussed. The microstructure evolution and surface morphologies of the samples were characterized by using X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM). The experimental results show that sample by high current pulsed electron beam treatment surface melting, martensitic phase transformation occurred, and volcanic crater morphology and fine microstructure in the remelted layer surface;with the increase of number of pulses, after processing the microhardness of the samples also with the increase, 15-pulsed sample microhardness than the original sample increased by 30.9%. Corrosion resistance of samples was studied with the impedance diagram and polarization curve. The electrochemical results show that corrosion resistance of samples by high current pulsed electron beam treatment presents different degrees of change, the 5-pulsed sample in 1 mol HNO<sub>3</sub> solution corrosion of the best, and 15-pulsed sample corrosion resistance is even lower than the original sample. Grain refinement, martensite transformation, dislocation and deformation twins are the main reasons for improving the micro hardness and corrosion resistance of the samples.
文摘目的:分析食管癌患者放疗期间预防性使用吡非尼酮对放射性肺炎的影响。方法:回顾性收集2017年11月至2020年1月于福建医科大学附属协和医院接受调强放疗(intensity-modulated radiation therapy,IMRT)的胸段食管癌患者资料,按是否使用吡非尼酮将患者分为吡非尼酮组和对照组,通过逆概率处理加权法(inverse probability of treatment weighting,IPTW)将各协变量在两组人群进行加权处理,分析两组人群2级及3级以上放射性肺炎的发生率。结果:共纳入170例符合要求的病例,其中吡非尼酮组40例,对照组130例。中位随访时间22.6个月,通过对年龄、吡非尼酮用药史、放疗剂量、双肺V_(5)及V_(20)等可能影响放射性肺炎发生的临床因素及肺体积剂量参数等进行IPTW法加权分析,加权后两组基线特征标准化均值差值下降99.72%,两组2级以上、3级以上放射性肺炎发生率分别为3.92%vs.14.73%(P=0.0007)及3.92%vs.10.99%(P=0.0141),差异均有统计学意义。多因素Logistic回归分析发现吡非尼酮用药史(2级P=0.0017,3级P=0.0191)、年龄(2级P=0.0336,3级P=0.0028)、放疗剂量(2级P=0.0119,3级P=0.0031)均与2级和3级以上放射性肺炎相关。吡非尼酮组未发现明显的不良反应。结论:接受IMRT治疗食管癌患者,放疗期间同步使用吡非尼酮可有效降低2级及3级以上放射性肺炎的发生,安全性好,值得开展进一步临床研究证实。
基金supported by the National Natural Science Foundation of China(61401196)the Jiangsu Provincial Natural Science Foundation of China(BK20140954)+1 种基金the Science and Technology on Information Transmission and Dissemination in Communication Networks Laboratory(KX152600015/ITD-U15006)the Beijing Shengfeifan Electronic System Technology Development Co.,Ltd(KY10800150036)
文摘A novel modulation recognition algorithm is proposed by introducing a Chen-Harker-Kanzow-Smale(CHKS) smooth function into the C-support vector machine deformation algorithm. A set of seven characteristic parameters is selected from a range of parameters of communication signals including instantaneous amplitude, phase, and frequency. And the Newton-Armijo algorithm is utilized to train the proposed algorithm, namely, smooth CHKS smooth support vector machine(SCHKS-SSVM). Compared with the existing algorithms, the proposed algorithm not only solves the non-differentiable problem of the second order objective function, but also reduces the recognition error. It significantly improves the training speed and also saves a large amount of storage space through large-scale sorting problems. The simulation results show that the recognition rate of the algorithm can batch training. Therefore, the proposed algorithm is suitable for solving the problem of high dimension and its recognition can exceed 95%when the signal-to-noise ratio is no less than 10 d B.
基金supported by the National Natural Science Foundation of China (No. 52074138)Basic research project of Yunnan Province (No. 202001AS070030)Open Foundation of State Key Laboratory of Mineral Processing (BGRIMM-KJSKL2020-03)。
文摘In this work,the growth of copper sulfide crystal onto azurite surfaces during sulfurization and its response to flotation are investigated.Filed emission scanning electron microscopy-energy dispersive X-ray spectroscopy(FESEM) and X-ray diffraction(XRD) studies confirmed that the sulfurization of azurite is not limited to the mineral surface,but rather penetrates into the bulk to form covellite crystal(synCuS),creating favorable conditions for the stable adsorption of xanthate and greatly promoting the azurite flotation.Additionally,as demonstrated by X-ray photoelectron spectroscopy(XPS) and time of flight secondary ion mass spectrometry(TOF-SIMS) analyses,a redox reaction occurred during this process,and Cu(Ⅱ) onto the mineral surface was reduced to Cu(Ⅰ).Correspondingly,reduced S^(2-) was oxidized to(S_(2))^(2-),(S_n)^(-2),and even to deeper oxidation state S~0,(S_(x)O_(y))^(n-) and SO_(4)^(2-).Excess sodium sulfide strengthens copper sulfide to form onto the azurite surface,and provides enough raw material for crystal copper sulfide to grow,resulting in the formation of "flake-like" covellite with a better crystallinity.However,the floatability of azurite decreased dramatically under this condition,because the generated massive colloidal copper sulfide in flotation pulp deteriorates the flotation environment,resulting in a decreased effective adsorption of collector onto azurite surfaces.
基金This research project was supported by the National Natural Science Foundation of China(No.52074138)Basic research project of Yunnan Province(No.202001AS070030)Open Foundation of State Key Laboratory of Mineral Processing(No.BGRIMM-KJSKL-2020-03).
文摘In this study,the role of(NH_(4))_(2)SO_(4)during the sulfurization of azurite and its response to flotation were investigated.The flotation results showed that adding(NH_(4))_(2)SO_(4)prior to sulfurization decreased the formation of colloid in flotation pulp,and the floatability of the suppressed azurite caused by excess sodium sulfide was restored.After adding(NH_(4))_(2)SO_(4)prior to sulfurization,the formation of Cu(NH_(3))_(n) ^(2+)intermediate products changed the path of the sulfurization reaction,which slowed the direct impact of HSon the azurite surface.The nucleation rate was reduced,and the growth of copper sulfide crystal was improved.Covellite(syn,CuS)with larger crystal grains was formed on the azurite surface,thereby enhancing the mechanical stability of copper sulfide products onto the mineral surface.Therefore,the generated copper sulfide colloid significantly reduced,ultimately promoting the effective adsorption of xanthate on the azurite surface.
基金Supported by the National Natural Science Foundation of China(21607080)the Natural Science Foundation of Jiangsu Province(BK20160946)Jiangsu Higher Education Institution NSF(16KJB610011)
文摘Polymer-supported hydrous iron oxides(HFOs) are promising for heavy metals removal from aqueous systems.The ubiquitous inorganic ligands, e.g., sulfate, are expected to exert considerable impacts on pollutants removal by these hybrid sorbents. Herein, we obtained a hybrid sorbent HFO-PS by encapsulating nanosized HFO into macroporous polystyrene(PS) resin. Both batch and column sorption experiments of Cu(Ⅱ) by HFO-PS were carried out in the presence of sulfate. Obviously, the presence of sulfate is favorable for Cu(Ⅱ) sorption onto HFO-PS.The performances of column Cu(Ⅱ) removal were fitted and predicted with Adams–Bohart, Clark, Thomas and BDST models. Thomas model is suggested best-fit to predict the breakthrough curves. Besides, a linear correlation is observed between breakthrough time and column length based on BDST model, which might be useful for predicting the breakthrough time for Cu(Ⅱ) removal by HFO-PS.
基金partially supported by the National Natural Science Foundation of China under Grant No.61601296, 61601295, and 61671304
文摘Global navigation satellite system could provide accurate positioning results in signal complete condition. However, the performance is severe when signal denied, especially for the single-mode Bei Dou receiver. This paper proposes a dual-satellite positioning algorithm to promote the positioning performance in the satellite signal gap. The new algorithm utilizes the previous positioning data stored in complete condition to simplify the positioning equations. As the clock bias persists for a short period, this proposed method could work out accurate positioning results by only two visible satellites, without the need of computing the clock bias. Also, the Kalman filtering algorithm is used to smooth the trajectories, and improve the positioning results. During the incomplete period, only two satellites for 30 seconds and three satellites for 60 seconds, the preliminary experiment result shows that, the presented method could provide almost the same positioning results as in complete condition.
文摘Soy whey(SW)is generated as process waste while preparing soy protein isolates(SPI),and causing severe environmental pollution.Therefore,its value-added utilization is of prime importance for transforming and upgrading traditional industry.This study aims to utilize SW as a substrate for the growth of probiotics and produce a SW based synbiotics.By a series of trials,the effect of the dietary supplementation with this fermented SW(FSW)was analyzed on ICR mice's body weight,metabolites,and intestinal microbiota in 4 weeks.The results showed that,when SW was concentrated 15 times,the count of viable Lactobacillus casei reached 3.4×10^(9) CFU/mL by liquid fermentation method,which was the highest viable cell count among all test strains.In this FSW,the protein,amino acid,total dietary fibre,soluble dietary fibre,and oligosaccharide were 2.10%,1.63%,0.52%,0.51% and 0.79%,respectively.Compared to two control group,the total yields of the short chain fatty acids(SCFAs)were significantly improved(75%-125% at average),while the SCFAs structure was also significantly changed(especially acetic acid and butyrate)in the faeces of mice fed FSW.Meanwhile,FSW dietary addition was associated with the diversity and richness of the intestinal microbiota.Obviously,with mice's body weight loss,Firmicutes/Bacteroides ratio reduced accordingly(<1.21),and the abundance of Akkermansia muciniphila was significantly increased(the maximum amount was about 0.013%).In summary,our results indicated that the dietary supplementation of FSW affected mice's intestinal microbiota and metabolism and improved their health profile.
基金supported by the Bureau of Geological Survey of China(1212011120116)the National Natural Science Foundation of China(40632010,41102005,91114201,and J0930006)the National Basic Research Program of China (2012CB821906)
文摘Based on the uncertainty theory, market demand information updating as the background, we study the coordination and optimization problem of three-stage supply chain in this paper. In half a asymmetric market information, participants are risk neutral;under the situation of the manufacturers and wholesalers having twice pre-season decision-making opportunity, wholesalers can be replenished in the season;manufacturers join the lowest supply contract of commitment: manufacturers for exchanging the information that they cannot get directly from the market will promise wholesalers to have a season lowest supply in pre-season. According to this contract, we establish optimization models of manufacturers and wholesalers respectively, and get the optimal strategy of supply chain members by analyzing the supply chain system. Finally, by giving a numerical example and comparing the results with that under random circumstances, the result is reasonable.
文摘Requirements for research assessments There are huge differences in mission, emphasis, inherent capability, and targeted utilization of research among scientific institutions. Hence, when it comes to assessments, a one-size-fits-all approach cannot meet the goal(s) of these assessments. Probably even larger differences exist between individuals, research teams and departments.
文摘The paper introduced the significance of risk control in food inspection organizations,expounded the risk points of food inspection organizations from the aspects of human,machine,material,law,environment and testing of laboratory operation and gave corresponding risk management measures.This will help food inspection organizations' risk prevention and control to achieve effective management of inspection organizations.
文摘[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theories such as Evaluation and expression of uncertainty in measurement,the uncertainty in the results of nitrofuran metabolites in chicken bone was analyzed and calculated combining with mathematical models. [Results] Under the addition amount of 1. 0 μg/kg,the uncertainty of the four nitrofuran metabolites was as follows: nitrofurazone metabolites C(SEM)= 0. 981 μg/kg,U = 0. 070 μg/kg,k = 2;furazolidone metabolites C(AOZ)= 1. 032 μg/kg,U = 0. 061 μg/kg,k = 2;furaltadone metabolites C(AMOZ)= 1. 068 μg/kg,U = 0. 076 μg/kg,k = 2;furadantin metabolites C(AHD)=1. 007 μg/kg,U = 0. 046 μg/kg,k = 2. [Conclusions]The uncertainty in the measurement process mainly comes from the purity of the standards,the preparation process,the sample weight,the number of repeated measurement and the recovery of spiked sample. The research results are of great significance for reducing uncertainty and improving data accuracy and reliability during actual operation.
文摘Open access(OA)resources are becoming a main part of scholarly information.The paper summarizes the fast growth of OA journals and OA repositories,the outstanding OA journal impact increase,the rise of mega-OA journals like PLoS ONE,the overwhelming support of research communities to open access of publicly funded research,and the quick building up of OA support structures.These forces work together to push scholarly communications toward a turning point where OA resources occupy a major and increasing share of scholarly research resources and when management of OA resources becomes a strategic,yet unfamiliar,and potentially disruptive task for research libraries.This paper is composed of two parts.The first part will focus on the development of OA resources,while the second part will analyze the challenges in management of OA resources and develop an OA resource strategy exemplified by some of NSL’s initiatives.
