[Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of si...[Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of single-factor experiment and orthogonal experiment, chromatographic conditions (mobile phase ratio, flow rate, col- umn temperature) for detecting ellagic acid using HPLC were optimized. Based on the optimal chromatographic conditions, the ellagic acid content in experimental pomegranate peels was determined. [Resull] The optimal chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method are: 1.2% phos- phoric acid:acetonitrile=85:15, column temperature of 35 ℃, and flow rate of 1.0 ml/min. The linear regression equation of ellagic acid is: y=2.9e+0.6x+4.4e+5 (FF=9 999). Ac- cording to the standard addition recovery test, the average recovery rate of ellagic acid is 98.20%, and RSD is 0.60%. Under above optimized chromatographic condi- tions, ellagic acid can be well separated from other interfering components in pomegranate peels, with shorter peak time and ideal effect, which is convenient for the detection in production practices. [Conclusion] This study laid the foundation for detecting ellagic acid in pomegranate peels using HPLC method.展开更多
Aim To raise the H-NE math model for designing engine radiators.Methods Thismodel was founded on multi-nonlinear regression technology,and the quadratic equatingmethod was used to smooth original data.Through the sens...Aim To raise the H-NE math model for designing engine radiators.Methods Thismodel was founded on multi-nonlinear regression technology,and the quadratic equatingmethod was used to smooth original data.Through the sensitivity analysis about radiatoroptimization designing,some major restraints were obtained.Results Type 1301C radiator wasoptimizingly renwed by use o this model,and the new radiator is more excellent than theold one in respect of the heat transfer factor and the manufacturing cost.Conclusion Theradiation performance can be improved,the area can be reduced,and the fitting scope can bewidened if this model is used in designing radiators.展开更多
Study on seasonal responses of terrestrial net primary production (NPP) to climate changes is to help understand feedback between climate systems and terrestrial ecosystems and mechanisms of increased NPP in the north...Study on seasonal responses of terrestrial net primary production (NPP) to climate changes is to help understand feedback between climate systems and terrestrial ecosystems and mechanisms of increased NPP in the northern middle and high latitudes. In this study, time series dataset of normalized difference vegetation index (NDVI) and corresponding ground-based information on vegetation, climate, soil, and solar radiation, together with an ecological process model, were used to explore the seasonal trends of terrestrial NPP and their geographical differences in China from 1982 to 1999. As the results,. seasonal total NPP in China showed a significant increase for all four seasons (spring, summer, autumn and winter) during the past 18 years. The spring NPP indicated the largest increase rate, while the summer NPP was with the largest increase in magnitude. The response of NPP to climate changes varied with different vegetation types. The increased NPP was primarily led by an advanced growing season for broadleaf evergreen forest, needle-leaf evergreen forest, and needle-leaf deciduous forest, whilst that was mainly due to enhanced vegetation activity (amplitude of growth cycle) during growing season for broadleaf deciduous forest, broadleaf and needle-leaf mixed forest, broadleaf trees with groundcover, perennial grasslands, broadleaf shrubs with grasslands, tundra, desert, and cultivation. The regions with the largest increase in spring NPP appeared mainly in eastern China, while the areas with the largest increase in summer NPP occurred in most parts of Northwestern China, Qinghai-Xizang Plateau, Mts. Xiaoxinganling-Changbaishan, Sanjiang Plain, Songliao Plain, Sichuan Basin, Leizhou Peninsula, part of the middle and lower Yangtze River, and southeastern mountainous areas of China. In autumn, the largest NPP increase appeared in Yunnan Plateau-Eastern Xizang and the areas around Hulun Lake. Such different ways of the NPP responses depended on regional climate attributes and their changes.展开更多
The Connolly (1999) elastic impedance (EI) equation is a function of P-wave velocity, S-wave velocity, density, and incidence angle. Conventional inversion methods based on this equation can only extract P-velocit...The Connolly (1999) elastic impedance (EI) equation is a function of P-wave velocity, S-wave velocity, density, and incidence angle. Conventional inversion methods based on this equation can only extract P-velocity, S-velocity, and density data directly and the elastic impedance at different incidence angles are not at the same scale, which makes comparison difficult. We propose a new elastic impedance equation based on the Gray et al. (1999) Zoeppritz approximation using Lamé parameters to address the conventional inversion method's deficiencies. This equation has been normalized to unify the elastic impedance dimensions at different angles and used for inversion. Lamé parameters can be extracted directly from the elastic impedance data obtained from inversion using the linear relation between Lamé parameters and elastic impedance. The application example shows that the elastic parameters extracted using this new method are more stable and correct and can recover the reservoir information very well. The new method is an improvement on the conventional method based on Connolly's equation.展开更多
Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·...Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.展开更多
2,5,6-Tribromo-l-methylgramine (TBG), isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its ...2,5,6-Tribromo-l-methylgramine (TBG), isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its analogues with other ingredients in antifouling paints, structural modification of TBG was focused mainly on halogen substitution and N-substitution. Two halogen-substitute gramines and their derivatives which contain ester functional groups at N-position of gramines were synthesized. Algal inhibition activities of the synthesized compounds against algae Nitzschia cIosterium were evaluated and the Median Effective Concentration (EC50) range was 1.06-6.74 lag ml^-1. Compounds that had a long chain ester group exhibited extremely high antifouling activity. Quantitive Structure Activity Relationship (QSAR) studies with multiple linear regression analysis were applied to fred correlation between different calculated molecular descriptors and biological activity of the synthesized compounds. The results show that the toxicity (log (I/EC50)) is correlated well with the partition coefficient log P. Thus, these products have potential function as antifouling agents.展开更多
During the 15th Conference of the Parties (COP 15), Parties agreed that reducing emissions from deforesta- tion and forest degradation and enhancing 'removals of greenhouse gas emission by forests' (REDD+) in d...During the 15th Conference of the Parties (COP 15), Parties agreed that reducing emissions from deforesta- tion and forest degradation and enhancing 'removals of greenhouse gas emission by forests' (REDD+) in developing countries through positive incentives under the United Nations Framework Convention on Climate Change (UNFCCC) was capable of dealing with global emissions. As REDD+ seeks to lower emissions by stopping deforestation and for- est degradation with an international payment tier according to baseline scenarios, opportunities for ecosystem benefits such as slowing habitat fragmentation, conservation of forest biodiversity, soil conservation may be also part of this effort. The primary objective of this study is to evaluate ecosystem-based benefits of REDD+, and to identify the rela- tionships with carbon stock changes. To achieve this goal, high resolution satellite images are combined with Normal- ized Difference Vegetation Index (NDVI) to identify historical deforestation in study area of Central Kalimantan, In- donesia. The carbon emissions for the period of 2000-2005 and 2005-2009 are 2.73 ×10^5 t CO2 and 1.47× 10^6 t CO2 respectively, showing an increasing trend in recent years. Dring 2005-2009, number of patches (NP), patch density (PD), mean shape index distribution (SHAPE_MN) increased 30.8%, 30.7% and 7.6%. Meanwhile, largest patch index (LPI), mean area (AREA MN), area-weighted mean of shape index distribution (SHAPE_AM), neighbor distance (ENN_MN) and interspersion and juxtaposition index (IJI) decreased by 55.3%, 29.7%, 15.8%, 53.4% and 21.5% re- spectively. The area regarding as positive correlation between carbon emissions and soil erosion was approximately 8.9 x l03 ha corresponding to 96.0% of the changing forest. These results support the view that there are strong syner- gies among carbon loss, forest fragmentation and soil erosion in tropical forests. Such mechanism of REDD+ is likely to present opportunities for multiple benefits that fall outside the scope of carbon stocks.展开更多
AIM:To assess the nourishment status and lifestyle of non-hospitalized patients with compensated cirrhosis by using noninvasive methods.METHODS:The subjects for this study consisted of 27 healthy volunteers,59 patient...AIM:To assess the nourishment status and lifestyle of non-hospitalized patients with compensated cirrhosis by using noninvasive methods.METHODS:The subjects for this study consisted of 27 healthy volunteers,59 patients with chronic viral hepatitis,and 74 patients with viral cirrhosis,from urban areas.We assessed the biochemical blood tests,anthropometric parameters,diet,lifestyle and physical activity of the patients.A homeostasis model assessment-insulin resistance(HOMA-IR) value of ≥ 2.5 was considered to indicate insulin resistance.We measured height,weight,waist circumference,arm circumference,triceps skin-fold thickness,and handgrip strength,and calculated body mass index,arm muscle circumference(AMC),and arm muscle area(AMA).We interviewed the subjects about their dietary habits and lifestyle using health assessment computer software.We surveyed daily physical activity using a pedometer.Univariate and multivariate logistic regression modeling were used to identify the relevant factors for insulin resistance.RESULTS:The rate of patients with HOMA-IR ≥ 2.5(which was considered to indicate insulin resistance) was 14(35.9%) in the chronic hepatitis and 17(37.8%) in the cirrhotic patients.AMC(%)(control vs chronic hepatitis,111.9% ± 10.5% vs 104.9% ± 10.7%,P = 0.021;control vs cirrhosis,111.9% ± 10.5% vs 102.7% ± 10.8%,P = 0.001) and AMA(%)(control vs chronic hepatitis,128.2% ± 25.1% vs 112.2% ± 22.9%,P = 0.013;control vs cirrhosis,128.2% ± 25.1% vs 107.5% ± 22.5%,P = 0.001) in patients with chronic hepatitis and liver cirrhosis were significantly lower than in the control subjects.Handgrip strength(%) in the cirrhosis group was significantly lower than in the controls(control vs cirrhosis,92.1% ± 16.2% vs 66.9% ± 17.6%,P < 0.001).The results might reflect a decrease in muscle mass.The total nutrition intake and amounts of carbohydrates,protein and fat were not significantly different amongst the groups.Physical activity levels(kcal/d)(control vs cirrhosis,210 ± 113 kcal/d vs 125 ± 74 kcal/d,P = 0.001),number of steps(step/d)(control vs cirrhosis,8070 ±3027 step/d vs 5789 ± 3368 step/d,P = 0.011),and exercise(Ex)(Ex/wk)(control vs cirrhosis,12.4 ± 9.3 Ex/wk vs 7.0 ± 7.7 Ex/wk,P = 0.013) in the cirrhosis group was significantly lower than the control group.The results indicate that the physical activity level of the chronic hepatitis and cirrhosis groups were low.Univariate and multivariate logistic regression modeling suggested that Ex was associated with insulin resistance(odds ratio,6.809;95% CI,1.288-36.001;P = 0.024).The results seem to point towards decreased physical activity being a relevant factor for insulin resistance.CONCLUSION:Non-hospitalized cirrhotic patients may need to maintain an adequate dietary intake and receive lifestyle guidance to increase their physical activity levels.展开更多
AIM:To assess the risk of biliary and pancreatic cancers in a large cohort of patients with type 2 diabetes mellitus(DM) .METHODS:Eligibility for this study included patients with type 2 DM(ICD-9 code 250.0) who were ...AIM:To assess the risk of biliary and pancreatic cancers in a large cohort of patients with type 2 diabetes mellitus(DM) .METHODS:Eligibility for this study included patients with type 2 DM(ICD-9 code 250.0) who were discharged from Department of Veteran Affairs hospitals between 1990 and 2000.Non-matched control patients without DM were selected from the same patient treatment files during the same period.Demographic information included age,sex and race.Secondary diagnoses included known risk factors based on their ICD-9 codes.By multivariate logistic regression,the occurrence of biliary and pancreatic cancer was compared between case subjects with DM and controls without DM.RESULTS:A total of 1172496 case and control subjects were analyzed.The mean age for study and control subjects was 65.8 ± 11.3 and 64.8 ± 12.6 years,respectively.The frequency of pancreatic cancer in subjects with DM was increased(0.9%) in comparison to control subjects(0.3%) with an OR of 3.22(95% CI:3.03-3.42) .The incidence of gallbladder andextrahepatic biliary cancers was increased by twofold in diabetic patients when compared to controls.The OR and 95% CI were 2.20(1.56-3.00) and 2.10(1.61-2.53) ,respectively.CONCLUSION:Our study demonstrated that patients with DM have a threefold increased risk for developing pancreatic cancer and a twofold risk for developing biliary cancer.展开更多
AIM: To compare the clinical characteristics of pyogenic liver abscess (PLA) in patients with and without hepatic neoplasm (HN). METHODS: We performed a retrospective analysis involving patients with PLA. The demograp...AIM: To compare the clinical characteristics of pyogenic liver abscess (PLA) in patients with and without hepatic neoplasm (HN). METHODS: We performed a retrospective analysis involving patients with PLA. The demographic, clinical features, laboratory and imaging findings, management and outcome of patients with and without HN were studied. RESULTS: From January 2000 to December 2009 inclusive, 318 patients (35 with HN) had PLA, and mean age and comorbidity were comparable between the two groups. More patients with HN experienced right upper quadrant pain (68.6% vs 52.7%, P < 0.04), developed jaundice (14.3% vs 5.7%, P < 0.03) and hepatomegaly (17.1% vs 3.9%, P < 0.01), and had higher serum total bilirubin level (43.3 μmol/L vs 30.0 μmol/L, P = 0.05). Most patients in both groups had PLAs in the right hepatic lobe, and biliary tract disorder was the most common underlying cause (71.4% and 61.8%). However, more PLAs in the HN group were associated with thicker abscess wall (37.1% vs 19.4%, P < 0.01), septal lobulation (77.1% vs 58%, P < 0.02), gaseous cavitation (17% vs 7.8%, P = 0.03), portal thrombophlebitis (11.4% vs 1.8%, P < 0.01) and aerobilia (25.9% vs 5.5%, P < 0.01). Mixed bacterial growth (40% vs 15.2%, P < 0.01) and Gram-negative bacilli (22.8% vs 60.4%, P < 0.01) were dominant isolates in PLAs with and without HN, respectively. Although incidence of the complications was comparable between the two groups, patients with HN had a higher mortality rate than those without (71.4% vs 8.8%, P < 0.01). Multivariate logistic regression analysis revealed underlying active malignancy [odds ratio (OR): 40.45, 95% CI: 14.76-111.65], hypoalbuminemia (OR: 1.22, 95% CI: 1.14-1.38), disseminated intravascular coagulation (OR: 3.32, 95% CI: 1.19-9.69) and acute coronary syndrome (OR: 4.48, 95% CI: 1.08-17.8) were independent risk factors associated with mortality. However, several HN cases, presented concurrently with PLAs, were found to have curative resectable tumors and had good prognosis after surgery. CONCLUSION: PLA associated with HN tends to form a distinct clinical syndrome with a different extent of clinical manifestations, radiological and microbiological features and complications.展开更多
In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has...In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has been descripted. Precisely, the aim of this research is showing how stepwise multiple linear regression contributes to solution of earthquakes localization, describing its conditions of use in HYPO71PC, a software devoted to computation of seismic sources’ collocation. This aim is reached treating a concrete case, that is computation of earthquakes localization happening on Mount Vesuvius, Italy.展开更多
Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpret...Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpretation, combined with digital processing of satellite images and analysis in GIS. The climate data in the surrounding area were analyzed by using linear regression, Mann-Kendall abrupt test, and Morlet wavelet analysis. Study results showed that: over the 23 years investigation, the glacier areas have markedly decreased. In the last 12 years(2000 to 2011), the rate of retreat has begun to accelerate. The most dramatic glacier shrinkage occurred in the central region, the lowest in the eastern region. The mean summer temperature and warm precipitation in Chinese Tianshan Mountains had an increasing trend, with rates of 0.22°C /10 a and 5.1mm/10 a from 1960 to 2011, respectively. Mean summer temperature have experienced a strong increase in 1998. The analysis of the results showed that the rise of mean summer temperature was the main factor that contributed to glacier shrinkage. Regional differences of glacier area changes were investigated by analyzing glacier behavior in five study sub-regions; regional differences are related to local climate, to the relative proportion of glaciers in different size classes, altitudinal and aspect distribution of glaciated areas. In addition, the lag theory indicated that glaciers may accelerate the retreat in the next decade, considering climate trends recognized for the period 2000-2011.展开更多
In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Prec...In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.展开更多
Spatial heterogeneity is widely used in diverse applications, such as recognizing ecological process, guiding ecological restoration, managing land use, etc. Many researches have focused on the inherent scale multipli...Spatial heterogeneity is widely used in diverse applications, such as recognizing ecological process, guiding ecological restoration, managing land use, etc. Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables. How these variables affect their corresponding spatial heterogeneities, however, have received little attention. In this paper, we examined the effects of characteristics of normalized difference vegetation index (NDVI) and its related bands variable images, namely red and near infrared (NIR), on their corresponding spatial heterogeneity detection based on variogram models. In a coastal wetland region, two groups of study sites with distinct fractal vegetation cover were tested and analyzed. The results show that: l) in high fractal vegetation cover (H-FVC) area, NDV! and NIR variables display a similar ability in detecting the spatial he- terogeneity caused by vegetation growing status structure; 2) in low fractal vegetation cover (L-FVC) area, the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3) generally, NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers. Moreover, as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account, the proposed variogram analysis method can make the variable selection objectively and scientifically, especially in studies related to spatial heterogeneity using remotely sensed data.展开更多
A newly developed Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) system is introduced and used for in-situ detection of acid radical ions in this paper. To evaluate the feasibility and capability of DOCAR...A newly developed Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) system is introduced and used for in-situ detection of acid radical ions in this paper. To evaluate the feasibility and capability of DOCARS for quantitative analysis of the acid radical ions in the deep ocean, extensive investigations have been carried out both in laboratory and sea trials during the development phase. In the laboratory investigations, Raman spectra of the prepared samples (acid radical ions solutions) were obtained, and analyzed using the method of internal standard normalization in data processing. The Raman signal of acid radical ions was normalized by that of water molecules. The calibration curve showed that the normalized Raman signal intensity of SO4^2-, NO3^-, and HCO^-3 increases linearly as the concentration rises with correlation coefficient R^2 of 0.99, 0.99, and 0.98 respectively. The linear function obtained from the calibration curve was then used for the analysis of the spectra ,data acquired in the sea trial under a simulating chemical field in the deep-sea environment. It was found that the detected concentration of NO3 according to the linear function can reflect the concentration changes of NO~ after the sample was released, and the detection accuracy of the DOCARS system for SO^2-_4 is 8%. All the results showed that the DOCARS system has great potential in quantitative detection of acid radical ions under the deep-sea environment, while the sensitivity of the DOCARS system is expected to be improved.展开更多
The adaptive neuro-fuzzy inference systems(ANFIS)are widely used in the concrete technology.In this research,the compressive strength of light weight concrete was determined.To this end,the scoria percentage and curin...The adaptive neuro-fuzzy inference systems(ANFIS)are widely used in the concrete technology.In this research,the compressive strength of light weight concrete was determined.To this end,the scoria percentage and curing day variables were used as the input parameters,and compressive strength and tensile strength were used as the output parameters.In addition,100 patterns were used,70%of which were used for training and 30%were used for testing.To assess the precision of the neuro-fuzzy system,it was compared using two linear regression models.The comparisons were carried out in the training and testing phases.Research results revealed that the neuro-fuzzy systems model offers more potential,flexibility,and precision than the statistical models.展开更多
文摘[Objective] This study aimed to optimize the chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method. [Method] By using 0.2 mg/ml ellagic acid standard solution, on the basis of single-factor experiment and orthogonal experiment, chromatographic conditions (mobile phase ratio, flow rate, col- umn temperature) for detecting ellagic acid using HPLC were optimized. Based on the optimal chromatographic conditions, the ellagic acid content in experimental pomegranate peels was determined. [Resull] The optimal chromatographic conditions for detecting ellagic acid in pomegranate peels using HPLC method are: 1.2% phos- phoric acid:acetonitrile=85:15, column temperature of 35 ℃, and flow rate of 1.0 ml/min. The linear regression equation of ellagic acid is: y=2.9e+0.6x+4.4e+5 (FF=9 999). Ac- cording to the standard addition recovery test, the average recovery rate of ellagic acid is 98.20%, and RSD is 0.60%. Under above optimized chromatographic condi- tions, ellagic acid can be well separated from other interfering components in pomegranate peels, with shorter peak time and ideal effect, which is convenient for the detection in production practices. [Conclusion] This study laid the foundation for detecting ellagic acid in pomegranate peels using HPLC method.
文摘Aim To raise the H-NE math model for designing engine radiators.Methods Thismodel was founded on multi-nonlinear regression technology,and the quadratic equatingmethod was used to smooth original data.Through the sensitivity analysis about radiatoroptimization designing,some major restraints were obtained.Results Type 1301C radiator wasoptimizingly renwed by use o this model,and the new radiator is more excellent than theold one in respect of the heat transfer factor and the manufacturing cost.Conclusion Theradiation performance can be improved,the area can be reduced,and the fitting scope can bewidened if this model is used in designing radiators.
文摘Study on seasonal responses of terrestrial net primary production (NPP) to climate changes is to help understand feedback between climate systems and terrestrial ecosystems and mechanisms of increased NPP in the northern middle and high latitudes. In this study, time series dataset of normalized difference vegetation index (NDVI) and corresponding ground-based information on vegetation, climate, soil, and solar radiation, together with an ecological process model, were used to explore the seasonal trends of terrestrial NPP and their geographical differences in China from 1982 to 1999. As the results,. seasonal total NPP in China showed a significant increase for all four seasons (spring, summer, autumn and winter) during the past 18 years. The spring NPP indicated the largest increase rate, while the summer NPP was with the largest increase in magnitude. The response of NPP to climate changes varied with different vegetation types. The increased NPP was primarily led by an advanced growing season for broadleaf evergreen forest, needle-leaf evergreen forest, and needle-leaf deciduous forest, whilst that was mainly due to enhanced vegetation activity (amplitude of growth cycle) during growing season for broadleaf deciduous forest, broadleaf and needle-leaf mixed forest, broadleaf trees with groundcover, perennial grasslands, broadleaf shrubs with grasslands, tundra, desert, and cultivation. The regions with the largest increase in spring NPP appeared mainly in eastern China, while the areas with the largest increase in summer NPP occurred in most parts of Northwestern China, Qinghai-Xizang Plateau, Mts. Xiaoxinganling-Changbaishan, Sanjiang Plain, Songliao Plain, Sichuan Basin, Leizhou Peninsula, part of the middle and lower Yangtze River, and southeastern mountainous areas of China. In autumn, the largest NPP increase appeared in Yunnan Plateau-Eastern Xizang and the areas around Hulun Lake. Such different ways of the NPP responses depended on regional climate attributes and their changes.
文摘The Connolly (1999) elastic impedance (EI) equation is a function of P-wave velocity, S-wave velocity, density, and incidence angle. Conventional inversion methods based on this equation can only extract P-velocity, S-velocity, and density data directly and the elastic impedance at different incidence angles are not at the same scale, which makes comparison difficult. We propose a new elastic impedance equation based on the Gray et al. (1999) Zoeppritz approximation using Lamé parameters to address the conventional inversion method's deficiencies. This equation has been normalized to unify the elastic impedance dimensions at different angles and used for inversion. Lamé parameters can be extracted directly from the elastic impedance data obtained from inversion using the linear relation between Lamé parameters and elastic impedance. The application example shows that the elastic parameters extracted using this new method are more stable and correct and can recover the reservoir information very well. The new method is an improvement on the conventional method based on Connolly's equation.
文摘Groundwater in Changchun City, Jilin Province of China tends to be influenced by human activities. Chemical types of groundwater were detected in both shallow and deep groundwater were: HCO3--Ca2+ and HCO3--Ca2+·Mg2+ or HCO3--Mg2+·Ca2+; SO42--Ca2+ and SO42--Ca2+·Mg2+; Cl--Ca2+; and CO32--Na+. The deteriorations of groundwater quality due to the increase of TDS, NO3-+ NO2-(as Nitrogen) and TH contents have been observed from 1991 to 1998. Scatter analyses showed strong positive correlations between Ca2+, Cl-and NO3-ions and weak negative correlations between the depth of water table and Ca2+, SO42-, Cl-and NO3-ions. A mapping of contaminant index based on Chinese standard of groundwater showed that a large proportion of the groundwater in 1998 was deteriorated by human process. Despite their low values of sodium adsorption ratio (SAR), the most of the sampled wells were not suitable for drinking and agriculture purposes due to higher contents of NO3-, NO2-and Mn2+ ions.
基金Supported by the National Natural Science Foundation of China (No. 50673085, 20060423017, A1420080191)National High-Technology Research Program of China (863 Program, No. 2006AA09Z224)
文摘2,5,6-Tribromo-l-methylgramine (TBG), isolated from bryozoan Zoobotryon pellucidum was shown to be very efficient in preventing recruitment of larval settlement. In order to improve the compatibility of TBG and its analogues with other ingredients in antifouling paints, structural modification of TBG was focused mainly on halogen substitution and N-substitution. Two halogen-substitute gramines and their derivatives which contain ester functional groups at N-position of gramines were synthesized. Algal inhibition activities of the synthesized compounds against algae Nitzschia cIosterium were evaluated and the Median Effective Concentration (EC50) range was 1.06-6.74 lag ml^-1. Compounds that had a long chain ester group exhibited extremely high antifouling activity. Quantitive Structure Activity Relationship (QSAR) studies with multiple linear regression analysis were applied to fred correlation between different calculated molecular descriptors and biological activity of the synthesized compounds. The results show that the toxicity (log (I/EC50)) is correlated well with the partition coefficient log P. Thus, these products have potential function as antifouling agents.
基金Under the auspices of National Basic Research Program of China (No. 2012CB955800,2012CB955804)National Natural Science Foundation of China (No. 41171438)+2 种基金Foundation of Asia-Pacific Network for Global Change Research (No.EBLU2010-01NSY-Suneetha)Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA05050000)Science Foundation of Government of Henan Province & Ministry of Education (No. SBGJ090110,2010YBZR043)
文摘During the 15th Conference of the Parties (COP 15), Parties agreed that reducing emissions from deforesta- tion and forest degradation and enhancing 'removals of greenhouse gas emission by forests' (REDD+) in developing countries through positive incentives under the United Nations Framework Convention on Climate Change (UNFCCC) was capable of dealing with global emissions. As REDD+ seeks to lower emissions by stopping deforestation and for- est degradation with an international payment tier according to baseline scenarios, opportunities for ecosystem benefits such as slowing habitat fragmentation, conservation of forest biodiversity, soil conservation may be also part of this effort. The primary objective of this study is to evaluate ecosystem-based benefits of REDD+, and to identify the rela- tionships with carbon stock changes. To achieve this goal, high resolution satellite images are combined with Normal- ized Difference Vegetation Index (NDVI) to identify historical deforestation in study area of Central Kalimantan, In- donesia. The carbon emissions for the period of 2000-2005 and 2005-2009 are 2.73 ×10^5 t CO2 and 1.47× 10^6 t CO2 respectively, showing an increasing trend in recent years. Dring 2005-2009, number of patches (NP), patch density (PD), mean shape index distribution (SHAPE_MN) increased 30.8%, 30.7% and 7.6%. Meanwhile, largest patch index (LPI), mean area (AREA MN), area-weighted mean of shape index distribution (SHAPE_AM), neighbor distance (ENN_MN) and interspersion and juxtaposition index (IJI) decreased by 55.3%, 29.7%, 15.8%, 53.4% and 21.5% re- spectively. The area regarding as positive correlation between carbon emissions and soil erosion was approximately 8.9 x l03 ha corresponding to 96.0% of the changing forest. These results support the view that there are strong syner- gies among carbon loss, forest fragmentation and soil erosion in tropical forests. Such mechanism of REDD+ is likely to present opportunities for multiple benefits that fall outside the scope of carbon stocks.
基金Supported by Japan Nutritional Study Group for Liver cirrhosis 2008,No.JNUS2008Health Labor Sciences Research Grant from the Ministry of Health,Labor and Welfare,Japan, No.H20-Hepatitis-General-005
文摘AIM:To assess the nourishment status and lifestyle of non-hospitalized patients with compensated cirrhosis by using noninvasive methods.METHODS:The subjects for this study consisted of 27 healthy volunteers,59 patients with chronic viral hepatitis,and 74 patients with viral cirrhosis,from urban areas.We assessed the biochemical blood tests,anthropometric parameters,diet,lifestyle and physical activity of the patients.A homeostasis model assessment-insulin resistance(HOMA-IR) value of ≥ 2.5 was considered to indicate insulin resistance.We measured height,weight,waist circumference,arm circumference,triceps skin-fold thickness,and handgrip strength,and calculated body mass index,arm muscle circumference(AMC),and arm muscle area(AMA).We interviewed the subjects about their dietary habits and lifestyle using health assessment computer software.We surveyed daily physical activity using a pedometer.Univariate and multivariate logistic regression modeling were used to identify the relevant factors for insulin resistance.RESULTS:The rate of patients with HOMA-IR ≥ 2.5(which was considered to indicate insulin resistance) was 14(35.9%) in the chronic hepatitis and 17(37.8%) in the cirrhotic patients.AMC(%)(control vs chronic hepatitis,111.9% ± 10.5% vs 104.9% ± 10.7%,P = 0.021;control vs cirrhosis,111.9% ± 10.5% vs 102.7% ± 10.8%,P = 0.001) and AMA(%)(control vs chronic hepatitis,128.2% ± 25.1% vs 112.2% ± 22.9%,P = 0.013;control vs cirrhosis,128.2% ± 25.1% vs 107.5% ± 22.5%,P = 0.001) in patients with chronic hepatitis and liver cirrhosis were significantly lower than in the control subjects.Handgrip strength(%) in the cirrhosis group was significantly lower than in the controls(control vs cirrhosis,92.1% ± 16.2% vs 66.9% ± 17.6%,P < 0.001).The results might reflect a decrease in muscle mass.The total nutrition intake and amounts of carbohydrates,protein and fat were not significantly different amongst the groups.Physical activity levels(kcal/d)(control vs cirrhosis,210 ± 113 kcal/d vs 125 ± 74 kcal/d,P = 0.001),number of steps(step/d)(control vs cirrhosis,8070 ±3027 step/d vs 5789 ± 3368 step/d,P = 0.011),and exercise(Ex)(Ex/wk)(control vs cirrhosis,12.4 ± 9.3 Ex/wk vs 7.0 ± 7.7 Ex/wk,P = 0.013) in the cirrhosis group was significantly lower than the control group.The results indicate that the physical activity level of the chronic hepatitis and cirrhosis groups were low.Univariate and multivariate logistic regression modeling suggested that Ex was associated with insulin resistance(odds ratio,6.809;95% CI,1.288-36.001;P = 0.024).The results seem to point towards decreased physical activity being a relevant factor for insulin resistance.CONCLUSION:Non-hospitalized cirrhotic patients may need to maintain an adequate dietary intake and receive lifestyle guidance to increase their physical activity levels.
文摘AIM:To assess the risk of biliary and pancreatic cancers in a large cohort of patients with type 2 diabetes mellitus(DM) .METHODS:Eligibility for this study included patients with type 2 DM(ICD-9 code 250.0) who were discharged from Department of Veteran Affairs hospitals between 1990 and 2000.Non-matched control patients without DM were selected from the same patient treatment files during the same period.Demographic information included age,sex and race.Secondary diagnoses included known risk factors based on their ICD-9 codes.By multivariate logistic regression,the occurrence of biliary and pancreatic cancer was compared between case subjects with DM and controls without DM.RESULTS:A total of 1172496 case and control subjects were analyzed.The mean age for study and control subjects was 65.8 ± 11.3 and 64.8 ± 12.6 years,respectively.The frequency of pancreatic cancer in subjects with DM was increased(0.9%) in comparison to control subjects(0.3%) with an OR of 3.22(95% CI:3.03-3.42) .The incidence of gallbladder andextrahepatic biliary cancers was increased by twofold in diabetic patients when compared to controls.The OR and 95% CI were 2.20(1.56-3.00) and 2.10(1.61-2.53) ,respectively.CONCLUSION:Our study demonstrated that patients with DM have a threefold increased risk for developing pancreatic cancer and a twofold risk for developing biliary cancer.
文摘AIM: To compare the clinical characteristics of pyogenic liver abscess (PLA) in patients with and without hepatic neoplasm (HN). METHODS: We performed a retrospective analysis involving patients with PLA. The demographic, clinical features, laboratory and imaging findings, management and outcome of patients with and without HN were studied. RESULTS: From January 2000 to December 2009 inclusive, 318 patients (35 with HN) had PLA, and mean age and comorbidity were comparable between the two groups. More patients with HN experienced right upper quadrant pain (68.6% vs 52.7%, P < 0.04), developed jaundice (14.3% vs 5.7%, P < 0.03) and hepatomegaly (17.1% vs 3.9%, P < 0.01), and had higher serum total bilirubin level (43.3 μmol/L vs 30.0 μmol/L, P = 0.05). Most patients in both groups had PLAs in the right hepatic lobe, and biliary tract disorder was the most common underlying cause (71.4% and 61.8%). However, more PLAs in the HN group were associated with thicker abscess wall (37.1% vs 19.4%, P < 0.01), septal lobulation (77.1% vs 58%, P < 0.02), gaseous cavitation (17% vs 7.8%, P = 0.03), portal thrombophlebitis (11.4% vs 1.8%, P < 0.01) and aerobilia (25.9% vs 5.5%, P < 0.01). Mixed bacterial growth (40% vs 15.2%, P < 0.01) and Gram-negative bacilli (22.8% vs 60.4%, P < 0.01) were dominant isolates in PLAs with and without HN, respectively. Although incidence of the complications was comparable between the two groups, patients with HN had a higher mortality rate than those without (71.4% vs 8.8%, P < 0.01). Multivariate logistic regression analysis revealed underlying active malignancy [odds ratio (OR): 40.45, 95% CI: 14.76-111.65], hypoalbuminemia (OR: 1.22, 95% CI: 1.14-1.38), disseminated intravascular coagulation (OR: 3.32, 95% CI: 1.19-9.69) and acute coronary syndrome (OR: 4.48, 95% CI: 1.08-17.8) were independent risk factors associated with mortality. However, several HN cases, presented concurrently with PLAs, were found to have curative resectable tumors and had good prognosis after surgery. CONCLUSION: PLA associated with HN tends to form a distinct clinical syndrome with a different extent of clinical manifestations, radiological and microbiological features and complications.
文摘In this paper, an overview of an important feature in statistics field has shown: the stepwise multiple linear regression. Likewise, a link between stepwise multiple linear regression and earthquakes localization has been descripted. Precisely, the aim of this research is showing how stepwise multiple linear regression contributes to solution of earthquakes localization, describing its conditions of use in HYPO71PC, a software devoted to computation of seismic sources’ collocation. This aim is reached treating a concrete case, that is computation of earthquakes localization happening on Mount Vesuvius, Italy.
基金supported by the National Science Foundation of China (Grant No. 41271024)the Fund Project for National Basic Science Talents Cultivation (Grant No. J1210065)the Fundamental Research Funds for the Central Universities- Excellent Graduate Innovation Project (Grant No. Lzujbky-2014-274)
文摘Based on the 1990, 2000 and 2011 Landsat TM/ETM+ remote sensing data, glacier information of three periods in the Chinese Tianshan Mountains were extracted by using ratio threshold method(TM3/TM5) and visual interpretation, combined with digital processing of satellite images and analysis in GIS. The climate data in the surrounding area were analyzed by using linear regression, Mann-Kendall abrupt test, and Morlet wavelet analysis. Study results showed that: over the 23 years investigation, the glacier areas have markedly decreased. In the last 12 years(2000 to 2011), the rate of retreat has begun to accelerate. The most dramatic glacier shrinkage occurred in the central region, the lowest in the eastern region. The mean summer temperature and warm precipitation in Chinese Tianshan Mountains had an increasing trend, with rates of 0.22°C /10 a and 5.1mm/10 a from 1960 to 2011, respectively. Mean summer temperature have experienced a strong increase in 1998. The analysis of the results showed that the rise of mean summer temperature was the main factor that contributed to glacier shrinkage. Regional differences of glacier area changes were investigated by analyzing glacier behavior in five study sub-regions; regional differences are related to local climate, to the relative proportion of glaciers in different size classes, altitudinal and aspect distribution of glaciated areas. In addition, the lag theory indicated that glaciers may accelerate the retreat in the next decade, considering climate trends recognized for the period 2000-2011.
基金National Natural Science Foundation of China,No.40830636 No.40671034Foundation of Isotopes in Precipitation of Chinese Ecosystem Research Network
文摘In order to reveal the characteristics and climatic controls on the stable isotopic composition of precipitation over Arid Northwestern China, eight stations have been selected from Chinese Network of Isotopes in Precipitation(CHNIP).During the year 2005 and 2006, monthly precipitation samples have been collected and analyzed for the composition of δD and δ18O.The established local meteoric water line δD=7.42δ18O+1.38, based on the 95 obtained monthly composite samples, could be treated as isotopic input function across the region.The deviations of slope and intercept from the Global Meteoric Water Line indicated the specific regional meteorological conditions.The monthly δ18O values were characterized by a positive correlation with surface air temperature(δ18O(‰) =0.33 T(℃)-13.12).The amount effect visualized during summer period(δ18O(‰) =-0.04P(mm)-3.44) though not appeared at a whole yearly-scale.Spatial distributions of δ18O have properly portrayed the atmospheric circulation background in each month over Arid Northwestern China.The quan-titative simulation of δ18O, which involved a Rayleigh fractionation and a kinetic fractionation, demonstrated that the latter one was the dominating function of condensation of raindrops.Furthermore, the raindrop suffered a re-evaporation during falling processes, and the precipitation vapor might have been mixed with a quantity of local recycled water vapor.Multiple linear regression equations and a δ18O-T relation have been gained by using meteorological parameters and δ18O data to evaluate physical controls on the long-term data.The established δ18O-T relation, which has been based on the present-day precipitation, could be considered as a first step of quantitatively reconstructing the historical environmental climate.
基金Under the auspices of National Key Technology Research and Development Program of China (No.2009BADB3B01-05)Knowledge Innovation Programs of Chinese Academy of Sciences (No. KSCX1-YW-09-13)
文摘Spatial heterogeneity is widely used in diverse applications, such as recognizing ecological process, guiding ecological restoration, managing land use, etc. Many researches have focused on the inherent scale multiplicity of spatial heterogeneity by using various environmental variables. How these variables affect their corresponding spatial heterogeneities, however, have received little attention. In this paper, we examined the effects of characteristics of normalized difference vegetation index (NDVI) and its related bands variable images, namely red and near infrared (NIR), on their corresponding spatial heterogeneity detection based on variogram models. In a coastal wetland region, two groups of study sites with distinct fractal vegetation cover were tested and analyzed. The results show that: l) in high fractal vegetation cover (H-FVC) area, NDV! and NIR variables display a similar ability in detecting the spatial he- terogeneity caused by vegetation growing status structure; 2) in low fractal vegetation cover (L-FVC) area, the NIR and red variables outperform NDVI in the survey of soil spatial heterogeneity; and 3) generally, NIR variable is ubiquitously applicable for vegetation spatial heterogeneity investigation in different fractal vegetation covers. Moreover, as variable selection for remote sensing applications should fully take the characteristics of variables and the study object into account, the proposed variogram analysis method can make the variable selection objectively and scientifically, especially in studies related to spatial heterogeneity using remotely sensed data.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(Nos.2006AA09Z243,2012AA09A405)
文摘A newly developed Deep Ocean Compact Autonomous Raman Spectrometer (DOCARS) system is introduced and used for in-situ detection of acid radical ions in this paper. To evaluate the feasibility and capability of DOCARS for quantitative analysis of the acid radical ions in the deep ocean, extensive investigations have been carried out both in laboratory and sea trials during the development phase. In the laboratory investigations, Raman spectra of the prepared samples (acid radical ions solutions) were obtained, and analyzed using the method of internal standard normalization in data processing. The Raman signal of acid radical ions was normalized by that of water molecules. The calibration curve showed that the normalized Raman signal intensity of SO4^2-, NO3^-, and HCO^-3 increases linearly as the concentration rises with correlation coefficient R^2 of 0.99, 0.99, and 0.98 respectively. The linear function obtained from the calibration curve was then used for the analysis of the spectra ,data acquired in the sea trial under a simulating chemical field in the deep-sea environment. It was found that the detected concentration of NO3 according to the linear function can reflect the concentration changes of NO~ after the sample was released, and the detection accuracy of the DOCARS system for SO^2-_4 is 8%. All the results showed that the DOCARS system has great potential in quantitative detection of acid radical ions under the deep-sea environment, while the sensitivity of the DOCARS system is expected to be improved.
文摘The adaptive neuro-fuzzy inference systems(ANFIS)are widely used in the concrete technology.In this research,the compressive strength of light weight concrete was determined.To this end,the scoria percentage and curing day variables were used as the input parameters,and compressive strength and tensile strength were used as the output parameters.In addition,100 patterns were used,70%of which were used for training and 30%were used for testing.To assess the precision of the neuro-fuzzy system,it was compared using two linear regression models.The comparisons were carried out in the training and testing phases.Research results revealed that the neuro-fuzzy systems model offers more potential,flexibility,and precision than the statistical models.