Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, ...Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, densification, microstructure and a.c. electrical conductivity have been studied. Under the effect of changing the firing temperature and Zn content, high sintered Li-Zn ferrite bodies are achieved. More fine structure bodies having high electrical resistance are obtained at high Zn content展开更多
Pot experiment was carried out to determine the allelopathic effects of Datura?stramonium on leaf chlorophyll content, root and shoot elongation, fresh and dry weight of two wild plant species: Cenchrus ciliaris and N...Pot experiment was carried out to determine the allelopathic effects of Datura?stramonium on leaf chlorophyll content, root and shoot elongation, fresh and dry weight of two wild plant species: Cenchrus ciliaris and Neonotonia wightii. Different concentrations (0%, 25%, 50%, 75% and 100%) from seed and leaf extracts of D. stramonium were used to investigate the allelopathic effects of D. stramonium on growth of tested species.?The total chlorophyll content of N. wightii was significantly reduced in all plants treated with both aqueous seed and leaf extracts of D. stramonium. In C. ciliaris, the total chlorophyll content was also significantly reduced for those plants treated with aqueous seed extract and leaf extract from D. stramonium. Relative to the control treatments, there was greater reduction in root and shoot length which was observed in higher concentrations of aqueous seed and leaf extracts. Fresh and dry weight of tested species significantly decreased after being treated with both seed and leaf aqueous extracts of D. stramonium. It was found that the allelopathic effect of aqueous seed and leaf extracts from D. stramonium on tested species was concentration-dependent. The inhibitory effects on all tested species increased as the concentration of both extracts increased from 0% to 100%. This study concluded that aqueous seed and leaf extract of D. stramonium have allelopathic effects on leaf chlorophyll content, root and shoot length, fresh and dry weight of grass (C. ciliaris) and legume (N. wightii) species.展开更多
The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepa...The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepatic GSH content of the riboflavin deficient rats decreased to 55-61% of the control rats. When NDMA was given 6 mg kg by gastric intubation to riboflavin deficient rats, hepatic GSH content decreased markedly to 39-43% of the control rats. After supplying riboflavin, hepatie GSH content of the deficient rats recovered to the level of the control rats. These results suggest that alterations of rat hepatic GSH content during riboflavin deficiency may imply as one of the promoting effects of riboflavin deficiency on the carcinogenesis of nitrosamines.展开更多
In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performanc...In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performance, a qoality control exawhnation was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37℃ and under 76% humidity than in that at 20 ~ 25℃ and under lower humidity. The retention of iodine varied with the kind of has and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36. 6% to 86. 1 % ). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48. 3 % of samples from markets were found to be in compliance with national standards (30 ~ 50 mg/kg), and 72.0% of samples from households were in compliance with national standartl (20 ~ 50 mg/kg). Analytical data collected from 8 of the cooperative laheratories foran analytical reference material showed a 95% codridence interval of the population mean for both precision and accuracy, falling within X± 2SD and passing quality control exdrination展开更多
Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the c...Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.展开更多
China’s deep coalbed methane(CBM)resources demonstrate immense potential with extensive developmental prospects.However,the coupling relationship between the negative adsorption effect and the positive desorption-pro...China’s deep coalbed methane(CBM)resources demonstrate immense potential with extensive developmental prospects.However,the coupling relationship between the negative adsorption effect and the positive desorption-promotion effect under high-temperature conditions remains unclear.In this study,a self-built high-temperature adsorption-desorption system was used to investigate the coupled effects of temperature and coal rank on methane adsorption-desorption behavior in deep CBM.The results show that elevated temperatures significantly reduce methane adsorption capacity,with high-rank coals exhibiting greater sensitivity.Conversely,high-temperature conditions significantly enhance methane desorption and diffusion behavior,accelerating initial desorption rates,enabling rapid gas release in a short period,and thus improving desorption efficiency.The desorption volume and desorption-diffusion rate exhibited an asymmetric U-shaped variation with coal rank.By coupling the positive and negative effects of temperature and defining the desorption ratio,it was found that a 10 K increase in temperature raised the desorption ratio by 3.78%-8.05%.Finally,an effective gas content prediction model is proposed,and the key regulatory role of temperature in the resource potential and gas production characteristics of deep CBM is clarified.These findings can provide theoretical guidance for the subsequent optimization of deep CBM exploration and development strategies.展开更多
An understanding of the genetic effects of em-bryo genes for rice quality traits is of impor-tance for rice quality improvement. Analysisof embryo, endosperm, cytoplasmic, and ma-ternal genetic effects and genotype...An understanding of the genetic effects of em-bryo genes for rice quality traits is of impor-tance for rice quality improvement. Analysisof embryo, endosperm, cytoplasmic, and ma-ternal genetic effects and genotype×environ-展开更多
BACKGROUND： Nitric oxide synthase （NOS） inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate t...BACKGROUND： Nitric oxide synthase （NOS） inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids （EAA） during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine （L-NA） reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE： By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid （GABA） in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN： A randomized and controlled experiment SETTING ： Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS： A total of 42 male healthy SD rats （grade Ⅱ, weighting 250-300 g） were provided by the Experimental Animal Center of Hebei Province （Certification： 04036）. Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride （TTC） were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS： The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups： sham-operated group （n = 6）, ischemic group （n = 18）, L-NA group （n = 18）. The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups （n = 6 for each）： drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion （MCAO） respectively. L-NA （20 mg/kg, ip） was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain （IV%） in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett＇s test. MAIN OUTCOME MEASURES： （1） The volume of cerebral infarction; （2） The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS ： All 42 rats were involved in the final analysis. （1） Infarcted volume： Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was （20.13±3.59）% and （23.12±5.84）% in L-NA group, which was not similar to that in ischemic group [（22.10±3.98）%, （25.38± 5.37）%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [（26.11±3.55）% and （37.15±3.58）%, P 〈 0.01]. Changes of amino acid content： At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group （ P〈 0.05-0.01）. However, contents in L-NA group were similar to those in ischemic group （P 〉 0.05）. At 12 hours after ischemia, the contents of aspartate [（0.21 ±0.06）, （0.36±0.05）, （0.29±0.12） mg/g] and glutamate [（0.55±0.06）, （0.78±0.10）, （0.52±0.10） mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [（0.49±0.17）, （0.63± 0.03）, （0.51±0.15） mg/g; （0.98±0.30）, （1.15±0.15）, （0.93±0.15） mg/g, P〈 0.05-0.01]. Glycine in hippocampus was （0.40±0.07） mg/g, which was higher than that in ischemic group [（0.21±0.07） mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was （0.93±0.10）, （0.62±0.12） and （0.81 ±0.10） mg/g, respectively, which was higher than that in ischemic group [（0.60±0.08）, （0.37±0.17）, （0.59±0.10） mg/g, P 〈 0.05-0.01]. CONCLUSION ： It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.展开更多
In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples a...In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples are 0.5, 1, 1.5, 1.75, 2, 2.5 and 3 cm edge with a respective initial water content of 2.7, 3.76, 3.48, 2.68, 3.28, 2.17 and 2.29 kg/kgms. For cylindrical samples, the radius is set at 0.5 cm and sample heights are 1, 1.5, 2, 2.5, 3, 3.5 and 4 cm with respective water contents of 2.2, 3.19, 2.85, 2.1, 2.17, 2.39 and 2.03 kg/kgms. The effective diffusion coefficients of cubic samples are of the order of 10−10 and 10−9 m2∙s−1 grew with sample edge. As for the cylindrical samples, the effective diffusion coefficients were of the order of 10−9 m2∙s−1 and there was no linear correlation between cylinder height and their effective diffusion coefficient. As for the examination of the initial water content on the effective diffusion coefficient, it turned out that the initial water content had no influence on the effective diffusion coefficient of the sweet potato samples.展开更多
The doping content of Mg plays an important role in the crystalline structure and morphology properties of Zn_(1-x )Mg_xO thin films. Here,using radio-frequency magnetron sputtering method,we prepared Zn_(1-x )Mg_xO t...The doping content of Mg plays an important role in the crystalline structure and morphology properties of Zn_(1-x )Mg_xO thin films. Here,using radio-frequency magnetron sputtering method,we prepared Zn_(1-x )Mg_xO thin films on single crystalline Si(100) substrates with a series of x values. By means of X-ray diffraction(XRD) and scanning electron microscope(SEM),the crystalline structure and morphology of Zn_(1-x )Mg_xO thin films with different x values are investigated. The crystalline structure of Zn_(1-x )Mg_xO thin film is single phase with x<0.3,while there is phase separation phenomenon with x>0.3,and hexagonal and cubic structures will coexist in Zn_(1-x )Mg_xO thin films with higher x values. Especially with lower x values,a shoulder peak of 35.1° appearing in the XRD pattern indicates a double-crystalline structure of Zn_(1-x )Mg_xO thin film. The crystalline quality has been improved and the inner stress has been released,after the Zn_(1-x )Mg_xO thin films were annealed at 600 °C in vacuum condition.展开更多
When evaluating ionic liquids （ILs） for extractive desulfurization （EDS） of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few...When evaluating ionic liquids （ILs） for extractive desulfurization （EDS） of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work, COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H20 mixtures, which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C4MIM]IH2P04], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the cross- solubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range （〈 10 wt%） was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent-solute interactions and the COSMO-RS based analysis.展开更多
The quantitative effects of chromium content on continuous cooling transformation （CCT） diagrams of novel air-cooled bainite steels were analyzed using artificial neural network models. The results showed that the c...The quantitative effects of chromium content on continuous cooling transformation （CCT） diagrams of novel air-cooled bainite steels were analyzed using artificial neural network models. The results showed that the chromium may retard the high and medium-temperature martensite transformation.展开更多
Systematic differences in the duration and frequency content of ground motions from the hanging wall and footwall during the 2008 Wenchuan earthquake are investigated,focusing on the influence of these differences on ...Systematic differences in the duration and frequency content of ground motions from the hanging wall and footwall during the 2008 Wenchuan earthquake are investigated,focusing on the influence of these differences on structural input energy based on the elastic and inelastic energy responses of structures.A comparison of the input energy spectra between the hanging wall and the footwall reveal that the structural input energy on the hanging wall is not amplified due to the short duration and low peak ground velocity to acceleration ratio（V/A）.However,the larger demand of structural input energy on the footwall in the range of medium and long periods is observed and the demand increases up to 50% relative to the average level of structural input energy for rupture distances larger than 30 km.The importance of considering the footwall effect on structural input energy when comparing ground motions in the range of medium and long periods is recognized.展开更多
The Portevin–Le Chatelier（PLC） effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensional digital imag...The Portevin–Le Chatelier（PLC） effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensional digital image correlation（3D-DIC） technique was applied to obtaining the further insight into the spatiotemporal characteristics, in particular the influence of Mg content on deformation behaviors. Mg content has a pronounced effect on serration characteristics, including the serration type and amplitude; Mg content tends to weaken the spatial correlation of the propagative bands. Additionally, the serration amplitude linearly increases with the maximum PLC band strain; high Mg content generates a higher PLC band strain at a given serration amplitude compared with low Mg content. Mg content is found to be effective to enhance the serration amplitude, the maximum PLC band strain and also the amount of elastic shrinkage outside PLC bands.展开更多
Objective:To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan,Vural&Kckdk against periodoutopathogenie bacteria,its antioxidant activity and cytotoxic effect on various cancer...Objective:To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan,Vural&Kckdk against periodoutopathogenie bacteria,its antioxidant activity and cytotoxic effect on various cancer cell lines.Methods:In vitro antimicrobial activities of elhanol.methanol,ethyl acetate(ElAc,n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria,Aggregatibacter actinnmycelemconilans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion,minimum inhibitory concentration(MIC)and minimal bactericidal concentration(MBC),Antioxidant properties of the extracts were evaluatod by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and p-carotene bleaching methods.Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent.Additionally,cytotoxic activity of the extracts on androgcn-insensilivc prostate cancer,androgen—sensitive prostate cancer,chronic myelogenous leukemia and acute promyelocytic leukemia bunian cancer cell lines were determined by 3-4,5-dimelhylthiazol-2-yh-2,5-diphenyltclrazolium bromide assay.Human gingival fibroblast cells were used as a control.Results:Our data showed that ELAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemitans(MIC:1.562 mg/ml_MHC:3.124 mg/ml.)and Porph yromonas gingiralis(MIC:0.781 mg/mL,MBC:1.562 mg/mL).In antioxidant assays.ElAc extract exhibited also the highest radical scavenging activity[IC_(50)=(30.0±0.3)μg/ml.]and the highest inhibition[(74.35±0.30)%]|against lineloic acide oxidation.The amount of phenolic content of it was also the highest[(l62.5±l.2)μg/mg gallic acid].In cytotoxic assay,only etbanol[IC_(50)=(80.00±1.21)μg/ml.]and EtAc extract[IC_(50)=(70.0±0.9)μg/ml]were toxic on acute promyeloeytic leukemia cells at 20—100μg/mL.P<0.05>.However,no toxic effect was observed on human gingival fibroblast cells.Cunclusions:According to our findings,owing to its antioxidant and cytotoxic potential,EtAc exlrael might include anticancer agents for acute promyelocytic leukemia.展开更多
The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period ...The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period Tp, smoothed spectral predominant period To, Fourier amplitude spectral mean period Tm, equivalent pulse period Tv, and the pseudo-velocity spectral predominant period Tpv) reflecting the characteristics of frequency content of strong ground motion to examine the near-fault three-component motions during the 1999 Chi-Chi earthquake. The result indicates that the frequency content of near-fault motions at the Hanging wall is less than that at the foot wall; Tp shows a smaller value than that of To and Tm and it emerges a reverse relation of three-component motions as compared with that of To and Tm; Tv and Tpv of the near-fault motions at the north end of the rupture display a similar trend to that generated by the rupture directivity effect of strike-slip faulting. We therefore conclude that these observations are useful in the formulation of near-fault design spectra for seismic codes and in zoning studies in seismic risk.展开更多
Content-based language teaching(CBLT)has come to be known as an effective and motivating way to develop higher levels of communicative ability than more traditional grammar-based approaches.Whereas traditional methods...Content-based language teaching(CBLT)has come to be known as an effective and motivating way to develop higher levels of communicative ability than more traditional grammar-based approaches.Whereas traditional methods isolate the target language from any substantive content except for the mechanical workings of the language itself,CBLT enriches classroom discourse in a way that provides both a cognitive basis for language learning and a motivational basis for purposeful communication.CBLT,how ever,does not preclude language instruction but instead promotes its integration through a counterbalanced approach that entails a dynamic interplay betw een language and content.Drawing on classroom-based research,this paper illustrates the feasibility and effectiveness of a counterbalanced approach to CBLT whose flexibility has the potential to accommodate a range of instructional settings.展开更多
通过比较不同基质中药用石斛生长量和有效成份质量分数,探究经过无害化处理的松材线虫病疫木在铁皮石斛(Dendrobium officinale Kimura et Migo)人工栽培中作为配方基质的使用效果。结果表明:在铁皮石斛人工种植中使用经过无害化处理后...通过比较不同基质中药用石斛生长量和有效成份质量分数,探究经过无害化处理的松材线虫病疫木在铁皮石斛(Dendrobium officinale Kimura et Migo)人工栽培中作为配方基质的使用效果。结果表明:在铁皮石斛人工种植中使用经过无害化处理后的松材线虫病疫木作为栽培基质切实可行。不同栽培方式适用的松材线虫病疫木替代基质的比例不同。以盆栽方式种植铁皮石斛时,1号基质(V(粒径9~12 mm疫木颗粒)∶V(新鲜树皮)∶V(饼肥)=1∶1∶1)充分发酵后可以在实际生产中替代常规栽培基质使用;以盘栽方式种植铁皮石斛时,3号基质(V(疫木锯末)∶V(新鲜树皮)∶V(饼肥)=1∶1∶1)充分发酵后可以在实际生产中替代常规栽培基质使用。展开更多
[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged pl...[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianchi Lake reduced the chlorophyll content of phytoplankton and submerged plant (P. pectinatus), and it showed that E. crassipes had certain inhibitory effect on their growth; the culture solution of E. crassipes root inhibited M. aeruginosa growth obviously. [Conclusion] The study could provide scientific references for the prevention and control of ecological safety of E. crassipes.展开更多
文摘Li-Zn mixed ferrites with composition formula ZnxLi0.5-x/2Fe2.5-x/2O4 (0.2≤x≤0.8) were prepared by the usual ceramic method in 1000~1150℃. The effects of Zn substitution and sintering temperature on the formation, densification, microstructure and a.c. electrical conductivity have been studied. Under the effect of changing the firing temperature and Zn content, high sintered Li-Zn ferrite bodies are achieved. More fine structure bodies having high electrical resistance are obtained at high Zn content
文摘Pot experiment was carried out to determine the allelopathic effects of Datura?stramonium on leaf chlorophyll content, root and shoot elongation, fresh and dry weight of two wild plant species: Cenchrus ciliaris and Neonotonia wightii. Different concentrations (0%, 25%, 50%, 75% and 100%) from seed and leaf extracts of D. stramonium were used to investigate the allelopathic effects of D. stramonium on growth of tested species.?The total chlorophyll content of N. wightii was significantly reduced in all plants treated with both aqueous seed and leaf extracts of D. stramonium. In C. ciliaris, the total chlorophyll content was also significantly reduced for those plants treated with aqueous seed extract and leaf extract from D. stramonium. Relative to the control treatments, there was greater reduction in root and shoot length which was observed in higher concentrations of aqueous seed and leaf extracts. Fresh and dry weight of tested species significantly decreased after being treated with both seed and leaf aqueous extracts of D. stramonium. It was found that the allelopathic effect of aqueous seed and leaf extracts from D. stramonium on tested species was concentration-dependent. The inhibitory effects on all tested species increased as the concentration of both extracts increased from 0% to 100%. This study concluded that aqueous seed and leaf extract of D. stramonium have allelopathic effects on leaf chlorophyll content, root and shoot length, fresh and dry weight of grass (C. ciliaris) and legume (N. wightii) species.
文摘The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepatic GSH content of the riboflavin deficient rats decreased to 55-61% of the control rats. When NDMA was given 6 mg kg by gastric intubation to riboflavin deficient rats, hepatic GSH content decreased markedly to 39-43% of the control rats. After supplying riboflavin, hepatie GSH content of the deficient rats recovered to the level of the control rats. These results suggest that alterations of rat hepatic GSH content during riboflavin deficiency may imply as one of the promoting effects of riboflavin deficiency on the carcinogenesis of nitrosamines.
文摘In order to ensure that the intake of iodine from iodized salt is adequate, the effects of cooking, storage and iedination on iodine content in iodized salt have been studied. For moni toring the analytical Performance, a qoality control exawhnation was also undertaken. The loss of iodine was greater when salt was stored in plastic bag than in glass bottle. The loss was greater in fortified salt stored at 37℃ and under 76% humidity than in that at 20 ~ 25℃ and under lower humidity. The retention of iodine varied with the kind of has and also was influenced by the water content of cooked food. In general, the retention of iodine during cooking varied considerably (from 36. 6% to 86. 1 % ). The iodine concentration in salts varied greater from 3.0 to 100.3 mg/kg in salt for markets, and from 0 to 90.0 mg/kg in salts for households. 48. 3 % of samples from markets were found to be in compliance with national standards (30 ~ 50 mg/kg), and 72.0% of samples from households were in compliance with national standartl (20 ~ 50 mg/kg). Analytical data collected from 8 of the cooperative laheratories foran analytical reference material showed a 95% codridence interval of the population mean for both precision and accuracy, falling within X± 2SD and passing quality control exdrination
文摘Soybean seed products contain isoflavones （genistein, daidzein, and glycitein） that display biological effects when ingested by humans and animals. These effects are species, dose and age dependent. Therefore, the content and quality of isoflavones in soybeans is a key factor to the biological effect. Our objective was to identify the genetic effects that underlie the isoflavone content in soybean seeds. A genetic model for quantitative traits of seeds in diploid plants was applied to estimate the genetic main effects and genotype x environment （GE） interaction effects for the isoflavone content （IC） of soybean seeds by using two years experimental data with an incomplete diallel mating design of six parents. Results showed that the IC of soybean seeds was simultaneously controlled by the genetic effects of maternal, embryo, and cytoplasm, of which maternal genetic effects were most important, followed by embryo and cytoplasmic genetic effects. The main effects of different genetic systems on IC trait were more important than environment interaction effects. The strong dominance effects on isoflavone from residual was made easily by environment conditions. Therefore, the improvement of the IC of soybean seeds would be more efficient when selection is based on maternal plants than that on the single seed. Maternal heritability （65.73%） was most important for IC, followed by embryo heritability （25.87%） and cytoplasmic heritability （8.39%）. Based on predicated genetic effects, Yudou 29 and Zheng 90007 were better than other parents for increasing IC in the progeny and improving the quality of soybean, The significant effects of maternal and embryo dominance effects in variance show that the embryo heterosis and maternal heterosis are existent and uninfluenced by environment interaction effects.
基金supported by the National Natural Science Fund of China(No.42272195)the National Natural Science Fund of China(No.42130802)+2 种基金the Fundamental Research Funds for the Central Universities(No.2025ZDPY10)the China National Petroleum Co.,Ltd..Research applied science and technology special(No.2023ZZ18)the PetroChina Changqing oilfield science and technology major project(No.2023DZZ01).
文摘China’s deep coalbed methane(CBM)resources demonstrate immense potential with extensive developmental prospects.However,the coupling relationship between the negative adsorption effect and the positive desorption-promotion effect under high-temperature conditions remains unclear.In this study,a self-built high-temperature adsorption-desorption system was used to investigate the coupled effects of temperature and coal rank on methane adsorption-desorption behavior in deep CBM.The results show that elevated temperatures significantly reduce methane adsorption capacity,with high-rank coals exhibiting greater sensitivity.Conversely,high-temperature conditions significantly enhance methane desorption and diffusion behavior,accelerating initial desorption rates,enabling rapid gas release in a short period,and thus improving desorption efficiency.The desorption volume and desorption-diffusion rate exhibited an asymmetric U-shaped variation with coal rank.By coupling the positive and negative effects of temperature and defining the desorption ratio,it was found that a 10 K increase in temperature raised the desorption ratio by 3.78%-8.05%.Finally,an effective gas content prediction model is proposed,and the key regulatory role of temperature in the resource potential and gas production characteristics of deep CBM is clarified.These findings can provide theoretical guidance for the subsequent optimization of deep CBM exploration and development strategies.
文摘An understanding of the genetic effects of em-bryo genes for rice quality traits is of impor-tance for rice quality improvement. Analysisof embryo, endosperm, cytoplasmic, and ma-ternal genetic effects and genotype×environ-
基金the Natural Sci-ence Foundation of HebeiProvince, No. C2005000840
文摘BACKGROUND： Nitric oxide synthase （NOS） inhibrtors have been widely used to investigate the role of NO on cerebral ischemic injury, but the results are controversial. Moreover, it has been considered to aggravate the ischemic neuronal damage with the release of excessively excitatory amino acids （EAA） during cerebral ischemia. On the other hand, some inhibitory amino acid is suggested to be important for the neuronal protection against ischemic brain damage. Our study has recently showed that treatment with the NOS inhibitor NG-nitro-L-arginine （L-NA） reduced focal cerebral ischemic damage. The effect of L-NA on the contents of excitatory and inhibitory amino acid in the rat brain following cerebral ischemia is still unclear. OBJECTIVE： By evaluating the effect of NOS inhibitor, L-NA on the contents of aspartate, glutamate, glycine and γ-aminobutyric acid （GABA） in striatum, hippocampus and cortex in the rat brain following cerebral ischemia respectively, to investigate the beneficial effect of L-NA on cerebral ischemic injury and the possible mechanism. DESIGN： A randomized and controlled experiment SETTING ： Department of Pharmacology, Hebei Academy of Medical Sciences MATERIALS： A total of 42 male healthy SD rats （grade Ⅱ, weighting 250-300 g） were provided by the Experimental Animal Center of Hebei Province （Certification： 04036）. Aspartate, glutamate, glycine, GABA, L-NA and 2,3,5-triphenyltetrazolium chloride （TTC） were obtained from Sigma Chemicals Co, St Louis, MO, USA. HPLC-ultraviolet detector system consisted of Agilent 1100 HPLC. METHODS： The experiment was carried out in Department of Pharmrcology, Hebei Academy of Medical Sciences from June 2005 to June 2006. Rats were randomly divided into three groups： sham-operated group （n = 6）, ischemic group （n = 18）, L-NA group （n = 18）. The model of focal cerebral ischemia in rat was prepared with intraluminal line occlusion methods. In sham-operated rats, the external carotid artery was surgically prepared, but the filament was not inserted. Each group was further divided into 3 subgroups （n = 6 for each）： drugs were administrated at 2, 6 and 12 hours after the middle cerebral artery occlusion （MCAO） respectively. L-NA （20 mg/kg, ip） was administrated, twice a day, for 3 consecutive days. Same volume of normal saline was administrated in ischemic and sham operation groups. The changes of infarcted volume and the contents of amino acids were respectively assayed. Image analysis software was used for the measurement of the infarcted area. The results were expressed as a percentage of the infarcted volume of cerebral/volume of whole brain （IV%） in order to control for edema formation. The contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in the rat brain following cerebral ischemia were respectively measured by HPLC method. All data were analyzed with one-way ANOVA and Dunnett＇s test. MAIN OUTCOME MEASURES： （1） The volume of cerebral infarction; （2） The contents of aspartate, glutamate glycine and GABA in brain tissue after cerebral ischemia. RESULTS ： All 42 rats were involved in the final analysis. （1） Infarcted volume： Volume was 0 in sham-operated group. When L-NA was administrated at 2 and 6 hours after MCAO, the infarcted volume was （20.13±3.59）% and （23.12±5.84）% in L-NA group, which was not similar to that in ischemic group [（22.10±3.98）%, （25.38± 5.37）%, P〉 0.05]. However, the infarcted volume was markedly decreased compared with that of ischemic group when L-NA was administrated at 12 hours after MCAO [（26.11±3.55）% and （37.15±3.58）%, P 〈 0.01]. Changes of amino acid content： At 2 and 6 hours after ischemia, the contents of aspartate, glutamate, glycine and GABA in striatum, hippocampus and cortex in ischemic group were significantly increased compared with those in sham-operated group （ P〈 0.05-0.01）. However, contents in L-NA group were similar to those in ischemic group （P 〉 0.05）. At 12 hours after ischemia, the contents of aspartate [（0.21 ±0.06）, （0.36±0.05）, （0.29±0.12） mg/g] and glutamate [（0.55±0.06）, （0.78±0.10）, （0.52±0.10） mg/g] in striatum, hippocampus and cortex in L-NA group were significantly decreased compared with those in ischemic group [（0.49±0.17）, （0.63± 0.03）, （0.51±0.15） mg/g; （0.98±0.30）, （1.15±0.15）, （0.93±0.15） mg/g, P〈 0.05-0.01]. Glycine in hippocampus was （0.40±0.07） mg/g, which was higher than that in ischemic group [（0.21±0.07） mg/g, P 〈 0.05]. GABA in striatum, hippocampus and cortex was （0.93±0.10）, （0.62±0.12） and （0.81 ±0.10） mg/g, respectively, which was higher than that in ischemic group [（0.60±0.08）, （0.37±0.17）, （0.59±0.10） mg/g, P 〈 0.05-0.01]. CONCLUSION ： It may be concluded that L-NA have beneficial effect on ischemic cerebral injury in ischemic later stage in rats. The possible mechanism is that L-NA can decrease the contents of aspartate and glutamate, increase the contents of glycine and GABA.
文摘In this article, we investigated the influence of size and initial water content on the effective diffusion coefficient of sweet potatoes samples cut into cubic and cylindrical shapes. The sizes of the cubic samples are 0.5, 1, 1.5, 1.75, 2, 2.5 and 3 cm edge with a respective initial water content of 2.7, 3.76, 3.48, 2.68, 3.28, 2.17 and 2.29 kg/kgms. For cylindrical samples, the radius is set at 0.5 cm and sample heights are 1, 1.5, 2, 2.5, 3, 3.5 and 4 cm with respective water contents of 2.2, 3.19, 2.85, 2.1, 2.17, 2.39 and 2.03 kg/kgms. The effective diffusion coefficients of cubic samples are of the order of 10−10 and 10−9 m2∙s−1 grew with sample edge. As for the cylindrical samples, the effective diffusion coefficients were of the order of 10−9 m2∙s−1 and there was no linear correlation between cylinder height and their effective diffusion coefficient. As for the examination of the initial water content on the effective diffusion coefficient, it turned out that the initial water content had no influence on the effective diffusion coefficient of the sweet potato samples.
基金supported by the National Natural Science Foundation of China(Nos.20473077 and 61540071)the Project of Natural Science Research of High Education in Jiangsu Province(No.15KJD140002)+2 种基金the Fundamental Research Funds of Changzhou Science and Technology Bureau(No.CJ20160026)the Changzhou Modern Optoelectronic Technology Research Institute Funds(No.CZGY13)the Natural Science Funds of Changzhou Institute of Technology(No.YN1408)
文摘The doping content of Mg plays an important role in the crystalline structure and morphology properties of Zn_(1-x )Mg_xO thin films. Here,using radio-frequency magnetron sputtering method,we prepared Zn_(1-x )Mg_xO thin films on single crystalline Si(100) substrates with a series of x values. By means of X-ray diffraction(XRD) and scanning electron microscope(SEM),the crystalline structure and morphology of Zn_(1-x )Mg_xO thin films with different x values are investigated. The crystalline structure of Zn_(1-x )Mg_xO thin film is single phase with x<0.3,while there is phase separation phenomenon with x>0.3,and hexagonal and cubic structures will coexist in Zn_(1-x )Mg_xO thin films with higher x values. Especially with lower x values,a shoulder peak of 35.1° appearing in the XRD pattern indicates a double-crystalline structure of Zn_(1-x )Mg_xO thin film. The crystalline quality has been improved and the inner stress has been released,after the Zn_(1-x )Mg_xO thin films were annealed at 600 °C in vacuum condition.
基金Supported by the National Natural Science Foundation of China(NSFC U1462123)PetroChina Innovation FoundationFundamental Research Funds for the Central Universities of China(22201313007)
文摘When evaluating ionic liquids （ILs） for extractive desulfurization （EDS） of fuel oils, the inevitable presence of water in the system may have a significant and in many cases strongly negative effect. However, few studies have considered this particular issue and a promoted water effect on EDS is scarcely reported. In this work, COSMO-RS was firstly employed to calculate the capacity and selectivity for EDS of various IL/H20 mixtures, which cover different IL characters and a wide water concentration range. Experiments were then conducted with a representative IL [C4MIM]IH2P04], whose stable and even promoted extraction performance with a small amount of water was suggested by COSMO-RS. Through analyses of the desulfurization ratio, the cross- solubility and the water content in the desulfurized fuel, the promoted effect of water within a certain range （〈 10 wt%） was experimentally demonstrated. Moreover, such effect of water was explained combining the viscosity, the solvent-solute interactions and the COSMO-RS based analysis.
文摘The quantitative effects of chromium content on continuous cooling transformation （CCT） diagrams of novel air-cooled bainite steels were analyzed using artificial neural network models. The results showed that the chromium may retard the high and medium-temperature martensite transformation.
基金Special Research Foundation of Earthquake Industry under Grant No. 201208013National Natural Science Foundation of China under Grant No. 51008101 & 51078117
文摘Systematic differences in the duration and frequency content of ground motions from the hanging wall and footwall during the 2008 Wenchuan earthquake are investigated,focusing on the influence of these differences on structural input energy based on the elastic and inelastic energy responses of structures.A comparison of the input energy spectra between the hanging wall and the footwall reveal that the structural input energy on the hanging wall is not amplified due to the short duration and low peak ground velocity to acceleration ratio（V/A）.However,the larger demand of structural input energy on the footwall in the range of medium and long periods is observed and the demand increases up to 50% relative to the average level of structural input energy for rupture distances larger than 30 km.The importance of considering the footwall effect on structural input energy when comparing ground motions in the range of medium and long periods is recognized.
基金financial support received from the National Natural Science Foundation of China (NSFC) under Grant Nos. 11332010, 51571013, 51271174, 11472266 and 11428206
文摘The Portevin–Le Chatelier（PLC） effect in Al–2.30wt%Mg, Al–4.57wt%Mg and Al–6.91wt%Mg alloys has been investigated at various applied strain rates at room temperature in this study. Three-dimensional digital image correlation（3D-DIC） technique was applied to obtaining the further insight into the spatiotemporal characteristics, in particular the influence of Mg content on deformation behaviors. Mg content has a pronounced effect on serration characteristics, including the serration type and amplitude; Mg content tends to weaken the spatial correlation of the propagative bands. Additionally, the serration amplitude linearly increases with the maximum PLC band strain; high Mg content generates a higher PLC band strain at a given serration amplitude compared with low Mg content. Mg content is found to be effective to enhance the serration amplitude, the maximum PLC band strain and also the amount of elastic shrinkage outside PLC bands.
基金Supported by Minsitry of Devetopment of Tuckish Republie for Foundation of Moleculer Biology Research Center(Grant No.1998K121480)
文摘Objective:To investigate the in vitro antimicrobial potential of Thermopsis turcica Kit Tan,Vural&Kckdk against periodoutopathogenie bacteria,its antioxidant activity and cytotoxic effect on various cancer cell lines.Methods:In vitro antimicrobial activities of elhanol.methanol,ethyl acetate(ElAc,n-hexane and water extracts of Thermopsis turcica herb against periodontopathogenic bacteria,Aggregatibacter actinnmycelemconilans ATCC 29523 and Porphyromonas gingivalis ATCC 33277 were tested by agar well diffusion,minimum inhibitory concentration(MIC)and minimal bactericidal concentration(MBC),Antioxidant properties of the extracts were evaluatod by 1,1-diphenyl-2-picryl-hydrazyl radical scavenging activity and p-carotene bleaching methods.Amounts of phenolic contents of the extracts were also analysed by using the Folin-Ciocalteu reagent.Additionally,cytotoxic activity of the extracts on androgcn-insensilivc prostate cancer,androgen—sensitive prostate cancer,chronic myelogenous leukemia and acute promyelocytic leukemia bunian cancer cell lines were determined by 3-4,5-dimelhylthiazol-2-yh-2,5-diphenyltclrazolium bromide assay.Human gingival fibroblast cells were used as a control.Results:Our data showed that ELAc extract had the highest antimicrobial effect on Aggregatibacter actinomycetemitans(MIC:1.562 mg/ml_MHC:3.124 mg/ml.)and Porph yromonas gingiralis(MIC:0.781 mg/mL,MBC:1.562 mg/mL).In antioxidant assays.ElAc extract exhibited also the highest radical scavenging activity[IC_(50)=(30.0±0.3)μg/ml.]and the highest inhibition[(74.35±0.30)%]|against lineloic acide oxidation.The amount of phenolic content of it was also the highest[(l62.5±l.2)μg/mg gallic acid].In cytotoxic assay,only etbanol[IC_(50)=(80.00±1.21)μg/ml.]and EtAc extract[IC_(50)=(70.0±0.9)μg/ml]were toxic on acute promyeloeytic leukemia cells at 20—100μg/mL.P<0.05>.However,no toxic effect was observed on human gingival fibroblast cells.Cunclusions:According to our findings,owing to its antioxidant and cytotoxic potential,EtAc exlrael might include anticancer agents for acute promyelocytic leukemia.
基金Heilongjiang Natural Science Frundation Project (ZGJ03-03)the Researth Fund for the Doctoral Program of Higher Education of China (20030213042).
文摘The frequency content of earthquake ground motion is very important because it affects the dynamic response of structural systems. In the paper, we use five scalar parameters (the response spectral predominant period Tp, smoothed spectral predominant period To, Fourier amplitude spectral mean period Tm, equivalent pulse period Tv, and the pseudo-velocity spectral predominant period Tpv) reflecting the characteristics of frequency content of strong ground motion to examine the near-fault three-component motions during the 1999 Chi-Chi earthquake. The result indicates that the frequency content of near-fault motions at the Hanging wall is less than that at the foot wall; Tp shows a smaller value than that of To and Tm and it emerges a reverse relation of three-component motions as compared with that of To and Tm; Tv and Tpv of the near-fault motions at the north end of the rupture display a similar trend to that generated by the rupture directivity effect of strike-slip faulting. We therefore conclude that these observations are useful in the formulation of near-fault design spectra for seismic codes and in zoning studies in seismic risk.
文摘Content-based language teaching(CBLT)has come to be known as an effective and motivating way to develop higher levels of communicative ability than more traditional grammar-based approaches.Whereas traditional methods isolate the target language from any substantive content except for the mechanical workings of the language itself,CBLT enriches classroom discourse in a way that provides both a cognitive basis for language learning and a motivational basis for purposeful communication.CBLT,how ever,does not preclude language instruction but instead promotes its integration through a counterbalanced approach that entails a dynamic interplay betw een language and content.Drawing on classroom-based research,this paper illustrates the feasibility and effectiveness of a counterbalanced approach to CBLT whose flexibility has the potential to accommodate a range of instructional settings.
基金Supported by Scientific Demonstration Engineering Project in Kunming City (109S010103)
文摘[Objective] The aim was to study the effects of Eichhornia crassipes as an invasive plant on aquatic plants in Dianchi Lake. [Method] Based on the determination of chlorophyll content of phytoplankton and submerged plant (Potamogeton pectinatus) in Dianchi Lake in different months, the effects of E. crassipes on aquatic plants in Dianchi Lake were studied, and the allelopathy effect of root culture solution of E. crassipes on Microcystis aquaticum was discussed. [Result] The growth of E. crassipes in Dianchi Lake reduced the chlorophyll content of phytoplankton and submerged plant (P. pectinatus), and it showed that E. crassipes had certain inhibitory effect on their growth; the culture solution of E. crassipes root inhibited M. aeruginosa growth obviously. [Conclusion] The study could provide scientific references for the prevention and control of ecological safety of E. crassipes.
