Fine Al（OH）3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks. By means of laser particle size analyzer and scanning electron microscopy, the influences of temperature and ...Fine Al（OH）3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks. By means of laser particle size analyzer and scanning electron microscopy, the influences of temperature and initial molar ratio of Na2O to Al2O3 （aK） on agglomeration of fine seed in Bayer process were investigated. The results show that agglomeration is almost finished in 8 h, and seeds with size less than 2 μm are easily aggregated together, and almost disappear in 8 h under the optimal process conditions. In the aluminate solution with the same moderate initial aK, when the reaction temperature reaches 75 ℃, the secondary nucleation does not occur, and the effect of agglomeration is better. And at the same reaction temperature, when the initial aK is 1.62, the initial supersaturation of aluminate solution is moderate, the binders on the surfaces of the seed are enough to maintain the agglomeration process, and the agglomeration degree is better. From SEM images, agglomeration mainly occurs in the fine particles, the combinations among the fine particles are loose and the new formed coarse crystal shapes are irregular.展开更多
In this paper, through the indoor free load swelling rate test, expansive soil in a section of a first- class highway reconstruction project in Yichang City was studied. It emphatically analyzed the interrelations amo...In this paper, through the indoor free load swelling rate test, expansive soil in a section of a first- class highway reconstruction project in Yichang City was studied. It emphatically analyzed the interrelations among free load swelling rate, non-load time, the proportion of mixed sand and initial dry density. Experimen- tal studies have shown that： Free load swelling deformation is mainly divided into three stages of rapid expan- sion, slow expansion and final stability; when the initial dry density is constant, free load swelling rate of the weathered sand modified soil will reduce rapidly before they slow down with the increase of sand proportion, and weathered sand modified soil free load swelling rate is not sensitive to the large amount of sand mixed; in the same mixed sand ratio, weathered sand modified soil free load swelling rate increases rapidly with the in- crease of initial dry density, there is a good linear correlation between them. To take appropriate control of the initial dry density during the expansive soil subgrade construction helps to reduce its swelling deformation and ensures the stability of the embankment.展开更多
A pot experiment was carried out on a marine saline soil to study the effect of initial soluble Na/Ca ratio of saline soil on the salinity tolerance of barley plant.The results showed that (1) the Na/Ca ratio affected...A pot experiment was carried out on a marine saline soil to study the effect of initial soluble Na/Ca ratio of saline soil on the salinity tolerance of barley plant.The results showed that (1) the Na/Ca ratio affected significantly the dry weight of the plant at an earlier stage of growth,the critical values of initial Na/Ca ratio at which the plant could grow normally on soils containing salts of 2.5,3.5 and 4.5g kg^-1 were 30,20 and 15,respectively;(2)smaller Na/Ca ratio resulted in a considerable decrease in Na accumulation but a great increase in K accumulation in the barley plant;and (3) the plasmallema of barley leaf were badly injured when the Na/Ca ratio was more than 30 and the increase of Na content of plant caused an exudation of K from the leaf cells.Some critical indexes were suggested for the cultivation of barley plant on marine saline soils and could be used as reference in the biological reclamation of marine saline soils.展开更多
Extensive oedometer tests and physical tests have been conducted on remolded and reconstituted marine soils with different initial water contents and liquid limits. The oedometer test data can be well fitted with a st...Extensive oedometer tests and physical tests have been conducted on remolded and reconstituted marine soils with different initial water contents and liquid limits. The oedometer test data can be well fitted with a straight line in the bilogarithmic ln(1+ e ) ～ lg p plot. The initial effective stress corresponding to the initial void ratio is determined by extrapolation of the bilogarithmic compression line. This new way of extrapolating oedometer test data to the initial void ratio overcomes the difficulty of measuring the residual effective stress of soils in the remolded state. The initial stable compression line of ocean floor deposits under different deposition environments corresponds to the compression line at the sensitivity equal to one. This initial stable compression line obtained in this study is consistent with the available compression line at the sensitivity equal to one which is proposed based on the experimental data of remolded undrained strength and the theoretical concept of Cam clay critical state line.展开更多
The problem regarding the reflection of plane waves in a transversely isotropic dissipative medium is considered, in which we are studying about the reflection of incidence waves in initially stressed dissipative half...The problem regarding the reflection of plane waves in a transversely isotropic dissipative medium is considered, in which we are studying about the reflection of incidence waves in initially stressed dissipative half space. After solving the governing equations, we find the two complex quasi-P (qP) and quasi-SV (qSV) waves. The occurrence of reflected waves is studied to calculate the reflection coefficient and the energy partition of incidence wave at the plane boundary of the dissipative medium. Numerical example is considered for the reflection coefficient and the partition of incident energy, in which we study about the effect of rotation, initial stresses and magnetic field.展开更多
In this paper, investigation on the initial fracture behavior was carried out on roving glass woven fabric reinforced composites which were manufactured by hand lay-up method. Two kinds of roving glass woven fabrics o...In this paper, investigation on the initial fracture behavior was carried out on roving glass woven fabric reinforced composites which were manufactured by hand lay-up method. Two kinds of roving glass woven fabrics of different FAW (Fabric Area Weight) and crimp ratio, Type A of 570 g/m2 and Type B of 800 g/m2, were adopted as reinforcement in this study. Tensile test was conducted and tensile properties were discussed on specimens of 6 degrees 0°/5°/10°/80°/85°/90°. The initial fracture behavior was observed on 0 degree and 90 degree and the fracture mechanism was compared and discussed among 5°/10°/80°/85°. The results showed that Type B has higher tensile modulus and tensile strength than that of Type A. And different initial fracture behaviors between two kinds of materials was observed and analyzed, which indicated that the crimp ratio plays an important role of woven fabric reinforced composites in fracture mechanism.展开更多
目的:评估中性粒细胞-淋巴细胞比值(NLR)对初始治疗失败的社区获得性肺炎(CAP)的预测价值,并探讨二代测序技术(NGS)在初始治疗失败的CAP病原体检测中的应用价值。方法:回顾性分析2023年1月~2024年1月188例在吉林省人民医院治疗的CAP患...目的:评估中性粒细胞-淋巴细胞比值(NLR)对初始治疗失败的社区获得性肺炎(CAP)的预测价值,并探讨二代测序技术(NGS)在初始治疗失败的CAP病原体检测中的应用价值。方法:回顾性分析2023年1月~2024年1月188例在吉林省人民医院治疗的CAP患者。根据患者对初始治疗72 h后的反应,将患者分为初始治疗有效组(n=139)和初始治疗失败组(n=49),比较组间血常规、降钙素原(PCT)、NLR水平差异,并根据二分类Logistic回归法筛选出影响CAP患者发生初始治疗失败的危险因素。根据受试者工作特征(ROC)曲线分析NLR对初始治疗失败的CAP的预测价值,并与CURB-65评分进行比较。其中30例初始治疗失败的CAP患者同时行NGS和传统病原学检测,比较两种检测方法在病原体检测结果中的差异。结果:初始治疗失败组NLR、PCT、血白细胞计数(WBC)、中性粒细胞计数(NEU)高于初始治疗有效组,淋巴细胞计数(LYM)低于初始治疗有效组,差异有统计学意义(P<0.05);初始治疗失败组CURB-65评分高于初始治疗有效组,差异有统计学意义(P<0.05)。二分类Logistic回归显示NLR是初始治疗失败的CAP的独立预测因素。ROC曲线分析显示,与经典指标CURB-65评分比较,NLR对初始治疗失败的CAP具有更高的预测价值[曲线下面积(AUC):0.746 vs 0.698,均P>0.05]。本研究中当NLR截断值为6.62时,敏感度为65.3%,特异度为77.7%。与传统检测方法比较,NGS检测病原微生物阳性率更高,差异有统计学意义(66.7%vs 33.3%,P<0.05),微生物检出种类更多(35 vs 14)。结论:NLR是CAP患者发生初始治疗失败的独立危险因素,具有较高的独立预测价值。NGS作为新型病原体检测技术,与传统检测方法相比具有较高的阳性率,为初始治疗失败的CAP提供了更加快速准确的病原体检测技术,不仅提高了患者的治愈率,而且改善患者的远期预后。展开更多
基金Project(2005CB623702)supported by the Major State Basic Research and Development Program of ChinaProject(20476107) supported by the National Natural Science Foundation of China
文摘Fine Al（OH）3 crystals were aggregated from supersaturated aluminate solution in the batch reaction tanks. By means of laser particle size analyzer and scanning electron microscopy, the influences of temperature and initial molar ratio of Na2O to Al2O3 （aK） on agglomeration of fine seed in Bayer process were investigated. The results show that agglomeration is almost finished in 8 h, and seeds with size less than 2 μm are easily aggregated together, and almost disappear in 8 h under the optimal process conditions. In the aluminate solution with the same moderate initial aK, when the reaction temperature reaches 75 ℃, the secondary nucleation does not occur, and the effect of agglomeration is better. And at the same reaction temperature, when the initial aK is 1.62, the initial supersaturation of aluminate solution is moderate, the binders on the surfaces of the seed are enough to maintain the agglomeration process, and the agglomeration degree is better. From SEM images, agglomeration mainly occurs in the fine particles, the combinations among the fine particles are loose and the new formed coarse crystal shapes are irregular.
文摘In this paper, through the indoor free load swelling rate test, expansive soil in a section of a first- class highway reconstruction project in Yichang City was studied. It emphatically analyzed the interrelations among free load swelling rate, non-load time, the proportion of mixed sand and initial dry density. Experimen- tal studies have shown that： Free load swelling deformation is mainly divided into three stages of rapid expan- sion, slow expansion and final stability; when the initial dry density is constant, free load swelling rate of the weathered sand modified soil will reduce rapidly before they slow down with the increase of sand proportion, and weathered sand modified soil free load swelling rate is not sensitive to the large amount of sand mixed; in the same mixed sand ratio, weathered sand modified soil free load swelling rate increases rapidly with the in- crease of initial dry density, there is a good linear correlation between them. To take appropriate control of the initial dry density during the expansive soil subgrade construction helps to reduce its swelling deformation and ensures the stability of the embankment.
文摘A pot experiment was carried out on a marine saline soil to study the effect of initial soluble Na/Ca ratio of saline soil on the salinity tolerance of barley plant.The results showed that (1) the Na/Ca ratio affected significantly the dry weight of the plant at an earlier stage of growth,the critical values of initial Na/Ca ratio at which the plant could grow normally on soils containing salts of 2.5,3.5 and 4.5g kg^-1 were 30,20 and 15,respectively;(2)smaller Na/Ca ratio resulted in a considerable decrease in Na accumulation but a great increase in K accumulation in the barley plant;and (3) the plasmallema of barley leaf were badly injured when the Na/Ca ratio was more than 30 and the increase of Na content of plant caused an exudation of K from the leaf cells.Some critical indexes were suggested for the cultivation of barley plant on marine saline soils and could be used as reference in the biological reclamation of marine saline soils.
文摘Extensive oedometer tests and physical tests have been conducted on remolded and reconstituted marine soils with different initial water contents and liquid limits. The oedometer test data can be well fitted with a straight line in the bilogarithmic ln(1+ e ) ～ lg p plot. The initial effective stress corresponding to the initial void ratio is determined by extrapolation of the bilogarithmic compression line. This new way of extrapolating oedometer test data to the initial void ratio overcomes the difficulty of measuring the residual effective stress of soils in the remolded state. The initial stable compression line of ocean floor deposits under different deposition environments corresponds to the compression line at the sensitivity equal to one. This initial stable compression line obtained in this study is consistent with the available compression line at the sensitivity equal to one which is proposed based on the experimental data of remolded undrained strength and the theoretical concept of Cam clay critical state line.
文摘The problem regarding the reflection of plane waves in a transversely isotropic dissipative medium is considered, in which we are studying about the reflection of incidence waves in initially stressed dissipative half space. After solving the governing equations, we find the two complex quasi-P (qP) and quasi-SV (qSV) waves. The occurrence of reflected waves is studied to calculate the reflection coefficient and the energy partition of incidence wave at the plane boundary of the dissipative medium. Numerical example is considered for the reflection coefficient and the partition of incident energy, in which we study about the effect of rotation, initial stresses and magnetic field.
文摘In this paper, investigation on the initial fracture behavior was carried out on roving glass woven fabric reinforced composites which were manufactured by hand lay-up method. Two kinds of roving glass woven fabrics of different FAW (Fabric Area Weight) and crimp ratio, Type A of 570 g/m2 and Type B of 800 g/m2, were adopted as reinforcement in this study. Tensile test was conducted and tensile properties were discussed on specimens of 6 degrees 0°/5°/10°/80°/85°/90°. The initial fracture behavior was observed on 0 degree and 90 degree and the fracture mechanism was compared and discussed among 5°/10°/80°/85°. The results showed that Type B has higher tensile modulus and tensile strength than that of Type A. And different initial fracture behaviors between two kinds of materials was observed and analyzed, which indicated that the crimp ratio plays an important role of woven fabric reinforced composites in fracture mechanism.
文摘目的:评估中性粒细胞-淋巴细胞比值(NLR)对初始治疗失败的社区获得性肺炎(CAP)的预测价值,并探讨二代测序技术(NGS)在初始治疗失败的CAP病原体检测中的应用价值。方法:回顾性分析2023年1月~2024年1月188例在吉林省人民医院治疗的CAP患者。根据患者对初始治疗72 h后的反应,将患者分为初始治疗有效组(n=139)和初始治疗失败组(n=49),比较组间血常规、降钙素原(PCT)、NLR水平差异,并根据二分类Logistic回归法筛选出影响CAP患者发生初始治疗失败的危险因素。根据受试者工作特征(ROC)曲线分析NLR对初始治疗失败的CAP的预测价值,并与CURB-65评分进行比较。其中30例初始治疗失败的CAP患者同时行NGS和传统病原学检测,比较两种检测方法在病原体检测结果中的差异。结果:初始治疗失败组NLR、PCT、血白细胞计数(WBC)、中性粒细胞计数(NEU)高于初始治疗有效组,淋巴细胞计数(LYM)低于初始治疗有效组,差异有统计学意义(P<0.05);初始治疗失败组CURB-65评分高于初始治疗有效组,差异有统计学意义(P<0.05)。二分类Logistic回归显示NLR是初始治疗失败的CAP的独立预测因素。ROC曲线分析显示,与经典指标CURB-65评分比较,NLR对初始治疗失败的CAP具有更高的预测价值[曲线下面积(AUC):0.746 vs 0.698,均P>0.05]。本研究中当NLR截断值为6.62时,敏感度为65.3%,特异度为77.7%。与传统检测方法比较,NGS检测病原微生物阳性率更高,差异有统计学意义(66.7%vs 33.3%,P<0.05),微生物检出种类更多(35 vs 14)。结论:NLR是CAP患者发生初始治疗失败的独立危险因素,具有较高的独立预测价值。NGS作为新型病原体检测技术,与传统检测方法相比具有较高的阳性率,为初始治疗失败的CAP提供了更加快速准确的病原体检测技术,不仅提高了患者的治愈率,而且改善患者的远期预后。
