利用slug试验测量渗透系数在国内外已有了比较成熟的发展,但是专门应用于潜水井裸井的slug数学模型却极少出现在各类文献中。通过注水高度对潜水含水层厚度的影响推导对潜水含水层完整井的slug数学模型,此模型与传统的Bouwer and Rice...利用slug试验测量渗透系数在国内外已有了比较成熟的发展,但是专门应用于潜水井裸井的slug数学模型却极少出现在各类文献中。通过注水高度对潜水含水层厚度的影响推导对潜水含水层完整井的slug数学模型,此模型与传统的Bouwer and Rice模型相比考虑了注水后潜水面水位的增加对渗透系数K的影响,并结合室内变水头渗透试验和前期抽水试验来验证在工程实例运用此模型算出的渗透系数的准确性。展开更多
目的筛选得到适于液态摇瓶发酵的杏鲍菇菌株,并优化其最佳培养条件。方法采用单因素方法筛选发酵最佳培养基成分及发酵条件、采用正交试验优化最佳培养基配方、利用Box-Behnken中心组合试验,对发酵过程中影响杏鲍菇菌丝生长的三个关键因...目的筛选得到适于液态摇瓶发酵的杏鲍菇菌株,并优化其最佳培养条件。方法采用单因素方法筛选发酵最佳培养基成分及发酵条件、采用正交试验优化最佳培养基配方、利用Box-Behnken中心组合试验,对发酵过程中影响杏鲍菇菌丝生长的三个关键因素(温度、转速和发酵周期)进行优化,最后用响应面分析方法对试验数据进行分析。结果优化后的发酵培养基组分为:葡萄糖3.50 g/100 m L,胰蛋白胨0.50 g/100 m L,磷酸二氢钾0.30 g/100 m L,硫酸镁0.20 g/100 m L,p H自然。当发酵温度为25℃,摇床转速170 r/min,发酵周期7.5d(180 h)时,杏鲍菇菌丝体生物量(干重)达1.687 g/100 m L。结论采用单因素、正交、响应面等试验方法筛选得到了菌株的最佳摇瓶发酵培养条件。展开更多
At jet pressures ranging from 80 to 120 MPa, submerged water jets are investigated by numerical simulation and experiment. Numerical simulation enables a systematic analysis of major flow parameters such as jet veloci...At jet pressures ranging from 80 to 120 MPa, submerged water jets are investigated by numerical simulation and experiment. Numerical simulation enables a systematic analysis of major flow parameters such as jet velocity, turbulent kinetic energy as well as void fraction of cavitation. Experiments facilitate an objective assessment of surface morphology, micro hardness and surface roughness of the impinged samples. A comparison is implemented between submerged and non-submerged water jets. The results show that submerged water jet is characterized by low velocity magnitudes relative to non-submerged water jet at the same jet pressure. Shear effect serves as a key factor underlying the inception of cavitation in submerged water jet stream. Predicted annular shape of cavity zone is substantiated by local height distributions associated with experimentally obtained footprints. As jet pressure increases, joint contribution of jet kinetic energy and cavitation is demonstrated. While for non-submerged water jet, impingement force stems exclusively from flow velocity.展开更多
As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model exper...As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model experiment of submerged floating tunnel （SFT） under the earthquake was carried out on the unique underwater shaking table in China. The experimental results show that vertical excitation induces larger response than horizontal and different inclination degrees of the tether also cause different seismic responses. Subsequently, based on the fluid-structure interaction theory, the corresponding numerical model is established. And comparing the numerical results with the experimental results, those of shaking table test. Numerical model adopted is effective for it is shown that the numerical results are basically identical with dynamic response of SFT.展开更多
文摘利用slug试验测量渗透系数在国内外已有了比较成熟的发展,但是专门应用于潜水井裸井的slug数学模型却极少出现在各类文献中。通过注水高度对潜水含水层厚度的影响推导对潜水含水层完整井的slug数学模型,此模型与传统的Bouwer and Rice模型相比考虑了注水后潜水面水位的增加对渗透系数K的影响,并结合室内变水头渗透试验和前期抽水试验来验证在工程实例运用此模型算出的渗透系数的准确性。
文摘目的筛选得到适于液态摇瓶发酵的杏鲍菇菌株,并优化其最佳培养条件。方法采用单因素方法筛选发酵最佳培养基成分及发酵条件、采用正交试验优化最佳培养基配方、利用Box-Behnken中心组合试验,对发酵过程中影响杏鲍菇菌丝生长的三个关键因素(温度、转速和发酵周期)进行优化,最后用响应面分析方法对试验数据进行分析。结果优化后的发酵培养基组分为:葡萄糖3.50 g/100 m L,胰蛋白胨0.50 g/100 m L,磷酸二氢钾0.30 g/100 m L,硫酸镁0.20 g/100 m L,p H自然。当发酵温度为25℃,摇床转速170 r/min,发酵周期7.5d(180 h)时,杏鲍菇菌丝体生物量(干重)达1.687 g/100 m L。结论采用单因素、正交、响应面等试验方法筛选得到了菌株的最佳摇瓶发酵培养条件。
基金Projects(51205171,51376081)supported by the National Natural Science Foundation of ChinaProject(1201026B)supported by the Postdoctoral Science Foundation of Jiangsu Province,China
文摘At jet pressures ranging from 80 to 120 MPa, submerged water jets are investigated by numerical simulation and experiment. Numerical simulation enables a systematic analysis of major flow parameters such as jet velocity, turbulent kinetic energy as well as void fraction of cavitation. Experiments facilitate an objective assessment of surface morphology, micro hardness and surface roughness of the impinged samples. A comparison is implemented between submerged and non-submerged water jets. The results show that submerged water jet is characterized by low velocity magnitudes relative to non-submerged water jet at the same jet pressure. Shear effect serves as a key factor underlying the inception of cavitation in submerged water jet stream. Predicted annular shape of cavity zone is substantiated by local height distributions associated with experimentally obtained footprints. As jet pressure increases, joint contribution of jet kinetic energy and cavitation is demonstrated. While for non-submerged water jet, impingement force stems exclusively from flow velocity.
基金Projects(51108224,51179026) supported by the National Natural Science Foundation of China
文摘As a new type of structure which has never been built, submerged floating tunnel was studied mainly by numerical simulations. To further study the seismic response of a submerged floating tunnel, the first model experiment of submerged floating tunnel （SFT） under the earthquake was carried out on the unique underwater shaking table in China. The experimental results show that vertical excitation induces larger response than horizontal and different inclination degrees of the tether also cause different seismic responses. Subsequently, based on the fluid-structure interaction theory, the corresponding numerical model is established. And comparing the numerical results with the experimental results, those of shaking table test. Numerical model adopted is effective for it is shown that the numerical results are basically identical with dynamic response of SFT.
