Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is...Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is analyzed at communication wavelengths so that the basic operation parameters can decide properly for efficient detection of single photon. The bias voltage has related to the punch-through voltage in combining the cooling technique with synchronization to decrease the dark counts.展开更多
Since 1960s the seatrade markets and the international ocean transport industry have undergone substantial changes. Freight origins and destinations shifted much more rapidly than in the past, and the types of cargo a...Since 1960s the seatrade markets and the international ocean transport industry have undergone substantial changes. Freight origins and destinations shifted much more rapidly than in the past, and the types of cargo and their forms of packaging kept changing. These trends became more and more pronounced since the beginning of the 1980s. This article descrihes the conditions of seatrade market and ocean transport industry, and analysts the reasons and effectiveness of the chaneges, well as the trend of seatrade market. 1 Development in the international seatrade markets In 1960 the annual volume of international seatrade had reached a level of one billion tons, with equal shares of dry cargo and liquid cargo.展开更多
This paper is concerned with the waves generated by a 3 D body advancing beneath the free surface with constant speed in a two layer fluid of finite depth. By applying Green’s theorem, a layered integral equation s...This paper is concerned with the waves generated by a 3 D body advancing beneath the free surface with constant speed in a two layer fluid of finite depth. By applying Green’s theorem, a layered integral equation system based on the Rankine source for the perturbed velocity potential generated by the moving body was derived with the potential flow theory. A four node isoparametric element method was used to treat with the solution of the layered integral equation system. The surface and interface waves generated by a moving ball were calculated numerically. The results were compared with the analytical results for a moving source with constant velocity.展开更多
Polymer solutions have very important applica-tions in the enhanced oil recovery due to their unique viscoe-lastic properties increasing microscale displacement effi-ciency. In this paper, the viscoelastic properties ...Polymer solutions have very important applica-tions in the enhanced oil recovery due to their unique viscoe-lastic properties increasing microscale displacement effi-ciency. In this paper, the viscoelastic properties of partially hydrolyzed polyacrylamide (HPAM) solution have been in-vestigated. Results show that the viscoelastic properties of HPAM increase with HPAM concentration increasing, and decrease with the increase of sodium dodecyl sulfate (SDS). Meanwhile, adding NaCl can destroy the viscoelastic proper-ties.展开更多
基金National"973"Project(G2001039302) Key S & T Project of Guangdong Province(2003A103405) Key S&T Project of Guangzhou City(1992-2-035-01)
文摘Based on the commercially available avalanche photodiodes, the basic needs of gated-mode operation for single photon are discussed. Gated-mode technique based on the experimental data for detection of single photon is analyzed at communication wavelengths so that the basic operation parameters can decide properly for efficient detection of single photon. The bias voltage has related to the punch-through voltage in combining the cooling technique with synchronization to decrease the dark counts.
文摘Since 1960s the seatrade markets and the international ocean transport industry have undergone substantial changes. Freight origins and destinations shifted much more rapidly than in the past, and the types of cargo and their forms of packaging kept changing. These trends became more and more pronounced since the beginning of the 1980s. This article descrihes the conditions of seatrade market and ocean transport industry, and analysts the reasons and effectiveness of the chaneges, well as the trend of seatrade market. 1 Development in the international seatrade markets In 1960 the annual volume of international seatrade had reached a level of one billion tons, with equal shares of dry cargo and liquid cargo.
基金Project supported by the Excellent Doctorial paper Foundation of China (Grant No: 200146) and the National Natural Science Foundation of China(Grant No: 10172059).
文摘This paper is concerned with the waves generated by a 3 D body advancing beneath the free surface with constant speed in a two layer fluid of finite depth. By applying Green’s theorem, a layered integral equation system based on the Rankine source for the perturbed velocity potential generated by the moving body was derived with the potential flow theory. A four node isoparametric element method was used to treat with the solution of the layered integral equation system. The surface and interface waves generated by a moving ball were calculated numerically. The results were compared with the analytical results for a moving source with constant velocity.
文摘Polymer solutions have very important applica-tions in the enhanced oil recovery due to their unique viscoe-lastic properties increasing microscale displacement effi-ciency. In this paper, the viscoelastic properties of partially hydrolyzed polyacrylamide (HPAM) solution have been in-vestigated. Results show that the viscoelastic properties of HPAM increase with HPAM concentration increasing, and decrease with the increase of sodium dodecyl sulfate (SDS). Meanwhile, adding NaCl can destroy the viscoelastic proper-ties.
