The Water-Bearing Numerical Model and Its Operational Forecasting Experiments PartII: The Operational Forecasting Experiments

おhe water-bearing numerical model is undergone all round examinations during the operational forecasting experiments from 1994 to 1996. A lot of difficult problems arising from the model′s water-bearing are successfully resolved in these experiments through developing and using a series of technical measures. The operational forecasting running of the water-bearing numerical model is realized stably and reliably, and satisfactory forecasts are obtained.

Effect of Wave Accessibility on Lower Hybrid Wave Current Drive in Experimental Advanced Superconductor Tokamak with H-Mode Operation

The effect of the wave accessibility condition on the lower hybrid cm＇rent drive in the experimental advanced superconductor Tokamak （EAST） plasma with H-mode operation is studied. Based on a simplified model, a mode conversion layer of the lower hybrid wave between the fast wave branch and the slow wave branch is proved to exist in the plasma periphery for typical EAST H-mode parameters. Under the framework of the lower hybrid wave simulation code （LSC）, the wave ray trajectory and the associated current drive are calculated numerically. The results show that the wave accessibility condition plays an important role on the lower hybrid current drive in EAST plasma. For wave rays with parallel refractive index n｜｜= 2.1 or n｜｜ = 2.5 launched from the outside midplane, the wave rays may penetrate the core plasma due to the toroida] geometry effect, while numerous reflections of the wave ray trajectories in the plasma periphery occur. However, low current drive efficiency is obtained. Meanwhile, the wave accessibility condition is improved if a higher confined magnetic field is applied. The simulation results show that for plasma parameters under present EAST H-mode operation, a significant lower hybrid wave current drive could be obtained for the wave spectrum with peak value n｜｜ = 2.1 if a toroidal magnetic field BT =2.5 T is applied.

Effects of hydraulic retention time, temperature, and effluent recycling on efficiency of anaerobic filter in treating rural domestic wastewater

With rural population expansion and improvement of the socio-economic standard of living, treatment of rural domestic wastewater has rapidly become a major aspect of environmental concern. Selection of a suitable method for treatment of rural domestic wastewater depends on its efficiency, simplicity, and cost-effectiveness. This study investigated the effects of hydraulic retention time （HRT）, temperature, and effluent recycling on the treatment efficiency of an anaerobic filter （AF） reactor. The first round of experimental operations was run for three months with HRTs of one, two, and three days, temperatures of 18℃, 21℃, and 24℃, and no effluent recycling. The second round of experimental operations was conducted for another three months with HRTs of three and four days; temperatures of 30.67℃, 30.57℃, and 26.91 ℃ ; and three effluent recycling ratios of 1：1, 1：2, and 2：1. The first round of operations showed removal rates of 32% to 44% for COD, 30% to 35% for TN, 32% to 36% for NH4-N, 19% to 23% for NO3-N, and 12% to 22% for TE In the second round of operations, the removal rates varied from 75% to 81% for COD, 35% to 41% for TN, 31% to 39% for NH4-N, 30% to 34% for NO3-N, and 41% to 48% for TP. The average gas production rates were 6.72 L/d and 7.26 L/d for the first and second rounds of operations, respectively. The gas production rate increased in the second round of operations as a result of applied effluent recycling. The best removal efficiency was obtained for an optimum HRT of three days, a temperature of 30℃, and an effluent recycling ratio of 2：1. The results show that the removal efficiency of the AF reactor was affected by HRT, temperature, and effluent recycling.

Transcranial surgery through pterional approach for removal of cranio-orbital tumors by an interdisciplinary team of nurosurgeons and ophthalmologists

AIM: To investigate the specialty of transcranial surgery through pterional approach for removal of cranio-orbital tumors, introduce the ophthalmological experiences of entering the orbit to reduce the incidence rate of associated complications of this operation. METHODS: We performed a retrospective analysis of a series of 37 cases involving patients who underwent transcranial surgery through pterional approach for treatment of cranio-orbital tumors in our department in the past 8 years. Pterion approach craniotomy was performed to all patients. After removing tumors in the skull by the neurosurgeon, ophthalmologist removed tumors in orbit. We took measures below to decrease complications, including grounding optic canal through an abrasive drilling when necessary, hanging various extraocular muscles to be exposed for protection, refrigerating by refrigeration heads to remove tumors, at last sewing up orbit septum after surgery. RESULTS: Tumors were removed completely in 32 cases, and incomplete in 5 cases due to extensive invasion into the cavernous sinus or sphenoid sinus. Of all the cases, benign tumors were demonstrated in 28 cases (75.6%, 28/37) and malignant in 9 (24.3%, 9/37). The most common lesion type was meningioma in 11 cases (29.7%, 11/37). Extraocular muscles (EOM) impairment, occurring in 21 cases (56.7%, 21/37), was the most frequent postoperative complication. The most serious consequence was vision loss occurred in 4 cases (10.8%, 4/37). Other complications, such as 11 cases of transient blepharoptosis 29.7% (11/37), 5 cases of mydriasis in 13.5% (5/7); 2 cases of cerebrospinal rhinorrhea in 5.4% (2/37). CONCLUSION: Cranio-orbital tumors can be removed completely using transcranial approach, and the pterional approach offers excellent exposure. Cooperation of interdisciplinary team of neurosurgeons and ophthalmologists conduces to full use of respective professional advantages. The experience of ophthalmic operation technology can decrease occurrence of ocular complications after surgery.

High-temperature characteristics of SiC module and 100 kW SiC AC–DC converter at a junction temperature of 180 ℃

High-temperature,high-power converters have gained importance in industrial applications given their ability to operate in adverse environments,such as in petroleum exploration,multi-electric aircrafts,and electric vehicles.SiC metaloxide-semiconductor field-effect transistor(MOSFET),a new,wide bandgap,high-temperature device,is the key component of these converters.In this study,the static and dynamic characteristics of the SiC MOSFET,half-bridge module,are investigated at the junction temperature of 180℃.A simplified experimental method is then proposed pertaining to the power operation of the SiC module at 180℃.This method is based on the use of a thermal resistance test platform and is proven convenient for the study of heat dissipation characteristics.The high-temperature characteristics of the module are verified based on the conducted experiments.Accordingly,a 100 kW high-temperature converter is built,and the test results show that the SiC converter can operate at a junction temperature of 180℃in a stable manner in compliance with the requirements of high-temperature,high-power applications.

Simulation Operating System and Integrated Simulation Software

In this paper, a new concept of simulation operating system (SIMOS) is described. A detailed definition of SIMOS is given, and two integrated simulation software (IPSOS and IMSS) are introduced based on SIMOS.

Safe operation of inverted siphon during ice period

Sixteen inverted siphons are in operation at the Beijing-Shijiazhuang section in the Middle Route of the South-to-North Water Diversion Project. Their safe operation is closely related to the safety and the water diversion efficiency of the whole project during an ice period. The ice accumulation process at the inlet of the inverted siphon is modeled under a real ice condition, and then the hydraulic conditions of the ice jam prevention are confirmed. According to the experimental results and the design sizes of the inverted siphons, the detailed safe water diversion discharge and the operational water level are studied. Analysis results of these inverted siphons provide references for the safe operation and the reasonable regulations during the ice period.