配水系统中水压供水量模型的一种确定方法

通过对给水系统中节点水压与水源供水量之间内在关系的分析，建立了一种新的数学模型，给出了节点水压与各水厂供水量间的显示表达式．该方法具有实测数据少，建模快的特点．经实践验证，该方法能较好地与实际相吻合，可直接用于给水系统的实际调度中．

中低压水压控制元件的研制

从设计难点、结构以及用材等方面介绍了笔者研制出的几种中低压水压控制元件 ,包括水压节流阀。

深孔水压爆破技术的探讨

结合国内深孔水压爆破的发展现状,较为系统地总结了目前对深孔水压爆破综合技术的研究状况,并对各种研究现状进行了阐述和评析,提出了目前国内深孔水压爆破需要解决的问题,并展望今后中深孔水压爆破的发展方向。

HPR1000： Advanced Pressurized Water Reactor with Active and Passive Safety

HPR1000 is an advanced nuclear power plant(NPP)with the significant feature of an active and passive safety design philosophy,developed by the China National Nuclear Corporation.On one hand,it is an evolutionary design based on proven technology of the existing pressurized water reactor NPP;on the other hand,it incorporates advanced design features including a 177-fuel-assembly core loaded with CF3 fuel assemblies,active and passive safety systems,comprehensive severe accident prevention and mitigation measures,enhanced protection against external events,and improved emergency response capability.Extensive verification experiments and tests have been performed for critical innovative improvements on passive systems,the reactor core,and the main equipment.The design of HPR1000fulfills the international utility requirements for advanced light water reactors and the latest nuclear safety requirements,and addresses the safety issues relevant to the Fukushima accident.Along with its outstanding safety and economy,HPR1000 provides an excellent and practicable solution for both domestic and international nuclear power markets.

Medium-Pressure Hydro-upgrading (MHUG) Technology for Producing Clean Diesel Fuel

Abstract： This article introduces the development and application of the medium-pressure hydro-upgrading （MHUG） tech- nology developed by the Research Institute of Petroleum Processing （RIPP）. The MHUG technology based on the chemistry of diesel hydro-upgrading reactions has the advantages of flexible product slate and excellent product quality that can in- crease the cetane rating of diesel fuel up to more than 15 units. The hydrotreating and hydro-upgrading catalysts associated with the MHUG technology have outstanding performance to meet the demand of MHUG technology for hydro-saturation and selective ring-opening of aromatic rings. New MHUG process flow scheme can further increase the yield and selectivity of target products. Commercial application of multiple MHUG units has revealed that the MHUG technology designated for clean diesel production features good feedstock adaptability and operating stability.

Analysis of the Medium Resistance for Constant Pressure Filtration

A mathematical model for constant pressure filtration is established. The distribution of hydraulic pressure within the cake and the medium resistance are measured. The medium resistance Rm is calculated from the suppositional filtration time θm. It is demonstrated that Rm is nearly a constant for a given filter cloth.

Strata behavior investigation for high-intensity mining in the water-rich coal seam

This paper describes a specific case of mining in a water-rich coal seam in western China. Water inrushes,roof caving and other disasters induced by intensive mining operation could pose great threats to the safety of coal mines. The strata behavior during the high-intensity extraction in the water-rich coal seam is analyzed by employing the numerical simulation method and in situ monitoring. The results show that about 10 m ahead of the workface, the front abutment pressure peaks is at 34.13 MPa, while the peak of the side abutment pressure is located about 8 m away from the gateway with the value of 12.41 MPa; the height of the fracture zone, the first weighting step and the cycle weighting step are calculated to be 45,50 and 20.8 m, respectively; pressure distribution in the workface is characterized by that the vertical pressure in the center occurs earlier and is stronger than those on both ends. Then, the results above are verified by in situ measurement, which may provide a basis for safe mining under similar conditions.

Effects of Heat Softening on Initiation of Landslides

Effects of heat softening on the initiation of slide surface(shear banding) in clayey slopes during fast deformation were discussed.Controlling equations considering heat,pore pressure and mechanical movement were presented.By perturbation method,the instability condition of localized zone(i.e.criterion for initiation of shear banding) for thermal related soils,such as clayey slope,was obtained.It is shown that slide surface initiates once the thermal-softening effects overcome the strain-hardening effects whether it is adiabatic or not.Without strain hardening effects,strain rate hardening obviously plays a role in initiation of shear band.During initiating process,heat is trapped inside the shear band,which leads rapidly to a pore pressure increase and fast loss of strength.The localized shear strain is concentrated in a narrow zone with a width of several centimeters at most and increases fast.This zone forms the sliding surface.Temperature can increase more than 2?C,pore pressure can increase 160% in about 0.1s inside this zone.These changes cause the fast decrease in friction-coefficient by about 36% over the initial value.That is how shear band initiated and developed in clayey slopes.

Focused fluid flow in the Baiyun Sag, northern South China Sea: implications for the source of gas in hydrate reservoirs

The origin and migration of natural gas and the accumulation of gas hydrates within the Pearl River Mouth Basin of the northern South China Sea are poorly understood. Based on high-resolution 2D/3D seismic data, three environments of focused fluid flow： gas chimneys, mud diapirs and active faults have been identified. Widespread gas chimneys that act as important conduits for fluid flow are located below bottom simulating reflections and above basal uplifts. The occurrence and evolution of gas chimneys can be divided into a violent eruptive stage and a quiet seepage stage. For most gas chimneys, the strong eruptions are deduced to have happened during the Dongsha Movement in the latest Miocene, which are observed below Pliocene strata and few active faults develop above the top of the Miocene. The formation pressures of the Baiyun Sag currently are considered to be normal, based on these terms： 1） Borehole pressure tests with pressure coefficients of 1.043-l.047; 2） The distribution of gas chimneys is limited to strata older than the Pliocene; 3） Disseminated methane hydrates, rather than fractured hydrates, are found in the hydrate samples; 4） The gas hydrate is mainly charged with biogenic gas rather than thermogenic gas based on the chemical tests from gas hydrates cores. However, periods of quiet focused fluid flow also enable the establishment of good conduits for the migration of abundant biogenic gas and lesser volumes ofthermogenic gas. A geological model goveming fluid flow has been proposed to interpret the release of overpressure, the migration of fluids and the formation of gas hydrates, in an integrated manner. This model suggests that gas chimneys positioned above basal uplifts were caused by the Dongsha Movement at about 5.5 Ma. Biogenic gas occupies the strata above the base of the middle Miocene and migrates slowly into the gas chimney columns. Some of the biogenic gas and small volumes ofthermogenic gas eventually contribute to the formation of the gas hydrates.

Equilibrating Pressure with Auto-Control Valve in Water Distribution Networks

This paper probes into the feasibility of equilibrating pressure of water distribution network through (using auto-control valves) in theory and in the economy. An optimal valve control model is designed to minimize the sum of squares of residual pressure in the network. Such an analog simulation has been performed on the year 2003 programming network of a certain littoral district in North China, through which this paper confirms that it is feasible to equilibrate pressure with auto-control valves in theory. The research work has brought about a discovery of applicable conditions of valves in economic feasibility, which avoids a great economic loss due to the wild use of auto-control valve. In addition, simulated annealing algorithm is applied to optimize valve settings and shown to identify global optimum or near-optimum.

Hydrochemistry of the Natural Low p H Groundwater in the Coastal Aquifers near Beihai, China

Natural weak acidic groundwater occurs in the unconfined and confined aquifers consisting of Quaternary and Neogene unconsolidated sediments near Beihai in southern Guangxi, China. Under natural conditions the groundwater has low TDS(less than 200 mg L-1) and low concentrations of trace elements(less than 100 μg L-1) with a deceasing tend in contents of the Lanthanides(rare earth elements, less than 1 μg L-1) towards higher atomic number. The groundwater ranges in p H from 3.33 to 7.0 with an average value of 5.12(even lower than that of local rainwater, 5.88). p H values in the groundwater are a bit higher in rainy seasons than those in dry seasons and do not show significant increasing or decreasing trend with time. The average p H value in groundwater in the confined aquifers is even a bit lower than that in the unconfined aquifer. Comprehensive analyses of the groundwater environment suggest that H+ in the groundwater may be derived from dissociation of H2CO3, release of the absorbed H3O+ in clay layers and the acidity of rainwater. The H2CO3 in the groundwater may be formed by dissolution of CO2(g). Minerals in the unconsolidated sediment are predominated by quartz with small amount of clay minerals. The sediments undergoing a long-term weathering contain low levels of soluble constitutes. Lack of alkaline substances in the groundwater system is also helpful in the accumulation of acidity of the groundwater.

Inversion of the Volumetric Strain of Aquifer According to the Tidal Effect of Groundwater in North China

The change of the confined aquifer level reflects the pore pressure change,and the pore pressure change of the aquifer is closely related to the aquifer pressure. This paper uses the tidal response of the well water level data in the North China region to calculate the tidal factor of each well and extract the effective water trend information. Then,the volumetric strain of an existing confined aquifer well in the North China region is inverted,and the contour maps are plotted on a half-year scale from 2009 to 2012. Results show that it can reflect the state of stress and strain in deep crust to a certain extent in the North China region.

Relationship between the Earth tidal factor and phase lag of groundwater levels in confined aquifers and the Wenchuan M_s8.0 earthquake of 2008

This work focuses on variations of the Earth tidal factor and phase lag derived from groundwater observations before and after major earthquakes.It is based on an analysis of the data from four observational wells at boundaries between distinct active blocks of China mainland.These wells are also situated on several active fault zones and have exhibited considerable responses to the Wenchuan Ms8.0 earthquake of 2008 in China.We collected hourly records of water levels of these wells from 2007to 2009 and processed these data for analysis.The tidal factors,phase lags,and phase-difference changes of tidal residuals of each well were calculated.We found that when the Wenchuan quake happened,the tidal factors of the 4 wells were changing rapidly,while their phase lags and phase differences of tidal residuals declined swiftly,which may reflect the stress and strain changes of the well-aquifer system during the seismic generation.