Research on Determination of the Main Factors Influencing the Gas Well Post-frac Productivity Prediction for Tight Sandstone Reservoirs

Tight sandstone reservoirs are always with the characteristics of such as low porosity, low permeability, low gas saturation, and o almost with no natural capacity. Therefore, they have to be fractured for productivity, and the prediction of capability is necessary. But there are so many factors, and the relations between the factors and the post-frac […]

Synthesis and Characterization of Calcium Acetylacetonate and its Application in Thermal Stabilizer

The calcium acetylacetonate was successfully synthesized using organic solvent as a dispersion medium, acetyl acetone and calcium hydroxide as raw material. The composites consisting of calcium acetylaeetonate and other kinds of heat stability were prepared with specific ration, and the effect of calcium acetylacetonate on thermal stability of PVC was investigated by static aging test, […]

Transformation of Scraper Slag Salvaging Machine without Overflow for 1 000 MW Units

Due to long-time operation of slag water circulating system of 1 000 MW boiler units , high-effi-ciency thickener, collecting basin and pit pump are blocked by deposited slag, which has great impact on water supply for cooling of slag salvaging machine. On the basis of investigation and system test , the slag salvaging machine is […]

Evolution of Phase Constitution and Mechanical Properties of Ti-30Nb-1Mo-4Sn Alloy Subjected to Thermo-mechanical Treatment

The evolution of phase constitution and mechanical properties of a low-modulus metastable β-type Ti-30Nb-1Mo-4Sn(wt%) titanium alloy subjected to thermo-mechanical treatment,is systematically investigated using X-ray diffraction apparatus (XRD),transmission electron microscopy (TEM) and mechanical testing.The results indicate that the solution-treated alloy exhibits low structural stability and undergoes stress-induced martensitic transformation,leading to a quite low yield stress.Even though […]

A Brief Analysis on Dialect Pronunciation of the Kinship Terms between Qinxian and Taiyuan

Qinxian dialect belongs to Shangdang dialect, Jin group. Taiyuan dialect belongs to Bingzhou dialect, Jin group. There are many similarities and differences on dialect pronunciation between Qinxian and Taiyuan. The kinship terms of Jin group are abundant and systematic and it is better to understand Jin group by analyzing the dialect pronunciation from the view […]

Research and design about integrated kiln for waste heat recovery of fused magnesia lump

Carrying out research on waste energy recovery technologies about magnesium melting lumps is important significance for innovation of magnesite melting process and achieving energy con-servation and emissions reduction in new situation.Based on analyzing and summarizing the existing technology about waste heat recovery of magnesium melt, the integrated kiln for waste heat recovery of magnesium melting […]

Cascade Observer Based Robust Fault Tolerant Control for VTOL Aircraft

A cascade observer-based robust fault tolerant control method is proposed for the nonlinear non-minimum phase vertical take-off and landing (VTOL) aircraft model, with a guarantee that the system outputs asymp- totically track desired trajectory. To begin with, two reduced-order cascade observers are designed to estimate unknown fault and disturbance information, respectively. Using the coordinate transformation […]

Study on Cold-state Rod Drop of the HTR CRDM

The control rod drive mechanism (CRDM) of high-temperature gas-cooled reactor pebble-bed module (HTR) is most important nuclear safety equipment, and serves as the first reactivity control and shutdown system. The CRDM provides a fail- safe operational mode. Once the electrical supply was cut off, the control rods would drop into their channels by gravity. In […]

Mineral Sources of Lead Aggregate about Early Qin Bronze Wares

The bronze wares in early Qin period constituted very important elements of early Qin culture. No relics of ancient copper ore and lead ore have been discovered in early Qin people's living areas, so the sources of lead of mineral aggregate about early Qin bronze wares are still undis- covered. This paper researches the sources […]