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The high-grade magnetite ores related to banded iron formations (BIFs) in the Anshan-Benxi area, Liaoning Province in China, have been widely interpreted as the product of replacement of protore by epigenetic hydrothermal fluids. The high-grade iron ore reserves in the mining area II (164 million tons) in the Gongchangling (G2) and Qidashan-Wangjiabuzi (QW) iron deposits (11.45 million tons) are the largest deposits in the Anshan-Benxi area. We present a detailed comparison of the geology, geochemical and stable isotopic compositions of the iron ores in the G2 with those in the QW to constrain the role of desilicification and iron activation–reprecipitation in converting the BIFs to high-grade magnetite ores. These two deposits show marked difference in wall-rock alteration, geochemical features, and oxygen and sulfur isotopic compositions. Wall-rock alteration in the G2 is characterized by garnetization, actinolitization, and chloritization, whereas the QW shows chloritization, biotitization and sericitization. The geochemistry of altered rocks in the G2 is characterized by slight REE fractionation, positive Eu and no significant Ce anomalies, whereas the QW is characterized by high ΣREE contents, strong REE fractionation, and the absence of significant Eu and Ce anomalies. High-grade iron ores in the G2 show similar δ 18 O V-SMOW values for magnetite, lower δ 18 O V-SMOW values for quartz and higher δ 34 S V-CDT values for pyrite when compared to the BIFs, whereas the QW shows lower δ 18 O V-SMOW values for magnetite, similar δ 18 O V-SMOW values for quartz and similar δ 34 S V-CDT values for pyrite. These features indicate that desilicification process by hypogene alkaline-rich hydrothermal fluids were possibly responsible for the formation of high-grade iron ores in the G2 whereas iron activation–reprecipitation process by migmatitic-hydrothermal fluids generated the high-grade iron orebodies in QW.

The Damiao type iron deposit is hosted in a typical Proterozoic anorthosite complex in the northern North China Craton. The types of ores in Damiao mainly comprise massive Fe ores, massive Fe–P ores, and disseminated Fe and Fe–P ores. The disseminated Fe and Fe–P ores formed by fractional crystallization are generally hosted in oxide-apatite gabbronorite and account for 70% of the proven reserve of the Damiao type iron ore. The massive Fe and Fe–P ores account for 30% of the proven reserve of the Damiao type deposit iron ore and generally occur as irregular dykes or veins filling vertical fractures of the previously consolidated anorthosite, showing typical features of hydrothermal mineralization. The contact between the massive orebodies and wall rocks is sharp and straight. The anorthosite comprises white and dark varieties, with the former resulted by the alteration of the latter that occurs as relicts. Petrographic observation and electron microprobe analyses show abundant Fe–Ti oxide inclusions in plagioclase which impart the dark color to the rock. The similar spider diagram patterns between fresh and altered plagioclase and between dark- and white-colored anorthosite imply a genetic relationship between the dark and white types. During the alteration of anorthosite, CaO and MgO were slightly decreased, the SiO2, Al2O3 and Na2O were significantly increased, and the TFe2O3 and TiO2 were significantly decreased. The TFe2O3 and TiO2 in the dark-colored anorthosite have a range of 4.86–12.18 wt.% and 0.37–1.65 wt.%, respectively. However, The TFe2O3 and TiO2 in the white-colored anorthosite have a range of 1.67–3.1 wt.% and 0.14–0.31 wt.%, respectively. These features suggest that the alteration of the anorthosite led the Fe element by leaching from the dark-colored anorthosite at highly oxidized condition, and then precipitated within the fractures of the anorthosite, thus forming the massive Fe and Fe–P orebodies. Because the estimated amount of transported Fe is much more abundant than the proven ore reserve, we infer that there should be huge potential for prospecting Damiao type iron ores.

With the deepening of the oilfield development, oil field has entered the high water cut period. The rate of water cut increasing and production decline are accelerate. It is needed to adjust the way of exploitation in order to improve oilfield exploitation effect. Cyclic water flooding is one of effective means to improve oilfield development effect with the advantages of small investment, quick effect, reduce inefficient output and improve oilfield overall development benefit. In this paper, we use the means of numerical simulation to study the injection timing and reasonable working systems of different types of Wells. Technical basis is provided for further study and field test.

The development direction of transformer monitoring and diagnosis is remote and intelligent. But the existing systems have the following problems: lack of diagnostic knowledge and methods, poor flexibility etc. To solve these problems, the architecture of a remote monitoring and diagnostic system for transformers based on multi-agent techniques is presented. On the basis of ultra high frequency (UHF) partial discharge (PD), core earth current and dissolved gas analysis (DGA), the hierarchical decomposition model is established. The tasks, functions and structure involved in the collaboration agents are defined. Then, the fusion strategy from multi-experts conclusions is proposed based on diagnostic confidence and weights. In final, the system implementation is described. Some functions of the system have been put into service and worked well.

An on-line monitoring system based on ultra high frequency (UHF) partial discharge (PD) measurements was developed for power transformers. The UHF PD signals were coupled by a UHF sensor and preprocessed by peak envelope detection technique. The system has high sensitivity, strong ability of interference suppression and well real-time capability according to the simulated experiment in lab and field test of a power transformer. Experimental results showed that the forepart PD faults could be discovered by the analysis of UHF PD signals. The on-line monitoring system has already been applied on a power transformer for years.

Ultra high frequency (UHF) partial discharge (PD) detection technique is drawing attention to transformer insulation accident prevention. However, the configuration of a large oil-immersed transformer is very complicated, so the reflection, refraction and absorption phenomena between PD sources and UHF sensors need to be considered. The phenomena make it difficult to calibrate the magnitude and locate the source of a PD activity. Therefore, detailed investigation of EM wave propagation inside the tank is carried out to enhance the performance of UHF method. Numerical simulations are performed on the 3D models using finite difference time domain (FDTD) method. From the results, the effects of transformer oil, cores and the tanks are clarified.

In high speed and accuracy positioning systems, torque control mode can achieve much better dynamic response and easy tuning of PID parameters compared to those of position and speed control modes. By adopting and implementing the improved PID control law with feed forward algorithm, the control system can provide much higher performance at high speed movement.

The concept of reliability of road service level was put forward and the threshold determination method based on this concept was studied in this paper. Results of case studies showed that the proposed method for threshold determination was valuable in practice.

The forming scheme of a side-plate of the core part in parallel flow evaporator was studied. Two forming schemes were compared and the explicit dynamic software DYNAFORM was applied to make simulations about the forming processes. According to comparisons between two forming schemes, the optimized scheme and process parameters were determined. Multi-station dies were designed based on the optimized process. Successful experiments with the dies showed that numerical simulation provided an efficient way for the optimization of the forming scheme in the side-plate production.

Pocket corner in the high-speed milling (HSM) often occur under-cut, over-cut, vibration and other phenomena. This not only reduces tool life, seriously affected the work-piece machining accuracy and processing efficiency. In the paper, the impact of cutting speed on cutting forces is studied in the pocket corner based on the high-speed milling experiments. The results show that cutting force increased slightly with the increase in cutting speed, and that cutting force no significant change with the increase in radial depth of cut.

The drawing scheme of a silencer cover in the progressive die was studied. This cover was formerly processed by several single punching dies and now was produced by a progressive die. The drawing scheme was hard to determine. Therefore, the explicit dynamic software DYNAFORM was applied to make simulations about the drawing process. According to comparisons between the simulation and experiment results, the optimized drawing scheme, blank layout, blank size, binding force and some other process parameters were determined. The defects were eliminated after the proper drawbead was set. Experiments showed that numerical simulation provided an efficient way for the optimization of the forming scheme in the progressive die production.

Based on Finite Element Analysis (FEA) module of Dynaform software, the paper made numerical simulation of a motor cover’s stamping process in the method of elastic-plastic flow, pointed out the behavior of deformation of stamping process, predicted and prevented stamping defect such as crack in the process, and calculated the degree of resilience. Consequently three forming numerical simulation schemes have been designed respectively, more feasible process parameters has been achieved in comparison with the features of each scheme.