Based on the event every year for selecting the annual important advances about science, technology and engineering held by our publishing house, with the same principles of evaluating within each branch, putting quality before quantity, and giving facts in time order, 10 important scientific achievements, 10 important technological achievements and 10 important engineering achievements in China in 2013 were selected from a lot of scientific news in Science & Technology Review, other key academic journals and scientific newspapers. These achievements were introduced by the Editorial Department of Science and Technology Review.

In order to solve the mining technical problem of low exploitation in Shengda iron ore, an improved AHP-TOPSIS comprehensive evaluation index system model was established to evaluate five kinds of mining methods. Considering the economy, technology and security, which impact the evaluation indexes of mining method, the weight matrix of the evaluation indexes was established according to the improved AHP method, and then the improved AHP-TOPSIS comprehensive evaluation model was established with the basic theory of TOPSIS. The degrees of mining method based on the comprehensive evaluation index were calculated. The results show that the synthetic superior degrees of the optional mining methods are 29%, 28%, 21%, 22%, 20%, and the first method named piecewise relay retrograded mining filling method is the optimal.

The exploration of Y oilfield seriously suffered from safety problems in the bitumen zone. Slight fluctuation of low drilling fluid pressure may trigger the mobilization and invasion of near-wellbore bitumen, which may lead to complex accidents or well abandonment. Analysis indicated that it is hard to control the drilling fluid pressure because properties of bitumen-contaminated drilling fluid quickly got worse. Bitumen has good liquidity at high temperature and adhered solid particles easily. Even worse, displacement loss of drilling fluid and bitumen accelerated invasion of bitumen. Thus, the degree and speed of bitumen invasion got out of hand. Test results in lab and field showed that, in order to control drilling fluid pressure, the contents of bentonite and plugging materials at about 1% and 8% respectively in drilling fluid are crucial while drilling. Meanwhile, invasion speed of bitumen can be reduced by thickening and plugging technology during circulation stop. The managed pressure drilling (MPD) technology can be used to effectively control wellbore drilling fluid pressure and drill through bitumen formation with lower drilling fluid density. Then the displacement amount of bitumen and drilling fluid, invasion degree and speed were reduced to a "controlable" level.

The layer of the North wing filling mining area in a certain coal mine uses the Ordovician limestone as coal-bearing strata rock, the Quaternary pore confined aquifer in the overburden is developed. Study the height of water flowing fractured zone after filling is significant to achieve safety mining. This study is based on equivalent mining height, using three methods of theoretical calculation, numerical simulation and similar material simulation to forecast the height of water flowing fractured zone in a certain coal mine, respectively. It is obtained that the heights of water flowing fractured zone are 12.72, 12.50 and 14.28 m, respectively. The result indicates that the three methods match well by comparison, and it provides important theoretical basis to mining engineering practice under water in a certain coal mine.

The southwest orebody in Xinli district of Sanshandao gold mine is deep-sea metal deposit mining. The undersea backfilling is characterized by high filling times line and strong resistance to transport, because the filling line reaches up to 13 and the horizontal pipe is over 2000 m. The physical-chemical properties of classified tailings, proportion of slurry with classical tailings as aggregate, the resistance of pipeline transportation are studied to solve the technological problems of filling including long filling pipe, high filling timesline, and high resistance. The results indicate that classified tailings, which are good for dehydration as coarse particles and easily settle, are fit for backfilling after adding fine particles. The suggested dosage is 1:6 -1:8 (cement to classified tailings) with mass fraction 72%. By the round-pipe test and theoretic calculation, the maximal transport resistance may reach 9 MPa, so a pumping pressure of 6 MPa is required besides the hydraulic pressure. The application in mine shows the feasibility of the technology, which can provide safety for deep sea mining in the future as well as realize high filling times line filling in deep sea mining .

As the number of domestic condensate gas wells increases, dynamic monitoring of production logging becomes more and more urgent. Because the traditional method is limited, an interpretation model based on condensate gas well of phase diagram is proposed by analyzing the characteristics of the fluid in the wellbore of the condensate gas well having a big steam oil ratio. The error of the interpretation of single-phase oil and gas well is within 8%, which evidently meets the application requirement.

Failure simulation experiments of multiple thermal fluid recovery sand control screen were firstly carried out in erosion, corrosion and erosion-corrosion superposition conditions. The experiments were carried out in high temperature and high pressure reaction still. The corrosion rates of screen block sand medium were respectively observed in three conditions by weight loss method, the corrosion rate of 434 material in superposition condition is 75 times higher than that in erosion condition and is 53% higher than that in corrosion condition. Macroscopic and microscopic analysis were carried out by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Results showed that corrosion rates in superposition conditions were observably higher than those in single erosion and single corrosion conditions. The destructive effect of corrosion to organism and erosion to corrosion protective film promote mutually, which leads to the increase of damage degree.

In order to predict the 28 day compressive strength of coal gangues as clay for cement, a prediction method of grey model and radial basis function (GM-RBF) neural network combination model is presented according to the data of cement physics test analysis. The method makes used of the advantage of both GM and RBF neural network. Firstly, the combination model built up GM(1, N) network based on its test analysis data, and the data were preprocessed. One accumulated generation operation (1-AGO) and normalization were carried out. Predicted precision and scatter constant were set up to the combination model. Then, these processed samples served as the input vectors for RBF neural network, the measurement data of 28 day compressive strength served as output expectation value for model. Comparisons were carried out between prediction data and measurement data, then the data were adjusted logically. Finally, the GM-RBF neural network combination model is fit for precision requirement. AGO and pretreatment were used for data processing which can reduce randomness of training samples. It also shows that the method is self-adaptive, self-organized and fast. The model can not only avoid the theoretical error of GM(1,N), but also predict the further period compressive strength. The results show that it is better than GM(1,N) model or RBF neural network model. The combination model owns a fine agreement and adapts to predict cement strength. It can provide efficient reference of quality analysis for coal gangues as clay for cement.

In the photovoltaic and thermoelectric system, the output voltage and current of the solar panels constantly changed with solar irradiance, resulting in the thermoelectric heat pump working under off-design conditions for a long time. To test the performance stability and affordability of the thermoelectric heat pump under off-design conditions, a DC power device replacing the solar panels was used to output unstable current to drive the thermoelectric heat pump. Under three different off-design conditions including continuously working, voltage jumping and limiting voltage, the mutual relation between hot side temperature T_h, cold side temperature T_c, temperature difference T_d, COP, cooling (heating) capacity and operating voltage were analysed. The results showed that the thermoelectric heat pump refrigerated fast, and it could remain stable. Its heating efficiency was about 0.8 higher than cooling efficiency which indicated that the effect of heating was obviously better than cooling. With the increasing of operating voltage, the temperature difference became greater, but the COP smaller. In addition, the best operating voltage of the thermoelectric heat pump should be between 2 V and 4 V and the effect of heat dissipation had a great influence on the cooling and heating performance of the thermoelectric heat pump.

With the economy development and population increase of Dunhuang, the pattern of water exploitation changes with each passing day. A tremendous demand for underground water results in excessive pumping, and water level falls sharply. Environments which focused on water resources become more and more maladjusted, and Crescent Spring which called as desert resort will dry up nearly. Finding out hydrogeological condition of Crescent Spring in Dunhuang and underground water circulation rules, and underground water recharging of Crescent Spring sufficiently and timely is an anxious problem to be resolved, which is important in economic merit and society significance. Based on the difference in physical property between fault, water conducted ancient riverways and their ambient rocks, an audio frequency magnetotelluric method was applied with geological data to determine distribution of water conducted structures, which provides reliable data for geological environment governance of Crescent Spring. The results obviously show that there are faults and water conducted ancient riverways in Crescent Spring and its ambient area. The conclusion can be drawn that evident geological effect can be obtained by audio frequency magnetotelluric method to define location of fault and water conducted ancient riverways and it can provide scientific foundation for underground water recharging in Crescent Spring.

To understand the influence of hop-pocket sand barrier on wind and sand flow and soil moisture, the wind-break potency, surface roughness, parameters of sediment transport rates and soil moisture of 1 m×1 m, 2 m×2 m, 3 m×3 m square hop-pocket sand barrier were studied through anemometry, sand collection of ground 30 cm and soil moisture of underground 0-40 cm on sand dune. The results showed that hop-pocket sand barrier can improve the wind-break potency of 0-30 cm height range effectively, increasing the sand dune surface roughness, reducing the sediment discharge of 0-30 cm height range significantly. The order of wind-break potency of hop-pocket sand barrier was 1 m×1 m>2 m×2 m>3 m×3 m. The difference of 1 m×1 m was significant compared to 2 m× 2 m and 3 m×3 m, and there was no significant difference between 2 m×2 m and 3 m×3 m. The order of surface roughness was 1 m× 1 m>2 m×2 m>3 m×3 m>CK; the roughness of 1 m×1 m, 2 m×2 m and 3 m×3 m were increased by 91.31%, 78.88% and 76.26% higher than the control and the differences were significant (P<0.001). 0-30 cm sediment discharge of the control reached 71.43 g/(min·cm²), and it was 32.98 times more than hop-pocket sand barrier.λ eigenvalues was the sediment discharge ratio of 2-10 cm and 0-1 cm of hop-pocket sand barrier and the control, and λ >1, deducing that their surfaces were wind eroded during the monitoring period. The order of soil moisture was CK>3 m×3 m>2 m×2 m>1 m×1 m, the trend of 0-20 cm layer was obvious, and soil moisture of the control was increased by 55.10%, 58.63% and 67.45% higher than 3 m×3 m、2 m×2 m and 1 m×1 m hop-pocket sand barrier.

Damping alloy is a kind of metallic functional materials with high damping capacity which can dissipate mechanical vibration rapidly. There are mainly four kinds of damping alloys, namely the multiple phase alloys, the ferromagnetic alloys, the dislocation alloys and the twin crystal alloys. Through using them to fabricate the component parts of vibration source, many vibration and noise problems in machine manufacturing and some other fields can be solved effectively. Currently, the corresponding research mainly focuses on the doping modification of the Mn-Cu and Mn-Fe alloys, as well as the damping mechanism of the emerging Mn-Ni alloys. So far, the Mn-Cu base alloys are the only damping alloys whose industrialization has been realized. Typically commercial damping alloys are Sonoston, Incramute and M2052. Meanwhile, with lower cost and better mechanical properties, the Mn-Fe damping alloy are promising substitutes for the traditional Mn-Cu damping alloys in the future. In this paper, the classification and features of the different damping alloys are briefly introduced, and the research progress and industrialization status of the above-mentioned alloys are also summarized. The results may provide a new idea and a reference for material choice for damping and noise reduction.