Feasibility of stochastic gradient boosting approach for predicting rockburst damage in burst-prone mines

The database of 254 rockburst events was examined for rockburst damage classification using stochastic gradient boosting （SGB） methods. Five potentially relevant indicators including the stress condition factor, the ground support system capacity, the excavation span, the geological structure and the peak particle velocity of rockburst sites were analyzed. The performance of the model was evaluated using a 10 folds cross-validation （CV） procedure with 80%of original data during modeling, and an external testing set （20%） was employed to validate the prediction performance of the SGB model. Two accuracy measures for multi-class problems were employed： classification accuracy rate and Cohen’s Kappa. The accuracy analysis together with Kappa for the rockburst damage dataset reveals that the SGB model for the prediction of rockburst damage is acceptable.

Vertically Band-based Orientation Cultivation for Dioscorea opposita

The author made innovation on cultivation technology of Dioscorea oppo- site based on orientation tuberization. According to large furrow, big tuber, and lots of soils, a tuber bed is established suitable for yam growth, and a vertically band- based orientation is introduced. Specifically, soils are ground and colored bands are paved in bottom of furrows where tubers can be cultivated. At harvest, band soils can be removed to collect tubers. It is simple and easy. The yield can be as high as 75 000 kg/hm2. It is applicable in a variety of lands, especially for arid areas, mountains areas or under-forest lands with slopes from 10°to 25°. Semi-mechanical or mechanical planting and harvest can be applied with promising prospects.

Chinese yam(Dioscorea opposita Thunb.) Notillage Ecological Cultivation Technique

For traditional cultivation of Chinese yam, it is necessary to dig a deep trench duringsowing and harvest, wasting labor and time, and Chinese yam requires good quality of cultivated land, causing serious impact on the development of yam industry due to the competition with food production. Yam no-tillage ecological cul- ture techniques, combined with advantage of yam directional tuberization, could en- able the cultivation of yam inlow-production field, barren hills and sloping field, forest land and other non-staple food land and thus could promote farmers＇ income as well as improving the ecological environment.

Study on unidirectional circuit problem in multi-fan-station ventilation type of Jinchuan No.2 mine

The calculating methods for path number and path matrix of ventilation net- works without unidirectional circuits were introduced,and the inapplicability problem of the matrix algorithm to determine paths in a ventilation network with unidirectional circuit was brought forward,and a depth-first search method based algorithm to determine path ma- trix by means of modifying search strategies was discussed.The method is suitable for ventilation networks with unidirectional circuits and ventilation networks without unidirec- tional circuits,moreover the complexity is less than the complexities of matrix based algo- rithms.A series of methods and means to avoid and to reduce the negative effects of un- idirectional circuits such as the optimum of the positions of fan stations,the increase or de-crease of fan station numbers,the optimum regulation of network and the analysis of diagonal structures were put forward.

场离子显微镜在析出强化微合金钢中的应用

将实验V-Nb-Mo微合金钢在1200℃固溶处理,在500℃回火不同时间,用场离子显微镜(FIM)研究实验钢中碳化物的析出过程。结果表明:回火0.5 h的样品中,碳化物处于形核长大时期,与基体的{110}呈共格关系;随着回火时间的延长,碳化物形成独立的晶体结构,与基体{110}之间呈半共格关系;回火100 h后,碳化物粗化长大,与基体呈非共格关系;形状系数随着回火时间的延长先变大再变小,析出相尺寸从1.6 nm逐渐增大至15 nm。500℃回火30 h的实验钢力学性能最佳,表明碳化物的析出强化效果最明显,相应的碳化物尺寸约为4 nm。

Shallow groundwater dynamics in North China Plain

The groundwater level of 39 observation wells including 35 unconfined wells and 4 confined wells from 2004 to 2006 in North China Plain(NCP) was monitored using automatic groundwater monitoring data loggers KADEC-MIZU II of Japan.The automatic groundwater sensors were installed for the corporation project between China and Japan.Combined with the monitoring results from 2004 to 2006 with the major factors affecting the dynamic patterns of groundwater, such as topography and landform, depth of groundwater level, exploitation or discharge extent, rivers and lakes, the dynamic regions of NCP groundwater were gotten.According to the dynamic features of groundwater in NCP, six dynamic patterns of groundwater level were identified, including discharge pattern in the piedmont plain, lateral recharge-runoff-discharge pattern in the piedmont plain, recharge-discharge pattern in the central channel zone, precipitation infiltration-evaporation pattern in the shallow groundwater region of the central plain, lateral recharge-evaporation pattern in the recharge-affected area along the Yellow River and infiltration-discharge-evaporation pattern in the littoral plain.Based on this, the groundwater fluctuation features of various dynamic patterns were interpreted and the influencing factors of different dynamic patterns were compared.

Omni-Directional Distribution Patterns of Montane Coniferous Forest in the Helan Mountains of China

Slope aspect has significant effect on the development and distribution of montane forest, especially in arid and semiarid regions. This paper, using SPOT5 images and 1：5o,ooo DEM, digitally extracts and analyzes the spatial information of montane coniferous forest （mainly Qinghai spruce）, and thereby explores how the upper and lower limits and the altitudinal range of coniferous forest vary and how the area of coniferous forest is related with annual insolation with all aspects in the Helan Mountains. The results show that： 1） In the eastern flank, the lower limit of coniferous forest is between 1,6oo m and a,ooo m a.s.l., and the upper limit between 2,800 m and 3,ooo m a.s.1.; in the western flank, the lower limit of coniferous forest is between a,ooo m and 2,300 m a.s.l., and the upper limit between 9,80o m and 3,1oo m a.s.1.2） The altitudinal ranges of coniferous forest are 8o6-1,435 m, 438-1,14o m for eastern flank and western flank, respectively. 3） The area of coniferous forest takes on a normal distribution with aspect, and it has a close relationship with annual insolation. This distribution model developed in this paper quantitatively reveals the significant effect of slope aspect on the distribution of coniferous forest in arid and semi-arid land.

FACTORS AFFECTING THE TRACK OF TROPICAL CYCLONES AFTER LANDFALL IN EASTERN CHINA

The correlation and composite analysis are carried out in this paper to study major factors affecting the track of tropical cyclones (TCs) after their landfall in the east of China. The mid-tropospheric environmental steering flow is found to dominate the movement of a TC even after landfall, with the inertia and Coriolis force two other subordinates. A key region is discovered covering the east of China and Yellow Sea, in which the environmental flow significantly affects the movement of TCs making landfall in this part of China. When the subtropical high in this region strengthens and extends westward, accompanied by northward shrink of the westerly trough, the TC tends to move westward after landfall and disappear inland. However, when the subtropical high in this region weakens and shrinks eastward, accompanied by southward push of the westerly trough, the TC tends to recurve after landfall and re-enter the sea at a location to the north of the site of landfall. The environment before the landfall of a TC has little impact on its post-landfall track, which is sensitive to the environmental change 12 – 24 hours after landfall. A 6-hour lag is found between the environmental change and the movement of a TC after landfall.

Work Organization at Farm Level： A Process-Led Approach to Understand Land Use Changes

In the French Alps, some grasslands have been abandoned, others are invaded by scrub whereas they are still used by farmers What are the relationships between land use changes and other changes at farm level that lead to scrub invasion？ We hypothesize that they are linked by two work organization processes： process of changes （changes in the household and farm） leading to less intensive land use; and annual processes （sequences of activities during the year） and their repetition from one year to another, leading to insufficient land maintenance. In this paper, we present a study carried out in the Northern French Alps, based on surveys with livestock farmers. It appears that land use changes are often the consequence of other changes made to address work problems, and land use sequences are defined according to workforce and prioritization of tasks. This highlights the importance of considering farmers as workers in order to evaluate land use changes at the farm level and to link them to the human dimension within farming systems.

Simultaneous Prediction of Retention Times and Peak Shapes of Sulfonamides in Reversed-Phase High-Performance Liquid Chromatography

In this paper, we propose a novelmethod based on the plate theory to simultaneously predict retention times and peak shapes under gradient elutions and different flow rates by reversed-phase high-performance liquid chromatography. The proposed method yielded excellent retention prediction results in experiments with 16 common sulfonamides under 18 gradient conditions and four different flow rates, including 0.7, 1.0, 1.3, and 1.5 mL/min. The mean absolute deviation was 0.70%, which indicates accurate prediction. Moreover, the proposed method predicts the change wellin peak shapes caused by the expansion or compression ofpeaks under different gradient conditions.

FORMATION AND EVOLUTION OF THE CENOZOIC THRUST FOLD BELT IN JINPING, SICHUAN

The Jinping orogenic belt in Sichuan, China consists mainly of the Jinpingshan intracontinental thrust-nappe belt, foreland thrust-nappe belt and foreland uplift belt. Based on analyses about the characteristics of the structural units in this area, the authors propose in this paper that Chapuzi-Bazhe revival fault belt is the regional boundary fault, and points out that after the formation of the Pre-Sinian basement, the western edge of the Yangtze paraplatform was turned into the passive continental margin in Sinian to Triassic, then into the Mesozoic collision orogenic belt, and finally into the Cenozoic orogenic belt through intracontinental orogeny.

论家居环境之选择

代表个体胚胎阶段呼吸门户的先天巽卦由代表母体的后天坤卦转化而来,此为家居环境养生之由来.后墙一起,家宅之山向确立 既已封顶,家宅地盘之中宫产生 成员入住,家宅天盘之中宫定位 灶火启动,家宅之当旺地运开始运转.

EW-trending uplifts along the southern side of the central segment of the Altyn Tagh Fault, NW China: Insight into the rising mechanism of the Altyn Mountain during the Cenozoic

The Altyn Tagh Fault and the Altyn Mountain define respectively the tectonic and geographical northern edges of the Tibetan Plateau, and figure prominently in the growth and rising mechanism of the plateau. The rhombus-shaped Altyn Mountain has long been thought to have an intimate relation with the Altyn Tagh Fault; however, its formation mechanism remains unclear and debatable. In this paper, we focus on the EW-trending uplifts in the Altyn Mountain, and investigated three Cenozoic sedimentary sections in the vicinity of the EW-trending uplifts located along the southern side of the central segment of the Altyn Tagh Fault. Magnetostratigraphy and pollen analysis were used to constrain ages of the sediments. Clast composition of conglomerate and paleocurrents obtained from clast imbrications were applied to determine the provenance. We also established a geological section parallel to the Altyn Tagh Fault on sedimentary facies across the northwestern Qaidam Basin. The results indicate that these en-echelon EW-trending uplifts formed as early as ca. 36 Ma and were preferred to be under the control of basal shear of the Altyn Tagh Fault in the middle-lower crust, symbolizing the early uplift of the Altyn Mountain during the Cenozoic. Left-slip along the Altyn Tagh Fault occurring during the Miocene and afterwards displaced and altered these uplifts, shaping the Altyn Mountain to its present fabric.

Upper mantle anisotropy in the Ordos Block and its margins

Based on the polarization analysis of teleseismic data,SKS (SKKS) fast-wave directions and delay times between fast and slow shear waves were determined for each of the 111 seismic stations from both permanent and temporary broadband seismograph networks deployed in the Ordos Block and its margins.Both the Silver and Chan and stacking analysis methods were used.In this way,an image of upper mantle anisotropy in the Ordos Block and its margins was acquired.In the western and northern margins of the Ordos Block,the fast-wave directions are consistently NW-SE.The fast-wave directions are mainly NWW-SEE and EW in the southern margin of the Ordos Block.In the eastern margin of the Ordos Block,the fast-wave directions are generally EW,although some run NEE-SWW or NWW-SEE.In the Ordos Block,the fast-wave directions trend near N-S in the north,but switch to near EW in the south.The delay time between fast and slow waves falls into the interval 0.48-1.50 s,and the average delay time at the stations in the Ordos Block is less than that in its margins.We suggest that the anisotropy of the stable Ordos Block is mainly caused by "fossil" anisotropy frozen in the ancient North China Craton.The NE-trending push of the northeastern margin of the Tibetan Plateau has caused NW-SE-trending lithospheric extension in the western and northern margins of the Ordos Block,and made the upper mantle flow southeastwards.This in turn has resulted in the alignment of the upper mantle peridotite lattice with the direction of material deformation.In the southern margin of the Ordos Block,the collision between the North China and Yangtze blocks resulted in the fast-wave direction running parallel to the collision boundary and the Qinling Orogen.Combining this with the APM and velocity structure of the Qinling Orogen,we propose that eastward-directed asthenospheric-mantle channel flow may have occurred beneath the Qinling Orogen.In the eastern margin of the Ordos Block,the complex anisotropic characteristics of the Fenhe Graben and Taihang Orogen may be caused by the interaction of western Pacific Plate subduction,regional extensional tectonics,and the orogeny.For station YCI,the apparent splitting parameters (the fast-wave directions range from 45° to 106° and the delay times range from 0.6 to 1.5 s) exhibit systematic variations as a function of incoming polarization with a periodicity of π/2.This variation can be best explained by a two-layer anisotropic model (φlower=132°,δtlower=0.8 s,φupper=83°,δtupper=0.5 s).The upper layer anisotropy beneath station YCI can again be attributed to "fossil" anisotropy frozen in the ancient North China Craton.The lower layer anisotropy is affected by the tectonic activity of the western Ordos Block.The NW-SE trending extension caused by the NE trending push of the northeastern margin of the Tibetan Plateau affected the deformation of the lower anisotropic layer beneath station YCI.By comparing the fast-wave directions with GPS velocity directions,we see that the crust and upper mantle possibly have vertically coherent deformation in the margins of the Ordos Block,whereas the internal deformation characteristics of the Ordos Block are complex and require further study.