Ground subsidence mechanism of a filling mine with a steeply inclined ore body

Long-term field monitoring finds that serious surface subsidence can still occur even if the high strength cemented fill method is adopted.Combining the results of numerical simulations with global position system(GPS)monitoring,we took a typical filling mining mine with a steeply inclined ore body as an example,and explored its ground subsidence mechanism.The results show that the ground subsidence caused by the mining of steep ore body is characterized by two settlement centers and a significantly uneven spatial distribution,which is visibly different from ground subsidence characteristic of the coal mine.The subsidence on the hanging wall is much larger than that on the footwall,and the settlement center tends to move to the hanging wall with the increase of mining depth.The backfill improves the strength and surrounding rock bearing capacity,which leads to a lag of about 3 years of the subsidence.However,under the actions of continuous and repeated mining disturbances,the supporting effect of the backfill can only reduce the amplitude of the deformation,but it cannot prevent the occurrence of settlement.

Geologic body three-dimensional model generation and visualization method

The divergence three-dimensional millet-seed body model and the continuous distributing layer-imitating model were introduced, which were used to express geologic body, and the procedure of generating these two models and their merits and demerits were synthesized. Three methods of geologic body’s three-dimensional expression were separately introduced, and the merits of the continuous distributing layer imitating model were proposed as comparing with the divergence three-dimensional millet-seed body model. The three-dimensional cubes were observed from any direction and any tangle with the application of dealing methods such as peeling, hollowing out, transparent or half-transparent.

Three-dimensional analysis of pedicle screw channel,screw entry point and lateral surface of cervical vertebral body

Objective To explore three-dimensional relations of pedicle screw channel (PSC) ,screw entry point and lateral surface of cervical vertebral body by digital techniques. Methods CT scan images of cervical

FINITE-PART INTEGRAL AND BOUNDARY ELEMENT METHOD FOR INTERACTION BETWEEN TWO PARALLEL PLANAR CRACKS IN THREE-DIMENSIONAL FINITE BODIES

By using the Somigliana representation and the concepts offinite-part integrals, a set of hypersingular integral equations ofthe interaction between two parallel planar cracks in a three-dimen-sional finite body subjected to arbitrary loads is derived, and thenits numerical method is proposed by the finite-part integral methodcombined with the boundary element method. According to the analytictheory of hypersingular integral equations, the square root models ofdisplacement discontinuities in the elements near the crack front areapplied, and thus the computational precision is raised. Based onthis, the stress intensity factors can be directly calculated.Finally, the stress intensity factors of sever- al typicalinteraction problems are calculated.

Geochemical Characteristics,Genesis of Concealed Cu-rich Ore Body in the Jinchuan Deposit,Northwestern China,and Its Prospecting

The Jinchuan deposit is hosted by the olivine-rich ultramafic rock body, which is the thirdlargest magmatic sulfide Ni-Cu deposit in the world currently being exploited. Seeking new relaying resources in the deep and the border of the deposit becomes more and more important. The ore body, ore and geochemistry characteristics of the concealed Cu-rich ore body are researched. Through spatial analysis and comparison with the neighboring II1 main ore body, the mineralization rule of the concealed Cu-rich ore body is summed up. It is also implied that Cu-rich magma may exist between Nirich magma and ore pulp during liquation differentiation in deep-stage chambers, which derives from deep-mantle Hi-MgO basalt magma. It is concluded that the type of ore body has features of both magmatic liquation and late reconstruction action. It has experienced three stages： deep liquation and pulsatory injection of the Cu- and PPGE-rich magma, concentration of tectonic activation, and the later magma hydrothermal superimposition. In addition, the Pb and S isotopes indicate the magma of I6 concealed Cu-rich ore body originates predominantly from mantle; however, it is interfused by minute crust material. Finally, it is inferred that the genesis of the Cu-Ni sulfide deposit is complex and diverse, and the prospect of seeking new deep ore bodies within similar deposits is promising, especially Cu-rich ore bodies.

Three-dimensional experimental study of loose top-coal drawing law for longwall top-coal caving mining technology

Based on the loose medium flow field theory, the loose top-coal drawing law of longwall top-coal caving（LTCC） mining technology is studied by using self-developed three-dimensional（3D） test device. The loose top-coal drawing test with shields and the controlled test without shields are performed in the condition without any boundary effect. Test results show that shields will cause reduction in drawing volume of coal in the LTCC mining. The deflection phenomenon of drawing body is also observed in the controlled test, which is verified that the deflection of drawing body is caused by shield. It is found that the deflection angle decreases with increasing caving height, with the maximum value of atailand the minimum value of 0. In addition, the formula to calculate the drawing volume is proposed subsequently.The deflection of drawing body is numerically simulated using particle flow code PFC3 Dand the proposed formula to calculate drawing volume in LTCC is also verified.

Application of Tectono Geochemical Study in Deep Concealed Ore Body Exploration--As the Huize Super-Large Lead-Zinc Deposit an exemple

1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou

Location Prediction of Blind Ore bodies in Shuijingtun Gold Mine, Zhangjiakou, China

By analyzing the metallogenic conditions and prospecting marks of F 8 fault belt in Shiujingtun Gold Mine, the geochemical samples were collected along F 8 fault belt and prospecting profile normal to the F 8 fault belt. Gold and its indicator elements were tested with X ray fluorescence spectrometry and the content distribution diagram of Au, Ag, Hg and As along the F 8 fault belt was performed. The geochemical primary halo model and the Grey system model of F 8 fault belt are established. With these element distribution features and models, the blind ore bodies in the F 8 fault belt were predicted. Engineering prospect shows that the industrial orebodies have been discovered and the prediction results are dependable.

Three-Dimensional Prototypes and Evaluation of Their Structure and Form

In order to reveal the appearance of the clothing prototype on the human body,the characteristics of the human body’s structure above the waist section were studied.Based on the experimental data of the fit prototype,three-dimensional prototypes features were comparatively analyzed.And then objectively evaluating the relationship was conducted between the planar structure lines of different prototypes and the human body.The results showed that the prototypes analyzed basically conformed to the size of the human body.However,when they were worn on the human body,there were problems in the structure and forming.The main reason was that the side seam was skewed to different degrees.The results of this study provide reference for many practitioners to choose prototypes.

Forecast of blind ore body in Zhangcaigou area around Wulaga gold deposit

By the study of metallogenetic conditions and ore-controlling factors, the metallogenetic indicators in geology, geochemistry and geophysics about Wulaga gold deposit have been obtained. Using the indicators the blind ore bodies have been forecasted in Zhangcaigou area. By drilling check, a gold-bearing ore body with 3 m thickness in an average tenor of 20.4×10 -6 at the depth of 70 m has been found in the forecast area. It shows that the forecast method should be effective.

Inducing human induced pluripotent stem cell differentiation through embryoid bodies:A practical and stable approach

Human induced pluripotent stem cells(hiPSCs)are invaluable resources for producing high-quality differentiated cells in unlimited quantities for both basic research and clinical use.They are particularly useful for studying human disease mechanisms in vitro by making it possible to circumvent the ethical issues of human embryonic stem cell research.However,significant limitations exist when using conventional flat culturing methods especially concerning cell expansion,differentiation efficiency,stability maintenance and multicellular 3D structure establishment,differentiation prediction.Embryoid bodies(EBs),the multicellular aggregates spontaneously generated from iPSCs in the suspension system,might help to address these issues.Due to the unique microenvironment and cell communication in EB structure that a 2D culture system cannot achieve,EBs have been widely applied in hiPSC-derived differentiation and show significant advantages especially in scaling up culturing,differentiation efficiency enhancement,ex vivo simulation,and organoid establishment.EBs can potentially also be used in early prediction of iPSC differentiation capability.To improve the stability and feasibility of EB-mediated differentiation and generate high quality EBs,critical factors including iPSC pluripotency maintenance,generation of uniform morphology using micro-pattern 3D culture systems,proper cellular density inoculation,and EB size control are discussed on the basis of both published data and our own laboratory experiences.Collectively,the production of a large quantity of homogeneous EBs with high quality is important for the stability and feasibility of many PSCs related studies.

Effects of lower body positive pressure treadmill on functional improvement in knee osteoarthritis:A randomized clinical trial study

BACKGROUND Knee joint pain and stiffness are the two main symptoms of knee osteoarthritis(OA)and thus restrict a patient’s activities,such as walking and walking up and downstairs.The lower body positive pressure(LBPP)treadmill as one of the emerging body weight support system devices brings new hope for exerciserelated rehabilitation for knee OA patients.AIM To investigate the biomechanical effects and the subjective clinical assessment of LBPP treadmill walking exercise when compared with conventional therapy in mild to moderate knee OA patients.METHODS Eighteen patients with mild-to-moderate knee OA were recruited in this randomized controlled trial(RCT)study.The eligible knee OA patients were randomly assigned to two groups:LBPP and control groups.The patients in the LBPP group performed an LBPP walking training program for 30 min/session per day,6 d per week for 2 wk whereas the patients in the control group performed walking on the ground for the same amount.All patients underwent clinical assessments and three-dimensional gait analysis at pre-and 2-wk post-treatment.RESULTS The Western Ontario and McMaster Universities Arthritis Index and visual analog scale scores in both the LBPP group and control group were found to decrease significantly at the post-treatment point than the pre-treatment point(LBPP:70.25±13.93 vs 40.50±11.86;3.88±0.99 vs 1.63±0.52;control:69.20±8.88 vs 48.10±8.67;3.80±0.79 vs 2.60±0.70,P<0.001).Moreover,compared with the control group,the LBPP group showed more improvements in walking speed(P=0.007),stride length(P=0.037),and knee range of motion(P=0.048)during walking,which represented more improvement in walking ability.CONCLUSION The results of our RCT study showed that the LBPP group has a greater effect on improving gait parameters than the conventional group,although there was no significant advantage in clinical assessment.This finding indicates that LBPP treadmill walking training might be an effective approach for alleviating pain symptoms and improving lower extremity locomotion in mild to moderate knee OA patients.

Interpretation of residual gravity anomaly caused by simple shaped bodies using very fast simulated annealing global optimization

A very fast simulated annealing（VFSA） global optimization is used to interpret residual gravity anomaly.Since,VFSA optimization yields a large number of best-fitted models in a vast model space;the nature of uncertainty in the interpretation is also examined simultaneously in the present study.The results of VFSA optimization reveal that various parameters show a number of equivalent solutions when shape of the target body is not known and shape factor ＇q＇ is also optimized together with other model parameters.The study reveals that amplitude coefficient k is strongly dependent on shape factor.This shows that there is a multi-model type uncertainty between these two model parameters derived from the analysis of cross-plots.However,the appraised values of shape factor from various VFSA runs clearly indicate whether the subsurface structure is sphere,horizontal or vertical cylinder type structure.Accordingly,the exact shape factor（1.5 for sphere,1.0 for horizontal cylinder and 0.5 for vertical cylinder）is fixed and optimization process is repeated.After fixing the shape factor,analysis of uncertainty and cross-plots shows a well-defined uni-model characteristic.The mean model computed after fixing the shape factor gives the utmost consistent results.Inversion of noise-free and noisy synthetic data as well as field data demonstrates the efficacy of the approach.

Occurrence of Manganese Ore Deposits and Their Mineralogy in Vizianagaram-Visakhapatnam Manganese Ores Belt (Andhra Pradesh) India

The Manganese deposits of Andhra Pradesh are associated with a thick sequence of Precambrian rocks, belonging to Khondalite and Charnockite groups of Dharwar Supergroup that forms part of 2500 to 3000 m.y. old Eastern Ghat complex of India. The study area is the Manganese deposits of Vizianagram-Visakhapatnam Manganese Belt of Andhra Pradesh. The study area lies about 150 km NE of Visakhapatnam between 18°12′N - 18°30′N and 83°20′E - 83°45′E. The mineralization of Manganese ores is confined to different rock types, belonging to both Khondalite and Charnockite groups, where they are dispersed throughout the country rocks as small lenses, pockets, veins and irregular bodies of varying dimensions. Quartz, garnet, clay, limonite and apatite are the common gangue minerals in the Manganese ores. The presence of quartz, garnet and apatite brings down the grade of the ore. Ferruginous laterite and ochre generally work as capping of the Manganese deposits. The various Manganese ore minerals present in these deposits are indentified as 1) Primary minerals-braunite, bixbyite, vredenburgite, jacobsite and hausmannite, 2) secondary minerals-psilomelane, cryptomelane, hollandite, pyrolusite and wad. The primary ore minerals are considered to be syngenetic and regionally metamorphosed while, the associated secondary ore minerals are formed due to alteration of the primary ores.

STUDY OF THREE-DIMENSIONAL SEPARATION OF BOUNDARY LAYER OVER BLUNT BODIES

In the case of three-dimensional flows, the separation can be defined in more than one way. Discussions about three-dimensional boundary layer separation in the literature have found a rational extension of the zero skin friction. Attempts have been made to establish the identity of “separation lines”. Among definitions, these may be found： （1） envelopes of limiting streamlines, （2） lines dividing flow which has come from different regions, （3） lines of singularities （problems of topology）, （4） lines on which some component of the skin friction vanishes. Each of these is valid under certain conditions, but none is universally valid. In the present work, we use the definition （4）, i.e. at low incidence of a blunt body the separation line is identified as the zero of the meridian skin friction component （Wang 1975）. So the separation line on a flattened spheroid （6：3：1） at 6° of incidence is calculated, as well as experimentally determined by using the electrochemical method, which allows to follow the evolution of the parietal velocity gradient.

A Preliminary Study on Fluid Inclusions and Mineralization of Xitieshan Sedimentary-Exhalative (SEDEX) Lead-Zinc Deposit

The Xitieshan lead-zinc deposit is located at the northern margin of the Qaidam Basin, Qinghai Province, China, and had developed a complete marine sedimentary-exhalative system. Our preliminary study of ore-forming fluids shows that fluid inclusions in quartz from altered stockwork rocks that represent the pipe facies have a wide range of temperature and salinity. The intense fluid activities are characteristics of the pipe facies of the exhalative system. Fluid inclusions in carbonates near the unstratified ore bodies hosted in the thick-bedded marble which represents vent-proximal facies are large in size and have moderate to high temperatures. They represent unerupted sub-seafloor fluid activity. Fluids in altered stockwork rocks and carbonates have similar H20-NaCI-CO2 system, both belonging to the sedimentary-exhalative system. The fluids migrate from the pipe facies to the unstratified ore bodies. Boiling of the fluids causes the separation of CO2 vapor and liquid H2O. When the fluids migrate into the unconsolidated thick-bedded marble, the escape of CO2, decreasing temperature and pressure as well as some involvement of seawater into the fluids result in the unmixing of fluids with high and low salinity and deposition of ore-forming materials. The two unmixed fluids were trapped in unconsolidated carbonates and the ore-forming materials were deposited in the unconsolidated carbonates to form the sedimentary-exhalative type unstratified ore bodies. The oreforming temperature of unstratified ore bodies is up to high temperature indicating that there is a huge ore-forming potential in its deep.

Vertical zoning model of fluorite ore-bodies in Zhejiang

THK fluortite in Zhejiang Province is well known. However, the known outcrop mines have been graduallyexhausted by the exploiting over a long time. It has been a task of top priority to explore blind deposits.Study on the vertical zoning model will be very important and useful in the exploration for blind fluoriteore-bodies. 1 Genetic characteristics of fluorite deposits The fluorite deposits in Zhejiang Province are typical vein filling deposits. The minerals forming theores and the alterations of the wall rocks are all relatively simple. Studies show that the ore-forming materials （F and Ca etc. ） mainly come from the Chencai Group metamorphic rocks and the J3-K1 series vol-

Changchengite—A New Iridium Bismuthide-Sulphide from the Yanshan Mountains

Changchengite occurs in chromite orebodies in dunite and in platinum placer deposits in chromite orebodies nearby. The mineral occurs as massive aggregates or veinlets on margins of iridisite (IrS2) and replaces it. Opaque. Lustre metallic. Colour steel-black. Streak black. Hm = 3.7. VHN20= 165 kg/ mm2. Isotropic. Cleavage none. Density 11.96 g/ cm3. Seven electron microprobe analyses give the following mean chemical results (wt. %): S 7.2, Cu 0.3, Te 0.4, Ir 41.2, Pt 2.8 and Bi 47.3 with total 99.1. The simplified formula is IrBiS. The strongest X-ray powder diffraction lines (hkl, d, I) are 210, 2.75 (70); 211, 2.51 (60); 311, 1.860 (100); 440. 1.090 (50) and 600, 1.027 (50). The X-ray powder diffraction pattern is similar to that of mayingite. After the diffraction data are indexed the mineral is determined to be cubic. The space group is P213 with a = 0.6164(4) nm, V = 0.2342 nm3 and Z = 4.

Source of ore-forming substances and theoretical problems of metallogeny relevant to the Bayan Obo Fe-REE ore deposits in Inner Mongolia,China

The source of rare earth elements （REE） ore-forming substances is identified to be extremelydistinct from that of iron ores.The Bayan Obo Fe-REE ore deposits were generated by a composite processof both crustal and mantle source mineralization.The original iron bodies are of a sedimentary deposit fromsupergenesis,while the REE ores have been formed by mantle fluid metasomatism superimposed upon thepre-existing iron bodies.It is believed that the REE ore deposit would be controlled by intracontinental hotspot.The H8 dolomite in mine regions belongs to normal sedimentary carbonate rock,its C and O isotopiccomposition rules out the possibility comparable with magrnatic carbonatite.The Sm-Nd isochrons of separatedREE minerals have shown two REE peak mineralization periods:early-middle Proterozoic （1 700 Ma±480 Ma） andCaledonia （424-402 Ma）.

Stability analysis of large-scale stope using stage subsequent fillingmining method in Sijiaying iron mine

To improve mining production capacity, a stage subsequent filling mining(SSFM) method is employed for Sijiaying iron mine. The height of the stage stope is approximately 100 m. As there are farmlands and villages on the surface of the mine, the surface deformation should be controlled when the ore is mined out for the purpose of stope stability and minimizing surface subsidence. In this paper, according to the site-specificgeological conditions, the self-stability of the stagefi lling body was analyzed, and the failure mechanism of back filling body was defined. Thus the relationship between the exposed height of filling body and the required strength was obtained. Next, the stability of back filling body and the characteristics of surface subsidence due to mining of 450 m level were analyzed using physical modeling.Finally, a three-dimensional numerical model was established using FLAC3 D, with which the surface subsidence and the stability of stope were achieved. The results show that the stope basically remains stable during the two-step recovery process. The maximum magnitude of the incline is 10.99 mm/m, a little larger than the permissible value of 10 mm/m, and the horizontal deformation is 5.9 mm/m,approaching the critical value of 6.0 mm/m, suggesting that the mine design is feasible for safety mining.