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BACKGROUND The pegmatite lithium deposit has become important for modern industries with strategic value, which is a key mineral resource in urgent need in China. However, the mineralization age restricts the research on the mineralization process and mechanism of this type of lithium deposit. The Jiajika rare metal deposit is the largest pegmatite lithium deposit of China in the western Sichuan, and the No.134 vein is the most typical pegmatite vein. The No.134 pegmatite vein is mainly composed of spodumene, tantalite, zircon, beryl, cassiterite, plagioclase, orthoclase, quartz and muscovite. OBJECTIVES To accurately constrain the mineralization age of the No.134 pegmatite vein. METHODS Laser ablation-multiple collector-inductively coupled plasma-mass spectrometry (LA-MC-ICP-MS) U-Pb geochronology was used on cassiterite. RESULTS The concordant age in the ore samples was 203.7±4.6Ma, which represented the mineralization age of No.134 pegmatite vein. This age indicated mineralization in the Late Indosinian period. CONCLUSIONS The stable tectonic environment in the Late Indosinian movement is the favorable condition for accumulation and mineralization of rare metals, which is beneficial for the formation of the super-large Jiajika rare metal deposit.

Many factors affect the success of dental implant surgery, such as surgical trauma, excessive chewing pressure, material performance mismatch, and improper abutment-implant connection. Among these factors, stress shielding caused by the mismatch of elastic modulus of the material is a major problem affecting the biomechanical compatibility of the implant. Also, the elastic modulus of the dental implant directly affects its binding to the surrounding support bone and stress distribution. Presently, most of the abutmentimplant systems on the market use the same material, with TC4 being popular because of its good biocompatibility. However, the elastic modulus of titanium implants is quite different from that of surrounding bone tissue; this difference can cause stress shielding. Additionally, stress concentration may cause implant surgery to fail. The abutment-implant with materials of different elastic modulus directly affect the stability and stress distribution of the bone tissue around the implant; thus, understanding the stress distribution under loading will help to establish a better elastic modulus combination of the dental implant system. In this paper, finite element analysis software was used to calculate the stress distribution of various abutments-implants under different loading conditions. Compared to other experimental abutment-implant systems, the simulation results show that Ti6Al4V abutment-(poly-ether-ether-ketone) (TC4-PEEK) can effectively reduce stress concentration, resulting in uniform stress distribution of surrounding bone tissue whose maximum stress value is 40-60 MPa. The stress level of PEEK implants in different abutment-implant systems is smaller under axial loading condition, whereas the stress level of surrounding bone tissue is larger. In the oblique direction of 45° loading condition, compared to two other abutment-implant systems, the stress level of the TC4-PEEK is lower, and the maximum stress value of the cortical and the cancellous bones in the surrounding bone tissue is 55 and 5 MPa, respectively, and the stress level is the smallest; such conditions contribute to the increase of bone deposition and bone formation, effectively improving the interface stability of the implant.

Based on the discrete phase model of the Euler-Lagrange equation,the concentration fields of three different types of zinc dross under a circulating purification system were calculated by using the numerical simulation method. The result shows that the deposition rate increases with the decrease of zinc dross size. When the zinc dross size is smaller than 80 μm,the order of deposition rate from high to low is suspending dross,top dross,and bottom dross. The average residence time of the top dross in the back area of the strip exit is the longest,and it will be beneficial to the removal of the top dross to install a pumping tube in this area. On the inner part of the V-shaped zone,the mass concentration of the suspending dross is the highest,and it has the biggest influence on the surface quality of steel strips. The main travel area of the bottom dross is close to the bottom of the zinc pot,and the bottom dross cannot adhere to the strip surface and it has minimal impact on the surface quality of steel strips.

Wall thickness uniformity is an important quality criterion of railway hollow shafts by multi-wedge synchrostep cross wedge rolling. The stable rolling condition of railway hollow shafts in this rolling process is analyzed,and a flattening instability criterion is presented. Based on this result,a rigid-plastic finite element model of hollow railway shafts by multi-wedge synchrostep rolling is established with DEFORM-3D software,the influence of processing parameters such as broadening angle and forming angle on the wall thickness uniformity is discussed,and the change law of wall thickness is obtained by changing these processing parameters. The bigger the forming angle,the more uniform the wall thickness is; the bigger the spreading angle,the more uniform the wall thickness is,but when the spreading angle is more than 10°,the wall thickness uniformity will decrease. A 1:5 ratio high-speed railway hollow shaft is rolled based on multi-wedge synchrostep cross wedge rolling experiment. Rolling torque measurements and wall thickness comparisons between experimental and simulated results show that the relative error is controlled within 10%,which verifies the validity of this finite element model.

For three unstable landslides of C area of Bayan Obo Iron Mine, with data of engineering geological exploration and rock mechanics test, the paper analyzed and calculated several measures for the secondary reinforcement including cutting slope, reinforcement by anchor cable and grouting by use of 5.5 edition of Lizheng soil analysis software and Canadian rock slope stability analysis software SLIDE5.0, and determined whether the secondary reinforcement measures are effective through the calculated safety factor. The analysis and calculation result showed that the secondary reinforcement measures can make safety factor of the most dangerous landslide to achieve 1.186, which meets requirement of designing safety factor of landslide's stability. At last, it proposed several notices about implementation of the secondary reinforcement measures.

The section of top Majiagou Formation is located in the east of Niumaoling Scenic Area of Benxi National Geopark. The sedimentary environment of the section is restored and its change rules are summarized through the microfacies analysis of carbonate rocks. According to the study of specimens, 14 microfacies types are classified, including 1 tempestite microfacies type, 9 gentle slope microfacies types, 3 standard microfacies types and 1 custom microfacies type. The section can be divided into 3 low-energy upward-shallowing tidal margin cycles from bottom to top: The sedimentary environment of Cycle I is tidal margin or lagoon of inner gentle slope--sandbeach and sand bank--tidal margin of tide gate; The sedimentary environment of Cycle II is from limited or open inner gentle slope to shallow subtidal zone of tidal margin and intertidal-supratidal zone of individual layer; The Cycle III is the most typical, with the sedimentary environment from the middle gentle slope of gray limestone, to tidal margin, then to the tidal margin shallow subtidal zone of yellow carbonate rocks, to the evaporative lagoons of intertidal-supratidal zones, and to the evaporative coast of intertidal-supratidal zones in arid climate. It is inferred that the stained Fe3+ and clay minerals are of terrigenous origin, and the section point is the tidal margin environment of carbonate rock island (bar). [ABSTRACT FROM AUTHOR]

In view of the serious membrane fouling problem in the treatment of oil wastewater by ultrafiltration membrane, the polyvinylidene fluoride (PVDF) ultrafiltration membrane modified by gel microspheres was prepared. P(MAAc-co-MAAm) multi-hydrogen bonding self-assembled gel microspheres were synthesized by free-radical polymerization combined with vigorously stirring, and grafted on the surface of carboxylated PVDF membrane through intermolecular hydrogen bonding interactions. The particle size of microspheres was measured by dynamic light scattering particle size analyzer (DLS), the surface morphology of membranes was observed by scanning electronic microscopy (SEM) and atomic force microscopy (AFM), and the performances of membranes were characterized by contact angle test, underwater oil droplet adhesion test and oil-water emulsion filtration test. The results show that the average diameter of gel microspheres is about 248 nm. Water contact angle of the modified membrane is as low as 25.4 ° ± 1.5 °, and the modified membrane has excellent resistance to oil droplet adhesion underwater. The rejection rate of PVDF modified membrane prepared with 40 mL P(MAAc-co-MAAm) gel microspheres suspension to the N-hexane oil-water emulsion with an average particle size of 220 nm is as high as 99.8%. After four oil-water emulsion cycle tests, the flux recovery rate of the modified PVDF membrane is 85.2%, while the one of pure PVDF membrane is only 41.5%. It indicates that the modified PVDF membrane has excellent anti-fouling performance, and separation performance as well. [ABSTRACT FROM AUTHOR]

The city hosting the Olympic Games are practitioners of sustainable development of Olympic Games and the creation and maintenance of the Olympic legacy. Focusing on the dilemma and opportunity for Olympic city, and interviewing with the world-wide famous Olympic researcher, Susan Brownell, this study deeply analyzes and discusses eight themes around the following topics: the essential changes on the reform of Olympic Games, the increasing attention on urban development for IOC, the logic behind the East Asian cities continually hosted the Olympics, the Olympic city and interest-related objects hosted the Olympics, the objective cognition about "anti-Olympics Games", the solidification trend and pioneering attempt for mega-city, the inspiration from success of Los Angel's greatness once again, and the future Olympic dreams for city in China, so as to inspiring the academic sparks of deeply contemplating the sustainable development of Olympic city and the Olympic Games. [ABSTRACT FROM AUTHOR]

In order to improve the mechanical properties of hydrogels and expand their applications, PVA/PAA/Fe3+ hydro-gels wjth high mechanical propertiesj+were prepared by using biocompatibie polyvinyl alcohol (PVA) and poly-acrylic acid (PAA) as matrix materials, hydrogen bonds and metal-coordination bonds as physical cross-linking points. The experiment was carried out to study the mechanical properties of the hydrogels by adjusting hydrochloric acid concentration, Fe concentration and soaking time. The stability of the hydrogel was investigated by the pH value of the solution. The self-recovery of the hydrogel was evaluated by cyclic loading-unloading experiment. The results show that the formation of hydrogen bonds and coordination bonds is confirmed by FTIR. The hydrogel has the best mechanical strength with breaking stress of 12.69 MPa and toughness of 41.64 MJ/m under the conditions of 0.2 mol/L hydrochloric acid, 0.09 mol/L Fe and 20 h soaking time. The hydrogel is stable when the pH of solution is 1-9. After a cyclic loading-unloading experiment and waiting for 240 minutes, the stress and strain recovery rates of hydrogels can reach 90% and 87.8% respectively. [ABSTRACT FROM AUTHOR]

Freeze-thaw erosion, one of the main types of soil erosion, is widely distributed in China. The distribution and harm of the combined erosion of freeze-thaw and other forces were greater than freeze-thaw erosion. We reviewed related research progress of the effects of freeze-thaw on soil physical and chemical properties, wind erosion, and water erosion, based on literatures from China and abroad. Under the condition of freeze-thaw, soil water was transported and soil structure was damaged. Soil porosity, bulk density, shear strength, aggregate stability and organic matter were all changed. The change tendency and amplitude were related to soil texture and the degree of freeze-thaw. The occurrence and process of soil wind erosion and water erosion were influenced by the condition of freeze-thaw. Soil erodibility and erosion intensity increased as a result of the changes of soil physical and chemical properties. At present, the research on freeze-thaw mainly based on indoor simulation, which was quite different from the actual freeze-thaw process in the field. The conclusions obtained were not unified or even contrary due to different test conditions. Therefore, through combining indoor simulation and field survey, to strengthen the research of soil erosion mechanism of freeze-thaw conditions was the focus of the future research, which was of great significance for forecasting and preventing of soil erosion in the periods of thawing and the regions of seasonal freeze-thaw. [ABSTRACT FROM AUTHOR]

Based on the technology neutrality theory as the analysis tool, from the perspective of media culture study, the authors interpreted the two-sided effects of new media on Olympic culture communication: on the one hand, new media have brought multiple values to Olympic culture communication, which embody in that new media enrich the way of narration of Olympic culture communication, cross the identity boundary of Olympic culture communication, and guide the scenario aesthetics of Olympic culture communication; on the other hand, new media have also brought multiple tests to Olympic culture communication, which embody in the impacts brought by new media to such aspects in Olympic culture communication as governance ability, attention maintaining, and value view inheritance etc. The authors concluded that media technology reflected in the Olympic domain plays an important role in people development, social transformation and cultural transition. [ABSTRACT FROM AUTHOR]

In order to improve the permeability of γ-Al2O3 ultrafiltration composite membranes, sol-gel method, emulsifier-free emulsion polymerization and electrostatic interaction were respectively applied to gain Boehmite sol, polystyrene-acrylic acid) (PSA) microspheres and self-assembled microspheres, combining dip-coating method and high-temperature calcination again, γ-Al2O3 hollow microspheres were introduced into the transition layer of the membrane. Physical adsorption instrument, dynamic contact angle equipment, and scanning electron microscope (SEM) were utilized to analyze the pore size, hydrophilicity and morphology of the membrane, respectively. The particle size distribution and zeta potentials of obtained Boehmite sol, PSA microspheres and self-assembled microspheres were characterized by nanoparticle size and potential analyzer. The antifouling behavior of γ-Al2O3 ultrafiltration composite membrane in the filtration of lysozyme (LYZ) solution as well as bovine serum albumin (BSA) solution and its water permeability were measured. The results show that self-assembled microspheres, with the average particle size of 412.0 nm, are prepared by the surface opposite charge attraction of Boehmite colloidal particles and PSA microspheres. The pure water permeability of the ultrafiltration membrane has been increased by introducing hollow microspheres, as high as 205.3 L/(m²⋅h) with water contact angle of 31.2°. The flux recovery rates of LYZ and BSA solutions are 81.5% and 72.2%, and the corresponding rejection rates are 91.2% and 82.0%, respectively. [ABSTRACT FROM AUTHOR]

A new hierarchical structure of TiO2-ZnO nanorod-nanosheet was prepared by two-step hydrothermal method without any seed layers. A spin-coating assisted successive ionic layer reaction method (SC-SILR) was used to deposit the CdS nanocrystals into the TiO2 nanorod array and the TiO2-ZnO hierarchical nanostructure to form the CdS/TiO2 and CdS/TiO2-ZnO nanocomposite films. Different analysis methods, such as SEM, TEM, XRD, UV-Vis and transient photocurrent, were utilized to characterize the morphologies, structures of the samples and investigate the light absorption properties, the photoelectric conversion performance of the electrodes. The results indicated that the transient photocurrent of the TiO2-ZnO hierarchical nanostructure film was apparently superior to the TiO2 nanorod array film after depositing the photosensitive layer of CdS and showed an evident enhancement at wavelength of 500 nm. Hybrid solar cells were assembled using P3HT as p- type polymer materials. Photovoltaic measurement results indicated that the energy conversion efficiency of the hybrid solar cell based on the hierarchical structure of P3HT/CdS/TiO2-ZnO composite film could reach 0.65%, which revealed an increasing of 58% compared with that of the hybrid solar cell based on the P3HT/CdS/ TiO2 composite film. [ABSTRACT FROM AUTHOR]

Viscoelastic suspension is a newly applicable suspension for a large power and heavy crawler vehicle. The viscoelastic suspension can support a heavy load efficiently when walking and working on the off road, raise the adhesion property of a vehicle, and decrease the impact vibration level of the vehicle. The suspension consists of a metal part and viscoelastic material which are spaced and arranged to notably control vibration by transforming vibration energy into thermal energy to dissipate it into the air due to the hysteretic characteristic of viscoelastic materials. To predict and accurately study the dynamic behavior of viscoelastic suspension and evaluate its vibration damping capability, fractional calculus was introduced because of the facts that the fractional calculus exhibits global correlation and data-fitting well when describing rheological phenomenon. In this context, a fractional order Kelvin-Voigt model considering the geometric factors i.e. A radius-thickness ratio incorporated into a dynamic model of viscoelastic suspension for crawler vehicle was established. In this model, the viscoelastic part was represented by a parallel-combination of a spring whose stress is in direct proportion to the strain and a spring pot whose stress is in direct proportion to the fractional derivative of the strain differentiating from the conventional damping pot with stress being proportional to the first derivative of the strain. A numerical solution was obtained by adoption of a Grumwald-Letnikov fractional derivative definition and a matrix function theory and its calculating codes were programming in Matlab. A history correlation coefficient was achieved to embody the afore-history influence of the viscoelastic suspension on its dynamic behavior. Parameters of a fractional model was acquired by fitting data using a least-square method based on a viscoelastic material tensile test carried out on a Testometric M350-10kN according to GB/T 528-1998 and GB/T 9865.1. For a pragmatic study case, a heavy crawler tractor installed with 8 viscoelastic suspensions was considered to analyze its vibration control effect by establishing its fractional model. Also the parameter influence on the vibration control effect, including exciting frequency, fractional order, and ratio of radius to thickness, was examined. The results showed that, compared with rigid suspension, the viscoelastic suspension exhibited remarkable vibration control capability, especially at the resonant frequency of about 4.5 Hz by reducing the response magnitude of the vehicle body by 64.10% in max value and 66.40% in RMS, thus satisfying the supporting and stable demands of the crawler tractor walking and working on the off road. Radius-thickness has a negative influence on the response magnitude of viscoelastic suspension, that is to say there is an effective way to reduce the vibration by introducing a geometry-modified viscoelastic suspension with higher thickness and lower action aero. Fractional order, however, exhibits a positive correlation to the behavior of the response magnitude, which inspires another valid method of altering the viscoelastic material parameter to perfect the vibration of the crawler tractor. The history-dependent factor gives evidence of the long range correlation of the fractional model, i.e., the system response at current time relates to the whole history whose influence increases with time closer to the current time. This research provides an essential theoretical basis for multi-objective optimization and dynamic design of a viscoelastic suspension for a higher power and heavy load crawler vehicle. Experiment study is an essential procedure as a further study. So our future work will stress the indoor test of a dynamic mechanical analysis (DMA) of viscoelasitc materials, deriving a fractional constitutive model considering the temperature-frequency effect of viscoelastic material, and carrying out an in-situ test of a real crawler vehicle establishing a different-parameter viscoelastic suspension to investigate stable/dynamic stiffness, fatigue features, and vibration control capability under working conditions of cutting, pulling, digging, and crossing over an obstacle. [ABSTRACT FROM AUTHOR]

Ordered rutile TiO2 nanorod arrays are prepared on fluorine doped transparent conductive glass (FTO) by hydrothermal method. CdTe-coated TiO2 core-shell nanorod arrays(CdTe/TiO2 ) are fabricated by electrodepositing CdTe nanoparticles on the TiO2 nanorods array. A composite structure of poly(3-hexylthiophene) (P3HT) coated CdTe/TiO2 core-shell nanorod arrays(P3 HT/CdTe/TiO2 ) is formed after P3HT in chlorobenzene solution is spin-coated onto the CdTe/TiO2 core-shell nanorod arrays. The hybrid solar cell is wade with the P3HT/CdTe/TiO2 core-shell nanorod array composite nanostructure film and Au film sputtered on the composite film. The energy conversion efficiency is up to 0. 91 % by using the designed hybrid solar cell. [ABSTRACT FROM AUTHOR]

In order to master the rules of heterogeneous reduction between NO and char edge models, and to reveal the microcosmic mechanisms of migration and transformation for char nitrogen, the processes of heterogeneous adsorption, reduction and desorption of NO on the char edge model compounds in armchair and zigzag configurations were researched. The algorithm of density functional theory was applied to calculate each bond's Mayer bond order. The results indicate that N2 and CO are released in the process of heterogeneous reduction reaction of NO on the char edge model surface in armchair configuration. The Mayer bond order of N-O is the minimum (0.984 6) so the bond of N-O is prone to be broken under a certain temperature. N2 is produced in the process of heterogeneous reduction reaction of two NO molecules on the char edge model in zigzag configuration. One NO molecule is adsorbed on the surface of char edge model in zigzag configuration by the side-on form and then an intermediate with five-membered ring is formed. The Mayer bond order of O4-N5 is the minimum (1.002 5) at the moment. The other NO molecule is adsorbed on the position of C3 by the O-down form. The theory of Mayer bond order can be effectively used to research the heterogeneous reduction reaction mechanisms of NO on the char edge models surface at the molecular level. [ABSTRACT FROM AUTHOR]

The article reports on the study of the variation of chicken anemia virus (CAV) in Guangdong, China using the coding sequences and polymerase chain reaction (PCR) detection method. The result showed that viral protein (VP)1 has 17 variations, VP2 has 11 variations, and the VP3 has six variations. Also mentioned that the coding sequence on the Guangdong isolates are located in two clusters including the nine CAV isolates with other 35 bigger group and one CAV is located in small group

Cui Yin was a writer enjoying the same celebrity as Ban Gu and Fu Yi in the early Eastern Han Dynasty. His works became obsolete after the Tang Dynasty. His works such as Odes to Northern Expedition («...») and Four Odes on the Royal Inspection Tours («...») have however been preserved in Wenguan Cilin in Japan («...»). A thorough inquiry is needed concerning such aspects as his circle of friends in the royal college, the exact writing time of his works, and their historical values. Firstly, although Cui Yin, Ban Gu and Fu Yi all had the experience of studying in the royal college, it does not mean Cui Yin was the schoolmate of the other two, who were more renowned than Cui Yin. After his early years of study in his hometown Pingling (now Xianyang, Shanxi Province), Fu Yi began his study in the royal college around 59 A. D. (the 2nd year in the reign of Emperor Ming of the Eastern Han Dynasty). In contrast, Ban Gu quit his studies in the royal college in 54 A. D. (the 30th year in the reign of Emperor Guangwu). When his father Ban Biao, a famous historian, died, he was obliged to go back to his hometown to mourn for three years in accordance with traditional practices. Afterwards, Ban Gu moved his family to Luoyang, the capital of the country, and was nominated as a royal secretary in 62 A. D. (the 5th year in the reign of Emperor Ming), which means Ban Gu had no chance of studying together with Fu Yi in the royal college. In fact, Fu Yi turned to Ban Gu for historical compilation, thereby making himself a student of the latter. On the other hand, Cui Yin did study together with Fu Yi in the royal college, but there was little chance for him to be a schoolmate of Ban Gu. Secondly, it is deduced that a great many works of Cui Yin were produced during his study in the royal college. As Emperor Zhang ascended to the throne, he summoned writers to compose odes to Emperor Ming. In response, Cui Yin composed Odes to Emperor Ming («...») around 78 A. D. (the 3rd year in the reign of Emperor Zhang). From 80 A. D. till 81 A. D. (the 5th and 6th year in the reign of Emperor Zhang), Emperor Zhang attached great importance to Winter Solstice. As a result, Cui Yin composed a series of works such as "Odes to Socks in Winter Solstice "(«...»), "Odes to Sewing"(«...»), and "Odes to a Cup"(«...»). Cui Yin composed his famous work Dazhi («...»), which reflected the historical events of Emperor Zhang carrying out Confucian education and heightening the social and political status of teachers. There were also some descriptions about the national carnivals for finding a phoenix in 85 A. D. (the 2nd year in the reign of Emperor Zhang) . Thirdly, Cui Yin's "Odes to Northern Expedition" («...») might have other titles. Li Shan, a scholar in the Tang Dynasty, once quoted a sentence from Cui Yin's "Wu Fu"(«...»)to annotate Wenxuan («...»). Besides, Yu Shinan, another scholar in the Tang Dynasty, also quoted a sentence from Cui Yin's Wudu Fu (...) in his Beitang Shuchao («...»). Coincidentally, both sentences can be found in Cui Yin's Odes to Northern Expedition. "It means that "Odes to Northern Expedition," "Wu Fu" and "Wudu Fu" are actually the same work with different titles. Lastly, as one of the greatest works of Cui Yin, "Four Odes on the Royal Inspection Tours («...»), consisting of Odes on the Eastern, Western, Northern and Southern Royal Inspection Tours, "was presented to Emperor Zhang when the latter finished the southern inspection tour in the October of 87 A. D. (the 1st year in the reign of Emperor Zhang in the Eastern Han Dynasty). Apparently, all of them have great historical values, but they tend to be ignored by contemporary scholars. "Odes on the Southern Royal Inspection Tours can supplement the records in The History of the Eastern Han Dynasty («...») regarding the southern inspection tour of Emperor Zhang. The descriptions of the worship of Qu Yuan also reveals the fact that Qu Yuan had gotten a higher status in the early Eastern Han Dynasty than before, which can help enrich the study of The Songs of Chu («...»). Odes on the Western, Northern and Southern Royal Inspection Tours" have important values as a supplement to The History of the Eastern Han Dynasty. It is worth mentioning that "Odes on the Western Royal Inspection Tours has more important historical values than the other three works, as it included the political motivation, the routes, the time of the start and end, and a series of sacrificial activities of this royal inspection tours, which could make up for the poor records in The History of the Eastern Han Dynasty where there were only less than twenty words of description. [ABSTRACT FROM AUTHOR]

Taking the long-term reforestation experimental base established in a severely degraded sub-tropical hilly red soil region in Taihe County of Jiangxi Province in 1991 as the object, this paper studied the changes of soil nutrients and microbial communities after 19 years reforestation of Pinus elliottii forest, Liquidambar formosana forest, and P. elliotti-L. formosana forest, with the naturally restored grassland as the control. The soil organic carbon content in the L. formosana and P. elliottii-L. formosana forests (15. 16±3. 53 and 16. 42±0. 49 g · kg-1, respectively) was significantly higher than that in the control (9. 30±1. 13 g · kg-1), the soil total phosphorus content was in the order of the control (0. 30±0. 02 g · kg-1 ) > P. elliottii-L. formosana forest (0.22±0.04 g · kg-1) > L. formosana forest (0. 14±0. 01 g.kg-1), while the soil available phosphorus content was 1. 66±0. 02 mg · kg-1 in L. formosana forest, 2. 47±0. 27 mg · kg-1 in P. elliottii-L. formosa- na forest, and 1. 15±0. 71 m g · kg-1 in P. elliottii forest, being significantly higher than that in the control (0. 01±0. 00 mg · kg-1). The total amounts of soil microbes, the amount and percentage of soil bacteria, and the amount of inorganic and organic phosphate-solubilizing microbes in L. formosana forest and P. elliottii-L. formosana forest were all significantly higher than those in P. elliottii forest and the control, while the amount and percentage of soil fungi and the percentage of soil actinomycetes in L. formosana forest and P. elliottii-L. formosana forest were significantly lower than those in the control. The soil organic carbon content was significantly positively correlated with the percentage of soil bactera, but negatively correlated with the percentage of soil fungi and actinomycetes, while the soil available phosphorus content was significantly positively correlated with the amount of organic phosphate-solubilizing microes, but not with the amount of inorganic phosphate- solubilizing microbes. It was suggested that L. formosana forest and P. elliottii-L. formosana forest could be the recommended reforestation models in sub-tropical degraded red soil region. [ABSTRACT FROM AUTHOR]

To study the charge safety during projectile penetrating process, split-step numerical simulation method was applied. The projectile penetration process was calculated first and then the responses of charge in the projectile were calculated. The methods of loading resistance on the surface of projectile, the coupled thermo-mechanical-chemical algorithm, and temperature rise mechanism induced by friction were used to simulate the responses of charge. The obtained critical striking velocity of projectile was consistent with the reported experimental results. The results suggest that the friction between projectile and charge is the key factor in the temperature rise of charge, and the ignition location of charge is close to the middle of charge. This study provides the theoretical evidence for the structural design of charge. The presented methods of loading resistance and coupled thermo-mechanical-chemical algorithm of charge during the projectile penetration would provide technique support for simulating responses of charge and system safety. [ABSTRACT FROM AUTHOR]

To investigate friction ignition mechanism of solid explosives, the nonlinear dynamic finite element LS-DYNA code, that was incorporated with thermo-elastic-plastic material model and thermal decomposition of explosive, and ALE algorithm were used. The numerical computations of assessmental test of friction ignition were performed. The critical curve of igniting of PBX-C03 was obtained at different pressures, velocities and friction coefficients. The results indicate that the thermo-elastic-plastic material model with thermal decomposition reaction could be used as the numerical computation model to simulate friction ignition in solid explosives. Increase of the sliding velocity and/or frictional efficient could lead to ignition of PBX C03, when the loading pressure is near yield stress. [ABSTRACT FROM AUTHOR]

A simulating incubation test was conducted to evaluate the effects of exogenous dissolved organic matter (DOM) and incubation temperature on the copper forms in red soil. Comparing with the control, adding different amount of DOM increased the content of soil exchangeable Cu, but decreased the content of soil Fe-Mn bound Cu. With increasing time of incubation, the content of soil exchangeable Cu in all DOM-added treatments had a decreasing trend. By the end of the incubation, treatment 250 mg DOM∙L-1 had the highest contents of soil exchangeable Cu and carbonate bound Cu, while treatment 500 mg DOM∙L-1 had the highest content of soil Fe-Mn bound Cu. In the treatments with DOM addition, the content of soil organic bound Cu increased by 10.67% - 23.66%, compared with the control. At incubation temperature 25 °C and 45 °C, the contents of soil exchangeable Cu and Fe-Mn bound Cu decreased with increasing time of incubation; while at 5 °C, an opposite trend was observed. At these three temperatures, the content of soil carbonate bound Cu in treatments with DOM addition increased with incubation time. The content of soil organic bound Cu increased with increasing temperature, but that of soil residual Cu decreased at lower temperature (5 °C). [ABSTRACT FROM AUTHOR]

According to the characteristics of bidirectional and reversible effect of multiple piezoelectric effects in single piezoelectrics, theoretical analysis is carried on for multiple piezoelectric effects realizing displacement self-sensing of piezoelectric actuators. Thus, one to one correspondence between multiple converse and multiple direct piezoelectric effects is illustrated, and the feasibility of separating electric displacement caused by multiple direct piezoelectric effects from dielectric electric displacement is analyzed. Through a referenced capacitor combined with current integration and differential proportional operational circuit,a decoupling method which is easier for practical engineering application than electric bridge circuit is obtained. The experiments justified the method through a PZT-5 stack actuator. Meanwhile,linear coefficient of the secondary direct piezoelectric effect is obtained for PZT-5 stack. And the influence of tertiary piezoelectric effect on resolution and precision of piezoelectric self-sensing actuators is further analyzed. The study results can provide a new approach for the performance improvement of self-sensing actuators. [ABSTRACT FROM AUTHOR]

With the theoretical basis of aerodynamics, using fluid dynamics software (Fluent), simulated examination has been performed to analyze near-surface air currents, wind speed profile and windbreak performance of sand-bag barrier with different sizes. The results show that, below the surface of 0.5 m height, the changes of wind profile of monitored section are consistent, with little difference, but the wind speed decreases between 0.5 ~ 2.0 m height. There are clearly three partitions of the near-surface air: accelerated upwards area, low-speed sink area and low-speed recirculation zone. They are located in front of the sand barrier protection projects, above the top of the protection zone and inside the barrier, respectively. In low-speed recirculation zone, there exist two horizontal axis eddy current and the velocity at eddy center is minimum. In addition, it can be seen that 0.5m height is a critical point to distinguish factors of affecting wind speed. In the range of 0~0. 5 m, the height of sand barrier is the main factor of wind speed, while in the range of 0.5 ~ 2.0 m, the size of sand barrier is the main factor. Considering comprehensively the above factors, it is realized that the sand-bag barrier with 2 m x 2 m size has the most remarkable protective effect. [ABSTRACT FROM AUTHOR]

Scallop (Patinopecten yessoensis) culturing by ear-hanging method demands drilling hole on the ear for which an equipment for automatic in-line positioning and posturing of the scallop shell is required. Normally, scallop is undergoing vibrating, bumping and wearing when it is touching the mechanical parts for orienting, which will cause the diseases or death. A novel method for ear-orienting recognizing of the scallop shell is developed based on machine vision. Images taken by digital camera are preprocessed and segmented automatically by a computer to get scallop feature parameters. Back-edge is detected through contour-extracting and enhanced random Hough-transform. And the ear-orient is confirmed by analyzing the relative positions of back-edge and center of gravity. The results show that the new method can do the ear-orienting work both rapidly and accurately without vibrating, bumping and damage because of touch-free between camera and scallop. [ABSTRACT FROM AUTHOR]

A transfer function was set up on the model of the thrust and thrust vector measuring platform for trajectory/attitude control rocket engine by using the principle of the mode-testing method to decouple the matrix. The finite-element analysis was used to evaluate the natural frequency. By using the mode-testing method, a more precise test of the measuring platform was done in order to get the natural frequency, damping ratio, principal modes of vibration and residual under 4 kHz of the measuring platform in the actual installation estate, which proved the validity of the finite-element analysis and the reasonableness of the measuring platform system. By using the model to analyze the influence on measure results of system parameters on MATLAB/Simulink environment, and experiment in the actual installation estate, the accuracy of the transfer function is proved. [ABSTRACT FROM AUTHOR]

A self-made directional solidification furnace was used to fabricate high purity aluminum (HPA) ingots, and the morphology of grains was studied. The results indicate that the original grains can recrystallize easily at the temperature under melting point. With the increase of holding time before pulling, the morphology of grains changes from equiax to columnar. In the transition area, new grains nucleate at the intersections of grain boundaries. During the competitive growth process, the grains with the inferior orientation are buried or elbowed out. When pulling halts, the combination of grains occurs, and the lattice orientation of new grain is not related to the original grains. [ABSTRACT FROM AUTHOR]

A low melting-point glass flux, JDN-II, was developed. The experimental results indicate that JDN-II flux has distinct effects of purification and protection on A356 alloy melt at super-high temperature. When the dosage of the flux is 0.03, the content of hydrogen in every gram of A356 melt is only 2.6 µL/g at 857 °C and 0.7 µL/g even at 750 °C. The purification mechanism of JDN-II glass flux was also discussed. [ABSTRACT FROM AUTHOR]

An experimental study of copper deoxidation by calcined charcoal filtration was conducted. The results show that it is an effective method for oxygen removal from molten copper, and charcoal filtration does little harm to the electrical conductivity of copper. Charcoal-filtration technique is also employed to produce oxygen free copper using recycled copper, and the oxygen concentration of samples are all less than 10/10-6, the electrical resistivities of as-drawn-3 mm-wires are about 1.75 µΩ · cm, which meets the requirements of oxygen-free copper. [ABSTRACT FROM AUTHOR]

The detonation wave generation was investigated through the numerical simulation of a gas detonation spray gun. The results show that the detonation characteristic of gas detonation spray gun mainly depends on different gas detonation system and mixed gases matching. C2H2+O2 system is more suitable for spraying ceramic, metal-ceramic and nanocomposite powders than H2+O2 system, and its optimized spraying parameters are selected in the vicinity of zero-oxygen balance. Whereas H2+O2 system is an adaptive alternative for spraying metal and metal alloy powders. The higher the melting point of the powders, the nearer the optimized spraying parameters to the zero-oxygen balance. [ABSTRACT FROM AUTHOR]

The fluxes, a rare earth flux--JDN-I flux, C2Cl6 and a three-functions flux--flux B, were used to purify A00 melt, respectively and then three kinds of flux films were obtained. Tested and analyzed with SEM, EPMA, EDS, XRD and XRF, it was found that a protection film of two layers is generated by JDN-I flux during the purification of aluminum melt. The internal layer of the film that contacts with aluminum melt has a kind of net structure that is tight and tenacious, which is interweaved with streaky structure. The external layer that contacts with atmosphere is also composed of crystalline substances. The other flux films have not the above characters. Therefore, JDN-I flux has covering, protecting, and low melting loss functions. [ABSTRACT FROM AUTHOR]

Active enamels with corrosion resistance to molten aluminum were coated on the surface of ceramic foam filter with different pore sizes to filter molten aluminum. The tensile samples were analyzed by SEM, ICP-AES, and metalloscope with image analysis software. It is observed that fracture cracks of filtered samples are finer and dimples are smaller and more homogeneous than that of unfiltered ones. The ultimate tensile strength of filtered samples is nearly the same as that of unfiltered samples, while elongation percentage of the filtered samples increases by 15%. There is no change in the components of filtered samples. Fewer inclusions are found in filtered samples, and the size of inclusions in filtered samples is approximately 7 µm. In conclusion, the active enamels on the surface of ceramic foam Jilter can effectively capture inclusions in molten aluminum. [ABSTRACT FROM AUTHOR]

An investigation was made on the average heat flux in the crystallizer of a slab continuous caster at BAOSTEEL. It was :found that, when the casting speed increases to 1.2 m/min and more, the average heat flux on broad faces does not increase further with the casting speed while the temperature of the inlet and the outlet cooling water does not changed. The average heat flux is also affected by the carbon content of casting steel. When a steel with about 0.11~ carbon is cast, the average heat flux of both the broad and narrow faces of the mold decreases to minimum values. When the casting speed is more than 1.0 m/ min and the carbon content is 0.002%~0.05% or 0.13%~0.15%, the average heat flux on narrow faces is very close to the average heat flux on broad faces or even higher. This fact indicates that the mold wall taper should be reduced for the high speed casting of the steels with those carbon contents. [ABSTRACT FROM AUTHOR]

To improve the anti-corrosion property of low carbon steel in zinc melt, the iron boride is synthesized on the surface of the low carbon steel with solid boriding processing. The parameters were optimized through an orthogonal experiment method. The mechanical and anti-corrosion properties of the boriding coating were analyzed systematically. Finally. the boriding coating was successfully manufactured with the premium anti-corrosion property in zinc melt. [ABSTRACT FROM AUTHOR]

Protecting flux was used to improve the function of melt thermal treatment (MTT) process. The result shows that the protecting flux can resolve the oxidation problem of high temperature melt in MTT. It can also refine the Si-phase in the alloy. The protecting flux can protect the melt, refine the crystal and remove the impurity at the same time. The research also shows that if the protecting flux is added, MTT can reduce the size of the crystall to the full extent. [ABSTRACT FROM AUTHOR]

In order to make the optical reflector of space remote sensor keep high rigid structure and fine thermal stability, a kind of flexible regulating structure is developed in the paper. The reasonable flexible structure is designed, its dynamic model and parameters are analyzed, and the FEM simulation on reflector module is conducted. Results indicate that the value of PV of the reflector surface is far less than 63.2 nm, and the surface accuracy of reflector meets the needs of imaging quality due to regulation of flexible structure under the environment of force and thermal constraints. It is indicated further that the flexible regulating structure is reasonable in the actual design. [ABSTRACT FROM AUTHOR]

In order to make the structure of optical space remote sensor keep both high rigidity and good thermal stability, a flexible supporting structure with two vertical axes is proposed. It solves the contradiction of force and thermal constraints availably, which are two key environmental constraints influencing the imaging quality of reflectors, accordingly it keeps the effective position of optical reflectors and ensures the imaging quality of remote sensor. Structure parameters of flexible hinge are analyzed, and its performance is simulated by FEM. The results show that this kind of flexible supporting structure can keep stability of structure under the load of force and thermal constraints. [ABSTRACT FROM AUTHOR]

In order to improve the survival ability of armored vehicles in the war, the protecting technology has been attached importance and developed completely by the world military powers. The paper presented the research state and protecting level of modern armor, and enumerated protecting furnishment of advanced armored vehicles, and summarized the research state and level of key protecting technology-armor material. After introducing situation of armor protecting technology, taking the research content of U. S. and U. K., the development trend to the modern armor technology-synthesis protection system were analyzed. [ABSTRACT FROM AUTHOR]