Distribution and origin of high magnetic anomalies at Luobusa Ophiolite in Southern Tibet

The Luobusa Ophiolite,Southern Tibet,lies in the eastern portion of Indus–Yarlung Zangbo suture zone that separates Eurasia from the Indian continent.An aeromagnetic reconnaissance survey has revealed an EWtrending Yarlung Zangbo River aeromagnetic anomaly zone,and it is considered to be caused mainly by the Indus–Yarlung Zangbo Ophiolite.The Luobusa Ophiolite reflects the eastern portion of the Yarlung Zangbo River aeromagnetic anomaly zone.Conventionally,the ultramafic rock in the Luobusa Ophiolite is considered as the origin of the high magnetic anomalies.However,results from the surface magnetic survey and the magnetic susceptibility measurements from drill cores indicate that the high magnetic anomalies are distributed inhomogeneously in the Luobusa Ophiolite.In some cases,the susceptibility exhibits more than 30 times difference between two sides of the same sample.A fact emerged that the susceptibility of dunite with serpentinization is higher than that of fresh dunite,harzburgite and chromite when we analyzed the measurement results.In order to understand the origin of the high magnetic anomalies,we measured the density and susceptibility of 17 samples,microscopic and electron probe analyses have been performed as well.The result indicates the presence of dunite with serpentinization containing an abundant of micro-fissures filled with magnetite.Olivine has a susceptibility of about 2.7–351(910-5SI),pyroxene about 16–320,and chromite about200–800.All these units feature relatively low susceptibility in ultramafic rock,and only the magnetite is characterized by a high susceptibility of about 200,000(910-5SI).Based on these observations,we conclude that the precipitation of magnetite in the process of serpentinization of the olivine caused by the geological process in the Luobusa Ophiolite is the origin of high magnetic anomalies.     

Anomalous top-quark coupling effects in rare B and K decays

The Large Hadron Collider at CERN is performing direct searches for top-quark anomalous flavor-changing neutral current （FCNC） processes. However, these processes may be correlated closely with the low-energy rare B and K meson decays. In this paper, we review the anomalous top-quark coupling effects in these low-energy flavor transitions, summarize the flavor constraints and discuss their implications for direct detection of top-FCNC processes at the Large Hadron Collider.     

4 K high frequency pulse tube cryocooler used for terahertz space application

Terahertz(THz) frequency region, defined from0.1 to 10 THz, is an important frequency band for radio astronomy and atmospheric science. As NbN Superconductor-Insulator-Superconductor(SIS) mixers used for terahertz detection, which are studied by the Purple Mountain Observatory(PMO), Chinese Academy of Sciences(CAS), work at 8–10 K, and require condition of micro vibrations, its astronomical observation in aerospace is limited by suitable refrigeration method. 4 K high frequency pulse tube cryocooler developed by Key Laboratory of Space Energy Conversion Technologies(SECT), Technical Institute of Physics and Chemistry(TIPC), CAS, offers an opportunity for the application of SIS mixers. This article introduces the progress of the two-stage high frequency pulse tube cryocooler researched by TIPC. The cryocooler has reached a no load temperature of 4.5 K which is the lowest temperature for this kind of cryocooler reported so far. The successful coupling between the THz component and the high frequency pulse tube cryocooler lays a solid foundation for space detection in the terahertz band.     

Spatiotemporal characteristics of freezing and thawing of the active layer in the source areas of the Yellow River （SAYR）

Based on the analysis of data on temperatures and moisture of soils in the active layer at four different permafrost sites in the source areas of the Yellow River(SAYR)in 2010–2012,the freeze–thaw processes of soils in the active layer were compared and contrasted for understanding the spatiotemporal variations.At the four studied sites,the thickness and mean annual temperature of permafrost are different.The temperatures at the top of permafrost(TTOP),i.e.,the maximum depth(s)of seasonal frost and/or thaw penetration,are-1.9°C at the Chalaping site(CLP),-0.9°C at the site on the southern bank of the Zhaling Lake(ZLH),-0.4°C at the Maduo Town site(MDX),and 1.1°C at the site on the northern bank of the Eling Lake(ELH).Differences in the mean annual ground temperature of permafrost and TTOPs may be responsible for the differentiations in the freeze–thaw processes of soils in the active layer.With rising TTOPs,the ground thawing started earlier:CLP in early June,ZLH in late May,MDX in early May,and ELH in mid-April,while the freezing began later:CLP in early October,ZLH in early to midOctober,MDX in mid-October,and ELH in the mid-to late October.With increasing TTOPs,the freeze-up periods for permafrost sites were shortened:202 days at CLP,130 days at ZLH,100 days at MDX,and the period of complete thaw was 89 days at ELH.At the CLP and ZLH sites,the two-directional ground freezing(downwards from ground surfaces and upwards from the permafrost table)and thawing finished in the same year,but the ground freezing at the MDX continued to the end of the nextJanuary,with very slow freezing rates in the end.At the ELH site,ground freezing kept on until early May when thawing began on the surface,and upward and downward thawing became increasingly stable in late June to early July.At each site,with rising TTOPs,the downward freezing accelerated in comparison with the upward freezing,and with an increasing proportion of downward frozen depth,and with the larger ratios of freezing to thawing duration.In summary,the patterns of thawing and freezing processes in the active layer in the SAYR differ from those in other parts of the Qinghai–Tibet Plateau to a noticeable extent.     

Research and design of the main equipments and structure of Xiangjiaba shiplift

The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams. But the design methods and methodologies have rarely been discussed in literature. The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift. Being aimed at the technological rationality of the design in synthetically considering security, economy and applicability, this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift, including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test, the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift, the finite element method （FEM） analysis of stress, vibration modes and the buckling of ship chamber, antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms. This research provides the theoretical basis for the design of the Xiangjiaba shiplift. The design principles and research methods are valuable for the design of the same type of shiplifts.     

Research on Mineral Processing of Low Quality Kalium-Natrium Feldspar

In light of characteristic of low quality feldspar ores in Wanzai County, Jiangxi Province, steel ball was taken as grinding medium, and selective grinding could make impurity separate from feldspar effectively. Through the flow of flotation-desliming-high gradient magnetic separation, the feldspar Concentration 1 was obtained with the yield of 70.19 % ,containing Fe2O3 0. 17 % and TiO2 0.07 %. The feldspar Concentrate 1 could meet the quality requirement of high-grade construction ceramic. And the slime that was deslimed in the flow was also separated and recovered; the feldspar Concentration 2 was obtained with the yield of 13.18 %, containing Fe2O3 0.31% and TiO2 0.17 %. The feldspar Concentrate 2 can be used for raw material of low-end ceramic. And gangue, with the yield of 16.63 %, was thrown away in this flow, the separating efficiency was high. Employing this flow could also bring high economy benefit and low influence of pollution to environment.     

Spatiotemporal pattern and regional characteristics of visibility in China during 1976–2010

Degradation in visibility occurs extensively across China,creating the urgent need to better understand visibility patterns and characteristics in China.Using daily observation data from the U.S.National Climatic Data Center(NCDC)during 1976–2010,the spatial distribution and temporal trends of visibility in China,as well as seasonal and regional characteristics,were determined.The distribution of visibility was characterized by a longitudinal gradient between west and east China.The northwest of China generally experienced consistent high visibility of[20 km,while central and eastern China experienced visibility degradation and increase in haziness.The 133stations with significant downward trends in visibility were clustered around central-east China and the average reduction rate was-1.65 km/decade(from 18.5 km).The96 stations with increasing trends of visibility were mostly on the Qinghai–Tibet Plateau and Xinjiang and were closely related to a reduction in local sand storms.The average visibility in 12 key regions in China varied between9.9–17.8 km(except for 23.9 km in Urumqi),which was lower than the national average of 18.7 km.The Taiyuan–Hohhot,Guanzhong,Yangtze River Delta,Pearl River Delta and Fuzhou–Xiamen areas all encountered significant decreases in visibility,while minor increases were observed in Beijing–Tianjin–Hebei and the Cheng-Yu region.At most stations,the worst visibility was measured in winter,but the season with best visibility varied between regions.A comparison of visibility trends with the emission trends of various pollutants revealed that SO2emissions dominated the visibility degradation in eastern Chinawith NOxand volatile organic compounds playing ascending roles during the 2000s.     

Effect of strain rate on the compressive deformation behaviors of lotus-type porous copper

Lotus-type porous copper was fabricated by unidirectional solidification, and compressive experiments were subsequently conducted in the strain rate range of 10-3–2400 s-1 with the compressive direction parallel to the pores. A GLEEBLE-1500 thermal-mechanical simulation system and a split Hopkinson pressure bar (SHPB) were used to investigate the effect of strain rate on the compressive deformation behaviors of lotus-type porous copper. The influence mechanism of strain rate was also analyzed by the strain-controlling method and by high-speed photography. The results indicated that the stress-strain curves of lotus-typed porous copper consist of a linear elastic stage, a plateau stage, and a densification stage at various strain rates. At low strain rate (< 1.0 s-1), the strain rate had little influence on the stress-strain curves; but when the strain rate exceeded 1.0 s-1, it was observed to strongly affect the plateau stage, showing obvious strain-rate-hardening characteristics. Strain rate also influenced the densification initial strain. The densification initial strain at high strain rate was less than that at low strain rate. No visible inhomogeneous deformation caused by shockwaves was observed in lotus-type porous copper during high-strain-rate deformation. However, at high strain rate, the bending deformation characteristics of the pore walls obviously differed from those at low strain rate, which was the main mechanism by which the plateau stress exhibited strain-rate sensitivity when the strain rate exceeded a certain value and exhibited less densification initial strain at high strain rate.     

Observations of thermospheric vector wind over Yellow River Station during auroral substorm events

Strong disturbances associated with auroral substorms originate from the ionosphere-magnetosphere owing to the effects of the solar wind, and the wind field in the ionosphere is related to such substorm activity. Here, we describe the analysis of four auroral substorm events, for which we employed an all-sky Fabry-Perot interferometer to observe the two-dimensional horizontal wind field and combined the results with data from an all-sky charge-coupled device imager, a fluxgate magnetometer installed at Yellow River Station, and the Super Dual Auroral Radar Network. The results demonstrate that, during auroral substorms, the vector wind field is related closely to variations in the ion drift and geomagnetic field. Moreover, we observed a changing wind field of approximately 300 rn/s in response to variations in the electric and magnetic fields （likely caused by ion drag） and a disturbance of about 200 m/s that we attribute to the interaction of Joule heating and ion drag.     

Role of Ferrel cell in daily variability of Northern Hemisphere Annular Mode

The Northern Hemisphere Annular Mode(NAM) represents the zonally symmetric planetary-scale atmospheric mass fluctuations between middle and high latitudes, whose variations have shown a large impact on other components of the climate system. Previous studies have indicated that the NAM is correlated with the Ferrel cell in their monthly or longer timescale variability.However, there have been few studies investigating their connections at daily timescale, though daily variability of NAM has been suggested to be an important component and has significant implication for weather forecast. The results from this study demonstrate that variability of the Ferrel cell leads that of the NAM by about 1–2 days. This statistically identified temporal phase difference between NAM and Ferrel cell variability can be elucidated by meridional mass redistribution. Intensified(weakened)Ferrel cell causes anomalously smaller(larger) poleward mass transport from the middle to the high latitudes,resulting in an increase(a decrease) in mass in the middle latitudes and a decrease(an increase) in the high latitudes.As a consequence, anomalously higher(lower) poleward pressure gradient forms and the NAM subsequently shifts to a positive(negative) phase at a time lag of 1–2 days. The findings here would augment the existing knowledge for better understanding the connection between the Ferrel Cell and the NAM, and may provide skillful information for improving NAM as well as daily scale weather prediction.     

Evaluation on Gambiered Guangdong Silk＇s Ecological Properties

To evaluate gambiered Guangdong silk＇s ecology properties, the raw materials ecology, production ecology and use ecology are analyzed; and the safety to human is tested according to GB/T18885 - 2002. Gambiered Guangdong silk is a kind of natural product. All its raw materials are reproducible and degradable natural resources, and it can decompose completely when being discarded. R is comfortable to wear, and easy to clean and dry. It is mainly manufactured by dip-dyeing in dye yam solution, and insolating under the burning sun. The production energy is solar, a kind of clean and reproducible energy. The production process is clean and environmental friendly. There is neither the utilization of synthetic dyestuff and chemical auxiliary, nor the discharge of environment pollutant, and even the dreg of dye yam is used as fuel. The safety test results show that pH value of water extract, heavy metal content （except for Pb content）, color fastness and odor meet the requirements of GB/T18885 - 2002 and Okeo-tex standard 100.     

Key technologies of precision demolition blasting of ultra-long urban viaduct in complicated surroundings

The key technologies of precision blasting were put forward based on the characteristics of urban via- duct blasting demolition in complicated surroundings. Initial bending instability mechanics model of reinforcing steel bar frame of blasting fragmented pier and sequenced collapsed dynamic model were established for quanti- tative blasting design. Technologies of water pressure blasting were applied in multi-cell box girder fragmenta- tion. The detonating network of non-electric duplication crossover was adopted for the safety and reliability of ultra-long delay. The rationality of blasting scheme and parameters were validated by physical model test. Harm- ful effects were forecasted and controlled by integrated protective technologies. Specialization, cooperation, pre- cision, execution （SCPE） project management method was put forward for precision management. The key tech- nologies of precision demolition blasting can provide reference for similar proiects.     

On the Functions of Euphemism in Social Communication

In the process of social linguistic communication, due to the different circumstances and conditions, people can not express certain things clearly in a direct way when they come across something painful, unpleasant, disgusted and even embarrassing. Instead, they have to use some vague, implicit, mild and euphemistic expressions, so as to achieve the purpose of expressing feelings and exchanging ideas and thoughts in an appropriate and light atmosphere. This paper tries to deal with the application of euphemisms in various fields, thereby reveal some main functions of euphemism, i.e. avoidance function, politeness function, gloss-over function and disguise function.     

An observational study of snow aging and the seasonal variation of snow albedo by using data from Col de Porte,France

An 18-year long （1993-2011） comprehensive dataset of snow and meteorological variables from Col de Porte, France is used to analyze the variation of shortwave broadband albedo with elapsed time after snowfalls （snow aging） during each snow season. The effects of air temperature, snow surface temperature and snow depth on snow albedo are investigated. An index based on the accumulation of air temperature over several consecutive days with daily mean higher than 2.5 ℃ is proposed to divide each snow-covered period into a dry and the following wet snow season when this index reaches 18 ℃. The results indicate that snow surface albedo decreases exponentially with time in both dry and wet snow seasons. Snow albedo reduction with snow aging is small at low surface temperature and the reduction rate increases with the rise of surface temperature. However, the reduction rate is widely scattered within the observed range of temperature, implying a loose relationship between snow albedo and snow surface temperature. Snow albedo in wet snow season is generally smaller and decreases faster than in dry snow season. For Col de Porte site, snow depths to effectively mask the underlying surface are 21 and 33 cm in dry and wet snow season respectively.     

Crystal structures,antibacterial activity and thermal decomposition kinetics of lanthanide complexes with 4-chloro-2-methoxybenzoic acid and 1,10-phenanthroline

A series of lanthanide complexes [Ln(4-Cl-2-MOBA)3phen]2(Ln=Sm(1), Nd(2), Ho(3), Eu(4), Dy(5), and Tb(6); 4-Cl-2-MOBA=4-chloro-2-methoxybenzoate, phen=1,10-phenanthroline) were synthesized and characterized. The single-crystal X-ray diffraction demonstrates that 1–3 are isomorphous, which present dimeric structures with four 4-Cl-2-MOBA anions function as bridging ligands. Complexes 1 and 4–6 display their characteristic luminescence emission bands of central Ln3?ions. The heat capacities, the thermodynamic functions and the thermogravimetry–Fourier transform infrared spectra of gaseous products of complexes 1–6 were investigated.Their non-isothermal kinetics of the second decomposition stage was studied by the integral isoconversional non-linear method and Stark method. Furthermore, 1–6 exhibited excellent antibacterial activity against Candida albicans,Escherichia coli and Staphylococcus aureu.     

Fabrication and Properties of Microencapsulated n-octadecane and Paraffin

Microencapsulated n-alkanes as energy- storage materials have promising application prospects. The ndcrocapsules containing 100 - 50 wt% of n - octadecane, 0 -20 wt% of paraffin and 0 - 30 wt% of cyclohexane were synthesized by in-situ polymerization using melamine- formaldehyde polymer as shell. Cyclohexane was removed after heat-treated the microcapsules at 100℃. The morphologies, cell parameters, phase change properties, thermal stable temperatures of these microcapsules were examined. The diameters of these microcapsules are lower than 5 μm. The effect of paraffin in the microcapsules on the cell parameters of n-octadecane is negligible. The paraff＇m is effectively used as a nucleating agent to decrease the degree of supercooling. The melting enthalpy is decreased from 132 J/g to 111 J/g due to the increase of the cyclohexane contents. The thermal stable temperature is enhanced 6 - 16℃ after heat-treated the microcapsules at 160℃ for 30 min.     

Thermoelectric properties of Al substituted misfit cobaltite Ca3（Co1-xAlx）4O9 at low temperature

Thermoelectric properties of Al substituted compounds Ca3（Co1-xAlx）4O9 （x=0, 0.03, 0.05）, prepared by a sol-gel process, have been investigated in the temperature range 305-20 K. The results indicate that after Al substitution for Co in Ca3（Co1-xAlx）4O9, the direct current electrical resistivity and thermopower increase due to the reduction of carrier concentration. Experiments show that Al substitution results in decreased lattice thermal conductivity. The figure of merit of temperature behavior suggests that Ca3（Co0.97Al0.03）4O9 would be a promising candidate thermoelectric material for high-temperature thermoelectric application.     

Equilibrium between titanium ions and high-purity titanium electrorefining in a NaCl-KCl melt

TiCl_x (x = 2.17) was prepared by using titanium sponge to reduce the concentration of TiCl₄ in a NaCl-KCl melt under negative pressure. The as-prepared NaCl-KCl-TiCl_x melt was employed as the electrolyte, and two parallel crude titanium plates and one high-purity titanium plate were used as the anode and cathode, respectively. A series of electrochemical tests were performed to investigate the influence of electrolytic parameters on the current efficiency and quality of cathodic products. The results indicated that the quality of cathodic products was related to the current efficiency, which is significantly dependent on the current density and the initial concentration of titanium ions. The significance of this study is the attainment of high-purity titanium with a low oxygen content of 30×10-6.     

A 14.5Gb/s word alignment circuit in 0.18μm CMOS technology for high-speed SerDes

This paper presents a word alignment circuit for high speed SerDes system.By using pipeline structure and circuit optimization techniques,the speed of the aligner is increased,and its performance is improved further through adopting the full custom design method.The proposed word aligner has fabricated in 0.18μm CMOS technology with total area of 1.075 ×0.775mm~2￣ including I/O pad.Measurement results show that this circuit achieves the maximum data rate of 14.5Gb/s,while consuming a total power of 34.9mW from a 1.8V supply.