Higher sea surface temperature in the northern South China Sea during the natural warm periods of late Holocene than recent decades

The large-scale syntheses of global mean temperatures in IPCC fourth report suggested that the Northern Hemisphere temperature in the second half of the 20th century was likely the highest in at least the past 1,300 years and the 1990s was likely the warmest decade. However, this remains debated and the controversy is centered on whether temperatures during the recent half century were higher than those during the Medieval Cli- mate Anomaly （MCA, AD 800-1300） and the Roman Warm Period （RWP, BC 200-AD 400）, the most recent two natural warm periods of the late Holocene. Here the high resolution sea surface temperatures （SSTs） of two time windows around AD 990 （±40） and AD 50 （±40）, which located in the MCA and RWP respectively, were reconstructed by the Sr/Ca ratio and 6180 of Tradacna gigas shells from the northern South China Sea. The resultssuggested that the mean SSTs around AD 990 （±40） and AD 50 （＋40） were 28.1 ℃ and 28.7 ℃, 0.8 ℃ and 1.4 ℃ higher than that during AD 199±2005, respectively. These records, together with the tree ring, lake sediment and literature records from the eastern China and northwest China, imply that the temperatures in recent decades do not seem to exceed the natural changes in MCA, at least in eastern Asia from northwest China to northern SCS.     

Ecological functioning of free-living marine nematodes in coastal wetlands: an overview

Nematodes are small multicellular, thread-like organisms, inhabiting almost all conceivable environments; among these, some 25 % are free-living marine forms with a population density of （1-12） × 10^6 inds m^-2 in seabed sediment, reaching maximum values in muddy estuaries and salt marshes. A large quantity of carbon from the salt marsh plants enters the ecosystem via the detritus pathway, in which nematodes play an important role through their feeding and bioturbation activities. Vegetation influences the sedimentary environment and modifies the distribution pattern of nematode communities in coastal wetlands. Nematodes are coupled closely with bacteria/detritus in microbial food webs, stimulating bacterial growth and subsequent nutrient remineralization; they provide food sources for higher trophic levels and serve as a linkage between micro- and macro-fauna. Furthermore, nematodes have a potential to provide proxies that can be used in diagnosing environmental quality. In China, only a limited number of nematode data sets are available for the coastal wetlands across several different climatic zones. It is necessary to carry out additional investigations into the biology and ecology of nematodes in order to delineate their ecological functioning in coastal wetlands. On such a basis, the contribution made by nematodes to material cycling and the ecological functioning in coastal wetlands can be quantified. The assessment of their biological diversity should be a focus, which is fundamental in the study of wetland ecosystem dynamic mechanisms. In addition to laboratory and mesocosm experiments, mathematical models should be established to predict the responses of ecosystem to the environmental disturbance. Finally, it is necessary to improve the techniques for nematode analysis, to enhance the efficiency of data acquisition.     

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.     

Formation of highly crystalline maghemite nanoparticles from ferrihydrite in the liquid phase

Fe5O7（OH）·4H2O ferrihydrite is a low-crystal- linity antiferromagnetic material, γ-Fe2O3 （maghemite） magnetic nanoparticles were prepared from a ferrihydrite precursor, by chemically induced transformation in FeCl2/ NaOH solution. The magnetization, morphology, crystal structure and chemical composition of the products were determined by vibrating sample magnetometry, transmission electron microscopy, X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy （XPS）. Ferrihydrite underwent aggregation growth and transformed into α-FeO（OH） （goethite） particles, which subsequently transformed into γ-Fe2O3 nanoparticles, that became coated with NaCI. The γ-Fe2O3 particles had a flake-like morphology, when prepared from 0.01 mol/L FeCl2 and a FeCl2：NaOH molar ratio of 0.4. The γ-Fe2O3 particles were more spherical, when prepared from a FeCl2：NaOH molar ratio of 0.6. The Fe content of the flake-like particles was lower than that of the spherical particles. Their magnetizations were similar, and the coercivity of the flake-like particles was larger. The differences in morphology and magnetization were attributed to the surface effect, and the difference in coercivity to the shape effect.     

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.     

40Ar/39Ar ages and stable isotopes of supergene jarosite from the Baiyin VHMS ore field,NE Tibetan Plateau with paleoclimatic implications

Supergene jarosite is widely distributed in weathering profiles derived from hypogene sulfide ores.Precise40Ar/39Ar dating and determination of hydrogen and oxygen isotopes of supergene jarosite can not only place tight constraints on the timing and history of continental weathering and supergene enrichment of sulfide ore deposits,but also shed significant insights into paleoclimatic conditions and tectonic uplift responsible for the weathering.In this paper,we present a preliminary study of40Ar/39Ar geochronology and stable isotope geochemistry of supergene jarosite from the early Paleozoic Zheyaoshan volcanic-hosted massive sulfide deposit of the Baiyin ore field located in the eastern portion of the Qilian Mountain along the northeastern(NE)margin of the Tibetan Plateau in an attempt to better understand the climatic conditions prevailed during the pervasive weathering in the region.Jarosite from the Zheyaoshan mining area occurs either as gravels within alluvial deposits over low-relief flat-top hills or cm-wide veins crosscutting weathered sulfide ores or their wall rocks.The gravels consist of massive jarosite aggregates with tabular crystal morphology and contain 8.21 wt%–8.31 wt%K2O on average.Two jarosite grains extracted from the gravels(08-02-2 and 08-02-5)yield well-defined40Ar/39Ar plateauages of 37.1±0.3 and 41.2±0.4 Ma(2r),respectively.They have dD values of-133%and-156%,and d18OSO4values of 2.6%and 2.5%.The vein-type jarosite consists of hexagonal pyramid crystals and contains much lower K2O,averaging at 2.44 wt%–2.72 wt%.Two jarosite veins(06-16-3 and 06-16-4)yield similar plateau ages of 3.2±0.1 and 3.3±0.1 Ma(2r),respectively.These jarosite veins have dD values of-158%and-160%,and d18OSO4values of 2.8%and 2.5%.The40Ar/39Ar ages indicate that sulfide ores of the Zheyaoshan deposit must have been brought to the surface since the late Eocene,and subsequently subjected to prolonged oxidation and supergene enrichment.The precipitation and preservation of jarosite in weathering profiles indicate that arid–semiarid climatic conditions must have been prevailed since the late Eocene.The hydrogen and oxygen isotopes of the jarosite further point to variation of climatic conditions in the area,with the Pliocene being slightly cooler relative to the late Eocene.Given that weathering profiles overlying sulfide ore deposits are widely distributed along the Qilian Mountain,systematic studies of40Ar/39Ar geochronology and stable isotope geochemistry of jarosite-group minerals from these profiles would provide valuable information on the timing and evolution of regional tectonic uplift,paleoclimatic changes,and supergene mineralization in this mountainous belt along the NE edge of the Tibetan Plateau.     

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.     

Resting state brain default network in patients with motor aphasia resulting from cerebral infarction

To explore the brain default mode network （DMN） in patients with motor aphasia resulting from cere- bral infarction, we used resting state functional magnetic resonance imaging （fMRI） to investigate the possible neural mechanism. Thirteen patients with motor aphasia resulting from cerebral infarction and ten matched controls were selected in this study. All subjects were examined using resting state fMRI. We chose the posterior cingulate cortex as the region of interest and then used functional connectivity analysis to calculate the DMN functional connectivity and analyze differences in the functional connectivity between the two groups. Compared with normal controls, aphasia patient group showed a significantly decreased functional connectivity in bilateral medial frontal gyrus, superior frontal gyrus, middle frontal gyrus, middle temporal gyrus, precuneus and cuneus. The aphasia patient group showed increased functional connectivity mainly in bilateral medial frontal gyrus, middle frontal gyrus, inferior frontal gyrus, precentral gyrus, insula. The DMN in cerebral infarction motor aphasia patients showed significantly decreased functional connectivity in the resting state. The DMN most likely plays an important role in motor aphasia resulting from cerebral infarction. Furthermore, functional connectivity inthe brain regions surrounding the left and right Broca＇s areas was significantly enhanced due to compensatory mecha- nisms. This may be helpful for the recovery of language function in cerebral infarction patients with motor aphasia.     

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.     

System integration and innovation of operating 20 kt combined heavy-haul train on Datong-Qinhuangdao line

Datong-Qinhuangdao line, as the first electrified double-track heavy-haul line dedicated to coal transport in China, extends from Datong in the west, and reaches Qinhuangdao in the east, opened to traffic in December, 1992, totaling 653 km with the designed annual traffic volume of 1 × 10^8 t. In order to meet the demands of national economic development, the transport capacity of the line must be enhanced greatly. Depending on independent innovation, MOR, for the first time in the world,realizes the integration between GSM-R and Locotrol, the integration between 800 MHz digital radio and Locotrol, and the integration between a single set of Locotrol and SS4 locomotive. Meanwhile, CR develops equipment portfolio for heavy-haul through combining 2 high power locomotives of HXD series （ means harmony） with controllable EOT. Relying on integration and innovation, it succeeds in operating 20 kt-level combined heavy-haul train on Datong-Qinhuangdao line, which tripled the annual traffic volume of the line from 1 × 10^8 t in 2002 to 3 × 10^8 t in 2007.     

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.     

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.     

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.     

World English and the Future of English Language Teaching in China

The development and wide spread of English language has led to the internationalization and localization of English language, during which English language is widely used in international communications by people with different mother tongues, in addition, English variations on different levels and local varieties have emerged. In consideration to the changes above, this paper aims to, firstly, examine the status of English language as an international language （EIL）; secondly, explore the future of English language teaching （ELT） in China under a global context.     

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.     

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.     

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.     

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.