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.     

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.     

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.     

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.     

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.     

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.     

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.     

Response of the East Asian summer monsoon to large volcanic eruptions during the last millennium

The responses of the East Asian summer monsoon （EASM） to large volcanic eruptions were analyzed using a millennial simulation with the FGOALS-gl climate system model. The model was driven by both natural （solar irradiance, volcanic eruptions） and anthro- pogenic （greenhouse gases, sulfate aerosols） forcing agents. The results showed cooling anomalies after large volcanic eruptions almost on a global scale. The cooling over the continental region is stronger than that over the ocean. The precipitation generally decreases in the tropical and subtropical regions in the first summer after large volcanic eruptions. Cooling with amplitudes up to -0.3 ℃ is seen over eastern China in the first summer after large volcanic eruptions. The East Asian continent is dominated by northeasterly wind anomalies and the corresponding summer rainfall exhibits a coherent reduction over the whole of eastern China. An analysis of the surface heat flux suggested the reduction in summer precipitation over eastern China can be attributed to a decrease of moisture vapor over the tropical oceans, and the weakening of the EASM may be attributed to the reduced land-sea thermal contrast after large volcanic eruptions.     

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.     

A Class of the Hamming Weight Hierarchy of Linear Codes with Dimension 5

The weight hierarchy of a [n; kI q] linear code C over Fq is the sequence(d1,… dr,… dk), where dr is the smallest support weight of an r-dimensional subcode of C. In this paper, by using the finite projective geometry method, we research a class of weight hierarchy of linear codes with dimension 5. We first find some new preconditions of this class. Then we divide its weight hierarchies into six subclasses, and research one subclass to determine nearly all the weight hierarchies of this subclass of weight hierarchies of linear codes with dimension 5.     

Thermodynamic analysis of the compositional control of inclusions in cutting-wire steel

Data from a thermodynamic database and the calculation software FactSage were used to investigate the phase diagrams of the MnO-CaO-SiO₂-Al₂O₃ system in cutting-wire steel and the effects of oxide components on the low-melting-point (LMP) zone in the corresponding phase diagrams. Furthermore, the activities of oxide components in the quaternary system at an Al₂O₃ content of 25wt% were calculated. The contents of dissolved [Al] and [O] in liquid steel in equilibrium with LMP inclusions in the MnO-CaO-SiO₂-Al₂O₃ system were optimized. The results show that the MnO-CaO-SiO₂-Al₂O₃ system possesses the largest LMP zone (below 1400°C) at an Al₂O₃ content of 25wt% and that the CaO content should be simultaneously controlled in the range of 40wt% to 45wt%. The activities of the oxide components CaO, MnO, and SiO₂ should be restricted in the ranges of 0 to 0.05, 0.01 to 0.6, and 0.001 to 0.8, respectively. To obtain LMP inclusions, the [Al] and [O] contents in cutting-wire steel must be controlled within the ranges of 0.5×10-6 to 1.0×10-5 and 3.0×10-6 to 5.0×10-5, respectively.     

Reliability analysis on bolt support structure of coal roadway under the influence of mining

Based on the features of the serious deformation of coal roadway, many random variables of the mechanics of the surrounding rocks and the influence of mining, the reliability analysis model of the support structure of coal roadway under the influence of mining is established, and the calculating formulas of reliability of the support structure is obtained with the engineering structure reliability theory. And the reliability is calculated based on the method of Monte Carlo to the coal roadway which is exampled on the influence of mining or not. The relationship between support parameters and reliability, the mining influence coefficients and reliability is established, which provides theory foundations for the design of the coal roadway bolt support.     

Kinetics of blue-green light-induced state transition and fluorescence quenching in the wild-type cyanobacterium Synechocystis PCC 6803 and apcD − and apcF − mutants

State transition and blue-green light-induced fluorescence quenching are two short-term processes in cyanobacteria. The details of their kinetics and the relationship between these processes have not been elucidated. In this work, these two processes were studied in the wildtype cyanobacterium Synechocystis PCC 6803 cells as well as in apcD^- and apcF^- mutants by monitoring their time- dependent 77 K fluorescence responses to blue-green light （430-540 nm） at a series of intensities ranging from 20-800 μE m^-2 s^-1. The lowest light intensity to induce fluorescence quenching in wild-type cells was 160 μE m^-2 s^-1 under the selected experimental conditions, while state transition took place at the intensities lower than 160 μE m^-2 s^-1 at a conservative level, but at variable rates. The quenching level increased at intensities higher than 160 μE m^-2 s^-1, reaching the maximum level at intensities equal to or higher than 200 μEm^-2 s^-1. Fluorescence kinetics indicated that both the length of the induction period and time required to reach the maximum level were functions of light intensity. State transitions as well as fluorescence quenching took place in both wildtype and mutant cells, but might involve different mechanisms.     

Significant isostatic imbalance near the seismic gap between the M8.0 Wenchuan and M7.0 Lushan earthquakes

A gravity network with 302 observation points has been established in the western Sichuan Foreland Basin （SFB） to explore Bouguer gravity anomalies （BGAs）. Our observational results reveal that the BGAs are negative as a whole, with a maximum value of -220 mGal （10^-5m s^-2） at the northwest region of the study area. The real Moho depths beneath the SFB revealed by BGA data change smoothly from 39.5 km in the southeast to 43.7 km in the northwest of the monitoring region. However, the isostatic ones deduced from Airy isostatic model and topographical data vary approximately 39.5-42.0 km. The maximum differences of 2.7 km between the real and isostatic Moho depths are found near the seismic gap between the M8.0 Wenchuan and M7.0 Lushan earthquakes, where the crust is in the greatest isostatic imbalance of the monitoring region. Analysis of the isostatic state indicates that the deep dynamic environment near the seismic gap between these two earthquakes indicates an M ≥ 7.0 earthquake in the future. This study indicates that we can use isostasy as a potential approach to study the dynamic process of crustal material movement and to analyze regional potential seismic risks.     

The two-body hadronic decays of Bc meson in the perturbative QCD approach： a short review

Along with the running of Large Hadron Collider （LHC） located at CERN in November 2009, a large number of data samples of Bc meson have been collected and some hadronic Bc decay modes have been measured by the LHC experiments. In view of the special and important roles of Bc meson decays playing in the heavy flavor sector, we here give a short review on the status of two body hadronic decays Bc→M1M2 at both experimental and theoretical aspects. For the theoretical progresses, specifically, we will show lots of theoretical studies on two body hadronic Bc decays involving pseudoscalar, vector, scalar, axial-vector, even tensor meson（s） in the final states by employing the perturbative QCD （pQCD） factorization approach. We will present a general analysis about the two- body hadronic decays of the heavy Bc meson and also provide some expectations for the future developments.     

Recent progress in studies layer in rock on the nano-sized particle shear planes

Since the 1990s, an ultramicro-particle texture in nano- or micron-sized scale has been continually found in shear planes of various rocks, and recently further progress was made in generic physical mechanisms. In this article, the characteristics of the nano-sized particle layer in rock shear planes （including widespread distribution, layering texture, non-linear genetic mechanism, and multiple functions） on an ultra micro-scale were briefly introduced and more information was obtained by analyzing cases from home and abroad. Our findings suggest that （1） there is a paragenetic relationship between the development of shear frictional- viscous and the formation of nano-sized particles, and （2） in the shear movement, partitioning, segregating, and layering in rocks are initiated by the sliding motion of the nano-sized particle layer. Moreover, the plastic rheology of rocks is essentially the movement of ultra-micro-sized particles （nano-size and micro-size）, and the nano-sized particle layer in rock shear planes is characterized by some particular physical and chemical effects.     

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.     

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.     

Minimization of influence by the drooping eyelid in extracting pupil center for eye tracking systems

Precise pupil center detection is an important factor for gaze tracking in video-oculography （VOG） systems. Existing methods perform well to extract the features when the area of pupil in eye image is clear, whereas, interferences, such as eyelashes, corneal reflection etc., will lead to a low success rate. One main reason is the closure of eyelids. In this paper, a systemic 3D transformation algorithm is proposed to accurately ascertain the pupil center, in spite of the complicating factors mentioned above. Experiments show the good performance of our method. And the pupil center could be extracted accurately, even though only 25% of the pupil is visible.