Distribution of methane and its homologues in low-layer atmosphere over eastern China and seas

Systematic, fixed_point and long observations and sample testing make clear distributions of methane and the homologues in the low_layer air over eastern China and sea areas. Within about 250 km from epicenter of moderate and strong earthquakes, oil_gas areas have methane concentration anomaly and CO\-2 anomaly in the low_layer atmosphere around the earthquakes, have a temperature increase by 1-6℃ at the occurrence of moderate and strong earthquakes and indicate that concentration anomaly of methane family in the low_layer air can be used as an important index for petroleum geochemical exploration.     

Study of the ionospheric anomaly before the Wenchuan earthquake

The behavior of the ionosphere before the Wenchuan earthquake is analyzed with the global TEC and ionospheric foF2 observed at Xiamen. It can be found from TEC maps that in the afternoon (16―18LT) on May 9, 2008, 3 days before the earthquake, there is an enhancement of TEC with an amplitude of 10―15 TECU appearing in the east-south direction of Wenchuan, and another enhancement appears at the conjugate region of the Southern Hemisphere with an amplitude of 10 TECU, but no obvious in-crement or decrement can be seen in other regions on global scale. It can also be found that on May 6 (6 days before the great earthquake), there is a decrement of TEC with small amplitude of 4TECU and larger area with 80° along the longitude in southern China, and there is no synchronous decrement observed at the conjugate region of the Southern Hemisphere. There are also many anomalies ob-served by ionosondes across China. The result shows that foF2 and TEC abnormally increased, which is different from pervious results that ionospheric parameters decreased prior to earthquakes. Pre-liminary results suggest that the enhancement on May 9 maybe has a close relationship with the pos-sible enhancement of ionospheric electric fields, and it may be an ionospheric precursor of earth-quakes. Whereas the decrement on May 6 may be attributed to the geomagnetic disturbance appearing on May 5.     

THE ORIGINS AND CLASSIFICATION OF EARTHQUAKE LANDFORMS IN THE ALLUVIAL PLAINS OF EASTERN CHINA

Based on observations of earthquakes that have occurredin theplains of eastern China during recent yeas, the characteristics origins, classification and distribution patterns of earthquake landforms in alluvial plains are discussed. In such flat areas, earthquakes are capable of complete reversal of topographic gradients; minor hills can be replaced by hollows and depressions can experience uplift. The major factors influencing the development of such landforms in alluvial plain are the force of the earthquake, surface and sub-surface characteristics, the thicknesses of different subsurface layers, the height of the groundwater table and the relief. Earthquake hndforms in alluvial plains may be classified hto three main groups (1) Landforms directly associated with the liquefaction of sand hyers; (2) Landforms associated with the passage of earthquake waves; and (3) Landforms associated with earthquake structures. In turn, these categories can be further sub-divided. Through analysis of the Tangshan earthquake landforms, several characteristics of the distribuinn patterns of earthquake landforms in allu vial plains have been recognised.     

Thoughts on studies of China continental geology and tectonics

As an important part of the global continents, China continent has long been situated in the peculiar tectonic position and experienced extremely complicated activities, which resulted in the regional unique characteristics for China continent on the global common geological background. These characteristics contain abundant information regarding scientific key issues of modern geological frontier. Thus, China continent can be a natural laboratory and excellent arena for the modern geosciences. The modern earth sciences have started entering the era featured with earth systematic science and beyond plate tectonics. How to take the regional advantage and exploit the treasure resource to participate the new theoretical and methodological creation is a historic opportunity and great challenge we are facing. This paper generalizes research priorities in four fields on China continental geology and tectonics for discussion. They are: China continental tectonics and dynamics; Mesozoic-Cenozoic crustal deformation and deep-seated processes in China continent and the adjacent regions; deep-seated dynamic background and evolutionary trend of crustal tectonic activities on the time scale of human existence; deep-seated background and processes of conjunction and transformation of different tectonic systems.     

Reference benchmarks relating to great groups of genetic soil classification of China with soil taxonomy

Soil classification forms the basis for the ex-change and extension of research findings in soil science and for the modernization of management of soil resources. This paper systematically reviews the compatibility of the genetic soil classification of China (GSCC) and soil taxonomy (ST). This includes a study of the evolution and consummation of the GSCC and assessment of the databases and methods of the study. Using the 揝oil Species of China (six volumes) and some provincial soil species as the basic material, the authors gathered information from 2540 soil species. Based on the key described in ST, the 2540 soil species were taxo-nomically classified into corresponding soil orders, suborders, great groups and subgroups and then matched with corre-sponding map units in the 1︰1000000 digital soil map of China. Using the high-level classification units of the two soil classification systems, and the attributes of each soil species, the sizes of distribution areas were mapped. The soil distri-bution results were analyzed and compared statistically. The reference compatibility between the great groups used in GSCC system and the soil orders of the ST is discussed. It is believed that 20 great groups display maximum referencibil-ity >95% and 15 great groups depict maximum referencibil-ity in the range of 70%—95%, which can be cited as refer-ence benchmarks. The remaining 25 great groups are less compatible (with maximum referencibility <70%) and need further study, or require referencing at lower classification levels or at a regional level to help to improve the accuracy of the reference.     

The M5.0 Suining-Tongnan （China） earthquake of 31 January 2010： A destructive earthquake occurring in sedimentary cover

Usually, only crystalline basement is strong enough to store the massive strain energy that can be released in a damaging earthquake. By contrast, sedimentary cover is weak, because of its relatively high porosity and fluids. Therefore, it generally cannot accumulate enough energy for strong earthquakes. On January 31, 2010, a M5.0 earthquake occurred near the border of Suining and Tongnan in China. It excited strong short-period Rayleigh waves Rg, indicative of its shallow focal depth. The focal depth is constrained to less than 4 km, most probably in the range of 1-3 km, by modeling amplitude dependence on the frequency and waveforms of teleseismic depth phases (pP, sP). Because the local Mesozoic sedimentary cover is about 6 km thick, this earthquake should have occurred in the sedimentary cover. Though some shallow earthquakes with magnitudes up to M4 occur in Paleozoic sediments, this earthquake is the first M5 event studied in Mesozoic sedimentary cover. This event provides a rare opportunity to study seismogenic processes of damaging earthquakes in sedimentary basins.     

Digitization characteristics of geothermal information and structural analysis of 2011 off the Pacific coast of Tohoku Ms9.0 earthquake

Earthquake is one of the difficult problems that can not be solved as of this writing since the time when modern science was initiated over 300 years ago, and irregular events cannot be dealt with by using quantities examples before and followed by a view of the number of analysis systems in modern science; meanwhile, it covers the problem that how to use changeable information. Structural analysis method is developed particularly for the study of evolutionary transitional processes of the changing events by employing irregular information, and emphasizes the primitiveness of changes in events. Based on the data of sounding observation every 08 o’clock and 20 o’clock per day from China Meteorological Administration, in this paper, we employ the digital structural analysis method to analyze the process of the special, structural characteristics of 2011 off the Pacific coast of Tohoku Ms9.0 earthquake. The result shows that the method can reflect the process of geothermal structures before and after earthquake; it can reflect the congruity between geothermal "heat level" and the level of earthquake energy. When the structure before the earthquake is "the counter clockwise rolling current and the unstable structures" with "dry in lower levels and wet in upper levels", we should be worry about the problem of earthquake. In a word, geothermal information could reveal that earthquakes really would be "heralded".     

Transient reconnection caused by non-homogenous dynamic pressure

It is proposed that local and transient reconnection in the plasma boundary layer can be caused by the impact and switch-off of non-homogenous dynamic pressure. Magnetohydrodynamic simulation is used to investigate the reconnection processes in these two cases. It is found that if the inflow is homogeneous, the reconnection will not take place; if the inflow is a shearing flow, no matter how great the shear of the flow is, the reconnection can be caused either during or after the impacting period. It is pointed out that a sudden stop of external force may be an important triggering mechanism of energy transformation and reconnection in the plasma boundary layer region.     

Research progress of heavy metal pollution in China: Sources, analytical methods, status, and toxicity

Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution.Extensive damage to human organs,such as liver,kidney,digestion system,and nervous system can be caused by uptake of excess heavy metals.Heavy metals in the environment can originate from both natural and anthropogenic sources.Although contamination of heavy metals has been known to be a severe environmental problem for decades,it is still getting worse in recent years and there are few feasible approaches to resolve this problem.Due to their high toxicity,prevalent existence and persistence in the environment,lead(Pb),mercury(Hg),cadmium(Cd),chromium(Cr) and arsenic(As) are commonly considered as the priority heavy metals which should be concerned and their emission should be controlled in China.This paper reviewed the pollution of heavy metals in China,focusing on the following four aspects:current status of heavy metal pollution in China,sources of heavy metals in China,toxicity and potential risk,and possible reduction strategies.     

Comparison of the Teaching Concepts between Chinese and Americans

This paper makes a comparative study on higher education in respect of four aspects in educational system between China and America,in the hope of finding reasons that can be useful to our cultivation in China.     

Cultural Connotation of Plant Words in English and Chinese

Cultural connotation and denotative meaning of plant terms in English and Chinese are of great signification in research.It is advisable to do the research from the following four aspects:a.plant terms with similar cultural connotation in English and Chinese;b.plant terms with different cultural connotation in English and Chinese;c.gaps of lexical plant terms in English and Chinese;d.peculiarity of plant terms in English and Chinese.It can be see clearly through the contrast and analysis of plant terms in these two languages that plant terms in any language are not only the symbol of that plant.Cultural differences have left a deep cultural marking on plant terms,making these words very rich in cultural connotation.So we should make great effort in understanding their cultural connotation in order to have a good command of these words.     

Operational and structural aspects of a vapor-feed semi-passive direct methanol fuel cell supplied with concentrated methanol

Direct methanol fuel cell （DMFC） has great potential to replace the traditional battery in the field of portable power sources. This study investigates the operational and structural aspects of a vapor-feed semi-passive DMFC supplied with concentrated methanol. The effec tiveness of using vaporous methanol to improve the cell performance is experimentally validated. Results indicate that there exits an optimal value of methanol concentration that favors both methanol supply and control of methanol crossover （MCO）. With the increase in vaporization temperature, the cell performance can be enhanced. Based on the traditional structural design, a sintered porous metal plate is further used to depress the impact of MCO so that the cell performance can be significantly improved at a relatively higher methanol concentration. This is of great importance to enhance the energy density and operating duration for portable applications. The mechanisms related to the performance behaviors are discussed in detail.     

K/T boundary: Discussion of the platinum group elements as indicators of extraterrestrial materials

Whether the platinum group elements (PGE) can be taken as the indicators of extraterrestrial materials is a very important and interesting scientific problem. It is discussed on the basis of systematic investigation and study of a great amount of related literature. The following conclusions can be obtained: (ⅰ) extraterrestrial impact event can cause the PGE anomaly; conversely, the PGE anomaly may not represent the existence of extraterrestrial impact event, because the PGE anomaly can be caused by many terrestrial events (e.g. volcanic activity); (ⅱ) the PGE anomaly, especially the global PGE anomaly can inspire us to think it from extraterrestrial event, but it may not be as useful as previously thought as unambiguous identifiers of large extraterrestrial impact event in the earth's history.     

Impact of Education on Productivity:A Model in China

Improving the quality of human resources through edu-cation and training is of great strategic significance.However, few people have done in depth and systematicstudies on the relationship between education and pro-ducttvity in China. This study developed an educationproductivity transform model and empirically tested themodel using data on the most districts of China. The ba-sic notion is that the effect depends both on the capabilityresulted from education, and on the environment inwhich this capability can be exercised, the effect is a re-sult of two factors combined.     

Imaging of apoptotic HeLa cells by using scanning near-field optical microscopy

By using scanning near-field optical microscopy (SNOM), HeLa cells in apoptosis process are imaged with a higher optical resolution beyond the diffraction limit. Since SNOM provides both topographic and transmitted light intensity information of a cell, it can correlate the structural characteristics and optical properties with the spatial position of the apoptotic cells. Wavelength imaging by using near-field spectroscopy shows that there is a great difference in light propagation and absorption in the cell. This unique technique can be applied to the super high resolution imaging of different components in the cell. The observations by near-field optical imaging and near-field spectroscopy indicate an inhomogeneous aggregation of the inner structure in the apoptotic HeLa cells and the change of transmission intensity of light with the apoptosis status.     

The Style of Business Letters

This study explores the application of Systemic Functional Grammar (SFG) to the analysis of English Business Letters (EBL). With China’s opening up to the outside, especially its entrance into WTO, international business is becoming more and more popular. Most of the transactions in international business are discussed in detail through airmail letters, telegrams, telexes, faxes or E- mails.As a world language, English is used widely in the negotiation of international businesses. Writing a piece of effective English Business Letter is of great importance. As a medium between the business partners, EBL affects the interaction and negotiation between them. This article is intended to seek the linguistic characteristics of business letters and prove that the theories of SFG can be used to analyze EBL discourse and they are actually effective.     

Focal depth research of earthquakes in Mainland China: Implication for tectonics

Focal depth data of earthquakes in Mainland China are processed and analyzed in this paper, as well as the relationship between the focal depths and large-scale tectonic structures. As a basic parameter for earthquakes, focal depth is used to investigate deep environment of seismogenic regions, tectonic backgrounds for concentration and release of seismic energy, the inner crustal deformation and its mechanic features. Depth data of 31282 ML≥2.0 events with 1st class and 2nd class precision in Mainland China from Jan. 1, 1970 to May 31, 2000 are used to get spatial features of earthquakes distributed with depth and to provide average depth for each grid area throughout China. Researches show that the average depth (D-) for all the earthquakes used in this paper is (16±7) km, and (13±6) km and (18±8) km for the events in eastern China and western China, respectively. The area with the deepest focal depth is located in southwest Xinjiang region, near the western and southwestern ends of the Tarim Basin. The focal depth related to large-scale tectonic structures, for instance, = (33±12), (21±10), (14±7), (11±5) and (10±4) km in Tibet plateau block, Xinjiang block, North China, Northeastern China and South China, respectively. The earthquakes are deeper at the bounders of the integrated tectonic blocks, including the southwestern and northern brims of the Tarim Basin, southern brim of the Zhunge'r Basin and that of the Alashan block, as well as the eastern and western sides of the Edos block and the western brim of the Sichuan Basin. The earthquakes at the newly ruptured belts are relatively shallower, for instance, at the southwestern Yunnan seismic belt and the Zhangjiakou-Bohai seismic belt. The mechanic behavior, deformation and features for the crust and mantle structures are also discussed.     

Data Reduction and Triangulation Approach to Scattered Points

For the generation of the model in reverse engineering, a laser scanner is currently used a lot due to the fast measuring speed and high precision. Direct triangulation of data points captured from a physical object has a great advantage in that it can reduce the time and error in modeling process. It is important to reduce the number of data points for triangulating points with maintaining precision. To triangulate data points within a tolerance ε a new approach is developed in this paper. Different level of triangulations can be generated directly from data points using the proposed strategy that reduces and triangulates data points based on triangulation of 3D parametric surfaces. An experimental example is presented to demonstrate the effectiveness and efficiency of the proposed algorithm.     

CHINESE SCIENCE BULLETIN (KEXUE TONGBAO)

<正> Aims and ScopeChinese Science Bulletin, a comprehensive academic journal of China, is sponsored by the Chinese Academy of Sciences and published semimonthly (on 15 and 30 of each month) by Science in China Press. This journal aims at presenting the up-to-date scientific achievements of the highest standard and great significance in various fields of natural sciences in China for scientific workers in both China and foreign countries.     

Zircon SHRIMP geochronology and geochemistry of TTG rocks in Sushui Complex from Zhongtiao Mountains with its geological implications

The tonalite-trondhjemite-granodiorite (TTG) rocks in Sushui Complex of Zhongtiao Block can be divided into two series according to their zircon U-Pb ages and geochemical characteristics: one is subduction-related (SR) and the other collision-related (CR). The SR TTG rocks, together with other Late Archean island arc magmatism, were developed as a result of oceanic subduction between the Eastern and Western blocks in Late Archean; while the CR TTG rocks formed in a thickened crustal environment, which was responding to the collision between the Eastern and Western blocks in Paleoproterozoic. All these features support a model that the Zhongtiao Block is a part of the Trans-North China Orogen in the middle of North China Craton.