作家的母语意识

语言的运作是作家的基本活动方式,而母语塑造了作家的符号形象、表达方式等。作家的母语意识则从语缘性、保有性和创化性这三个方面显示出来,并使语言活动成了其最直接的创造活动。母语总是在滋养和成全着自己的作家,而作家又总是用自己的语言活动丰富和表现母语,乃至形成新的式样。

True-amplitude wavefield separation using staggered-grid interpolation in the wavenumber domain

Wavefield separation of multicomponent seismic data to image subsurface structures can be realized in either the space domain or the wavenumber domain. However, as the particle velocity components used in the wavenumber-domain wavefield separation are not defined at the same grid point with the staggered-grid finite-difference method for elastic wavefield simulation, we propose the wavenumber-domain interpolation method to estimate the required values at the common grid points prior to the wavenumber-domain true-amplitude wavefield separation. Moreover, numerical experiments show that the wavenumber-domain interpolation method has high interpolation accuracy and the trueamplitude wavefield separation method shows good amplitude preservation. The application of the proposed methodology to elastic reverse-time migration can obtain good amplitudepreserved images even in the case of some velocity error.

HIGH RESOLUTION POSITIVITY-PRESERVING DIFFERENCE SCHEMES FOR TWO DIMENSIONAL EULER EQUATIONS

A class of high resolution positivity preserving Boltzmann type difference schemes for one and two dimensional Euler equations is studied. First, the relation between Boltzmann and Euler equations is analyzed. By using a kind of special interpolation, the high resolution Boltzmann type difference scheme is constructed. Finally, numerical tests show that the schemes are effective and useful.

Symmetries and Mei Conserved Quantities of Nonholonomic Controllable Mechanical Systems

This paper concentrates on studying the symmetries and a new type of conserved quantities called Mei conserved quantity. The criterions of the Mei symmetry, the Noether symmetry and the Lie symmetry are given. The conditions and the forms of the Mei conserved quantities deduced from these three symmetries are obtained. An example is given to illustrate the application of the result.

Unified Symmetry of Nonholonomic Mechanical Systems with Non-Chetaev＇s Type Constraints

Based on the total time derivative along the trajectory of the system, the unified symmetry of nonholonomic mechanical system with non-Chetaev＇s type constraints is studied. The definition and criterion of the unified symmetry of nonholonomic mechanical systems with non-Ohetaev＇s type constraints are given. A new conserved quantity, as well as the Noether conserved quantity and the Hojman conserved quantity, deduced from the unified symmetry, is obtained. Two examples are given to illustrate the application of the results.

Diversity, Endemism and Conservation of Ferns(Polypodiales) in the Mexican Mountain Component

We analyzed the distributional patterns of95 selected species of leptosporangiate ferns inhabiting the Mexican Mountain Component, using grid-cells of one geographical degree as unit areas,applying endemism indices and richness and beta diversity analyses.Distributional data were obtained from several herbaria and specialized literature.Five grid-cells appear to be important for fern species richness, as they contain 35 to 49 species.These gridcells are located in the Sierra Madre Oriental(SMO),Trans-Mexican Volcanic Belt(TMVB) and the Sierra Madre del Sur(SMS).Mean richness by latitudinal belts of one degree showed that the belts with highest values are related to the TMVB and SMS.A total of 13grid-cells were recognized as important from theperspective of endemism; most of them are located also in the SMO, TMVB and SMS.The richest gridcells coincided with one of the main centres of endemism for ferns obtained in this study, located in the convergence of the southern part of the SMO, the eastern portion of the TMVB and the northern part of the SMS, reflecting the high humidity existing on the mountain slopes facing the Gulf of Mexico.Some important grid-cells recognized from richness and endemism analyses coincide with Mexican Natural Protected Areas.The beta diversity analysis showed a low degree of similarity among grid-cells, implying a high species replacement, as the result of environmental heterogeneity occurring in the Mexican mountain systems.On the other hand, the spatial analysis suggested a pattern of phytogeographical regionalization comprising twomain areas: the Mexican Transition Zone and the Mexican Central Plateau.Ferns play an important role in the Mexican biodiversity and contributing to the beta diversity of Mexico.

Lie Symmetry and Conserved Quantities for Nonholonomic Vacco Dynamical Systems

In this paper the Lie symmetry and conserved quantities for nonholonomic Vacco dynamical systems are studied. The determining equation of the Lie symmetry for the system is given. The general Hojman conserved quantity and the Lutzky conserved quantity deduced from the symmetry are obtained.

Soil Wettability as Affected by Soil Characteristics and Land Use

Depth distribution of soil wettability and its correlations with vegetation type, soil texture, and pH were investigated under various land use (cropland, grassland, and forestland) and soil management systems. Wettability was evaluated by contact angle with the Wilhelmy plate method. Water repellency was likely to be present under permanently vegetated land, but less common on tilled agricultural land. It was mostly prevalent in the topsoil, especially in coarse-textured soils, and decreased in the subsoil. However, the depth dependency of wettability could not be derived from the investigated wide range of soils. The correlation and multiple regression analysis revealed that the wettability in repellent soils was affected more by soil organic carbon (SOC) than by soil texture and pH, whereas in wettable soils, soil texture and pH were more effective than SOC. Furthermore, the quality of SOC seemed to be more important in determining wettability than its quantity, as proofed by stronger hydrophobicity under coniferous than under deciduous forestland. Soil management had a minor effect on wettability if conventional and conservation tillage or different grazing intensities were considered.

Evaluation of Ecological Effectiveness of Protected Areas in Northwest China

Protected areas(PAs) have experienced explosive growth in Northwest China over the last three decades, but their effectiveness in representing regional ecological system diversity has not attracted considerable attention. Low effectiveness would exacerbate the conservation-development conflicts, particularly those that arise as a result of the Great Western Development Strategy(GWDS). Thus, an assessment of the effectiveness of the PA network has become quite important. We proposed natural vegetation communities to represent regional ecological system diversities, and proposed Global 200 Priority Ecoregions, Important Bird Areas, and ecosystem function regions to represent important conservation areas. To determine their effectiveness, we studied the extent to which ecological system diversities and important conservation areas are represented by the existing 96 PAs. Our results indicated that the total coverage of vegetation communities in PAs in Northwest China is not sufficiently comprehensive. As the PA system has expanded, the growth in the total area of the PAs has been greater than that of their vegetation community richness. While most of the important conservation areas are covered by PAs, some regions have not yet reached the 10% threshold; further, PAs are distributed unevenly and conservation gaps remain in the region. Therefore, these regions should receive more attention when planning new PAs. It is vital that more biodiversity datasets and assessment of ecosystem function regions are integrated in order to provide a basis for the government to formulate appropriate protection and development strategies.

Laser Device for the Protection of Biological Objects from the Damaging Action of Ionizing Radiation

Laser irradiation device for the protection of biological objects from the action of ionizing radiation to be used in practice has been manufactured （invention patent RU 2 428 228 C2）. Research of the action of y-radiation itself as well as of the combined action of laser devices on survival, weight, skin and the general mitotic index of the bone marrow cells （mitotic index of all nucleus-containing cells of the bone marrow） of C57BL/6 experimental young mice was carried out. The mice were irradiated with ionizing （whole body irradiation） and laser radiation, separately one by one in a special frame device. Laser radiation in the dose 1 mJ/cm^2 irradiated only the back of a mouse, or both the back and the abdomen of mice. In case of combined irradiation of mice, the time interval between two types of irradiation did not exceed 30 min. First, the mice were exposed to y-radiation then to laser radiation. The method of the laser radiation-protection of biological subjects contributes to an increase in the viability of mice, prevents the damages of skin and also increases the mitotic activity of mice bone marrow cells.

Protective effects of non-mitogenic human acidic fibroblast growth factor on hydrogen peroxide-induced damage to cardiomyocytes in vitro

AIM： To study the protective effect of non-mitogenic human acidic fibroblast growth factor （FGF） on cardiac oxidative injury in vivo. METHODS： Ventricular cardiomyocytes were isolated from 1- to 3-d-old neonatal SD mice and cultured in Dulbecco＇s minimum essential medium supplemented with 15% fetal bovine serum under an atmosphere of 50 mL/L CO2-95% air at 37℃, as well as assessed by immunooltochemical assay. We constructed the cardiomyoolte injury model by exposure to a certain concentration of H2O2. Cellular viability, superoxide dismutase （SOD） activity, leakage of maleic dialdehyde and anti-apoptosis effect were included to evaluate the cardiac protective effect of non-mitogenic human acidic FGF. RESULTS： Over 50% of the cardiomyocytes beat spontaneously on the 2nd d of culture and synchronously beat after being cultured for 3 d. Forty-eight hours after plating was completed, the purity of such cultures was 95% myocytes, assessed by an immunocytochemical assay. Cellular viability dramatically decreased with the increasing of the concentration of H2O2. Non-mitogenic human acidic FGF showed significant resistance to thetoxic effect of H2O2, significantly increased the cellular viability as well as the activity of SOD, and dramatically decreased the leakage of maleic dialdehyde as well as the cellular apoptosis rate. CONCLUSION： Hydrogen peroxide shows strong cytotoxicity to the cultured cardiac myocytes, and non-mitogenic human acidic FGF shows strong cardio-protective effect when exposed to a certain concentration of H2O2.

A Unified Symmetry of Mechanical Systems with Variable Mass in Phase Space

In this paper, the definition and the criterion of a unified symmetry of the mechanical system with variable mass in phase space are given. The Noether conserved quantity, the generalized Hojman conserved quantity, and Mei conserved quantity deduced from the unified symmetry are obtained. An example is given to illustrate the application of the results.

Effects of Conservation Tillage on the Content of Carbon, Nitrogen in Fluvo-aquic Soil

In order to verify organic carbon cycle under conservation tillage condition and the promotion mechanism of soil fertility and offer scientific theory support for the popularization and application of conservation tillage technological, the research investigated effects of different tillage treatments on the content of total organic car- bon, total nitrogen and different components of them in fluvo-aquic soil based on a long-term experiment site of conservation tillage. The research revealed effects of conservation tillage on the content of carbon, nitrogen in fluvo-aquic soil by study the distribution of soil total organic carbon, total nitrogen, dissolved organic carbon, dissolved organic nitrogen, microbial biomass carbon, liable carbon in different soil depth under different tillage treatments. The results showed that compared to con- ventional tillage treatment, contents of soil total organic carbon under intermittent tillage （tillage once every 2 or 4 years） and no-tillage treatment improved by 1.81%, 6.43%, 14.04%, respectively and contents of soil total nitrogen went up by 0.80%, 10.04%, 7.93%, respectively. Contents of soil total organic carbon and total nitrogen in 10-20 cm soil layer under no-tillage treatment were significantly lower than the other treatments. Under the condition of straw returned, intermittent tillage and no- tillage could significantly improve the content of soil dissolved organic carbon and ni- trogen in 0-5 cm and 5-10 cm soil. Compared to conventional tillage treatment, content of soil microbial biomass carbon and liable carbon in 0-5 cm soil under in- termittent tillage and no-tillage were improved in varying degrees. Content of soil microbial biomass carbon in 10-20 cm soil layer under no-tillage treatment was sig- nificantly lower than the other treatments. Straw returning had improved the content of soil total organic carbon, total nitrogen, dissolved organic carbon and other com- ponents of active organic carbon in varying degrees. In general, conservation tillage measures could increase carbon and nitrogen storage in 0-5 cm soil layer, the negative effects of ＂nutrients enrichment in surface＂ under no-tillage condition could be ameliorated by intermittent tillage.

Toxic Effects of Phthalates on Ocean Algae

This article discusses the interaction of phthalates and ocean algae based on the standard appraisal method of chemical medicine for algae toxicity. Through the experiments on the toxic effects of dimethyl (o-) phthalate (DMP), diethyl (o-) phthalate (DEP), dibutyl (o-) phthalate (DBP) on ocean algae, the 50 % lethal concentration of the three substances in 48 h and 96 h for plaeodectylum tricornutum, platymonas sp, isochrysis galbana, and skeletonema costatum is obtained. Tolerance limits of the above ocean algae of DMP, DEP, and DBP are discussed.

Ecological effects of Tongren City land transferring

The ecological effects of land transfer are mainly around the ecological effects of land itself. One is environmental and ecological effects of land, such as flood controlling, preventing soil erosion, preventing the collapse debris, water conservation and maintenance of biodiversity and conservation of wildlife. Second, it is crop residue use of land, including： treatment of organic waste, decomposing and eliminating contaminants, regulating microclimate and air purification, maintaining and revitalizing rural communities. Third, the geographical landscape effects of land, such as providing idyllic pastures and other entertainment services. In a conclusion, there is little exploration to the ecological effects of rural land. This paper attempts to analyze the environmental problems related to the land transferring in Tongren City.

Spatial Quality Evaluation of Pedestrian Streets

This paper presents an assessment of the spatial quality of a pedestrian street located in downtown Bauru, S^o Paulo State, Brazil, from the application of some urban sustainability indicators. Multi-method was used to evaluate the thermal comfort quality of users, urban accessibility and preservation of architectural heritage. The results show that the sustainability indicators, apart from being effective tools in identifying problems, can assist local managers in decision making, planning and monitoring of pedestrian public space. These indicators contribute to a broad diagnosis of the pedestrian street and also the formulation of programs, projects and municipal policies, aimed at providing a better life quality for pedestrians.

Risk Analysis of Historic Urban Areas： A Case Study of the Salerno City, Italy

The preservation of historical and cultural heritage from seismic risk is a question of interest in Italy. However, too little has been done to deal with this problem. First of all, the seismic safety of cultural heritage should be a topic of prevention. The research described in the paper presents a multi-approach procedure to address risk assessment of large-scale urban systems with the aim to contribute at the development of risk mitigation policies for historical centers buildings. The observation of the earthquakes effects in Italy clearly highlights the role of the high vulnerability of the existing building on the consequences in terms of casualties and damage, rather than the severity of seismic events, especially in historical contexts. Unlike the new buildings which should be planned and designed to respect seismic safety requirements, existing buildings require a careful safety assessment on the basis of their susceptibility to damage which depends on building techniques, past damage events, maintenance, changes, etc.

Corrected Nonconservative Schemes

Derivatives of discontinuities being Dirac singularities, it is usually not possible to multiply them by discontinuous functions. However in the context of conservation laws we have shown in a recent paper that it can be done. We shall make use of this new framework to revisit some upwind methods, mostly characteristic schemes, and show that they can be corrected to be conservative and to work on difficult problems such as Euler＇s equations for fluids. Numerous numerical results are given.

Hollow-in-hollow carbon spheres with hollow foam-like cores for lithium-sulfur batteries

Lithium-sulfur batteries have attracted increasing attention because of their high theoretical capadty. Using sulfur/carbon composites as the cathode materials has been demonstrated as an effective strategy to optimize sulfur utilization and enhance cycle stability as well. In this work hollow-in-hollow carbon spheres with hollow foam-like cores （HCSF@C） are prepared to improve both capability and cycling stability of lithium-sulfur batteries. With high surface area and large pore volumes, the loading of sulfur in HCSF@C reaches up to 70 wt.%. In the resulting S/HCSF@C composites, the outer carbon shell serves as an effective protection layer to trap the soluble polysulfide intermediates derived from the inner component. Consequently, the S/HCSF@C cathode retains a high capacity of 780 mAh/g after 300 cycles at a high charge/discharge rate of 1 A/g.

Positivity and boundedness preserving schemes for the fractional reaction-difusion equation

In this paper, we design a semi-implicit scheme for the scalar time fractional reaction-diffusion equation. We theoretically prove that the numerical scheme is stable without the restriction on the ratio of the time and space stepsizes, and numerically show that the convergence orders are 1 in time and 2 in space. As a concrete model, the subdiffusive predator-prey system is discussed in detail. First, we prove that the analytical solution to the system is positive and bounded. Then, we use the provided numerical scheme to solve the subdiffusive predator-prey system, and theoretically prove and numerically verify that the numerical scheme preserves the positivity and boundedness.