Nurse plant theory and its application in ecological restoration in lower subtropics of China

Nurse plants are those that facilitate the growth and development of other plant species （target species） beneath their canopy because they offer benign microhabitats that are more favorable for seed germination and/or seedling recruitment than their surrounding environment. Nurse plants have been mainly used to restore vegetation in arid and sub-arid zones in recent years. Based on summarizing the definition of nurse plant and target plant, we review the nursing effect mechanisms, ecological factors that influence nursing effect, relationships between nurse plant and ecological restoration. This review also brings forward possible pairs of nurse and target species at lower subtropical areas. Furthermore, we provide the potential tendency in nurse plant research and application.     

Vegetation Landscape, Ecological Characteristics and Soil Fixation for Riverbank in Taiwan, China

This study is aimed to investigate and analyze the vegetation landscape around Rivers of Hou-lung, Fa-tz, Da-li, Ching-shuei and Gau- ping, and to select the suitable plant species that could be applied for the area of riverbank ecological engineering in Taiwan. Studying the vegetation established the key point and procedure of ecological engineering in the riverside and revetment, to compile and edit the dominant plants＇ types, life form, propagating method, root systems＇ characteristics and functions for soil conservation. This research choses three dominant plants for roots strength test. The fitting models of plants pulling resistance（Rp, kg） between plant height （H, cm）, diameter near ground （Dn, mm）, diameter above ground 100 mm （Da, mm）, The research finished the relative abundant, types and cluster analysis of riverbank dominant plants that generalize vegetative distribution and ecological restoration for different river types to apply and manage in Taiwan.     

The impact of biofuel plantation on biodiversity: a review

Because plants convert solar energy into chemical energy stored in organisms, biomass production as an energy source can help to reduce the world＇s reliance on fossil energy and mitigate global warming. Biofuel production is a fast-growing industry that represents a new type of large-scale human disturbance on ecosystems. Thus, the benefits of biofuel production bring environmental risks that include its potential impact on biodiversity, which is still an open question. In this review, we start first with a brief overview of the evolution of biofuel concept; second, we review the state of biofuel production across the continents, with a major emphasis on the main species used and their major feedstock. For which, we found significant differences for land use and environmental cultural management of biofuel plantation between tropical and temperate regions. Third, we summarize the impacts of biofuel plantation on biodiversity at multiple scales, based on the case studied with respect to the corresponding issues. At the genetic level, introgression and contamination by aggressive genotypes are a primary risk. At the species level, habitat pollution, degradation, and disturbance caused by intensive management of biofuel plantation significantly raise the risk of habitat fragmentation, native extinction, and bio-invasion. At the ecosystem level, the large-scale homogeneous landscape of biofuel plantation results in simplified community and food web that severely damage ecosystem services, including ecosystem diversity. Finally, we compare the current and potential benefits and risks of biofuel plantations for the practical application of a biofuel industry of China. We emphasize the land use constraint from food security and biodiversity conservation, and the need for scientific research and systematic monitoring as a critical support for the sustainable development of biofuel production in China.     

Quantitative Assessment on Endangerment Degree of Rare Animal and Plant Species in Tibet, China

It is of profound theoretical and practical significance to study endangerment status of rare species in Tibet. Index system is firstly set down for quantitative assessment of rare animal and plant species, then endangerment degree of wildlife under special state protection are calculated, which is expressed by value E. The results reveal that Yunnan snub-nosed monkey （Rhinopithecus bieti）, Himalayan tahr （Hemitragus jemlahicus） and Gigantic Cypress （Cupressus gigantea） have the highest E respectively in animals and plants. According to value E, all species are categorized into 4 ranks： critically endangered（0.6-0.8）, endangered （0.4- 0.6）, vulnerable （0.2-0.4） and lower risk （ E ≤ 0.2）. By comparison of the first five animals and plants of the highest E, each sub-ecozone bears a distinct identity.     

Chilli anthracnose disease caused by Colletotrichum species

Anthracnose disease is one of the major economic constraints to chilli production worldwide, especially in tropical and subtropical regions. Accurate taxonomic information is necessary for effective disease control management. In the Colletotrichum patho-system, different Colletotrichum species can be associated with anthracnose of the same host. Little information is known concerning the interactions of the species associated with the chilli anthracnose although several Colletotrichum species have been reported as causal agents of chilli anthracnose disease worldwide. The ambiguous taxonomic status of Colletotrichum species has resulted in inaccurate identification which may cause practical problems in plant breeding and disease management. Although the management and control of anthracnose disease are still being extensively researched, commercial cultivars of Capsicum annuum that are resistant to the pathogens that cause chilli anthracnose have not yet been developed. This paper reviews the causal agents of chilli anthracnose, the disease cycle, conventional methods in identification of the pathogen and molecular approaches that have been used for the identification of Colletotrichum species. Pathogenetic variation and population structure of the causal agents of chilli anthracnose along with the current taxonomic status of Colletotrichum species are discussed. Future developments leading to the disease management strategies are suggested.     

Diversity of arbuscular mycorrhizal fungal spore communities and its relations to plants under increased temperature and precipitation in a natural grassland

Arbuscular mycorrhizal fungi(AMF)form mutualisms with most plant species,and therefore,understanding how AMF communities will respond to climate change is essential for predictions of changes in plant communities.To evaluate the impact of global climate change on AMFs and plant-AMF interactions in a natural grassland in Inner Mongolia,both artificial warming and watering treatments were assigned to experimental plots.Our results indicate that(1)warming and precipitation significantly affected the relative spore abundance of abundant sporulating AMF species;(2)the relative abundance of weak sporulating AMF species and AMF diversity decreased under experimental warming;(3)evidence was found that the composition of the AMF community in a given year might be correlated with plant community composition in the following year;and(4)grasses and forbs showing different preferences to Claroideoglomus etunicatum or Ambispora gerdemannii dominated plots.Our results imply that climate change appears to induce changes in AMF assemblages with knock-on effects on grassland plant communities.AMF communities may play a much more important role than we have thought in the responses of ecosystem to global climate changes.     

Economics and Performance Forecast of Gas Turbine Combined Cycle

Forecasts of the various types of gas turbines economics and performance of gas turbine combined cycle （GTCC） with will help power plant designers to select the best type of gas turbine for future Chinese powerplants. The cost and performance of various designs were estimated using the commercial software GT PRO. Improved GTCC output will increase the system efficiency which may induce total investment and will certainly increase the cumulative cash which then will induce the cost and the payback period. The relative annual fuel output increases almost in proportion to the relative GTCC output. China should select the gas turbine that provides the most economical output according to its specific conditions. The analysis shows that a GTCC power plant with a medium-sized 100 to 200 MW output gas turbine is the most suitable for Chinese investors.     

Crucial function of histone lysine methylation in plant reproduction

Unlike animals, plants do not set aside germ cells early in development. In angiosperm species, reproduction occurs in the adult plant upon flowering. The multicellular male and female gametophytes differentiate from meiotic products within reproductive floral organs. Double fertilization is another remarkable feature of most angiosperm species. The zygote derived from fertilization of the egg cell by one of the sperm cells and the endosperm from fertilization of the central cell by the second sperm cell develop in a coordinated manner together and enclosed in the sporophytic maternal integuments, forming the seed. Understanding plant reproduction is biologically pertinent and agronomically and ecologically important. Here, we describe the known functions of histone lysine methylations in various steps of reproduction in the reference plant Arabidopsis thaliana. It is emerging that histone lysine methylation is key for understanding epigenetic regulation networks of genome function.     

Nitric oxide:A potential key point of the signaling network leading to plant secondary metabolite biosynthesis

The endogenous signaling network of plants plays important roles in mediating the exogenous factor-induced biosynthesis of secondary metabolites. Nitric oxide (NO) has emerged as a key signaling molecule in plants recently. Numerous studies demonstrated that the main signaling molecules such as salicylic acid (SA), jasmonic acid (JA), reactive oxygen species (ROS), and NO were not only involved in regulating plant secondary metabolite biosynthesis but also interacted to form a complex signaling network by mutual inhibition and/or synergy. The recent progress in the signal network of plant secondary metabolite biosynthesis has been discussed in this paper. Furthermore, we propose a hypothetical model to show that NO might act as a potential molecular switch in the signaling network leading to plant secondary metabolite biosynthesis.     

基于云模型和混合半定量决策方法的闭矿风险管理

Mine closure is associated with many negative impacts on society and the environment. If these effects are not rationally addressed, they would pose risks of mine closure. Thus, a risk management method is needed to mitigate these adverse impacts and address mine-closure issues. An integral framework for mine-closure risk management that includes risk assessment and risk treatment was proposed. Given the fuzziness and randomness of the transformation between qualitative and quantitative knowledge in the risk assessment process, a novel risk assessment method based on the cloud model was presented, which fully considers the uncertainty in risks themselves and in the reasoning process. Closed mine reutilization is an effective risk treatment option in response to the identified high risks, but it requires selecting optimal reutilization strategies for the successful implementation of the reuse plan. To this end, a hybrid semi-quantitative decision method is proposed to optimize decision-making. The results of a case study showed that this risk management methodology can help budget planning for risk treatment and provide an instructional framework to effectively reduce the negative effects of closed mines.     

Influence of Te doping on the dielectric and optical properties of InBi crystals grown by directional freezing

Stoichiometric pure and tellurium （Te） doped indium bismuthide （InBi） were grown using the directional freezing technique in a fabricated furnace. The X-ray diffraction profiles identified the crystallinity and phase composition. The surface topographical features were observed by scanning electron microscopy and atomic force microscopy. The energy dispersive analysis by X-rays was performed to identify the atomic proportion of elements. Studies on the temperature dependence of dielectric constant （e）, loss tangent （tan6）, and AC conductivity （cry） reveal the existence of a ferroelectric phase transition in the doped material at 403 K. When InBi is doped with tellurium （4.04 at%）, a band gap of 0.20 eV can be achieved, and this is confirmed using Fourier transform infrared studies. The results thus show the conversion of semimetallic InBi to a semiconductor with the optical properties suitable for use in infrared detectors.     

Microstructure, crystallography and nucleation mechanism of NANOBAIN steel

The microstructure of bainite ferrite in NANOBAIN steel transformed at different temperatures was investigated by scanning electron microscopy, transmission electron microscopy, electron back-scattered diffraction, and vickers hardness tester in detail. It is found that the average width of bainitic ferrite （BF） plates can be refined to be thinner with the reduction of temperature （473-573 K）, and the bainitic ferrite plates can reach up to 20-74 nm at 473 K. Crystallographic analysis reveals that the bainitic ferrite laths are close to the Nishiyama-Wasserman orientation relationship with their parent austenite. Temperature shows a significant effect on the variant selection, and a decrease in temperature generally weakens the variant selection. Thermodynamic analyses indicates that the Lacher, Fowler and Guggenheim （LFG） model is more suitable than the Kaufman, Radcliffe and Cohen （KRC） model dealing with NANOBAIN steel at a low temperature range. The free energy change △G^γ→BF is about -1500 J.mol^-1 at 473 K, which indicates that nucleation in NANOBAIN steel is the shear mechanism. Finally, the formation of carbon poor regions is thermodynamically possible, and the existence of carbon poor regions can greatly increase the possibility of the shear mechanism.     

Subsurface macro-inclusions and solidified hook character in aluminum-killed deep-drawing steel slabs

Subsurface macro-inclusions and hooks are detrimental to the surface quality of deep-drawing steel sheets. However, little is known about the relationship between macro-inclusions and hooks. Thus, in this work, two ultralow carbon （ULC） steel slabs and two low carbon （LC） aluminum-killed steel slabs were sampled to study the relationship between hooks and subsurface macro-inclusions, which were detected on the cross-sections of steel samples with an area of 56058 mm2 using an automated scanning electron microscopy/energy-disper-sive X-ray spectroscopy system. Results show that subsurface inclusions larger than 200 μm were almost entrapped by hook structures, whereas the location of other inclusions smaller than 200μm had no obvious dependence on the location of solidified hooks. Furthermore, the number density （ND） of subsurface inclusions larger than 200μm decreased from 0.02 to 0 cm-2 in ULC steel as the mean hook depth decreased from 1.57 to 1.01 mm. Similar trends were also observed in LC steel. In addition, the detected inclusions larger than 200μm were concentrated in the region near the slab center （3/8 width-5/8 width）, where hook depths were also larger than those at any other locations. Therefore, minimizing the hook depth is an effective way to reduce inclusion-induced sliver defects in deep-drawing steels.     

Effects of basicity and MgO content on the viscosity of the SiO2-CaO-MgO-9wt%Al2O3 slag system

The effects of basicity and MgO content on the viscosity of SiO2-CaO-MgO-9wt%Al2O3 slags with basicity from 0.4 to 1.0 and MgO content from 13wt%to 19wt%were investigated using the rotating cylinder method. A correlation between the viscosity and the slag structure was determined by Fourier transform infrared （FTIR） spectroscopy. It is indicated that the complex network structure of the slag melt is depolymerized into simpler network units with increasing basicity or MgO content, resulting in a continuous decrease in viscosity of the slag. The viscosity is strongly dependent on the combined action of basic oxide components in the slag. Under the present experimental conditions, increasing the basicity is found to be more effective than increasing the MgO content in decreasing the viscosity of the slag. At higher temperatures, the increase of basicity or MgO content does not appreciably decrease the viscosity of the slag, as it does at lower tem-peratures. The calculated activation energy of viscous flow is between 154 and 200 kJ＆#183;mol-1, which decreases with an increase in basicity from 0.4 to 1.0 at a fixed MgO content in the range of 13wt%to 19wt%.     

A dynamic programming algorithm for network selection in 3G/WLAN

An essential characteristic of the 4th Generation （4G） wireless networks is integrating various heterogeneous wireless access networks.This paper considers the network selection for both admission and handoff strategy problems in heterogeneous network of 3G/WLAN.A novel dynamic programming algorithm is proposed by taking heterogeneous network characteristics,user mobility and different service types into account.The specificity of our approach is that it puts the situations in a new model and makes decisions in stages of different states.Simulation results validate that the proposed scheme can obtain better new call blocking and handoff dropping probability performance than traditional schemes while ensuring quality-of-services （QoS） for both real-time and data connections.     

General Design of Sutong Bridge

The main span of Sutong Bridge is a double-pylon, double-plane cable-stayed bridge with steel box girder, which has the world＇ s longest central span of 1 088 m within cable-stayed bridges. To overcome problems caused by severe meteorological conditions, perplexing hydrological conditions, deep buried bedrock and higher navigation level, many new technics and methods were created. Keys including structural system, steel box girder, stayed cable, tower, pier, tower foundation, collision avoidance system, wind-resistance, seismic-resistance, structural nonlinear response and structural static stability were presented individually in this paper.     

Design and evaluation of a Laval-type supersonic atomizer for low-pressure gas atomization of molten metals

A Laval-type supersonic gas atomizer was designed for low-pressure gas atomization of molten metals. The principal design ob-jectives were to produce small-particle uniform powders at lower operating pressures by improving the gas inlet and outlet structures and op-timizing structural parameters. A computational fluid flow model was developed to study the flow field characteristics of the designed atom-izer. Simulation results show that the maximum gas velocity in the atomization zone can reach 440 m＆#183;s-1;this value is independent of the atomization gas pressure P0 when P0〉0.7 MPa. When P0=1.1 MPa, the aspiration pressure at the tip of the delivery tube reaches a mini-mum, indicating that the atomizer can attain the best atomization efficiency at a relatively low atomization pressure. In addition, atomization experiments with pure tin at P0=1.0 MPa and with 7055Al alloy at P0=0.8 and 0.4 MPa were conducted to evaluate the atomization capa-bility of the designed atomizer. Nearly spherical powders were obtained with the mass median diameters of 28.6, 43.4, and 63.5μm, respec-tively. Compared with commonly used atomizers, the designed Laval-type atomizer has a better low-pressure gas atomization capability.     

Effect of light response on the photocatalytic activity of BiOCl x Br1−x in the removal of Rhodamine B from water

BiOClxBr1-x catalysts were synthesized through an alcoholysis method and characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, and diffuse reflectance spectroscopy （DRS）. The as-prepared photocatalysts were found to be tetragonal crystal structure and lamellar plate morphology. Their band gaps were between 3.44 and 2.83 eV. The effect of light response on the photocatalytic activity of BiOClxBrl-x was investigated by degradation of Rhodamine B （RhB）. Complete removal of RhB from water was realized under simulated sunlight irradiation for 50 min with BiOC10.5Br0.5. Mechanism studies showed that photo- generated holes and superoxide anion radicals played important roles in RhB photodegradation. The results of chemical oxygen demand （COD） confirmed RhB mineralization. The effect of light response on the activity of BiOClxBr1-x was further investigated under monochromatic light irradiation, and BiOCl0.5Br0.5 catalyst exhibited the highest activity. Furthermore, BiOC10.5Br0.5 exhibited high stability, suggesting its practical application for the removal of RhB pollutant from water.     

A Rhodamine-Based Sensor-for Chromogenic Detection of Cu^2＋ and Fluorescent Detection of Fe^3＋

A rhodamine-benzimidazole conjugate(RB) as a probe was investigated.UV-Vis analysis showed that a strong absorption band at 552 nm was formed with the addition of Cu~(2+),while other transition metal ions induced a little more absorption.The absorption value of RB solution at 552 nm has a linear correlation with Cu~(2+) concentration between 35-70 μmol/L;the detection limit reached 6.82×10~(-2) μmol/L,which is lower than the settled limitation for copper in the drinking water(~30 μmol/L) standardized by World Health Organization(WHO).Moreover,FL analysis showed that only Fe~(3+) could induce large fluorescence intensity enhancement at 582 nm;other common metal ions including Cu~(2+) cannot induce the enhancement.There was a good linear correlation between relative fluorescence intensity and Fe~(3+) concentration ranging from 2 μmol/L to 20 μmol/L,and the detection limit reached1.70×10~(-2) μmol/L.The results showed that RB could detect Cu~(2+)and Fe~(3+) simultaneously,with the UV-Vis and fluorescence spectroscopy,respectively.     

Cascading failure prevention of complex systems based on brittleness entropy game

A non-cooperative game model based on brittleness entropy is formulated for preventing cascading failure of complex systems.Subsystems of a complex system are mapped to the players of the game.The influence of collapsed subsystems to other subsystems is also taken into account in the definition of payoff function except for their own entropy increase.This influence is named brittleness entropy.Each player has two optional strategies：rational for negative entropy and irrational for negative entropy.The model is designed to identify the players who select an irrational strategy for negative entropy.The players who select the irrational strategy for negative entropy continue to compete for negative entropy after the recovery of ordered state and make other subsystems can＇ t get enough negative entropy to reduce entropy increase.It leads to cascading failure of the complex system in the end.Genetic algorithm is used to seek the solution of game model,and the simulation result verifies the effectiveness of the proposed model.The model provides a new way to prevent cascading failure of complex systems.