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During the range expansion of invasive plants, competitors shared different co-evolutionary history with invasive plants, as well as population differentiation, would have different effects on the response of invaders to global change factors such as increased nitrogen deposition. Disregard the community responses and potential adaptations of invaders during the range expansion might bring misleading answers. To address these challenges, we conducted a greenhouse experiment to explore the synergistic effects between population differentiation during range expansion and competitors on the invasion of Galinsoga quadriradiata in response to increased nitrogen deposition. Competitors (new or old that shared short or long co-evolutionary history with the invader, respectively) were set to compete with the invasive central and edge populations under different nitrogen addition treatments. Galinsoga quadriradiata from the central population (i.e., with longer residence time since invasion) showed significantly higher total mass, reproduction, interspecific competitiveness when compared to the individuals from the edge population, and the magnitude of response to nitrogen addition treatments was larger in the central population when planted in isolation (single-culture). Nitrogen addition promoted growth and reproductive performance of G. quadriradiata in single-culture, in the presence of competitors this effect was weakened. The old competitors acted more effectively than new competitors in inhibiting the invader performance, mainly for the central population. Our results indicate that population differentiation on growth and competitiveness occurred during the range expansion of G. quadriradiata, with the central population displaying higher invasiveness than the edge population. The co-evolutionary history between invasive species and its competitors has been suggested to be probably not in favor of invasive plants, especially for central populations. Our results highlight the synergistic and non-additive role of population differentiation and shared co-evolution history between invasive species and its competitors in the range expansion of invaders in the context of global change factors.

Fungal communities related to invasive plants may change with an elevational gradient, which may affect the performance and invasiveness of invasive plants. Our recent study revealed that root arbuscular mycorrhizal fungi colonization rate of invasive plant Galinsoga quadriradiata decreased with elevation. However, it is unclear whether it is caused by the changes in the fungal community along elevation. To address this issue, we used high-throughput sequencing techniques, functional groupings and linear statistics to examine how fungal communities in the rhizosphere and roots of G. quadriradiata are changed across the elevation in Qinling and Bashan Mountains, China. Our results revealed that species diversity and composition of the rhizosphere and root fungal communities changed along the elevation. The Shannon–Wiener diversity index in the rhizosphere and roots increased and decreased with elevation, respectively. In contrast, the relative abundance of pathotroph in the rhizosphere decreased while it increased in the roots with elevation. These suggest that, when the invasive plant colonizes into high altitudes, it may not suffer from limited rhizosphere fungal symbionts, but rather the ability of the plant to create and maintain these associations decreases. The invader tends to accumulate more pathogenic fungi in the roots, while the dependence on symbiotic fungi is reduced during expansion into higher elevations. These results highlight that the interactions between invasive plants and fungal community substantially change along elevation, and that belowground interactions may be key in our understanding of how invasive plants derive success in stressful, high-elevation environments.

Transition metal dichalcogenides (TMDs) have attracted tremendous research attention because of their potential performance in the electrochemical hydrogen evolution reaction. Also, the three-dimensional (3D) hollow structure can provide additional excellent electrochemical activities. Here, we report for the first time that a carbon-based metallic cobalt pyrite (C@CoS2) hollow tubelike structure (nanotubes) can be achieved by a sulfuration process. This process adopts a simple one-step chemical vapor diffusion-controlled strategy, and the growth of nanotubes can be adjusted by simply changing the gas reaction condition. The obtained C@CoS2 nanotubes have an outstanding electrocatalytic performance. The results show the overpotential (220 mV) and Tafel slope (55.04 mV dec–1) of C@CoS2 nanotubes are much lower than those of C@CoS2 nanorods (slightly higher than the Pt electrode) when the cathode current density is 10 mA cm–2. Additionally, the current density of the C@CoS2 electrode does not decrease much at an overpotential of −250 mV (vs the reversible hydrogen electrode, RHE) after a 36 h test, demonstrating a good durability. The hollow structure of the nanotubes plays a key role in the hydrogen evolution reaction (HER), the polyporous carbon materials work for improving the conductivity, and exposed active sites increase the catalytic activity, which together enhance the whole HER activities. The facile strategy may provide an alternative to prepare other multifunctional TMD nanomaterials for water splitting or other electrochemical reactions.

Detecting shifts in trait values among populations of an invasive plant is important for assessing invasion risks and predicting future spread. Although a growing number of studies suggest that the dispersal propensity of invasive plants increases during range expansion, there has been relatively little attention paid to dispersal patterns along elevational gradients. In this study, we tested the differentiation of dispersal-related traits in an invasive plant, Galinsoga quadriradiata, across populations at different elevations in the Qinling and Bashan Mountains in central China. Seed mass–area ratio (MAR), an important seed dispersal-related trait, of 45 populations from along an elevational gradient was measured, and genetic variation of 23 populations was quantified using inter-simple sequence repeat (ISSR) markers. Individuals from four populations were then planted in a greenhouse to compare their performance under shared conditions. Changing patterns of seed dispersal-related traits and populations genetic diversity along elevation were tested using linear regression. Mass–area ratio of G. quadriradiata increased, while genetic diversity decreased with elevation in the field survey. In the greenhouse, populations of G. quadriradiata sourced from different elevations showed a difference response of MAR. These results suggest that although rapid evolution may contribute to the range expansion of G. quadriradiata in mountain ranges, dispersal-related traits will also likely be affected by phenotypic plasticity. This challenges the common argument that dispersal ability of invasive plants increases along dispersal routes. Furthermore, our results suggest that high-altitude populations would be more effective at seed dispersal once they continue to expand their range downslope on the other side. Our experiment provides novel evidence that the spread of these high-altitude populations may be more likely than previously theorized and that they should thus be cautiously monitored., In this study, we tested the differentiation of dispersal-related traits in an invasive plant Galinsoga quadriradiata across populations at different elevations in Qinling and Bashan Mountains, China. Our results suggest that the dispersal ability of G. quadriradiata decreases along elevational dispersal routes as a result of genetically based rapid evolution and phenotypic plasticity, challenging the common argument that dispersal ability of invasive plants increases along dispersal routes. Our findings provide new insight into how the dispersal ability of invasive plants may change along the elevational gradient. This is important for revealing the upward expansion dynamic of invasive plants in high mountains.

Gold is a classical metal with the Fermi level lying in the sp-band, while graphene is a zero-bandgap semiconductor with Dirac band structure. Thus, the photon emission from both gold and graphene can not be effectively achieved by electron–holes recombination as direct bandgap semiconductors. Alternatively, optical emission from hot carriers is possible in graphene and gold, but usually with very low efficiency. This is because the hot carrier relaxation time is much faster than the radiative lifetime in both graphene and gold. To solve this problem, here we show that in suspended graphene structures the photon emission intensity can be enhanced by increasing the hot carrier relaxation time, while in suspended gold/graphene hybrid structures, the photon emission intensity also increased with increasing holes sizes. Since nowadays most semiconductor light sources are based on bandgap design and also restricted by it, the study could help to develop materials with the emission wavelength not being limited ...

Controlling thermal radiation in nanoscale is critical for verifying the Planck’s law in subwavelength limit, and is the key for a range of innovative technologies including energy, display and sec...

Transition metal dichalcogenides, such as monolayer MoS2 and WS2, can be easily transferred onto or integrated with various substrates, and are therefore promising on-chip light sources. Although are direct-bandgap materials with more efficient optical gain compared to indirect band-gap materials such as silicon, they are more sensitive to the surrounding environment and substrate materials than bulk direct-bandgap semiconductors. Herein, the photoluminescence intensity of WS2 transferred onto silicon nitride is demonstrated to be tunable and substantially enhanced by violet laser excitation, owing to irradiation-induced chemical doping with atmospheric moisture and oxygen, which lead to changes in the densities of neutral excitons and trions; this process is reversible in vacuum conditions. However, with continuous excitation, WS2 with trapped molecules is more easily damaged by laser irradiation than bulk semiconductors. Upon coating with Al2O3, the stability of WS2 under laser irradiation is enhanced. We show that the isolation of WS2 from air can extend the lifetime of transition metal dichalcogenides on chip-communication devices. The results of this study indicate that further optimization is required to realize practical on-chip applications of these monolayer materials as light sources.

Background Invasive Trichosporon asahii (T. asahii) infection frequently occurs with a high mortality in immunodeficient hosts, but the pathogenesis of T. asahii infection remains elusive. Circular RNAs (circRNAs) are a type of endogenous noncoding RNA that participate in various disease processes. However, the mechanism of circRNAs in T. asahii infection remains completely unknown. Methods RNA sequencing (RNA-seq) was performed to analyze the expression profiles of circRNAs, microRNAs (miRNAs), and mRNAs in THP-1 cells infected with T. asahii or uninfected samples. Some of the RNA-seq results were verified by RT-qPCR. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to analyze the differentially expressed mRNAs. A circRNA-miRNA-mRNA network was constructed and verified by dual-luciferase reporter assay and overexpression experiments. Results A total of 46 circRNAs, 412 mRNAs and 47 miRNAs were differentially expressed at 12 h after T. asahii infection. GO and KEGG analyses showed that the differentially expressed mRNAs were primarily linked to the leukocyte migration involved in the inflammatory response, the Toll-like receptor signaling pathway, and the TNF signaling pathway. A competing endogenous RNA (ceRNA) network was constructed with 5 differentially expressed circRNAs, 5 differentially expressed miRNAs and 42 differentially expressed mRNAs. Among them, hsa_circ_0065336 was found to indirectly regulate PTPN11 expression by sponging miR-505-3p. Conclusions These data revealed a comprehensive circRNA-associated ceRNA network during T. asahii infection, thus providing new insights into the pathogenesis of the T. asahii-host interactions.

The knowledge graph analysis method was used to study the literature related to the collaborative innovation of industry-university-research published in CSSCI from 2007 to 2019. The literature measurement analysis was conducted in terms of the number of papers published annually, research evolution path, hot spots and frontiers. The results show that the theoretical research on collaborative innovation of industry-university-institute is gradually maturing. The cooperation of industry-university-institute, influencing factors of collaborative innovation of industry-university-institute, talent cultivation and management, and regional construction are hot research topics. The research frontier is knowledge transfer, modularization, profit distribution, government-industry-university-research.

Background: Trichosporon asahii (T. asahii) invasive infection frequently occurs in immunodeficient hosts with high mortality, but the pathogenesis of T. asahii infection remains elusive. Circular RNAs (circRNAs) are a type of endogenous noncoding RNAs that participant various disease processes. However, the mechanism of circRNAs in T. asahii infection are still completely unknown.Methods: RNA sequencing (RNA-seq) was performed to analyse the expression profiles of circRNA, microRNA (miRNA), and mRNA in THP-1 cells infected with T. asahii or uninfected samples. Part of the RNA-seq results were verified by RT-qPCR. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were used to analyse the differentially expressed (DE) mRNA. The circRNA-miRNA-mRNA network was constructed and verified with dual-luciferase reporter assay and overexpression experiment.Results: A total of 46 circRNAs , 412 mRNAs and 47 miRNAs were DE after T. asahii infection at 12 h. GO and KEGG analysis showed that the DE mRNAs were primary linked to the leukocyte migration involved in inflammatory response, Toll-like receptor signaling pathway, and TNF signaling pathway. A competing endogenous RNA (ceRNA) network was constructed with five DE circRNAs, five DE miRNAs and 42 DE mRNAs. Among them, we verified that hsa_circ_0065336 indirectly regulate PTPN11 expression by sponging miR-505-3p.Conclusions: These data revealed a comprehensive circRNA-associated ceRNA network during T. asahii infection, thus providing new insights to clarify the pathogenesis between T. asahii-host interation.

The stacking order plays a critical role in the electronic and optical properties of two-dimensional materials. It is however of great challenge to achieve large-size and homogeneous bilayer crystals with precisely controlled stacking orders. Here, we demonstrate an optimized chemical vapor deposition strategy to grow MoSe

The p-n junction is one of the most important basic structures in the semiconductor field, with vast applications in photodetectors, transistors, light emitting diodes, and solar cells. Here, an new in-plane intramolecular WSe2 p-n junction is realized, in which the n-type region and p-type region are chemically doped by polyethyleneimine and electrically doped by the back-gate, respectively. An ideal factor of 1.66 is achieved, proving the high quality of the p-n junction realized by this method. As a photovoltaic detector, the device possesses a responsivity of 80 mAW-1 (≈20% external quantum efficiency), a specific detectivity of over 1011 Jones and fast response features (200 μs rising time and 16 μs falling time) at zero bias, simultaneously. Moreover, a large open-circuit voltage of 0.38 V and an external power conversion efficiency of ≈1.4% realized by the device also promises its potential in microcell applications.

Galinsoga quadriradiata, an annual herbaceous plant originating in Central and South America, has caused great harm to agriculture and natural communities in China recently. However, the distribution and influence of this invader are poorly documented. It is also unclear how climate change will affect the expansion of G. quadriradiata. In this study, we built a series of maximum entropy (Maxent) models to predict the potential distribution areas of G. quadriradiata under current and future (2030s, 2050s, and 2080s) climatic scenarios using six uncorrelated bioclimatic variables (obtained from the fifth report of the IPCC) and 274 occurrences. The Maxent model obtained high AUC value of 0.960, and the prediction showed that highly suitable areas for G. quadriradiata mainly locate in central, eastern, southwestern, and southern China. In the context of climate change, its suitable area will tend to contract in the future and disappear in southern and eastern China, but will expand in northeastern China. Overall, by the end of the century, its suitable area will be reduced by 12.1% and move northward in China. Our study suggests that G. quadriradiata has high invasive potential currently; however, to some extent, ongoing climate change will inhibit its expansion in China. In addition, the invasion risk of G. quadriradiata in northeastern China will continuously increase, keeping pace with global climate change in the coming decades, while the invasion risk in central, southwestern, and eastern China will stay continuously. Urgent preventative measures against G. quadriradiata invasion are necessary in these areas.

In order to prepare angiopep-2 modified fluorescein isothiocyanate-labeled neurotoxin nanoparticles( ANG-NPs/FITCNT),emulsion/solvent evaporation method was used with m PEG-PLA and ANG-PEG-PLA( in proper proportions) as carriers and with FITC-NT as drug. With particle size and encapsulation efficiency as comprehensive indexes,the effects of different ultrasound power and ultrasound time combinations on the process were investigated. The in vitro release characteristics of nanoparticles in PBS buffer at p H 7. 4 and p H 6. 5 were investigated by dialysis method. The results indicated that the optimum process for preparing ANG-NPs/FITC-NT was as follows: ultrasonic power 90 W,ultrasonic time 30 s. In such optimal process,ANG-NPs/FITC-NT were well-shaped under the transmission electron microscope,with an average particle size of( 123. 9±0. 5) nm,Zeta potential of(-10. 5±0. 5) m V,encapsulation efficiency of( 68. 1±0. 4) %,and the drug loading of( 0. 82±0. 01) %. The in vitro drug release profiles of the nanoparticles in PBS buffer at p H 7. 4 and p H 6. 5 were both consistent with Ritger-Peppas equation,ln Q = 0. 508 8 lnt-2. 285 0,r = 0. 961 5( p H 7. 4) and ln Q= 0. 449 9 lnt-1. 855 3,r = 0. 970 3( p H 6. 5),respectively. The experiment results proved that the nanoparticles prepared by emulsion/solvent evaporation method had uniform particle size,high encapsulation efficiency and in vitro sustained release characteristic,which might be a potential carrier for NT intracerebral drug delivery.

Reduction in the thickness of air-suspended mirrors to the deep subwavelength scale can facilitate efficient optical and mechanical design. The thinner the mirror, the smaller is its mass, and the more excellent mechanical properties it presents. Thin mirrors are easily displaced by optical radiation pressure, and could present more intense light-mirror interactions than their thicker counterparts. Herein, we present this kind of ultraflat air-suspended mirrors that can reflect light at the telecom region, with a mirror thickness of approximately 25 nm and total thickness of 50 nm. This kind of mirrors shows many unique properties, e.g., the mirrors become increasingly transparent with diminishing film thickness at nonresonant wavelength; there is a strong evanescent field distribution outside the mirrors; the reflection wavelength is almost independent of the refractive index of the mirror materials, and nearly only depends on the lattice geometry at the deep subwavelength scale; moreover, their quality factor significantly improves, which is important for applications in laser, cavity optomechanics, and cavity quantum electrodynamics.

Two-dimensional materials are compatible with silicon complementary metal-oxide semiconductor processes. As such, the integration of two-dimensional materials with silicon-based semiconductors could lead to an amalgamation of the beneficial properties of both silicon and the two-dimensional material thereby facilitating improved performance. Single-layer transition metal dichalcogenide materials like MoS2, MoTe2 and WS2 are characterized by direct band gaps and possess high emission efficiencies. These materials are, therefore, perfectly suited for ameliorating the optical emission inadequacies of silicon-based-materials. In this study, we integrate WS2 with a silicon-based silicon-nitride waveguide to modulate a 532-nm pump light source, and successfully modulate and amplify an optical signal at 640 nm. Compared to other modulators based on two-dimensional materials, e.g., graphene, the proposed WS2-based modulator theoretically incurs lower losses and exhibits higher contrast levels and signal-to-noise ...

Molten salt heat exchangers are key components in some advanced power systems. Two shell-and-tube molten salt heat exchangers are experimentally investigated, including a gas cooled one with finned tubes and a molten salt to salt one with segmental baffles in the shell side. Based on a nonlinear regression scheme, heat transfer coefficients in both the tube and shell sides are obtained. Heat transfer characteristics of molten salt in the tube side are discussed and compared with three empirical correlations. It is found that Wu’s Equation has better agreement with the experimental data than Gnielinski’s and Hausen’s Equations in transitional flow region. For the developing laminar flow in the tube side, the widely used Sieder–Tate correlation underestimates heat transfer coefficients of molten salt by up to 30%. Compared with oil and a chart method proposed from sufficient database, molten salt seems to have better heat transfer performance than other working fluids in the baffled shell side. Further researches on the heat transfer characteristics of molten salt in the shell side with baffles are needed and significant.

A novel model for the charging station planning problem of plug-in electric vehicles is proposed in this paper considering the users’ daily travel. With the objective of minimizing the total cost, including the charging stations’ cost (including installing cost and management cost) and the users’ cost (including station access cost and charging cost), the proposed model simultaneously handles the problems where to locate the charging stations and how many chargers to be established in each charging station. Considering that different users may have different perception of station access cost and charging cost, two cases (i.e., homogeneous users and heterogeneous users) are typically investigated. The impacts of different discount rates, operating period of the charging stations, number of electric vehicles and number of charging stations on the location of the charging station are also studied. The simulation results not only show that it is very important to locate the charging stations according to the traveling behavior of users, but also verify the validity of the proposed model.

AIM: To identify the underlying cellular and molecular changes in retinitis pigmentosa (RP). METHODS: Label-free quantification-based proteomics analysis, with its advantages of being more economic and consisting of simpler procedures, has been used with increasing frequency in modern biological research. Dystrophic RCS rats, the first laboratory animal model for the study of RP, possess a similar pathological course as human beings with the diseases. Thus, we employed a comparative proteomics analysis approach for in-depth proteome profiling of retinas from dystrophic RCS rats and non-dystrophic congenic controls through Linear Trap Quadrupole - orbitrap MS/MS, to identify the significant differentially expressed proteins (DEPs). Bioinformatics analyses, including Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway annotation and upstream regulatory analysis, were then performed on these retina proteins. Finally, a Western blotting experiment was carried out to verify the difference in the abundance of transcript factor E2F1. RESULTS: In this study, we identified a total of 2375 protein groups from the retinal protein samples of RCS rats and non-dystrophic congenic controls. Four hundred thirty-four significantly DEPs were selected by Student’s t-test. Based on the results of the bioinformatics analysis, we identified mitochondrial dysfunction and transcription factor E2F1 as the key initiation factors in early retinal degenerative process. CONCLUSION: We showed that the mitochondrial dysfunction and the transcription factor E2F1 substantially contribute to the disease etiology of RP. The results provide a new potential therapeutic approach for this retinal degenerative disease.

Graphene is a gapless material with a linear energy–momentum dispersion relationship. Because of its unique band structure, graphene has been demonstrated as an ultra-broadband photon absorption material from the visible to terahertz frequency ranges. Here, we study the reverse process: photon emission from graphene. Using silica microsphere structures and femtosecond laser pulse excitation, photon emission enhancement at visible, near infrared, and terahertz ranges were achieved. These results help to promote graphene as a new type of light generation material, which can overcome the restriction that the emission wavelength is determined by the material bandgap. It is also found that the graphene's electrical properties, such as the nonlinear conductivity, changed significantly with the enhancement of the absorption during the ultrafast process.

A novel model for the charging station location problem of plug-in electric vehicles is proposed in this paper. With the objective of minimizing the total cost, the proposed model simultaneously handles the problem of where to locate the charging stations and how many chargers should be established in each charging station. Furthermore, the model is expanded to consider a more general case. A genetic algorithm-based method is proposed for solving the expanded model. The results show that a better location scheme can be obtained using the expanded model.

A facile strategy has been constructed for the highly efficient discrimination of single nucleotide polymorphisms (SNPs) based on magnetic functionalized graphene oxide (GO@Fe3O4) modified poly(dimethylsiloxane) microchip system coupled with electrochemical detection. A methylene blue-labeled single stranded DNA (P1) can complete complementary with target mircoRNA-21 (T1) to form a perfectly matched DNA/RNA heteroduplex (P1T1), while the hybridization of the P1 with single-base mismatched sequence of mircoRNA-21 (M1) can form a loose DNA/ms-RNA heteroduplex (P1M1). The π-stacking interaction between the loose DNA/ms-RNA heteroduplex and the GO is much stronger than that of the perfectly matched DNA/RNA heteroduplex. Moreover, GO can enhance the unwinding of unstable DNA/ms-RNA through strong interaction between GO and single stranded DNA (ssDNA) and consequently increase the retention time of single-base mismatch microRNA-21 in the GO@Fe3O4-based microchip system. Therefore, the GO@Fe3O4-based microchip system exhibited high performance for the separation and detection of microRNA-21 and single-base mismatch microRNA-21, which provide a powerful protocol for SNPs discrimination within a short analytical time. More importantly, this platform can be used for other small molecules and proteins assay in various systems by simply changing the sequence of the probe DNA.

Splitting water is a key challenge in the production of chemical fuels from electricity. Although several catalysts have been developed for these reactions, substantial challenges remain towards the ultimate goal of an efficient, inexpensive and robust electrocatalyst. Until now, there is as yet no report on both water oxidation and reduction by identical catalyst. Reported here is the first soluble copper-based catalyst, Cu(Me2oxpn)Cu(OH)2] 1 (Me2oxpn: N,N′-bis(2,2′-dimethyl-3-aminopropyl)oxamido) for both electrolytic water oxidation and reduction. Water oxidation occurs at an overpotential of 636 mV vs SHE to give O2 with a turnover frequency (TOF) of ∼2.14 s−1. Electrochemical studies also indicate that 1 is a soluble molecular species, that is among the most rapid homogeneous water reduction catalysts, with a TOF of 654 mol of hydrogen per mole of catalyst per hour at an overpotential of 789 mV vs SHE (pH 7.0). Sustained water reduction catalysis occurs at glassy carbon (GC) to give H2 over a 32 h electrolysis period with 95% Faradaic yield and no observable decomposition of the catalyst.

The volume–capacity ratio ( v / c ) is one of the most important indexes to measure the congestion of a traffic network. If v / c is very small, the traffic demand is deficient and/or the transportation supply or capacity is surplus, leading to a waste of capacity; on the contrary, a large value of v / c means that the traffic network is seriously congested. This paper investigates the properties of v / c in complex small-world and scale-free networks by introducing the congestion effects, described by link cost functions. The relationship between v / c and the degree of the node is mainly discussed. Finally, a simple strategy is presented to balance the tradeoff between traffic congestion and a waste of capacity.

Aims Fully understanding the assembly patterns of plant functional traits in plant communities is a big challenge in the study of community ecology. The assembly patterns in alpline meadow and driving factors are still poorly known. In this study, experiments with different mowing intensities and various treatments of fertilization were conducted in alpline meadow for the purpose of improving the understanding of the assembly patterns of plant functional traits in plant community. Methods Data on functional diversity of 10 traits for 33 species from 108 quadrats (with varying combinations of mowing and fertilization) were analyzed by randomizations tests, ANCOVA and regression analysis, respectively, for the trait convergence/divergence. Important findings None of the traits studied showed consistently significant convergence or divergence pattern in integral gradients of fertilization and mowing treatments, while the ratios of quadrats assembled under deterministic and stochastic processes were 82.7% and 17.3%, respectively. Among the functional traits tested, growth form, life cycle, aboveground dry mass per plant, leaf area and leaf dry mass showed a stochastic pattern of assembly, but they were not affected by variations in mowing treatments and community characteristics (i.e. aboveground net primary productivity, biomass loss and vegetation height). Convergence or divergence patterns were shown in traits such as plant inclination, reproductive modes, nitrogen fixation, plant height and specific leaf area, which were affected by variations in mowing treatments and community characteristics. Among them, assembly patterns of plant inclination and specific leaf area were only affected by community characteristics, while nitrogen fixation, reproductive modes and plant height were affected by both mowing treatments and community characteristics. Moreover, the patterns of assembly varied by traits. Aboveground net primary productivity and biomass 吕美强等: 刈割与施肥干扰下高寒草甸植物功能性状的构建模式 917 doi: 10.3724/SP.J.1258.2014.00086 loss well explained variations in the assembly pattern of plant functional traits. Mowing and fertilization showed the reversed effects on the assembly pattern of plant height, while no significant interaction was found between mowing and fertilization. The results suggested that there were different assembly patterns of functional traits in the community: stochastic pattern of assembly was the primary, and the deterministic pattern was secondary. Deterministic pattern was trait-dependent and correlated with variations in mowing treatments and community characteristics. The balancing effect of opposite selection forces, on the other hand, could lead to stochastic assembly patterns in plant functional traits.

Aims Our objective was to study vegetation dynamics and changes in ecosystem functions based on plant traits and characteristics of plant functional types (PFTs). Methods A field manipulation experiment with a split-plot design was conducted in alpine meadow at the Haibei Research Station of the Chinese Academy of Sciences from 2007 to 2011. Three clipping levels (stubbled 1 cm, 3 cm and unclipped) were used on the whole plot and subplots were treated with or without fertilizer and watering. The recursive algorithm and multivariate analysis were implemented to search for optimal trait subsets and plant response types (PRTs), which could response to experimental treatments, and to identify plant effect types (PETs) impacting the aboveground net primary productivity of community. Important findings Under each of four resource conditions, i.e., unfertilized and unwatered (NFNW), fertilized only (F), watered only (W) and fertilized and watered (FW), the optimal response trait subsets were different, i.e., leaf margin-plant height-leaf weight-specific leaf area, life cycle-plant height-leaf weight-specific leaf area, life cycle-chlorophyll content-leaf surface-plant height-leaf weight-specific leaf area, and propagative organ-leaf margin-plant height, respectively. Of these responses, plant height, leaf weight and specific leaf area were more sensitive to treatments than others. Under the resource conditions, we found 14 optimal PRTs and four PETs in all of the PFTs. These PETs can explain 50.3%–86.4% of variation in productivity. The optimal PRTs and the optimal PETs account for 70% and 20% of all PFTs. PETs account for 28.5% of PRTs, therefore, there was partial overlap between PETs and PRTs. These results indicate that both vegetation response to grazing disturbance and ecosystem functioning changes could be accurately reflected by easily measurable plant functional traits. However, theoptimal trait subsets and PFTs could be different depending on when the heterogeneity of resources is taken into account. PETs are the optimal PFTs reflecting vegetation response to grazing disturbance, but also changes in ecosystem functioning.

For the research about the protection of intellectual property , scholars both at home and abroad mostly focus on the protection of the law itself and macroscopic protection strength. Whats more, from the micro perspective, there are very few study about the protection of intellectual property rights inside the business enterprise, and also there are few study that could identify property value and promote the effective protection of the property through auditing the information about intellectual property. Therefore, based on Chinese reality, this paper puts forward the information audit which focus on the independent innovatively intellectual property, defined the audit main body, object, emphasized some points about the audit process based on the particularity of property information and finally gave some related suggestions.

Analyzing modes in a micro-ring waveguide coupled with a feedback resonator reveals that with appropriate parameters, the quality factors of two neighboring ring modes vary periodically and considerably. The effect occurs upon changing the length of the feedback waveguide, whereas the two resonant frequencies remain almost invariant with length change. On the basis of this property, four methods are theoretically demonstrated to realize laser switching: two for frequency switching, one for clockwise to counterclockwise mode switching, and one for even to odd mode switching. The analysis provides methods for bistable lasing and optical logic device design.

In this paper, a so-called discrete-time modified weak-pseudo-sliding mode controller with one sampling period computation delay is proposed for the system with system parameter uncertainty. In the meantime, the upper bound of the sampling period is also determined to guarantee the existence of the modified weak-pseudo-sliding mode along the prescribed sliding surface in the proposed discrete-time sliding mode control system.

A novel hybrid material of chitosan/nano-sized SiO2/hydroxyapatite (HAp) composite was prepared through a biomimetic approach. HAp deposited in situ on the surface of chitosan/ nano-sized SiO2 composite film in simulate body fluid (SBF) solution at 36.5°C. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to study composition and morphological characteristics of the HAp crystal. The results indicated that nano-sized SiO2 dispersed in the chitosan film provided initial nucleation sites for the growth of the HAp in SBF solution by adsorbing further PO4 3−, Ca2+ due to the induction of HAp formed. The strength of the composite was largely improved because of the addition of nano-sized SiO2.

The Pre-Ca procedure was applied to the titanium surfaces before immersion in the SBF to accelerate the apatite precipitation. The process of apatite formation on the titanium surfaces was investigated by using scanning electron microscopy (SEM). A QCM system was applied to quantitatively monitor the apatite formation process using biomimetic method in situ in real time and to estimate the effect of pre-calcification in the biomemetic process effectively combined with SEM technique.

We report the femtosecond laser propagation in a hybrid graphene/silicon ridge waveguide with demonstration of the ultra-large Kerr coefficient of graphene. We also fabricated a slot-like graphene/silicon ridge waveguide which can enhance its effective Kerr coefficient 1.5 times compared with the graphene/silicon ridge waveguide. Both transverse-electric-like (TE-like) mode and transverse-magnetic-like (TM-like) mode are experimentally measured and numerically analyzed. The results show nonlinearity dependence on mode polarization not in graphene/silicon ridge waveguide but in slot-like graphene/silicon ridge waveguide. Great spectral broadening was observed due to self-phase modulation (SPM) after propagation in the hybrid waveguide with length of 2 mm. Power dependence property of the slot-like hybrid waveguide is also measured and numerically analyzed. The results also confirm the effective Kerr coefficient estimation of the hybrid structures. Spectral blue shift of the output pulse was observed in the slot-like graphene/silicon ridge waveguide. One possible explanation is that the blue shift was caused by the ultra-fast free carrier effect with the optical absorption of the doped graphene. This interesting effect can be used for soliton compression in femtosecond region. We also discussed the broadband anomalous dispersion of the Kerr coefficient of graphene.

A multiwall carbon nanotubes (MWNTs)-chitosan modified glassy carbon electrode (GCE) exhibits attractive ability for highly sensitive cathodic stripping voltammetric measurements of bromide (Br−). In pH 1.8 H2SO4 solution, a substantial increase in the stripping peak current of Br− (compared to bare GCE and chitosan modified GCE) is observed using MWNTs-chitosan modified electrode. Operational parameters were optimized and the electrochemical behaviors of Br− were studied by different electrochemical methods. The kinetics parameters were measured, the number of electron transfer (n) was 1 and the transfer coefficient (α) is 0.17. A wide linear calibration range (3.6 × 10−7–1.4 × 10−5 g mL−1) was achieved, with a detection limit of 9.6 × 10−8 g mL−1. The mechanism of electrode reaction was fully discussed.

In this paper, a discrete-time sliding mode control law is developed to guarantee the existence of the weak pseudo sliding mode along the prescribed hyperplane. Meanwhile, the upper bound of the sampling period is also determined in order to ensure the stability of the controlled system. Finally, some simulation results are given to illustrate the performance of the proposed discrete-time sliding mode control scheme.

To study the in situ intestinal absorption kinetics of flrubiprofen in rats, the absorption of flurbiprofen in small intestine (duodenum, jejunum and ileum) and colon of rats was investigated using in situ single-pass perfusion method and the drug content was measured by HPLC. The effects of drug concentration on the intestinal absorption were investigated. The K(a) and P(app) values of flurbiprofen in the small intestine and colon had no significant difference (P0.05). Drug concentration (4.0, 10.0 and 16.0 mg x L(-1)) had no significant influence on the K(a) values (P0.05). However, when concentration was 4.0 mg x L(-1) and 10.0 mg x L(-1), significant effect on the P(app) values (P0.05) was found, but significant effect on the P(app) values was not shown between 10.0 mg x L(-1) and 16.0 mg x L(-1) (P0.05). The K(a) and P(app) values of flurbiprofen on the perfusion flow rate had significant difference (P0.05). Flurbiprofen could be absorbed at all segments of the intestine in rats and had no special absorption window. The absorption of flurbiprofen complies with the facilitated diffusion in the general intestinal segments, and accompany with the cytopsistransport mechanism probably. The perfusion flow rate had significant effect on the K(a) and P(app).

The confinement of light within nanometer-scale regions may result in the significant enhancement of light-matter interactions. However, light confinement to nanometers is hindered by the diffraction limit of a dielectric material. For a dielectric cavity, if the material loss is negligible, reducing the cavity size usually causes a significantly increase in radiation loss. Surface plasmons show great promise for potential subwavelength light confinement. However, in most circumstances, light confinement by dissipative metallic materials can cause ohmic losses at optical frequencies. In such cases, the realization of light confinement with deep subwavelength mode sizes results in great losses and thus has low quality factors. In the present study, a three-dimensional light confinement with deep subwavelength mode sizes is achieved using dielectric spheres in metal cavities. Contrary to other mechanisms for subwavelength light confinement that are based on the use of dielectric or metal cavities, the nanometer-scale regions ensure that most of the light energy is confined away from the metal-dielectric interfaces, thereby decreasing light absorption in the metal cavity. In turn, the metal cavity decreases the radiation loss of light. Thus, high quality factors ranging from 2×10(2) to 6×10(2) can be obtained at room temperature. An effective electrical mode volume ranging from 7×10(-5)λ(0)(3) to 2×10(-4)λ(0)(3) (where λ(0) is the resonant wavelength in a vacuum) can be achieved. Therefore, this method of three-dimensional light confinement with deep subwavelength mode sizes using dielectric spheres in metal cavities may have potential applications in the design of nanolasers, nanophoton detectors, nonlinear optical switches, and so on.

We show that optical transmission of linearly polarized light through a plasmonic subwavelength metallic grating cascaded with a dielectric grating at a 45° angle to each other is asymmetric in opposite directions. A key characteristic of this asymmetric transmission is that the polarization of the transmitted light is changed. Simulation results reveal that transmission of 0.92 in one direction and 10(-5) in the opposite direction can be obtained at normal incidence at a wavelength of 1550 nm. Because of their high optical performance and loose fabrication requirements, the structures may provide practical applications in the control of light transmission.

We numerically demonstrate that electro-optic switching in the mid-infrared range can be realized using a waveguide-ring resonator made of dielectric-loaded graphene plasmon waveguides (DLGPWs). The numerical results are in good agreement with the results of physical analysis. The switching mechanism is based on dynamic modification of the resonant wavelengths of the ring resonator, achieved by varying the Fermi energy of a graphene sheet. The results reveal that a switching ratio of ∼24 dB can be achieved with only a 0.01 eV change in the Fermi energy. Such electrically controlled switching operation may find use in actively tunable integrated photonic circuits.