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This work investigates the problem of input–output finite-time stability (IO-FTS) for one-sided Lipschitz switched systems by sliding mode control (SMC) approach. A key issue is how to ensure the IO-FTS of the switched systems during the whole finite-time interval under the unknown one-sided Lipschitz nonlinearity. To this end, a sliding mode law is constructed to ensure the state trajectories can be driven onto the sliding surface during the assigned finite time interval. By means of partitioning strategy and the multiple Lyapunov function (MLF) approach, the corresponding IO-FTS over reaching phase and sliding motion phase are guaranteed, respectively. And then, some sufficient conditions are derived by utilizing the one-sided Lipschitz and quadratically inner-bounded conditions. Finally, an illustrative example is given to illustrate the proposed method.

This study aimed to isolate a novel archaeon capable of simultaneously producing methane and bioflocculants. The isolated methanogen was identified as Methanosarcina spelaei RK-23 by molecular characterization. Strain RK-23 grew with different carbon sources, but acetate was found to be the most beneficial carbon source for the production of methane and bioflocculants. Moreover, RK-23 produced methane and bioflocculants within an initial pH range of 5.0–8.0, with an optimal pH for methane production of 6.5 and flocculating activity of 7.0. In addition, strain RK-23 exhibited tolerance to high-salinity conditions and produced methane and bioflocculants within 0–1.2 M NaCl, with an optimum NaCl concentration of 0.3 M. The methane production and flocculating activity of strain RK-23 under optimal culture conditions were 17.4 mmol methane/mol acetate and 95.6%, respectively. MBF-23 mostly consisted of 83.5% carbohydrates and 14.3% proteins. Furthermore, the bridging of adsorption is believed to be the main bioflocculation mechanism in this study.

This work addresses the sliding mode control (SMC) problem for a class of cyber-physical switched systems, in which both the Round-Robin (RR) protocol scheduling and the deception attacks may happen on the controller-to-actuator (C/A) channels. Under the regulation of RR protocol, only one controller node at each instant can access the network and transmit its signal to the corresponding actuator node, that is, the other actuators cannot obtain any new control information. Especially, the transmitted signal could be contaminated by randomly injecting false data. Thus, a key problem is how to design a suitable sliding surface and a desirable sliding mode controller for guaranteeing the dynamic performance of the closed-loop switched systems. To this end, a compensation strategy is proposed for those actuator nodes that don’t receive any new control signals at certain instant, based which a token-dependent SMC law is designed. Besides, the method of input-to-state stability in probability (ISSiP) is introduced and the sufficient conditions are established for the reachability of the specified sliding surface and the ISSiP of the resultant switched systems. Finally, some numerical simulation results are provided.

This study is concerned with the event-triggered sliding mode control problem for a class of cyber-physical switched systems, in which the Denial-of-Service (DoS) attacks may randomly occur according to the Bernoulli distribution. A key issue is how to design the output feedback sliding mode control (SMC) law for guaranteeing the dynamical performance of the closed-loop system under DoS attacks. To this end, an event-triggered mechanism is firstly introduced to reduce the communication load, under which the measurement signal is transmitted only when a certain triggering condition is satisfied. An usable output signal for the controller is constructed to compensate the effect of unmeasured states and DoS attacks. And then, a dynamic output feedback sliding mode controller is designed by means of the attack probability and the compensated output signals. Both the reachability and the mean-square exponential stability of sliding mode dynamics are investigated and the corresponding sufficient conditions are obtained. Finally, some numerical simulation results are provided.

Aquatic photosynthesis transforms inorganic carbon to organic carbon (OC), which contributes to autochthonous organic carbon (AOC) in sediment and particulate organic carbon in surface karst aquatic systems. Aquatic plant and microbes are participated in autochthonous dissolved organic carbon (ADOC) formation in surface karst aquatic systems, but the composition and formation of ADOC remains little known, which leaves problem on calculation of organic carbon flux. In this study, the Lijiang River was chosen as typical surface karst river to identify the DOC composition and its origin, and to explore the environmental influencing factors. Samples were collected seasonally from the upper to lower reaches of the river to analyze hydrochemical parameters and the excitation-emission matrix (EEM) spectrum of chromophoric dissolved organic matter (CDOM). Three CDOM components were calculated by parallel factor analysis (PARAFAC) from EEM spectra, which were allochthonous soil-sourced DOC (SDOC), autochthonous aquatic plant-sourced DOC (APDOC), and microbial-sourced DOC (MDOC). Based on the DOC component concentrations, SDOC is induced by large amounts of precipitation causing soil erosion in summer. APDOC formation is encouraged by moderate water temperatures in spring and fall restricted by high water turbidity in summer. The significant positive linear correlations between APDOC and dissolved inorganic carbon (DIC) and MDOC indicate DIC fertilization effect in karst aquatic systems directly promotes APDOC formation and indirectly promotes MDOC. Our study develops a relatively simple way to calculate composition of karst aquatic DOC, which demonstrates the participation of aquatic plants and microbes in APDOC production and reiterate that autochthonous DOC should be considered when calculating the carbon sink in surface karst aquatic systems.

Bioflocculants are widely used in a large variety of applications, because of their wide range of flocculation. There is limited information in the literature about the ability of bioflocculants to perform beneficial functions without having adverse effects on blood components. In this study, general hemocompatibility of a bioflocculant (MBF-06) was investigated in an in vitro system, measuring flocculation of plasma proteins, red blood cell integrity, blood cell counts, platelet activation, clot formation, complement activation, cytotoxicity and inflammatory response. Effects of MBF-06 included low plasma protein flocculation, low platelet activation, low inflammatory response, no hemolysis or cytotoxicity and increased expression of coagulation markers, including prothrombin fragments 1+2. These findings suggested that the rapid hemostasis caused by MBF-06 resulted, essentially, from humoral coagulation. Overall, our observations revealed the great potential of MBF-06 as a novel hemostatic agent.

A novel bioflocculant (MBF-79) prepared using formaldehyde wastewater as carbon resource was investigated in the study. The optimal conditions for bioflocculant production were determined to be an inoculum size of 7.0%, initial pH of 6.0, and formaldehyde concentration of 350 mg/L. An MBF-79 of 8.97 g/L was achieved as the maximum yield. Three main elements, namely C, H, and O, were present in MBF-79 with relative weigh percentages of 39.17%, 6.74%, and 34.55%, respectively. The Gel permeation chromatography analysis indicated that the approximate molecular weight (MW) of MBF-79 was 230 kDa. MBF-79 primarily comprised polysaccharide (71.2%) and protein (27.9%). Additionally, conditions for the removal of arsenic by MBF-79 were found to be MBF-79 at 120 mg/L, an initial pH 7.0, and a contact time 60 min. Under the optimal conditions, the removal efficiencies of arsenate (0.5 mg/L) and arsenite (0.5 mg/L) were 98.9% and 84.6%, respectively. Overall, these findings indicate bioflocculation offers an effective alternative method of decreasing arsenic during water treatment.

Background There is controversy about whether the amniotic fluid contains bacteria. With the use of sequencing-based methods, recent studies report that the amniotic fluid is colonized by microorganisms. However, background-contaminating DNA might lead to false-positive findings when such a low microbial biomass sample is examined. Objective The purpose of this study was to determine whether the midtrimester amniotic fluid of patients who subsequently had normal pregnancy outcomes contains a microbial signature. Study Design In this prospective cohort study, 42 amniotic fluid samples were collected from 37 pregnancies (5 twin and 32 singletons) during genetic amniocentesis in the midtrimester. The subsequent pregnancy outcomes of all the participants were followed. Multiple methods were used to detect the presence of microorganisms in this study, which included cultivation, quantitative real-time polymerase chain reaction, and 16S ribosomal RNA gene sequencing. Multiple positive control samples (n=16) served as quality control samples and included 3 adult fecal samples, 4 vaginal swabs, and 9 artificial bacterial communities that were run in parallel with negative control samples (n=12) that included 4 samples from the hospital operating room and 8 samples from the laboratory, to account for background-contaminating DNA during each step of the experiments. Results No bacteria under anaerobic or aerobic conditions or genital mycoplasmas were cultured from any of the amniotic fluid samples. Quantitative polymerase chain reaction did not reveal greater copy numbers of 16S ribosomal RNA gene in amniotic fluid samples than in negative control samples. 16S Ribosomal RNA gene sequencing did not indicate a significant difference in the microbial richness or community structures between amniotic fluid and negative control samples. Conclusion With multiple methods of microbiologic inquiry, no microorganisms were identified in the midtrimester amniotic fluid of healthy pregnancies with a normal pregnancy outcome.

We analysed precipitation and river water samples from the Lijiang River basin with the aim of understanding the important role of acid rain components, especially NH4, in chemical weathering of karst areas. First, analysis of the hydrochemical characteristics revealed the following: In the precipitation samples, the volume-weighted mean pH was 4.91, and the acid rain rate was 65%. The major ion composition was characterized by a dominance of NH4, Ca, SO4 and NO3, accounting for 40.0%, 35.3%, 46.3% and 30.5%, respectively, of the total cation and anion concentrations. In the river water samples, the pH ranged from 6.75 to 9.16, with an average of 7.55. The major hydrogeochemical species in the river water samples were Ca–HCO3 and Mg–HCO3. Second, by employing chloride-normalized ratios of the other major ions in precipitation, we estimated that the contributions of SO4 and NO3 from the atmosphere to the river were53.6% and 35.0%, respectively. Third, combining the hydrochemical index with the value of δ13CDIC and using the hydrochemical composition method showed that the proportion of carbonate weathered (R) by NH4, H2SO4 and HNO3 from acid rain accounted for 9.3%, 9.4% and 3.1% of the total weathering rate, respectively, and the proportions in the upper reaches were significantly higher than those in the lower reaches of the river. The average values of the carbonate weathering proportion (R) and the carbonate weathering rate (CWR) due to acid rain were approximately 22.0% and 2.1 t/km2/yr, respectively. Taken together, our results revealed that carbonate weathering by acid rain can significantly increase the carbonate weathering rate, which is essential information for accurate estimation of the carbon cycle (namely, inorganic carbon sources and sinks).

Pinewood nematode (PWN) is the causal agent of the pine wilt disease. Previous studies have suggested that secretions from the esophageal glands of PWN play an important role in pathogenicity. A cluster of three venom allergen-like protein genes and one pseudogene, Bx-vap-1, Bx-vap-2, Bx-vap-3 and Bx-vap-P, were identified within a 3.7-kb region. Additionally, three putative modification, transport and regulatory protein genes were also detected in the same flanking region of the Bx-vap gene cluster. Genes vap-1, -2 and -3 are functional and encode three major allelic variants of PWN venom allergen-like proteins. But Bx-vap-P is an untranscribed pseudogene. Genes vap-1, -2 and -3 produce predicted products of 204, 206 and 203 amino acid residues, respectively, including the putative signal peptide sequence at the amino termini. In situ mRNA hybridization analysis showed that the transcripts of genes vap-1, -2 and -3 accumulated exclusively within the esophageal gland cells of Bursaphelenchus xylophilus.

This investigation centers upon calculating the vertical electric current densities from the two transverse components of vector magnetograms. The electric current density calculated by using the differential form of Ampere's law, j(z) = 1/mu(0) (del x B)(z), on the basis of spatially sampled transverse magnetic fields varies widely over an active region. In order to investigate how errors in the vector magnetograph measurements produce errors in the vertical electric current densities, we have numerically simulated the effects of random noise on a standard photospheric magnetic configuration produced by electric currents satisfying the force-free field conditions. We have also compared the results of the densities calculated by three different methods, and analyzed the reason inducing the differences in the results. The three methods are (1) to calculate the density using the differential form of Ampere's law j(z) = 1/mu(0) (del x B)(z); (2) to calculate the density using the integral form of Ampere's law along the square with edges at (x - Delta x, y - Delta y), (x + Delta x, y - Delta y), (x + Delta x, y + Delta y), (x - Delta x, y + Delta y) (hereafter small integral path) j(z) = (1/mu(0) closed integral(C1) B(t).dl)/dS; (3) to calculate the density by using the integral form of Ampere's law along the square with edges at (x - 2 Delta x, y - 2 Delta y), (x + 2 Delta x, y - 2 Delta y), (x + 2 Delta x, y + 2 Delta y), (x - 2 Delta x, y + 2 Delta y) (hereafter big integral path), j(z) = (1/mu(0) closed integral(C2) B(t).dl)/dS. It is found that the uncertainty of the measured electric current density increases along with the decreasing of the spatial pixel size ds. When the spatial pixel size of vector magnetograms is small enough, properly expanding the integral path can help us decrease the effect of random noise and demodulate the "true" electric current density from the measured transverse magnetograms. Close attention should be paid to the fact that some true fine-structure of the electric current density will be lost when the integral path exceeds the linear size of the smallest spatially resolved structure in the studied magnetogram. (C) 2008 Elsevier B.V. All rights reserved.

By quantitative analysis of AR NOAA 10484 two-dimensional Stokes spectra obtained from the Solar Stokes Spectral Telescope (S(3)7) at the Yunnan Observatory, we have derived three components, the flux intensity B, the inclination gamma and the azimuth chi of the vector magnetic fields in the AR. The contours of the flux intensity B have a basic agreement to the morphological configuration of the sunspot group in white-light. Comparing the vector magnetograms obtained by (ST)-T-3 and by the NASA/Marshall Space Flight Center (MSFC), basic agreement on the longitudinal and transverse components between the S3T and MSFC magnetograms is found, resulting in correlation coefficients rho(B parallel to) = 0.904, rho(B1) = 0.749 and rho(az), = 0.941. There is a split of 241 m angstrom between the two sigma lines of Fe I 6302.5 angstrom which implies the field flux intensity near the center of the west umbra is 2600 G. This value is consistent with the result obtained by fitting the Stokes profiles. (C) 2007 Elsevier B.V. All rights reserved.

A time series of H-alpha filtergrams and two-dimensional H-alpha spectral data of the well-known post-flare loop system of April 27, 1981 are obtained at the Yunnan Observatory. The two-dimensional spectral data are analyzed quantitatively by means of the 'multi-cloud model' method. The line-of-sight velocity fields of the post-flare loop system are derived for three different times. The post-flare loop system is composed of a loop and an ejection. The loop almost faces the observer and the ejection is along the line-of-sight. A 'double-loop' model is proposed in order to explain the structure and evolution of the post-flare loop system. The distributions of the line-of-sight velocity and the evolution time of the post-flare loop system derived from a free-fall model are similar to those obtained from the observations. (C) 2004 Elsevier B.V. All rights reserved.

The method proposed by Hathaway et al. [SoPh 151 (1994) 177] was employed to predict the magnitude of sunspot activities in the declining phase of solar Cycle 23, based on the monthly averages of sunspot number and the smoothed monthly averages of sunspot number, respectively. Our results show that: (1) the application of smoothed monthly averages of sunspot number gives better and less fluctuating (or more stable) predictions of sunspot activity at the early stage of the cycle than predictions based on monthly averages of sunspot number, and (2) a starting date of October 1996 works better than a starting date of May 1996 for Cycle 23. Both the validity and advantage of Hathaway et al.'s [SoPh 151 (1994) 177] approach are discussed in detail. (C) 2002 Elsevier B.V. All rights reserved.