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Chitin deacetylase (CDA) is a key enzyme involved in the modification of chitin and plays critical roles in molting and pupation, which catalyzes the removal of acetyl groups from N-acetyl-D-glucosamine residues in chitin to form chitosan and release acetic acid. Defects in the CDA genes or their expression may lead to stunted insect development and even death. Therefore, CDA can be used as a potential pest control target. However, there are no effective pesticides known to target CDA. Although there has been some exciting research progress on bacterial or fungal CDAs, insect CDA characteristics are less understood. This review summarizes the current understanding of insect CDAs, especially very recent advances in our understanding of crystal structures and the catalytic mechanism. Progress in developing small-molecule CDA inhibitors is also summarized. We hope the information included in this review will help facilitate new pesticide development through a novel action mode, such as targeting CDA.

In recent decades, riparian floodplains have undergone intensive reclamation worldwide, which has potential to influence soil carbon (C) accumulation. Such influence generally varies based on reclamation duration. Therefore, a study on changes in soil C stock along the reclamation chronosequence can help reveal the impact of reclamation on terrestrial C cycling. We chose natural floodplains (as the control) and croplands reclaimed for 13, 24, and 33 years in the lower reaches of the Yellow River and determined soil organic C (SOC) and soil inorganic C (SIC) contents at different depths and the stocks in 0–100 cm profiles. The SOC and SIC stocks generally increased at average rates of 2.73 and 5.54 Mg C ha−1 yr−1, respectively, and the SIC stock was closely related with the SOC stock across the reclamation chronosequence. The SOC content increased more at 0–20 cm depth in the profile along the reclamation chronosequence, but the SIC content often had a higher rate of increase in the deep soil layers. Significantly, the contents of SOC and SIC were both positively correlated with the proportion of silt fractions. Our findings suggest that reclaimed croplands from riparian floodplain play an important role in C accumulation, highlighting the importance of soil inorganic C in C budget. Moreover, soil C accumulation relates closely to soil texture, which changes continuously along the reclamation chronosequence and often varies due to spatial heterogeneity.

Mast cells are widely distributed in various parts of the human body and play a vital role in the progression of many diseases. Recently, the close relationship between mast cells and acupoints was elucidated, and the role of mast cells in acupuncture analgesia has attracted the attention of researchers worldwide. Using mast cells, acupuncture analgesia and acupoint as key words to search CNKI, PubMed, Web of Science and other databases, combining the representative articles in these databases with the published research papers of our group, we summarized: The enrichment of mast cells and the dense arrangement of collagen fibers, microvessels, and nerves form the basis for acupoints as the reaction sites of acupuncture; acupuncture can cause the deformation of collagen fibers and activate TRPV channels on mast cells membrane, so as to stimulate mast cells to release bioactive substances and activate nerve receptors to generate analgesic effect; system biology models are set up to explain the quantitative process of information initiation and transmission at acupuncture points, and indicate that the acupuncture effect depends on the local mast cells density. In a conclusion, this review will give a scientific explanation of acupuncture analgesia from the material basis of acupoints, the local initiation, and afferent biological mechanism.

Accurate and timely acquisition of plant diversity information downstream of the reservoir is helpful to understand the impact mechanism of reservoir operation on wetland plant diversity and formulate reasonable water and sediment regulation strategies. In this study, we conducted field surveys in two communities (Phragmites australis and Tamarix chinensis) at a typical wetland in the lower reaches of Xiaolangdi Reservoir on the Yellow River, and employed UAV and Gaofen 1B multispectral images to estimate the wetland plant diversity. Results showed that most diversity indexes had a higher correlation with the mean of spectral vegetation indexes (DVI, RVI, NDVI, SAVI, and MSAVI). The diversity indexes (C_SP and C_SW) constructed by relative coverage had a better overall correlation with spectral indexes. Interestingly, opposite correlations were found between Tamarix chinensis and Phragmites australis plots. We further gave a deep insight into the interspecific associations in Phragmites australis and Tamarix chinensis plots with the variance ratio (VR) method. It was found that plant species in Tamarix chinensis plot showed positive association (VR1), with a VR value of 1.095. Plant species in Phragmites australis plot had a negative association (VR1), with a VR value of 0.983. In Phragmites australis plot, C_SP and C_SW showed a significant decreasing trend (r

BackgroundStroke is the first leading cause of mortality and disability worldwide, and post-stroke spasticity (PSS) is the common complication of stroke. Sangdantongluo Granule, a modern patent Traditional Chinese medicine (TCM), is widely used in clinical practice to treat PSS. Whereas, there is limited evidence of effectiveness for Sangdantongluo Granule to treat PSS. This study will evaluate the clinical efficacy and safety of Sangdantongluo granule in the treatment of PSS. MethodsThis multicenter, randomized, double-blind and placebo-controlled study will recruit 132 participants in China who develops PSS 15 days to 90 days after stroke. Participants will be randomly assigned in an equal ratio to receive either Sangdantongluo granule or placebo for 2 months twice a day orally. The primary measure is the Modified Ashworth Scale (MAS), Secondary outcome measures include Compopsite Spasticity Scale (CSS), Simplified Fugl-Meyer Motor Scale (S-FM), National Institute of Health stroke scale (NIHSS), Modified Rankin Scale (mRS), Modified Barther Index (MBI), and Surface electromyography. Adverse events will be supervised throughout the trial. DiscussionThe results of this study will present whether Sangdantongluo granule is clinical effective and safe for managing PSS.Trial registrationClinicalTrials.gov ChiCTR2100044544. Registered on 23 March 2021.

In this paper, a dynamic model of cytosolic calcium concentration () oscillations is established for mast cells (MCs). This model includes the cytoplasm (Cyt), endoplasmic reticulum (ER), mitochondria (Mt), and functional region (μd), formed by the ER and Mt, also with channels in these cellular compartments. By this model, we calculate oscillations that are driven by distinct mechanisms at varying (degradation coefficient of inositol 1, 4, 5-trisphosphate, and production coefficient of ), as well as at different distances between the ER and Mt (ER–Mt distance). The model predicts that (i) Mt and μd compartments can reduce the amplitude of oscillations, and cause the ER to release less during oscillations, (ii) with increasing cytosolic concentration (), the amplitude of oscillations increases (from 0.1 μM to several μM), but the frequency decreases, (iii) the frequency of oscillations decreases as the ER–Mt distance increases. What is more, when the ER–Mt distance is greater than 65 nm, the μd compartment has less effect on oscillations. These results suggest that Mt, μd, and can all affect the amplitude and frequency of oscillations, but the mechanism is different. The model provides a comprehensive mechanism for predicting cytosolic concentration oscillations in mast cells, and a theoretical basis for calcium oscillations observed in mast cells, so as to better understand the regulation mechanism of calcium signaling in mast cells.

Litter decomposition plays a crucial role in controlling carbon (C) cycling and nutrient turnover in agroecosystems. In this study, the litterbag method was used to investigate the mass loss and ni...

It is very urgent to build memristive synapses and even wearable devices to simulate the basic functions of biological synapses. The linear conductance modulation is the basis of analog memristor for neuromorphic computing. By optimizing the interface engineering wherein Ta/TiO

The mechanism and extent of changes in greenhouse gas (GHG) emissions from seasonal river-floodplain wetlands subjected to land-type conversion are unknown. We monitored GHG fluxes and characterized soil microbial communities in four types of wetland (Riverside lower-beach wetland (RLW), Riverside higher-beach wetland (RHW), Cultivated wetland (CW), Mesophytic wetland (MW)) in the Yellow River flood land. Results revealed that land reclamation activities altered the distribution patterns of carbon (C) and nitrogen (N) in soil, as well as the structure and activities of microbial communities, leading to changes in the GHG emissions. Cumulative CO

Satellite-based precipitation estimates with high spatial and temporal resolution and large areal coverage have provided hydrologists a potential alternative source for hydrological applications since the last few years, especially for ungauged regions. This study evaluates five satellite-based precipitation datasets, namely, Fengyun, TRMM 3B42, TRMM 3B42RT, CMORPH_BLD and CMORPH_RAW, against gauge observations for streamflow simulation with a distributed hydrological model (SWAT) over the Huifa river basin, Northeast China. Results show that, by comparing the statistical indices (MA, M5P, STDE, ME, BIAS and CC) and inter-annual precipitation, it is demonstrated that Fengyun TRMM 3B42 and CMORPH_BLD show better agreement with gauge precipitation data than CMORPH_RAW and TRMM 3B42RT. When the SWAT model for each dataset calibrated and validated individually, satisfactory model performances (defined as: NS > 0.5) are achieved at daily scale for Fengyun, TRMM 3B42 and gauge-driven model, and very good performances (defined as: NS > 0.75) are achieved at monthly scale for Fengyun and gauge-driven model, respectively. The CMORPH_BLD forced daily simulations also yield higher values of NS and R2 than CMORPH_RAW and TRMM 3B42RT at daily and monthly step. From the uncertainty results, variations of P-factor values and frequency distribution curves of NS suggest that the simulation uncertainty increase when operating the Fengyun, 3B42RT, CMORPH_BLD and CMORPH_RAW-driven model with best fitted parameters for rain gauge SWAT model. The results also indicate that the influence of parameter uncertainty on model simulation results may be greater than the effect of input data accuracy. It is noted that uncertainty analysis is necessary to evaluate the hydrological applications of satellite-based precipitation datasets.

Node localisation technology is one of the most challenging and important issues in wireless sensor networks. This study puts forward a novel and high accuracy estimation method by combining distance-measuring with angle-measuring. An anchor node equipped with a directional antenna periodically sends beacons containing its position and antenna orientation to unknown nodes. By observing the variation of received signal strength indication values of beacons and the time of flight values, an unknown node can estimate the distance and orientation relative to the beacon node simultaneously. This study proposed an online modelling method to calibrate the shift of the estimated distance. Meanwhile, an angle estimation method is presented to avoid an ambiguous result, which is a new weighted curve fitting method based on least square principle. The experimental results show that the proposed ranging and angle measurement reaches a better localisation accuracy compared with the original ranging and angle method.

The performance of resistive switching (RS) device based on sandwich structure is greatly affected by the characteristics of the RS layer, electrode, and interface. In this work, the effect of rapid thermal annealing (RTA) (300 °C for 120 s) on the RS performance of Ta/TaOx/Ru device was investigated. The discrete distribution in high resistance state (HRS) and low resistance state (LRS) was suppressed after RTA. Meanwhile, the endurance in oxygen RTA is higher 104 times than that of vacuum RTA. The optimized oxygen RTA is contributed to change the microstructure of TaOx (amorphous to nanocrystal), providing the local conductive path, and implant oxygens in top electrode (TE) Ta, acting as an oxygen source (reservoir). It is shown that the nanocrystal TaOx and the oxygen content in TE are intrinsically crucial to the RS behavior and the simple low temperature oxygen RTA is a powerful technique to optimize the RS performance.

It is very urgent to build memristive synapses and even wearable devices to simulate the basic functions of biological synapses. The linear conductance modulation is the basis of analog memristor for neuromorphic computing. By optimizing the interface engineering wherein Ta/TiO x /TaO x /Ru was fabricated, all the memristor devices with different TiO x thickness showed electroforming-free property. The short-term and long-term plasticity in both potentiation and depression behaviors can be mimicked when TiO x was fixed at 25 nm. The presented memristive synapses simulated the stable paired-pulse facilitation and spike-timing dependent plasticity performance. The potentiation and depression in linearity and symmetry improved with the TiO x thickness increasing, which provides the feasibility for the application of artificial neural network. In addition, the device deposited on polyimide (PI) still exhibits the synaptic performance until the bending radii reaches 6 mm. By carefully tuning the interface engineering, this study can provide general revelation for continuous improvement of the memristive performance in neuromorphic applications.

With the increase of computational power, more sophisticated computational methods can be used, larger systems simulated, and complex phenomena predicted more reliably. Nevertheless, up to now, when turbomachinery systems are numerically optimized, each of the components, i.e., the compressor, combustor, and turbine, is simulated separately from the other two. While this approach allows the use of highly dedicated simulation tools, it does not account for the interactions between the different components. With the purpose to meet the future requirements in terms of low emissions, high reliability and efficiency, a novel, highly efficient, fully-coupled, approach based on the Reynolds-Averaged Navier-Stokes equations (RANS) has been developed, enabling a steady or time-accurate simulation of a full aero-engine within a single code. One of the advantages of a steady, fully coupled approach over a steady component-by-component approach, is that the boundary conditions at the interfaces do not need to be guessed. A fully coupled, time-accurate simulation has furthermore the advantage that the effect of the non-uniform temperature distribution at the outlet of the combustor is accounted for in the determination of the thermal field of the turbine. A Smart Interface methodology permits a direct coupling between the different engine components, compressor-combustor-turbine, and allows the Computational Fluid Dynamics (CFD) models to vary between each component within the same code. This allows the user to switch off, for instance, the combustion model in the turbine and compressor blocks. For the simulation of the combustion process, the Flamelet Generated Manifold (FGM) method is applied. While the approach is superior to classical tabulated chemistry approaches and reliably captures finite-rate effects, it is computationally inexpensive since it only requires the solution of a few extra scalars and the look-up of a combustion table. The model has been extended so that high-speed compressible flows can be simulated and the potential effects between the combustor and the adjacent blade rows can be accounted for. The Nonlinear Harmonic (NLH) method is used to model the unsteady interactions between the blade rows as well as the influence of the inhomogeneities at the combustor outlet on the downstream turbine blade rows. Compared to conventional time-accurate RANS simulations (URANS), this method is two to three orders of magnitude faster and makes time-accurate turbomachinery simulations affordable. With the aim of ensuring thermodynamic consistency between the different components of the engine, the same form of the energy equation is solved in all engine elements. Furthermore, the same thermodynamic coefficients, which are used to describe the reacting processes in the combustor, are used for a caloric description of the fluid in the compressor and turbine blocks. The thermodynamic data between the blocks is transferred using the OpenLabs™ module. The developed approach is described in detail and the potential of the novel full-engine methodology is exploited on the KJ66 micro-turbine gas engine case. The results of both the steady and the time-accurate, fully coupled approaches are analyzed and the interaction between the different components of the KJ66 engine discussed.

Based on the Ta/TaOx/ITO structure, self-current compliance behavior in the resistive switching (RS) properties was investigated. The formation and rupture of metallic indium (In) conducting filaments (CFs), which contributes to the RS in this device, are confirmed by the variable temperature electrical test combined with X-ray photoelectron spectroscopy (XPS) analysis. It showed high uniformity and endurance performance up to 108 switching cycles, including a lower power consumption. The excellent electrical performance can be attributed to the role of a series resistor of ITO because the adverse effects of the voltage (or current) overshooting can be efficiently suppressed, resulting in the controllability of the In CF formation and rupture. The XPS depth profile results confirmed the oxygen exchange at the TaOx/ITO interface, combined with the Ohmic conduction mechanism at low resistance state, indicating that the ITO interface acts as the series resistor rather than the Schottky barrier.

A series of novel porous center-hollow ZnO/ZnSe microspheres were synthesized via two-step hydrothermal and ion-exchange method. It is found the load of ZnSe improves photocatalytic activity of the nanocomposites and ZSe-3 sample shows the most prominent performance, 88.8% of Cr(VI) can be reduced in 60 min under the irradiation of visible light (λ > 420 nm). ZnSe nanoparticles can be used to sensitize the ZnO microspheres and further extend the visible light response range. The n-p heterojunction formed at the interface between ZnO and ZnSe can also contribute to improve the separation and transfer properties of charge carriers in ZnO.

Asynchronous mast seeding of sympatric tree species can affect seed dispersal, but it is not clear how the relative abundances of seeds might influence indirect seed–seed interaction mediated by seed dispersal agents. In this study, we investigated how seed abundance variations of the two sympatric tree species (Quercus variabilis and Pinus armandii) with asynchronous masting events influenced seed dispersal in the eastern Qinling Mountains, China. Although seed removal and seed consumption were influenced by both seed abundance and seed species, seed caching was only species-dependent, i.e., Q. variabilis acorns were more likely to be cached than P. armandii seeds irrespective of seed abundance. The proportion of scatter-hoarded P. armandii seeds depended on the abundance of Q. variabilis acorns. Regardless of seed abundance, Q. variabilis acorns were dispersed further than P. armandii seeds. Our results collectively indicate that the ecological effects of indirect seed–seed interaction mediated by seed dispersers on seed dispersal are asymmetrical and are potentially regulated by seed abundance as well as seed species (or seed traits). We recommend future studies focus on indirect seed–seed interactions among multiple species with contrasting seed traits, to better understand how they influence seed dispersal, plant regeneration and dynamics.

Energy saving and environmental protection has always been a new innovation goal of various industries in China in the new era. At present, a lot of energy-saving and environmental protection concepts and related design have been put forward. The traditional city bus energy is gasoline[1]. In order to meet the requirements of energy conservation and environmental protection, the energy of city buses has been changed into electricity. The dispatching work of urban electric bus is the core of bus enterprise management and related operation. Under the goal of energy saving, the arrangement and optimization of urban electric bus timetable has become the main concern of urban public transport.

In order to evaluate the influence of Daphnia magna and Ceratophyllum demersum on the control of algae under different phosphorus concentrations, Cyclotella sp., Microcystis aeruginosa, and Chlorella vulgaris were selected to establish an aquatic microcosmic model. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, D. magna significantly inhibited the three species of algae from different phylum, particularly M. aeruginosa, and the total growth rates of the three species of algae decreased with the increase of phosphorus concentration. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, C. demersum imparted a significant inhibition of the three species of algae, particularly M. aeruginosa. The total growth rates of the three species of algae were reduced with higher phosphorus concentrations; however, the effect was lower than that of D. magna, with C. vulgaris as the dominant species. When the phosphorus concentration ranged from 0.05 to 2 mg L−1, D. magna combined with C. demersum inhibited the growth of the three species of algae to a considerable degree, which was an improvement over that of other experimental groups using only D. magna or C. demersum by themselves. The total growth rates of algae were reduced with higher phosphorus concentrations. When the phosphorus concentration ranged from 0.05 to 0.1 mg L−1, the removal rates of phosphorus exceeded 90%, and the phosphorus concentration became the limiting factor in the culture system. We observed that under higher initial phosphorus concentrations, the nitrogen removal rate increased, whereas the phosphorus removal rate decreased.

Background: Prior studies have proposed several electrocardiogram (ECG) criteria in limb leads for identifying the culprit coronary artery (CCA) in patients with acute inferior wall myocardial infarction (IWMI). The aim of our study was to conduct an evidence-based evaluation and test accuracy comparison of these criteria. Methods: We searched the PubMed, Embase, and Ovid. Eligible studies to assess the diagnostic performance of ECG criteria predicting CCA in IWMI were reviewed for inclusion. A diagnostic meta-analysis of bivariate approach was performed for pooled estimates of sensitivity and specificity, and meta-regression was implemented to investigate sources of heterogeneity. Results: Twenty-four studies with 4431 unique participants met the inclusion criteria. The pooled sensitivity and specificity for ST-segment elevation (STE) in III > II, ST-segment depression (STD) in I, STD in aVL, STD in aVL > I, STE in III > II, and STD in aVL > I were 0.91 (0.88–0.94) and 0.69 (0.53–0.81), 0.80 (0.73–0.87) and 0.69 (0.62–0.76), 0.90 (0.81–0.95) and 0.41 (0.22–0.62), 0.84 (0.75–0.91) and 0.72 (0.48–0.88), and 0.79 (0.62–0.90) and 1.00 (0.37–1.00), respectively. Heterogeneity investigation showed that whether multi-vessel diseased patients were excluded, sample size, publication year, etc., could influence the diagnostic performance. Conclusion: STE in III > II performed better than other criteria for predicting RCA as CCA in IWMI, and STE in III > II and STD in aVL > I were potential and simple algorithms. ECG could be an effective tool to identify the CCA, but future studies are clearly needed to address the potential of diagnostic and prognostic value.

A stroke is a focal cerebral insult that frequently causes severe neurological deficit and mortality. Recent studies have demonstrated that multipotent mesenchymal stromal cells (MSCs) hold great promise for neurovascular remodeling and neurological function recovery following a stroke. Rather than a direct replacement of parenchymal brain cells, the therapeutic mechanism of MSCs is suggested to be the secretion of soluble factors. Specifically, emerging data described MSCs as being able to release extracellular vesicles (EVs), which contain a variety of cargo including proteins, lipids, DNA and various RNA species. The released EVs can target neurocytes and vascular cells and modify the cell's functions by delivering the cargo, which are considered to mediate the neural restoration effects of MSCs. Therefore, EVs may be developed as a novel cell-free therapy for neurological disorders. In the present review, the current advances regarding the components, functions and therapeutic potential of EVs are summarized and the use of MSC-derived EVs as a promising approach in the treatment of stroke are highlighted.

Ischemic stroke is a focal cerebral insult that often leads to many adverse neurological complications severely affecting the quality of life. The prevalence of stroke is increasing throughout the world, while the efficacy of current pharmacological therapies remains unclear. As a neuroregenerative therapy, the implantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) has shown great possibility to restore function after stroke. This review article provides an update role of hUC-MSCs implantation in the treatment of ischemic stroke. With the unique "immunosuppressive and immunoprivilege" property, hUC-MSCs are advised to be an important candidate for allogeneic cell treatment. Nevertheless, most of the treatments are still at primary stage and not clinically feasible at the current time. Several uncertain problems, such as culture conditions, allograft rejection, and potential tumorigenicity, are the choke points in this cellular therapy. More preclinical researches and clinical studies are needed before hUC-MSCs implantation can be used as a routinely applied clinical therapy.

Nitrogen (N) is commonly a limited nutrient in wetland ecosystems. Nitrogen addition affects the ecosystem carbon (C) balance and alters soil C storage through soil chemical and biological changes. In the present study, the effects of N addition and vegetation removal after one growing season on soil properties were examined in a Calamagrostis angustifolia freshwater marsh in Northeast China. Specifically, available N (NH4+–N and NO3−–N), microbial biomass C (MBC), and dissolved organic C (DOC) concentrations in the soil were analyzed. In addition, activities of soil enzyme (β-glucosidase, invertase, and urease) were investigated. The results showed that N addition resulted in significant increase of NH4+–N and NO3−–N in both topsoil and subsoil, and vegetation removal enhanced these effects. Soil MBC concentrations increased after N addition and vegetation removal but DOC concentrations did not change significantly. As to soil enzyme activities, N addition stimulated the β-glucosidase activity in the topsoil and invertase and urease activities in both soil layers. Vegetation removal enhanced the effect of N addition on β-glucosidase and invertase activities but inhibited the effect on urease activity. These results suggested that N addition affects soil biochemical process indirectly through marshland vegetation.

Nitrogen (N) addition can affect soil organic matter (SOM) decomposition by enhancing soil enzyme activity, increasing labile organic carbon (C) fractions and decreasing litter C/N ratio. This study was designed to investigate the short-term effect of N addition on litter and soil chemical and biological properties in Calamagrostis angustifolia freshwater marshes. A field experiment was conducted in which soil was treated with N addition of 0 (N0), 12 (N1), and 24 (N2) g N m−2 year−1, respectively. Above-ground biomass increased by 40 % and 32 % for N1 and N2 treatment, respectively. Added N increased litter C and N concentrations as well as β-glucosidase and invertase activities. However, litter C/N ratio decreased with N addition. N1 treatment increased microbial biomass carbon (MBC) in both topsoil and subsoil, but no changes in dissolved organic carbon (DOC) were observed. Total N concentrations in subsoil increased both in N1 and N2 treatments; NH4 +-N decreased in the N1 treatment, while NO3 −-N increased in the N2 treatment in topsoil. N2 treatment increased β-glucosidase, invertase, and urease activities in both soil layers. The differences in litter and soil characteristics caused by N addition suggest that N addition has the capacity to increase soil C transformation rates in marshland.

Based on control theory, adjoint system for the general problem of turbomachinery aerodynamic optimization was studied and developed in the present paper by using the variation technique in the grid node coordinates combined with Jacobian Matrics of flow fluxes. Then the adjoint system for aerodynamic design optimization of turbine cascade governed by compressible Navier-Stokes equations was derived in detail. With the purpose of saving computation resources, the mathematic method presented in this paper avoids the coordinate system transforming in the traditional derivation process of the adjoint system and makes the adjoint system much more sententious. Given the general expression of objective functions consisting of both boundary integral and field integral, the adjoint equations and their boundary conditions were derived, and the final expression of the objective function gradient including only boundary integrals was formulated to reduce the CPU cost, especially for the complex 3D configurations. The adjoint system was solved numerically by using the finite volume method with an explicit 5-step Runge-Kutta scheme and Riemann approximate solution of Roe’s scheme combined with multi-grid technique and local time step to accelerate the convergence procedure. Finally, based on the aerodynamic optimization theory in the present work, 2D and 3D inviscid and viscous inverse design programs of axial turbomachinery cascade for both pressure distribution and isentropic Mach number distribution on the blade wall were developed, and several design optimization cases were performed successfully to demonstrate the ability and economy of the present optimization system.

Plants play an important role in CH4 emissions from wetlands. Vascular plants transport CH4 from the anaerobic zone to the atmosphere through their aerenchyma, thereby bypassing the aerobic zone and strongly increasing CH4 emission rates. However, most studies of the effect of plants on wetland CH4 emissions are based on observations made during the growing seasons. The effects in non-growing seasons are still unclear. In this study, we conducted a clipping experiment to investigate the effects of plants on CH4 emissions from a temperate marsh in the growing and non-growing seasons. The results show that the influence of plants on CH4 emissions from the wetland varied among different seasons. Plant-mediated CH4 accounted for 38% of the total fluxes in the plant-growing season. After the growing season, whether the plants transported CH4 from the soil to the atmosphere in situ was determined by the involved environmental conditions. In autumn, the plants did not transport CH4. This is because the CH4 diffused easily in the soil and water, rather than via the plants' organs. In the surface soil freezing period, CH4 diffusion was blocked and accumulated under the frozen surface. The highly concentrated CH4 in the pore water was compelled to enter the organs of the plants and diffused by them. The ‘passive diffusion’ via plants transported 84% of the total CH4 emissions during this period. Nonetheless, the plants did not transport CH4 again in the deep soil freezing season. By synthesizing our data together with previous studies, we suggested that this is because the frozen soil layer was deep enough in this period to exceed the depth horizon of the plants' roots and the CH4 in free water could not enter the plants' organs.

Separating the two major components of soil respiration, root respiration (R r) and heterotrophic respiration (R h), is an important step for understanding and modelling carbon cycling in organic soils. However, few partitioning studies exist regarding wetland ecosystems. For this study, we selected a freshwater marsh on Sanjiang Plain, Northeast China and used a trenching method to determine the contribution of R r to soil respiration during the two growing seasons in 2010 and 2011. The decomposition rate of dead roots (R D) was estimated to correct the soil respiration of the trenching plots. The soil respiration rates in the control plot increased from May (288–508 mg CO2 m−2 h−1) to late June (1103 mg CO2 m−2 h−1 in 2010) or early July (1278 mg CO2 m−2 h−1 in 2011) and later decreased during the last growing season. The soil respiration rate in the trenching plot exhibited a similar pattern of seasonal change, but the rates were lower than in the control plot, except at the beginning of trenching. When considering the dead root decomposition in the trenching plots, the contributions of R r to total soil respiration in the two growing seasons were estimated to range from 22 to 77 % (2010) and 46 to 81 % (2011). The mean contribution of R D was approximately 12 % in the growing season of the first year (2010) and later decreased to approximately 6 % in the second year (2011). The contents of soil NH4 +-N and NO3 −-N were significantly greater in the trenching plots than in the control plots. The content of microbial biomass nitrogen tended to increase after trenching for the 0- to 30-cm soil depth. These results indicate that the microbial community may change in the second year, which may affect the estimation of the contribution of root respiration to total soil respiration.

A field control experiment was carried out to determine the influence of water table changes on soil CO2, CH4, and N2O emissions in Calamagrostis angustifolia freshwater marsh in Northeast of China. The results showed that the water depth of 5 cm below the ground surface increased soil CO2 emission, but there was no significant influence of deeper water table on gas emission. CH4 emission was accelerated by deep standing water and approached the peak in the plant booming time. This suggests that root activity has influence on CH4 production. The result also demonstrated that both low water table level and inundated environment would inhibit N2O emission. Comparing the total global warming potential of three gases under different conditions, it can be concluded that maintaining a comparatively steady water table near the soil surface can benefit soil carbon sequestration in the C. angustifolia marsh, and decrease of the greenhouse gases emissions to the atmosphere.