Spatiotemporal Evolution of Ecosystem Service Value in Caohai National Nature Reserve

Wetland ecosystems are important regulators of global climate change.Studying the spatiotemporal changes and driving mechanisms of their ecosystem service values(ESV)is beneficial for the sustainable development of wetlands.This paper uses the equivalent factor method,based on land use changes,to reveal the spatiotemporal evolution of the ecosystem service value in the Caohai National Nature Reserve(CNNR).The results show the following:①from 2000 to 2020,there was a significant decrease in the core zone s arable land area,with an increase in forest and water areas.Construction land mainly increased in the experimental area,and the grassland area showed a fluctuating change of first increasing and then decreasing;②in 2000,2010,and 2020,the ecosystem service value of the study area was 302 million,296 million,and 325 million yuan,respectively,showing a trend of fluctuating growth,with the value of wetland ecosystems playing a dominant role;③regulatory services are the main contributors to the ecosystem service value in the study area,with a contribution rate of 60%.Hydrological regulation is the ecosystem function with the highest value in wetland ecosystem services,contributing more than 35%to the ESV in all three periods;④in terms of spatial distribution,the core zone s ecosystem service value is dominant.Looking at the total ecosystem service value of the region,the core zone>the experimental area>the buffer zone.In terms of ESV per unit area,the core zone(89000 yuan/hm^(2))is significantly higher than the buffer zone(39100 yuan/hm^(2))and the experimental area(15800 yuan/hm^(2)).The study can provide a basis for research and spatial management of ecosystem services in wetland ecosystems and nature reserves.

Spatiotemporal Evolution of Ecological Quality in Alpine Freshwater Lake Nature Reserves in the Past 20 Years

The Caohai Nature Reserve is one of the three major plateau freshwater lakes in China.Since the 1950s,human activities such as land reclamation and population relocation have greatly damaged Caohai.A rapid evaluation of the spatiotemporal evolution trend of the ecological quality of the Caohai Nature Reserve is significant for the maintenance and construction of the ecosystem in this area.The research is based on the Google Earth Engine(GEE)remote sensing cloud computing platform.Landsat TM/OLI images from May to October in five time periods:2000-2002,2004-2006,2009-2011,2014-2016,and 2019-2021 were obtained to reconstruct the optimal cloud image set by averaging the images in each time period.By constructing four ecological indicators:Greenness(NDVI),Wetness(Wet),Hotness(LST),and Dryness(NDBSI),and using Principal Component Analysis(PCA)method to obtain the Remote Sensing Ecological Index(RSEI)for the corresponding years,the spatiotemporal variation of ecological quality in the Caohai Nature Reserve over 20 years was analyzed.The results indicate:①the mean value of RSEI increased from 0.460 in 2000-2002 to 0.772 in 2019-2021,a 67.83%increase,indicating a significant improvement in the ecological quality of the reserve over the 20 years;②from the perspective of functional zoning of the Caohai Nature Reserve,the ecological quality of the core area showed a degrading trend,while the ecological quality of the buffer zone and experimental zone significantly improved;③with the implementation of ecological restoration projects,the ecological quality of the reserve gradually recovered and improved from 2014 to 2021.The trend of RSEI value changes is well correlated with human interventions,indicating that the PCA-based RSEI model can be effectively used for ecological quality assessment in lake areas.

Spatiotemporal Evolution of Ecological Quality in Typical Karst Ecologically Fragile Areas Based on Remote Sensing Ecological Indexes

Fast and effective remote sensing monitoring is an important means for analyzing the spatio-temporal changes in ecological quality in fragile karst regions.This study focuses on Guanling Autonomous County,a national-level demonstration county for comprehensive desertification control.Based on Landsat TM/OLI remote sensing image data from 2005,2010,2015,and 2020,remote sensing ecological indices were used to analyze the spatio-temporal changes in ecological quality in Guanling Autonomous County from 2005 to 2020.The results show that:①the variance contribution rates of the first principal component for the four periods were 66.31%,71.59%,63.18%,and 75.24%,indicating that PC1 integrated most of the characteristics of the four indices,making the RSEI suitable for evaluating ecological quality in karst mountain areas;②the remote sensing ecological index grades have been increasing year by year,with an overall trend of improving ecological quality.The area of higher-grade ecological quality has increased spatially,while fragmented patches have gradually decreased,becoming more concentrated in the low-altitude areas in the northwest and east,and there is a trend of expansion towards higher-altitude areas;③the ecological environment quality in most areas has improved,with the improvement in RSEI spatio-temporal variation becoming more noticeable with increasing slope.Areas of higher-grade quality appeared in 2010,and the range of higher-grade quality expanded with increasing slope.

棉织物洗涤中染料转移抑制的影响因素研究

研究了水硬度、用水量、洗涤温度和染料转移抑制剂(Dye transfer inhibitor,DTI)对直接蓝6的转移抑制影响。实验结果显示水硬度越小,用水量越大,温度越高,染料转移抑制效果越好。洗涤体系中Ca^(2+)和Mg^(2+)的存在不仅降低了纤维表面的Zeta电位,还降低了染料与纤维之间的静电排斥力,染料不易脱落。水量越大,染料质量浓度越低,洗涤体系中的初始动压增大,织物内的染料较快流过,减少在织物上的沉积。高温下染料分子解吸速率大于染色速率,20 min的洗涤时间足以使染料从纤维上脱落。在0.3 g/L质量浓度范围内DTI中仅有聚乙烯吡咯烷酮和它的交联聚合物对染料有明显的抑制作用。聚合物因具有许多亲水基团,易与染料结合。而吡啶-n-氧化物和月桂基甜菜碱属于小分子表面活性剂。

4.3 THz quantum-well photodetectors with high detection sensitivity

We demonstrate a high performance GaAs/AlGaAs-based quantum-well photodetector(QWP)device with a peak response frequency of 4.3 THz.The negative differential resistance(NDR)phenomenon is found in the dark currentvoltage(I-V)curve in the current sweeping measurement mode,from which the breakdown voltage is determined.The photocurrent spectra and blackbody current responsivities at different voltages are measured.Based on the experimental data,the peak responsivity of 0.3 A/W(at 0.15 V,8 K)is derived,and the detection sensitivity is higher than 10^(11)Jones,which is in the similar level as that of the commercialized liquid-helium-cooled silicon bolometers.We attribute the high detection performance of the device to the small ohmic contact resistance of-2Ωand the big breakdown bias.

Video Inter-Frame Forgery Identification Based on Consistency of Correlation Coefficients of Gray Values

Identifying inter-frame forgery is a hot topic in video forensics. In this paper, we propose a method based on the assumption that the correlation coefficients of gray values is consistent in an original video, while in forgeries the consistency will be destroyed. We first extract the consistency of correlation coefficients of gray values (CCCoGV for short) after normalization and quantization as distinguishing feature to identify interframe forgeries. Then we test the CCCoGV in a large database with the help of SVM (Support Vector Machine). Experimental results show that the proposed method is efficient in classifying original videos and forgeries. Furthermore, the proposed method performs also pretty well in classifying frame insertion and frame deletion forgeries.

Resveratrol compares with melatonin in improving in vitro porcine oocyte maturation under heat stress

Background： Resveratrol, an important phyto-antioxidant commonly found in grapes, mulberry, and other plants,has a variety of functions including anti-aging, anti-cancer and anti-inflammatory activities. In the current study, we investigated the beneficial effects of resveratrol on in vitro porcine oocyte maturation under heat stress（HS）. The effect of resveratrol, melatonin and their combination on alleviating HS was compared according to the maturation rate of oocytes and the development competence of embryos after parthenogenetic activation（PA）.Results： Supplementation with resveratrol（2.0 μmol/L） not only improved the nuclear maturation but also raised the blastocyst rate of porcine embryos＇ PA from oocytes that underwent HS by increasing their glutathione（GSH）level, reducing reactive oxygen species（ROS） and up-regulating the expression of Sirtuin 1（SIRT1）. It was also found that melatonin（10^-7mol/L） and the combination of resveratrol（2.0 μmol/L） plus melatonin（10^-7mol/L） exhibited more potent effects than resveratrol alone regarding their protective activities on oocyte maturation under HS.Conclusions： This study compared the efficiencies of resveratrol, melatonin and their combination for protecting porcine oocytes from heat stress. The mechanisms are attributed to the fact that each treatment may have different ability to regulate the synthesis of steroid hormones and the expression of mature related genes.

文昌鱼左右体轴建立机制的研究进展

两侧对称动物左右体轴建立机制研究是发育生物学领域重要的基础科学问题之一。文昌鱼(amphioxus)由于其特殊的进化地位以及与脊椎动物相似的胚胎发育模式和身体构筑方式,是研究动物左右体轴建立机制的理想模式物种。近年来随着文昌鱼室内全人工繁育技术、高效显微注射技术和基因敲除技术的建立,国内外学者在左右体轴建立机制研究上取得了丰硕的成果。本文从文昌鱼胚胎左右不对称发育特点出发,总结了近期文昌鱼左右体轴建立方面取得的研究进展,并提出了文昌鱼左右体轴调控网络图:纤毛运动导致Hh蛋白在文昌鱼中不对称分布(L<R),从而导致Hh信号通路的不对称激活以及Cer的不对称表达(L<R),Cer对Nodal具有抑制作用,由此导致依赖于Nodal活性的基因呈左右不对称表达并最终诱导胚胎左右体轴的正确建立;BMP信号可能并不提供左右不对称信号,但却是Cer和Nodal正确表达的必要条件。

Effects of Three Nitrification Inhibitors on the Nitrogen Conversion in Purple Soil and Its Effect on the Nitrogen Uptake of Citrus Seedlings

Experiments were carried out to study the effects of nitrification inhibitors (NI) on the transformation of soil nitrogen (N) in purple soil and the effects on the N accumulation in different organs of citrus seedlings. In incubation and pot experiments, the rate of nitrification inhibitors 2-chloro-6-trichloro-methyl pyridine (Nitrapyrin), 3,4-dimethylpyrazole phosphate (DMPP) and dicyandiamide (DCD) was 2.4%, 1.0% and 5.0% of N rate, respectively. The trend of different nitrification inhibitors on ammonium nitrogen ( NH+4-N ), nitrate nitrogen ( NO-3-N ) content and pH was compared in incubation experiment;and the effect of different NI on the dry matter quality, N uptake of citrus seedling was studied in pot experiment. The results showed that NI could significantly inhibit soil nitrification in the early culture period (p DMPP > En (calculated as nitrogen application rate). Application of NI increased the height and dry matter accumulation, N accumulation of citrus seedling grown in pot experiment. Thus, application of NI would be helpful for improving N use efficiency in purple soil which is one of major soil types for citrus production in China.

Application of Improved Artificial Bee Colony Algorithm in Urban Vegetable Distribution Route Optimization

According to the characteristics and requirements of urban vegetable logistics and distribution, the optimization model is established to achieve the minimum distribution cost of distribution center. The algorithm of artificial bee colony is improved, and the algorithm based on MATLAB software is designed to solve the model successfully. At the same time, combined with the actual case, the two algorithms are compared to verify the effectiveness of the improved artificial bee colony algorithm in the optimization of urban vegetable distribution path.

Understanding the Impacts of Plant Capacities and Uncertainties on the Techno- Economic Analysis of Cross-Laminated Timber Production in the Southern U.S.

Understanding the economic feasibility of cross-laminated timber(CLT),an emerging and sustainable alternative to concrete and steel,is critical for the rapid expansion of the mass timber industry.However,previous studies on economic performance of CLT have not fully considered the variations in the feedstock,plant capacities,manu-facturing parameters,and capital and operating costs.This study fills this gap by developing a techno-economic analysis of producing CLT panels in the Southern United States.The effects of those variations on minimum sell-ing price(MSP)of CLT panels are explored by Monte Carlo simulation.The results show that,across all the plant capacities from 30,000 to 150,000 m^(3)/year,the MSP ranges from$345 to$609/m^(3) with a±6%–9%range caused by the variations in feedstocks,key manufacturing parameters,capital and operating cost.The MSP decreases sig-nificantly along the increasing capacities.A sensitivity analysis exhibits that the lumber price,lumber preparing loss,plant capacity,and the installed costs of layering and gluing,finishing,and miscellaneous,are the top driving factors to CLT MSP.Supported by Geographic Information System,this study also studies the transportation cost of delivering CLT to customers under three CLT demanding levels(1%,5%,15%).The results show that the trans-portation cost is 1%–8%of the MSP.Lower demanding level or higher plant capacity can increase the transporta-tion cost due to average longer delivering distance.When considering the delivered cost that sums MSP and transportation cost,larger plant capacity does not necessarily generate lower delivered cost.

Incomplete charge transfer in CMOS image sensor caused by Si/SiO_(2)interface states in the TG channel

CMOS image sensors produced by the existing CMOS manufacturing process usually have difficulty achieving complete charge transfer owing to the introduction of potential barriers or Si/SiO_(2)interface state traps in the charge transfer path,which reduces the charge transfer efficiency and image quality.Until now,scholars have only considered mechanisms that limit charge transfer from the perspectives of potential barriers and spill back effect under high illumination condition.However,the existing models have thus far ignored the charge transfer limitation due to Si/SiO_(2)interface state traps in the transfer gate channel,particularly under low illumination.Therefore,this paper proposes,for the first time,an analytical model for quantifying the incomplete charge transfer caused by Si/SiO_(2)interface state traps in the transfer gate channel under low illumination.This model can predict the variation rules of the number of untransferred charges and charge transfer efficiency when the trap energy level follows Gaussian distribution,exponential distribution and measured distribution.The model was verified with technology computer-aided design simulations,and the results showed that the simulation results exhibit the consistency with the proposed model.

Research on Optimal Configuration of Energy Storage in Wind-Solar Microgrid Considering Real-Time Electricity Price

Capacity allocation and energy management strategies for energy storage are critical to the safety and economical operation of microgrids.In this paper,an improved energymanagement strategy based on real-time electricity price combined with state of charge is proposed to optimize the economic operation of wind and solar microgrids,and the optimal allocation of energy storage capacity is carried out by using this strategy.Firstly,the structure and model of microgrid are analyzed,and the outputmodel of wind power,photovoltaic and energy storage is established.Then,considering the interactive power cost between the microgrid and the main grid and the charge-discharge penalty cost of energy storage,an optimization objective function is established,and an improved energy management strategy is proposed on this basis.Finally,a physicalmodel is built inMATLAB/Simulink for simulation verification,and the energy management strategy is compared and analyzed on sunny and rainy days.The initial configuration cost function of energy storage is added to optimize the allocation of energy storage capacity.The simulation results show that the improved energy management strategy can make the battery charge-discharge response to real-time electricity price and state of charge better than the traditional strategy on sunny or rainy days,reduce the interactive power cost between the microgrid system and the power grid.After analyzing the change of energy storage power with cost,we obtain the best energy storage capacity and energy storage power.

AC-DC Fuzzy Linear Active Disturbance Rejection Control Strategy of Front Stage of Bidirectional Converter Based on V2G

Aiming at the problems of output voltage fluctuation and current total harmonic distortion(THD)in the front stage totem-pole bridgeless PFC of two-stage V2G(Vehicle to Grid)vehicle-mounted bi-directional converter,a fuzzy linear active disturbance rejection control strategy for V2G front-stage AC-DC power conversion system is proposed.Firstly,the topologicalworkingmode of the totem-pole bridgeless PFC is analyzed,and themathematical model is established.Combined with the system model and the linear active disturbance rejection theory,a double closed-loop controller is designed with the second-order linear active disturbance rejection control as the voltage outer loop and PI control as the current inner loop.The controller can realize self-adaptive tuning of the proportional gain coefficient of the active disturbance rejection controller through fuzzy reasoning and realize self-adaptive control.Simulation and experimental results show that this method can better solve the problems of slow system response and high total harmonic distortion rate of input current and effectively improve the system’s robustness.

Standardization of a Real-time PCR System for Quantitative Detection of Mycoplasma hyopneumoniae

This study was conducted to develop a method for accurate quantification of Mycoplasma hyopneumoniae during vaccine production or experimental research. Primer and probe concentration that gave the highest ΔRn and the lowest Ct were selected to establish the real-time PCR system for the detection of M. hyopneumoniae. Template DNA of M. hyopneumoniae was extracted by boiling under different conditions and detected by real-time PCR to determine the optimal conditions for DNA extraction. Thereafter, intra-and inter-batch reproducibility tests were carried out using a standard plasmid to evaluate the stability of the PCR system. Subsequently, the effect of medium composition on the quantitative detection was evaluated. Finally, the correlation between real-time PCR and CCU method was explored. The optimal primer and probe concentration for real-time PCR were 0.4 and 0.2 μmol/L, respectively. The intra-and inter-batch coefficients of variation(CV) in Ct value of 10~4-10~9 copies/μl standard plasmid were <5%, indicating good reproducibility of the real-time PCR system. Following incubation in a boiling water bath for 10 min, M. hyopneumoniae samples can be used directly as a template in subsequent real-time PCR assays,and good intra-batch and inter-batch reproducibility was observed. The working concentration of KM2 medium should be less than the 1/10 of the concentration of the stock solution to minimize its influence on the quantitative detection. Spearman's correlation analysis revealed that the log of CCU and the log of DNA copy number had a significant positive relationship(r=0.797,P=0.000). Thus, the two methods can be used in combination in the quantitative detection of M. hyopneumoniae. In summary, a rapid, stable and accurate quantitative PCR system for detecting M. hyopneumoniae culture was established in this study, which provides a technical means for accurate quantification of M. hyopneumoniae in vaccine production and laboratory tests.

Angiopoietins/Tie-2 expression and angiogenesis in stomach carcinoma

Objective： To explore angiopoietins （Ang-1, Ang-2）/Tie-2 expression and angiogenesis in stomach carcinomas. Methods： RT-PCR and immunohistochemistry were used to detect angiopoietins/Tie- 2 mRNA and protein expression in stomach carcinomas and their adjacent normal mucosa. Microvessel density （MVD） was counted according to CD34 immunohistochemical staining. Results： There was positive expression of Angiopoietins/Tie-2 mRNA and protein in stomach carcinomas and their paired adjacent normal mucosa. It was found that correlation between Ang-1 protein, Tie-2 mRNA expression and MVD was negative （F=-0.440, F=-0.267; P〈0.05）, while the correlation between Ang-2 mRNA and its protein, Ang-2/Ang-1 protein ratio and MVD was positive （F=0.319, F=-729, F=739; P〈0.05）. Moreover, MVD in groups with Ang-2 mRNAT/N ratio over 1.2 （the ratio of Ang-2 mRNA in stomach carcinoma to its adjacent normal mucosa） was higher than those with the ratio under 1.2. Conclusion： It was suggested that Ang-1 and Ang-2 antagonizes in the angiogenesis and the anglogenesis in tumor ultimately depended on Ang-2/Ang-1 ratio, once the expression of Ang-2 is higher than Ang-1 in some degree, the angiogenesis in tumors was promoted, otherwise oppositely. In other words, Ang-2 plays dominant role in the action of angiogenesis in tumors.

Multi-scale analysis on last millennium climate variations in Greenland by its ice core oxygen isotope

The empirical mode decomposition method is used for analyzing the paleoclimate proxy δ18O from Greenland GISP2 ice core.The results show that millennium climate change trends in Greenland record the Medieval Warm Period (MWP) from 860AD-1350AD lasting for about 490 years,and the Little Ice Age (LIA) from 1350AD-1920AD lasting about 570 years.During these events,sub cooling-warming variations occurred.Its multi-scale oscillations changed with quasi-period of 3-year,6.5-year,12-year,24-year,49-year,96-year,213-year and 468-year,and are not only affected by ENSO but also by solar activity.The oscillation of intrinsic mode function IMF7,IMF8 and their tendency obviously appear in 1350AD which is considered as the key stage of transformation between MWP and LIA.The results give more detailed changes and their stages of millennium climate change in high latitude areas of the Northern Hemisphere.

Fuzzy Comprehensive Evaluation of Air Quality in Shijiazhuang City Based on Grey Correlation

[Objectives]This study was conducted to evaluate the air quality of Shijiazhuang City,in order to facilitate the government to correctly formulate measures to prevent and control air pollution and protect Shijiazhuang's ambient air quality. [Methods] With the air quality data of Shijiazhuang City from February to March in 2019 as the research object,the gray correlation analysis method was used to determine weight A of each pollutant factor first,and then a single factor evaluation matrix R was constructed. The weight A and the single factor evaluation matrix R were synthesized using the M( ·,+) fuzzy composite operator,obtaining a fuzzy matrix B between the factor set and the evaluation level. [Results] The eigenvalue of air quality was calculated according to matrix B: H = 2. 259 5.[Conclusions]The air quality in Shijiazhuang City from February to March was between grade 2 and grade 3,closer to grade 2,indicating that the air quality was good.

Virtual Synchronous Generator Adaptive Control of Energy Storage Power Station Based on Physical Constraints

The virtual synchronous generator(VSG)can simulate synchronous machine’s operation mechanism in the control link of an energy storage converter,so that an electrochemical energy storage power station has the ability to actively support the power grid,from passive regulation to active support.Since energy storage is an important physical basis for realizing the inertia and damping characteristics in VSG control,energy storage constraints of the physical characteristics on the system control parameters are analyzed to provide a basis for the system parameter tuning.In a classic VSG control,its virtual inertia and damping coefficient remain unchanged.When the grid load changes greatly,the constant control strategy most likely result in the grid frequency deviation beyond the stable operation standard limitations.To solve this problem,a comprehensive control strategy considering electrified wire netting demand and energy storage unit state of charge(SOC)is proposed,and an adaptive optimization method of VSG parameters under different SOC is given.The energy storage battery can maintain a safe working state at any time and be smoothly disconnected,which can effectively improve the output frequency performance of energy storage system.Simulation results further demonstrated the effectiveness of the VSG control theoretical analysis.

Efficient production of ligand-free microscintillators at gram-scale for high-resolution X-ray luminescence imaging

The efficient production of high-quality scintillators with long radioluminescence afterglow is crucial for high-performance X-ray luminescence extension imaging.However,scaling-up the synthesis of ligand-free scintillators to fabricate large-area X-ray imaging screens for industrial applications remains a challenge.In this study,we report an efficient method to synthesize ligand-free,lanthanide-doped microscintillators by a one-pot reaction via the concentrated hydrothermal method.The as-synthesized microscintillators exhibit prolonged persistent radioluminescence for up to 30 days after X-ray exposure and remain high stability in air or water for more than 18 months without deterioration.Monte Carlo simulations indicate that the size effect is responsible for the excellent afterglow performance of the microscintillators.We employ these high-quality lanthanide-doped microscintillators to fabricate a large-area X-ray imaging detector using a blade-coating method,a spatial resolution of 24.9 lp/mm for X-ray imaging.Our study offers a solution for scaling-up the synthesis of low-cost microscintillators for practical applications.