Understanding the drivers of woody plant diversity in urban parks in a snow climate city of China

Urban parks are an important part of urban ecosystems and play an important role in biodiversity conservation.However,it is still unclear how park characteristics aff ect plant diversity which could hinder the conservation of urban biodiversity due to the ineff ective design of urban parks.The diversity of woody plants in 33 parks of Changchun,China,was measured with plot measurements and linked with urban park characteristics(e.g.,size and age of the park)to uncover the relationship between them.The results show that urban woody plant species were abundant,with 98 species belonging to 51 genera and 26 families in the snow climate city of Changchun.The variation in woody plant diversity was largely explained by internal patch characteristics(e.g.,size,age,shape),and external factors surrounding the park(e.g.,land use type and socioeconomic level)accounted for only 16.0%in our study.For internal patch characteristics,older urban parks with larger areas demonstrated a richer level of plant diversity and increased nonlinearly with increasing park area.The threshold size signifi cantly aff ecting plant diversity variation was approximately 30 ha.Plant diversity had positive linear relationships with the ages of urban parks,supporting the legacy eff ect.In addition,woody plant diversity nonlinearly decreased with increasing park shape index,which suggested that the plant diversity could also be increased by optimizing the park shape.Regarding the external factors surrounding parks,the spatial distribution of woody plant diversity varied greatly from the urban center to the suburbs.House prices around the park had positive linear relationships with woody plant diversity in parks,supporting the luxury eff ect.However,building and road proportions,and green space proportion had no relationship with plant diversity in parks.This study can provide a robust reference for enriching plant diversity in urban parks,thus improving the development of urban sustainable cities.

Microstructure and toughness of thick-gauge pipeline steel joint via double-sided friction stir welding combined with preheating

Fusion welding easily causes microstructural coarsening in the heat-affected zone(HAZ) of a thick-gauge pipeline steel joint. This is most significant in the inter-critically coarse-grained HAZ(ICCGHAZ), which considerably deteriorates the toughness of the joint. In the present work, 11-mm thick pipeline steel was joined by preheating and double-sided friction stir welding(FSW). A comparative study on the microstructure and toughness in the ICCGHAZs for FSW and gas metal arc welding(GMAW) was performed. The toughness in the ICCGHAZ for FSW was improved significantly than that in the ICCGHAZ for GMAW. Generally, the nugget zone(NZ) has a coarse microstructure in the FSW steel joint formed at the highest peak temperature. However, in the current study, the microstructure in the one-pass NZ was remarkably refined owing to the static recrystallization of ferrite. An excellent toughness was achieved in the NZ of the pipeline steel joint that employed FSW.

Observation of plasma dynamics in a theta pinch by a novel method

A novel experimental method is proposed for observing plasma dynamics subjected to magnetic fields based on a newly developed cylindrical theta-pinch device.By measuring simultaneously the temporal profiles of multiple parameters including the drive current,luminosity,plasma density,and plasma temperature,it provides a basis for observing the plasma dynamics of the theta pinch,such as shock transport and magnetohydrodynamic instability.We show that the plasma evolution can be distinguished as three phases.First,in the radial implosion phase,the trajectories of the current sheath and shock wave are ascertained by combining experimental data with a snowplow model(Lee model)in a self-consistent way.Second,in the axial flow phase,we demonstrate that m=0(sausage)instability associated with the plasma axial flow suppresses the plasma end-loss.Third,in the newly observed anomalous heating phase,the lower-hybrid-drift instability may develop near the current sheath,which induces anomalous resistivity and enhanced plasma heating.The present experimental data and novel method offer better understanding of plasma dynamics in the presence of magnetic fields,thereby providing important support for relevant research in magneto-inertial fusion.

Improving the Heat Resistance ofβ-1,4 Glucanase by Introducing Disulfide Bonds

Each possible pair of residues inβ-1,4 glucanase for disulfide formation was assessed using online websites,and four pairs L28C-S256C,Q41C-P278C,S122C-N163C and A184C-A215C were selected.Accordingly,four recombinant plasmids pET28a(+)EccslH28,pET28a(+)EccslH41,pET28a(+)EccslH122 and pET28a(+)EccslH184 were prepared and transformed into E.coli to express the recombinant enzymes.Then analysis on enzymatic properties showed that T50 of the recombinant enzymes was increased from 10 min for EccslHt2 to 90 min for EccslH28 and 40 min for EccslH41 at 70℃,while their optimum pH value and pH stability were not affected,which proved that the introduction of disulfide bond improved the thermal stability ofβ-1,4 glucanase.

Iodine Content of Processed Foods and Condiments Sampled in China, 2017-2019

Introduction: Facing the challenge of increasing consumption of processed foods in China, along with the demand for salt reduction, and dynamic adjustment of universal salt iodization (USI) policy, it is necessary to timely evaluate the distribution of iodine content in processed foods and condiments, so as to provide more accurate data for population dietary iodine intake assessment. Methods: From markets in 6 cities and e-commerce platforms, cereal, tuber, legume, meat, fish, egg, and dairy products, and condiments, consumed by volunteers who attended in iodine intake investigation, and top selling products in particular with well-noted brands were preferentially sampled during 2017 to 2019. After being mixed and homogenized, each sample was detected by ICP-MS method. The range and medium of iodine content in each type of product were given. Results: After merging samples with close value in the same style of the same brand, and screening out samples with no added salt or low sodium content (≤120 mg/100g), total 725 data were sub-grouped and analyzed. In comparison with the 95th percentile of the iodine distribution in relative nature source, assessed by our previous study, nearly 77% of products made from grains, potatoes, beans, nuts, livestock and poultry meat were presumed to be processed with iodized salt. In somewhat, related with sodium value marked on food labeling, the median iodine ranged from 1.1 mg/100g to 149 mg/100g. The variation of iodine in egg, milk and fish made products, and seaweed or with seaweed products was greatly affected by the background of ingredients, the median content most floated between 12.8 mg/100g and 86.8 mg/100g, even up to 1800 mg/100g in seasoned seaweed. Based on the frequency of iodine digital and the ratio of iodine to sodium, it was speculated that nearly 90% of soy sauce and 73.5% of other seasonings like vinegar, sauce, paste, etc., were not added iodized salt, with overall median iodine 4.0 mg/100g and 12 mg/100g respectively. Conclusion: Using iodized salt in processed foods is an approach of USI police. Affected by the nature backgrounds of ingredients composed, the amount of salt used, and the regulated fortification level, iodine content in each kind of product varied largely. It’s important to establish a monitoring system in processed foods, as well as fortification salt, to control the benefit and risk of iodine health.

Sodium Content in Takeaway Meals Sampled from Three Large China Cities

Objective: The aim of the present study was to evaluate salt levels in popular hot takeaway meals in three large China cities, and to compare the difference in sodium content in different types of takeaway meals. Methods: We randomly collected a total of 4450 samples of 7 different types of takeaway meals, which were the most consumed by local residents from takeaway platforms. The main ingredients, auxiliary ingredients, as well as the weight used in takeaway meals were collected. The sodium content in takeaway meals was obtained by calculation. Results: Obtained results show that the sodium content in three large China cities is alarmingly high. Comparing medians (interquartile range) of takeaway meals from different cities, Beijing contained the highest sodium content per portion (1371.3 mg (890.3 - 2137.4)), followed by Hangzhou (1348.45 mg (694.25 - 1541.62)) and Shanghai (340.1 (259.75 - 942.25)). In addition, the sodium content between pasta and porridge, Chinese meals, and western meals show significant differences (p 0.05). Compared with Chinese Dietary Reference Intakes, the average sodium content exceeded dietary recommendations for one takeaway meal. The sodium content differed among takeaway meals prepared with various cooking methods and meats. Conclusion: Notable differences are detected in takeaway meals’ sodium content between several large cities in China. To meet China’s target salt intake, consumers in these cities are highly recommended to reduce sodium content in their everyday meals.

Photonics Improvement of the Time-Bandwidth Product for a Linearly Chirped Waveform

A photonics approach to generate a linearly chirped waveform with increased TBWP is proposed and investigated. The time bandwidth product (TBWP) of the linearly chirped waveform is improved based on optical microwave frequency multiplying combined with temporal synthesis. An integrated dual-polarization modulator and an optical filter are utilized to perform frequency doubling operation by generating an orthogonally polarized optical signal, which consists of an optical carrier in one polarization direction and a second-order chirped optical sideband in another. Then the orthogonally polarized optical signal puts into a polarization modulator (PolM) to perform phase coding process. By driving a Pseudorandom (PN) sequence to the PolM, the time duration of the generated bandwidth doubled linearly chirped waveform can be synthesized to arbitrary length. The approach is verified by simulation. A linearly chirped waveform with central frequency of 8.25 GHz, bandwidth of 500 MHz, time duration of 6.4 ns is used to generate a synthesized waveform with central frequency of 16.5 GHz, bandwidth of 1 GHz, time duration of 819.2 ns. The TBWP of the linearly chirped signal is improved from 3.2 to 819.2. The proposed method features arbitrary large TBWP, and it can be used in a radar system to improve its resolution.

Photonic Generation of Frequency 16-Tupling Millimeter-Wave Signal without Optical Filter

A generalized optical filterless approach to achieve photonic generation of frequency 16-tupling millimeter-wave (mm-wave) signal based on two cascaded dual-parallel Mach-Zehnder modulators (DPMZMs) is presented. A theoretical analysis leading to the operating conditions to achieve frequency 16-tupling is developed. Different modulation indices (MIs) can be implemented to achieve the frequency multiplication by adjusting the delay of tunable optical delay line (TODL). It is confirmed by simulation that the proposed scheme is effective, and the radio frequency spurious suppression ratio (RFSSR) of the generated frequency 16-tupling signal can be as high as 40 dB when the sub-MZMs have extinction ratios of 30 dB. Influencing factors such as extinction ratio, DC bias drift, phase shift deviation and RF voltage deviation on the performance of optical sideband suppression ratio (OSSR) and RFSSR are also investigated.

Zeolite P synthesis based on fly ash and its removal of Cu(Ⅱ) and Ni(Ⅱ) ions

Zeolite P was synthesized through hydrothermal method based on a kind of Class C fly ash(FA). X-ray diffraction(XRD), scanning electron microscopy(SEM), and Brunauer–Emmett–Teller(BET) were used to analyze and characterize the synthetic sample. The kinetics and thermodynamics of copper and nickel ions removed by the zeolite samples were experimentally explored in detail. The results of kinetic treatment showed the second-order exchange second-order saturation model(SESSM) can well describe the removal process of copper ions, while the first-order empirical kinetic model(FEKM) is the best kinetic model for nickel ions. Langmuir and Freundlich isotherms were used to fit the equilibrium concentration of Cu(Ⅱ) or Ni(Ⅱ) under certain conditions. Whether for copper or nickel ion, the Langmuir model is in good agreement with the experimental equilibrium concentration.The apparent theoretical removal capacities for Cu(Ⅱ) and Ni(Ⅱ) can reach to 138.1 mg·g^(-1) and 77.0 mg·g^(-1),respectively.

Petrogenesis and tectonic implications of the Triassic rhyolites in the East Kunlun Orogenic Belt, northern Tibetan Plateau

The East Kunlun Orogenic Belt(EKOB),which is in the northern part of the Greater Tibetan Plateau,contains voluminous Late Triassic intermediate-felsic volcanic rocks.In the east end of the EKOB,we identified highly differentiated peralkaline-like Xiangride rhyolites(~209 Ma)that differ from the widespread andesitic-rhyolitic Elashan volcanics(~232–225 Ma)in terms of their field occurrences and mineral assemblages.The older,more common calc-alkaline felsic Elashan volcanics may have originated from partial melting of the underthrust Paleo-Tethys oceanic crust under amphibolite facies conditions associated with continental collision.The felsic Elashan volcanics and syn-collisional granitoids of the EKOB are different products of the same magmatic event related to continental collision.The Xiangride rhyolites are characterized by elevated abundances of high field strength elements,especially the very high Nb and Ta contents,the very low Ba,Sr,Eu,P,and Ti contents;and the variably high ^(87)Sr/^(86)Sr ratios(up to 0.96),exhibiting remarkable similarities to the characteristic peralkaline rhyolites.The primitive magmas parental to the Xiangride rhyolites were most likely alkali basaltic magmas that underwent protracted fractional crystallization with continental crust contamination.The rock associations from the early granitoids and calc-alkaline volcanic rocks to the late alkaline basaltic dikes and peralkaline-like rhyolites in the Triassic provide important information about the tectonic evolution of the EKOB from syn-collisional to post-collisional.We infer that the transition from collisional compression to postcollisional extension occurred at about 220 Ma.

A feature selection method combined with ridge regression and recursive feature elimination in quantitative analysis of laser induced breakdown spectroscopy

In the spectral analysis of laser-induced breakdown spectroscopy,abundant characteristic spectral lines and severe interference information exist simultaneously in the original spectral data.Here,a feature selection method called recursive feature elimination based on ridge regression(Ridge-RFE)for the original spectral data is recommended to make full use of the valid information of spectra.In the Ridge-RFE method,the absolute value of the ridge regression coefficient was used as a criterion to screen spectral characteristic,the feature with the absolute value of minimum weight in the input subset features was removed by recursive feature elimination(RFE),and the selected features were used as inputs of the partial least squares regression(PLS)model.The Ridge-RFE method based PLS model was used to measure the Fe,Si,Mg,Cu,Zn and Mn for 51 aluminum alloy samples,and the results showed that the root mean square error of prediction decreased greatly compared to the PLS model with full spectrum as input.The overall results demonstrate that the Ridge-RFE method is more efficient to extract the redundant features,make PLS model for better quantitative analysis results and improve model generalization ability.

Risk factors associated with early recurrence of adenocarcinoma of gastroesophageal junction after curative resection

Objective： To clarify the important clinicopathological factors affecting the early recurrence of adenocarcinoma of esophagogastric junction （/kEG）. Methods： We retrospectively reviewed the clinical data of 147 AEG patients who underwent R0 resection during the period from December 1995 to December 2007. Risk factors asssociated with the early recurrence were analyzed by X2 test and logistic regression test. Results： The mean time to tumor recurrence was 16.3 months after R0 resection, and the 1-year recurrence rate was 48.3%. Univariate analysis showed that the histological grade （poorly and moderately differentiated）, number of positive lymph nodes, and vascular invasion were significantly related with the early recurrence （P〈0.05）. Logistic multivariate regression analysis showed that only histological grade and vascular invasion were independently related with early tumor recurrence （P〈0.05）, Conclusions： Histological grade and vascular tumor recurrence after R0 resection for/kEG. invasion are independent factors for predicting the early

High resolution continuous sedimentary records of Upper Cretaceous obtained from the continental drilling(SK-1) borehole in Songliao Basin:Sifangtai and Mingshui Formations

The Sifangtai and Mingshui formations were continuously cored in the SK-1 n borehole（China Cretaceous Continental Scientific Drilling-SongKe1-the north borehole）.The core is 767.96 m long,and the recovery is 94.7%.The ages of the formations range from middle Campanian to Danian.The sequence and process of lithology-lithofacies and cyclic stratigraphy were described in detail.Eight litho-types compose the Sifangtai Formation,and 15 litho-types compose the Mingshui Formation.Deposition was predominantly in meandering river and lacustrine environments,including 10 microfacies in the Sifangtai Formation and 15 microfacies in the Mingshui Formation.The complete sequence is composed of 535 m-scale cycles（sixth-order cycle）,152 fifth-order cycles,42 fourth-order cycles and five third-order cycles.The centimeter-scale description of the section revealed some previously unknown horizons such as a special type of mudstone,marl,volcanic ash and favorable sand reservoirs in the formations.The new-found evidence is very important for the interpretation of the evolution of the basin,conditions such as lake oxic events,the K/Pg boundary,tectonism in the late sag basin stage,and the reservoir-cap rock assemblages in the shallow stratigraphy.

Carbon and nitrogen budget in fish-polychaete integrated aquaculture system

Integrated multi-tropic aquaculture(IMTA)systems have been used in China for many years and have achieved significant economic,social,and ecological benefits.However,there is still a lack of benthic bioremediation species that can effectively utilize the aquaculture particulate organic waste in the system.Polychaete Perinereis aibuhitensis Grube is used as an environmental remediation species for large-scale aquaculture to reduce particulate organic waste,which is of great significance to environmental protection.To improve bio-elements utilization efficiency,P.aibuhitensis was applied for IMTA indoor fish(Hexagrammos otakii)farming.Results showed that in the system,production of 1 kg of the fish discharged 2141-2338 mg of carbon and 529-532 mg of nitrogen,while in the monoculture of the fish,the figures were 3033-3390 mg and 764-794 mg,or 24.84%-35.26%and 30.35%-33.32%less,respectively.This approach promoted IMTA technology that could utilize the particulate organic waste from intensive aquaculture and reduce the adverse environmental effects.

Growth Behavior of a Phase in Ti-5.6Al-4.8Sn-2.0Zr-1.OMo-0.35Si-0.7Nd Titanium Alloy

The thermal stability of the microstructure of a near-α titanium alloy after aging at 750℃ was investigated using optical microscope and transmission electron microscope as well as composition analysis. Aging treatment brings about significant coarsening of grain boundary α and α platelets within the colonies for martensitic microstructure. The observed changes are related to the growth steps or ledges of the interface and lamellar termination presented in the microstructure. The composition analysis of the coarsened α plate is consistent with the growth kinetics. The α Widmanstaetten plates were coarsened due to the movement of α /β interface for Widmanstaetten microstructure, and the phase boundaries of primary α（αp） phase directly moved into the transformed β for bimodal microstructure.

An improved theoretical procedure for the pore-size analysis of activated carbon by gas adsorption

Amorphous carbon materials play a vital role in adsorbed natural gas(ANG) storage. One of the key issues in the more prevalent use of ANG is the limited adsorption capacity, which is primarily determined by the porosity and surface characteristics of porous materials. To identify suitable adsorbents, we need a reliable computational tool for pore characterization and, subsequently, quantitative prediction of the adsorption behavior. Within the framework of adsorption integral equation(AIE), the pore-size distribution(PSD) is sensitive to the adopted theoretical models and numerical algorithms through isotherm fitting. In recent years, the classical density functional theory(DFT) has emerged as a common choice to describe adsorption isotherms for AIE kernel construction. However,rarely considered is the accuracy of the mean-field approximation(MFA) commonly used in commercial software. In this work, we calibrate four versions of DFT methods with grand canonical Monte Carlo(GCMC) molecular simulation for the adsorption of CH_4 and CO_2 gas in slit pores at 298 K with the pore width varying from 0.65 to 5.00 nm and pressure from 0.2 to 2.0 MPa. It is found that a weighted-density approximation proposed by Yu(WDA-Yu) is more accurate than MFA and other non-local DFT methods. In combination with the trapezoid discretization of AIE, the WDA-Yu method provides a faithful representation of experimental data, with the accuracy and stability improved by 90.0% and 91.2%, respectively, in comparison with the corresponding results from MFA for fitting CO_2 isotherms. In particular, those distributions in the feature pore width range(FPWR)are proved more representative for the pore-size analysis. The new theoretical procedure for pore characterization has also been tested with the methane adsorption capacity in seven activated carbon samples.

SDN-Based Switch Implementation on Network Processors

Virtualization is the key technology of cloud computing. Network virtualization plays an important role in this field. Its performance is very relevant to network virtualizing. Nowadays its implementations are mainly based on the idea of Software Define Network (SDN). Open vSwitch is a sort of software virtual switch, which conforms to the OpenFlow protocol standard. It is basically deployed in the Linux kernel hypervisor. This leads to its performance relatively poor because of the limited system resource. In turn, the packet process throughput is very low.In this paper, we present a Cavium-based Open vSwitch implementation. The Cavium platform features with multi cores and couples of hard ac-celerators. It supports zero-copy of packets and handles packet more quickly. We also carry some experiments on the platform. It indicates that we can use it in the enterprise network or campus network as convergence layer and core layer device.

Numerical Simulation of Two Types of Electromagnetic Edge Dam Used in Twin Roll Strip Casting

Two types of electromagnetic edge dams were analyzed by using finite element method in present paper. The magnetic vector potential method and edge element method were used. The distributions of the magnetic field, the eddy current intensity and the magnetic force were obtained from the computing. The differences in these fields were explained according to the two types of electromagnetic dam, and characters of their application in twin roll casting were also discussed.

Numerical Modeling of Growth Kinetics of Pro-eutectoid Ferrite Transformed from Austenite in Fe-C-∑X Alloys

In the present paper, a numerical modeling was developed to simulate the growth kinetics of ferrite transformed from austenite in Fe-C-∑X （X denotes substitution elements, such as Mn, Ni, Cr etc.） steels by solving the diffusion equation using finite difference method （FDM）. Coupled with the kinetic modeling, thermodynamic calculations were carried out to determine the γ/α phase equilibrium conditions using a para-equilibrium （PE） model. The dissipation of free energy for γ→α phase transformation due to the so-called solute drag effect （SDE） was taken into account in the thermodynamic modeling. With this modeling, simulations on the growth kinetics of ferrite in the steels containing austenite-stabilizing and ferrite-stabilizing elements （such as Ni, Mn and Si, Cr, respectively） were performed, which indicates that it deviates from the parabolic growth rate law after the initial stage of transformation. The results were compared with the experimental values given by Bradley and Aaronson, showing that this model has a reasonably good accuracy to predict the growth kinetics of ferrite.

How to Adjust XPCC's Planting Structure of Grain,Cotton,Oil and Sugar?

XPCC has long shouldered the mission of exploitation of virgin land in border area,but the special geographic distribution leads to regional segmentation and administrative division in the planting structure of grain,cotton,oil and sugar for XPCC. Since 1980,XPCC's total planting area of grain,cotton,oil and sugar has increased steadily year by year. The yield levels show a unimodal trend; the total yield of cotton has been showing a geometric growth trend; the total yield of oil crops and sugar beet shows a fluctuating growth trend,but the total yield of grain crops shows a bimodal growth trend. XPCC's grain crops are mainly in the farms of Division 4 in Ili Valley and Division 6 in Changji;cotton production in South and North Xinjiang is basically the same,and the yield in South Xinjiang is slightly higher than in North Xinjiang,but cotton can not be planted in most farms of Division 9 and Division 10; oil crops are grown mainly in cold regions; sugar beet is mainly in the farms of Division 2,Division 4,Division 7 and Division 9. Some factors are limiting XPCC's farming development such as unreasonable agricultural structure,quite different regional production levels and great grain crop yield fluctuations. Therefore,it is recommended to optimize regional distribution,increase efforts to promote new technologies,and strengthen brand building to help XPCC to give play to the agricultural resource advantages.