Magnetic and magnetocaloric effect of Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass

Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass exhibited excellent magnetic refrigeration material with a wide temperature range and high refrigeration capacity(RC)was reported.Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass was observed with typical spin glass behavior around 15.5 K.In addition,we find that the magnetic entropy change(-△S_(M))originates from the sample undergoing a ferromagnetic(FM)to paramagnetic(PM)transition around 20 K.Under a field change from 0 T to 7 T,the value of maximum magnetic entropy change(-△S_(M)^(max))reaches 12.5 J/kg·K,and the corresponding value of RC reaches 487.7 J/kg in the temperature range from 6 K to 60 K.The large RC and wide temperature range make the Er_(20)Ho_(20)Dy_(20)Cu_(20)Ni_(20)high-entropy metallic glass be a promising material for application in magnetic refrigerators.

Immunomodulation of adipose-derived mesenchymal stem cells on peripheral blood mononuclear cells in colorectal cancer patients with COVID-19

BACKGROUND Accumulating evidence has shown that adipose tissue-derived mesenchymal stem cells(ADSCs)are an effective therapeutic approach for managing coronavirus disease 2019(COVID-19);however,further elucidation is required to determine their underlying immunomodulatory effect on the mRNA expression of T helper cell-related transcription factors(TFs)and cytokine release in peripheral blood mononuclear cells(PBMCs).AIM To investigate the impact of ADSCs on the mRNA expression of TFs and cytokine release in PBMCs from colorectal cancer(CRC)patients with severe COVID-19(CRC^(+)patients).METHODS PBMCs from CRC^(+)patients(PBMCs-C+)and age-matched CRC patients(PBMCs-C)were stimulated and cultured in the presence/absence of ADSCs.The mRNA levels of T-box TF TBX21(T-bet),GATA binding protein 3(GATA-3),RAR-related orphan receptor C(RORC),and forkhead box P3(FoxP3)in the PBMCs were determined by reverse transcriptase-polymerase chain reaction.Culture supernatants were evaluated for levels of interferon gamma(IFN-γ),interleukin 4(IL-4),IL-17A,and transforming growth factor beta 1(TGF-β1)using an enzyme-linked immunosorbent assay.RESULTS Compared with PBMCs-C,PBMCs-C+exhibited higher mRNA levels of T-bet and RORC,and increased levels of IFN-γ and IL-17A.Additionally,a significant decrease in FoxP3 mRNA and TGF-β1,as well as an increase in Tbet/GATA-3,RORC/FoxP3,IFN-γ/IL-4,and IL-17A/TGF-β1 ratios were observed in PBMCs-C+.Furthermore,ADSCs significantly induced a functional regulatory T cell(Treg)subset,as evidenced by an increase in FoxP3 mRNA and TGF-β1 release levels.This was accompanied by a significant decrease in the mRNA levels of T-bet and RORC,release of IFN-γ and IL-17A,and T-bet/GATA-3,RORC/FoxP3,IFN-γ/IL-4,and IL-17A/TGF-β1 ratios,compared with the PBMCs-C+alone.CONCLUSION The present in vitro studies showed that ADSCs contributed to the immunosuppressive effects on PBMCs-C+,favoring Treg responses.Thus,ADSC-based cell therapy could be a beneficial approach for patients with severe COVID-19 who fail to respond to conventional therapies.

Anomalous Hall effect in ferromagnetic LaCo_(2)As_(2) and ferrimagnetic NdCo_(2)As_(2)

We conducted a comparative study of the magnetic and transport properties of single-crystalline LaCo_(2)As_(2) and NdCo_(2)As_(2).LaCo_(2)As_(2) is a soft metallic ferromagnet which exhibits purely intrinsic anomalous Hall effect(AHE) due to Co-3d electrons. With Nd-4f electronic magnetism, ferrimagnetic NdCo_(2)As_(2) manifests pronounced sign reversal and multiple hysteresis loops in temperature-and field-dependent magnetization, Hall resistivity, and magnetoresistance, due to complicated magnetic structural changes. We reveal that the AHE for NdCo_(2)As_(2) is stemming from the Co sub-lattice and deduce its phase diagram which includes magnetic compensation and two meta-magnetic phase transitions. The sensitivity of the Hall effect on the details of the magnetic structures in ferrimagnetic NdCo_(2)As_(2) provides a unique opportunity to explore the magnetic interaction between 4f and 3d electrons and its impact on the electronic structure.

考虑结块形成的铝电解氧化铝颗粒溶解全过程数值模拟

基于前期研究结果,改进和建立铝电解槽内氧化铝颗粒溶解全过程的数值计算模型,重点考虑氧化铝结块形成的影响。结果表明,氧化铝结块总质量和最大尺寸主要依赖于氧化铝的下料量,且随着下料量的增加而增大。电解质过热度越高,更容易抑制结块的形成,从而促进氧化铝颗粒溶解行为。氧化铝颗粒溶解全过程主要分为快速溶解阶段和缓慢溶解阶段,两者平均溶解速率分别为17.24 kg/min和1.53 kg/min。快速溶解阶段溶解时间大概持续10 s,且约有质量分数为50%的氧化铝颗粒(几乎全部为扩散特性好的氧化铝细颗粒)完全溶解。当下料量为1.8kg、过热度为12℃时,平均溶解速率和累计溶解质量百分数均达到最大值。氧化铝结块形成和缓慢溶解行为在氧化铝颗粒溶解全过程中起到主导作用。

腹腔镜手术治疗重症急性胰腺炎及对TNF-α、IL-6和sIL-2R水平的影响

目的探讨重症急性胰腺炎(SAP)腹腔镜手术治疗的临床疗效及对肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和可溶性白细胞介素-2受体(s IL-2R)水平的影响。方法收集到西安交通大学第一附属医院接受外科手术治疗的SAP患者92例作为本次研究对象,将其分为开腹组46例,给予传统开腹手术治疗,腹腔镜组46例,实施腹腔镜手术治疗,对比两组相关指标差异及对TNF-α、IL-6、s IL-2R水平的影响。结果腹腔镜组手术时间(82.21±14.56)min、术中出血量(172.23±23.31)ml、手术总费用(21 512.46±121.35)元及住院天数(16.81±0.58)d均少于开腹组;腹腔镜组治愈率93.48%(43/46)明显高于开腹组76.08%(35/46);其并发症率10.86%(5/46),死亡率2.17%(1/46)均明显低于开腹组;术后腹腔镜组TNF-α(24.70±6.90)ng/L、IL-6(18.31±8.91)ng/L及s IL-2R(98.60±8.91)pmol/L明显低于开腹组,以上数据组间对比差异有统计学意义(P<0.05)。结论采用腹腔镜手术治疗SAP,其疗效显著,可有效降低并发症率与死亡率,且提高治愈率,值得推广应用。

The investigation of NTO/HMX-based plastic-bonded explosives and its safety performance

3-nitro-1,2,4-triazol-5-one(NTO)is the main component of insensitive munitions(IM)formulation because of its outstanding insensitive properties.In this paper,a series of NTO/HMX-based compositeexplosives were prepared and characterized.The study focuses on the effect of NTO on the perfommance of the formulations,especially the safety performance.The results revealed that the mechanical sensi-tivity of fomulations was associated with NTO content,as well as the thermal conductivity,specific heat capacity and Arrhenius parameters.Then,the high amount of NTO using in formulation was proved to be helpful for NTO/HMX-based formulation to exhibit good thermal safety.Besides,by accelerating rate calorimeter(ARC)and a modified cook-off equipment,the pressure and pressure rise rate were proved as the important indicator for judging the thermal safety performance in confined spaces.Finally,the numerical simulation was used as a credible method for predicting the respond temperature of cook-off experiment.

D-serine reduces memory impairment and neuronal damage induced by chronic lead exposure

Although exogenous D-serine has been applied as a neural regulatory intervention in many studies,the role played by D-serine in hippocampal injuries caused by lead exposure remains poorly understood.Rat models of chronic lead exposure were established through the administration of 0.05%lead acetate for 8 weeks.Simultaneously,rats were administered 30 or 60 mg/kg D-serine,intraperitoneally,twice a day.Our results showed that D-serine treatment shortened the escape latency from the Morris water maze,increased the number of times that mice crossed the original platform location,and alleviated the pathological damage experienced by hippocampal neurons in response to lead exposure.Although D-serine administration did not increase the expression levels of the N-methyl-D-aspartate receptor subtype 2B(NR2B)in the hippocampi of lead-exposed rats,60 mg/kg D-serine treatment restored the expression levels of NR2A,which are reduced by lead exposure.These findings suggested that D-serine can alleviate learning and memory impairments induced by lead exposure and that the underlying mechanism is associated with the increased expression of NR2A in the hippocampus.This study was approved by the Animal Ethics Committee of North China University of Science and Technology,China(approval No.LX2018155)on December 21,2018.

Thermal hazard assessment of TKX-50-based melt-cast explosive

In the present study, thermal hazards of TNT and DNAN used as the molten binder in TKX-50-based meltcast explosives were comparatively studied through accelerating rate calorimeter(ARC) and Cook-off experiments. Two kinds of ARC operation modes were performed to investigate the thermal safety performance under adiabatic conditions(HWS mode) and constant heating(CHR mode). The obtained results demonstrated that at both heating modes, DNAN/TKX-50 outperformed TNT/TKX-50 from the thermal safety point of view. However, the sensitivity to heat of the samples was reverse because of the different heating modes. In addition, the results of thermal hazard assessment obtained from the cookoff experiment complied with ARC analysis which indicated the molten binder TNT replaced by DNAN would reduce the hazard of the TKX-50 melt cast explosive. Furthermore, the results of cook-off experiments also showed that DNAN/TKX-50 outperformed TNT/TKX-50 from the aspect of thermal stability, which was consistent with the result of CHR mode because of the similar heating process.

Primary rectal squamous cell carcinoma treated with surgery and radiotherapy

Primary squamous cell carcinoma of the rectum is a rare malignancy,and the discrete dual lesions of rectum are even rarer.There is currently no effective and satisfactory treatment for this disease.Here we report a case of an elderly female with bi-primary squamous cell carcinoma of the rectum treated with radical resection and radiotherapy.The patient is still alive 43mo after the initial curative resection of the tumor.We suggest that surgery as the primary treatment followed by concomitant radiotherapy may be an effective protocol for elderly patients with rectal squamous cell carcinoma.

Clinical characteristics and prognosis of non-small cell lung cancer patients with liver metastasis:A population-based study

BACKGROUND The presence of liver metastasis(LM) is an independent prognostic factor for shorter survival in non-small cell lung cancer(NSCLC) patients.The median overall survival of patients with involvement of the liver is less than 5 mo.At present,identifying prognostic factors and constructing survival prediction nomogram for NSCLC patients with LM(NSCLC-LM) are highly desirable.AIM To build a forecasting model to predict the survival time of NSCLC-LM patients.METHODS Data on NSCLC-LM patients were collected from the Surveillance,Epidemiology,and End Results database between 2010 and 2018.Joinpoint analysis was used to estimate the incidence trend of NSCLC-LM.Kaplan-Meier curves were constructed to assess survival time.Cox regression was applied to select the independent prognostic predictors of cancer-specific survival(CSS).A nomogram was established and its prognostic performance was evaluated.RESULTS The age-adjusted incidence of NSCLC-LM increased from 22.7 per 1000000 in 2010to 25.2 in 2013,and then declined to 22.1 in 2018.According to the multivariable Cox regression analysis of the training set,age,marital status,sex,race,histological type,T stage,metastatic pattern,and whether the patient received chemotherapy or not were identified as independent prognostic factors for CSS(P < 0.05) and were further used to construct a nomogram.The C-indices of the training and validation sets were 0.726 and 0.722,respectively.The results of decision curve analyses(DCAs) and calibration curves showed that the nomogram was well-discriminated and had great clinical utility.CONCLUSION We designed a nomogram model and further constructed a novel risk classification system based on easily accessible clinical factors which demonstrated excellent performance to predict the individual CSS of NSCLC-LM patients.

New thoughts on the diagnosis and treatment of patients with diabetes mellitus in relation to coronavirus disease

The coronavirus disease 2019(COVID-19)outbreak that occurred in late 2019 has posed a huge threat to the health of all humans,especially for individuals who already have diabetes mellitus(DM).DM is one of the most serious diseases that affect human health,with high morbidity and rates of complications.Medical scientists worldwide have been working to control blood sugar levels and the complications associated with sugar level alterations,with an aim to reduce the adverse consequences of acute and chronic complications caused by DM.Patients with DM face great challenges during the pandemic owing to not only changes in the allocation of medical resources but also their abnormal autoimmune status,which reduces their resistance to infections.This increases the difficulty in treatment and the risk of mortality.This review presents,from an epidemiological viewpoint,information on the susceptibility of patients with DM to COVID-19 and the related treatment plans and strategies used in this population.

Potential mechanism of Simiao powder in treatment of synovitis based on network pharmacology

Objective:Based on the technology and method of network pharmacology,to explore the active components and specific mechanism of Simiao powder in the treatment of synovitis.Methods:by using tcmsp database,the potential active components and related target proteins of Simiao powder were screened.Genecards and digenet database were used to predict the target of synovitis.UniProt database was used to query the corresponding gene names.The compound synovitis target network and protein of Simiao powder were constructed by using Cytoscape and string software In R language,bio conductor data package was used to analyze the enrichment of go biological function and KEGG pathway,and the effective components and targets of Simiao powder in the treatment of synovitis were obtained.Results:64 key active components of Simiao powder were screened out from tcmsp database,71 of them were involved in the interaction of main chemical components of Simiao powder-chemical components and synovitis treatment target-synovitis.95 PPI core genes were obtained,and 90 go biological enrichment processes were obtained by go enrichment analysis.The results of network pharmacology indicate that Simiaosan can regulate 32 signaling pathways in the treatment of synovitis,including IL-17 signaling pathway,TNF signaling pathway,T cell receptor signaling pathway and toll like receptor signaling pathway.Conclusion:the treatment of synovitis with Simiao powder is a complex process of multi-component,multi-target and multi-channel,which is related to the coordinated regulation of multiple targets and signal pathways.

Research advancement of traditional Chinese medicine in affecting on signaling pathways of osteoarthritis

Osteoarthritis(OA)is a common chronic degenerative disease of the bone and joint,which occurs frequently in the middle-aged and old people.The main clinical symptoms are joint pain,stiffness,swelling,and dyskinesia.In recent years,there have been many researches on traditional Chinese medicine treatment of bone and joint,and the therapeutic effect is significant.This paper analyzes and summarizes the domestic and foreign literature in recent years,based on the cellular signaling pathway of OA,discusses the mechanism of action of traditional Chinese medicine monomer,compound,acupuncture and so on for OA,in order to provide the corresponding reference for the research and treatment of OA.

The contracting and unshearing motion of flare loops in the X 7.1 flare on 2005 January 20 during its rising phase

With the aim of studying the relationship between the relative motions of the loop-top （LT） source and footpoints （FPs） during the rising phase of solar flares, we give a detailed analysis of the X7.1 class flare that occurred on 2005 January 20. The flare was clearly observed by RHESSI, showing a distinct X-ray flaring loop with a bright LT source and two well-defined hard X-ray （HXR） FPs. In particular, we correct the projection effect for the positions of the FPs and magnetic polarity inversion line. We find that： （1） The LT source showed an obvious U-shaped trajectory. The source of the higher energy LT shows a faster downward/upward speed. （2） The evolution of FPs was temporally correlated with that of the LT source. The converging/separating motion of FPs corresponds to the downward/upward motion of the LT source. （3） The initial flare shear of this event is found to be nearly 50 degrees, and it has a fluctuating decrease throughout the contraction phase as well as the expansion phase. （4） Four peaks of the time profile of the unshearing rate are found to be temporally correlated with peaks in the HXR emission flux. This flare supports the overall contraction pic- ture of flares： a descending motion of the LT source, in addition to converging and unshearing motion of FPs. All results indicate that the magnetic field was very highly sheared before the onset of the flare.

Unsatisfied methodological qualities assessment of systematic reviews/Meta-analyses on Chinese medicine for stroke and their risk factors

Background:Stroke is not only high in morbidity and mortality but also poses a great burden of disease and it is also the most reported disease in Chinese medicine systematic reviews.Therefore,the quality of such evidence couldn’t be ignored.This study aims to use a measurement tool to assess systematic reviews(AMSTAR)to assess the methodological qualities of SR/Meta-analyses of Chinese medicine on stroke.Methods:Systematic searching of seven electronic databases and PROSPERO registration platform was carried out.Two researchers separately selected studies,extracted bibliographical characteristics and scored every included study independently after training.Total score and the proportion of each item completion were explored in different subgroup comparisons.Spearman rank correlation and multivariable logistic regression were used to measure the association between bibliographical characteristics and total score or each item.Results:Total average score of AMSTAR 1.0 checklists of 234 systematic reviews/Meta-analyses was 4.47(95%CI 4.27–4.68)and the qualities were unsatisfied especially in terms of priori setting(2.14%),grey literature inclusion(5.13%),providing a list of excluded studies(2.14%)and conflict of interest(0.00%).No improvement was found in 3 years even after the publication of AMSTAR.Chinese or nonregistered systematic reviews/Meta-analyses showed even worse methodological qualities(P<0.01).Positive correlation was found between individual items and number of pages,number of authors,research questions,languages or Meta-analyse separately(P<0.05).Conclusion:The methodological qualities of systematic reviews/Meta-analyses of Chinese medicine on stroke are poor especially Chinese studies,non-registered studies,brief studies and studies without Meta-analyse or cooperation.There is no obvious improvement over these years even after the publication of AMSTAR tool,so it is urgent to promote the use of AMSTAR or develop other efficient methods to control the quantity and monitor the quality in future.

Effect of hydraulic fracture deformation hysteresis on CO_(2)huff-n-puff performance in shale gas reservoirs

As a promising enhanced gas recovery technique,CO_(2)huff-n-puff has attracted great attention recently.However,hydraulic fracture deformation hysteresis is rarely considered,and its effect on CO_(2)huff-n-puff performance is not well understood.In this study,we present a fully coupled multi-component flow and geomechanics model for simulating CO_(2)huff-n-puff in shale gas reservoirs considering hydraulic fracture deformation hysteresis.Specifically,a shale gas reservoir after hydraulic fracturing is modeled using an efficient hybrid model incorporating an embedded discrete fracture model(EDFM),multiple porosity model,and single porosity model.In flow equations,Fick’s law,extended Langmuir isotherms,and the Peng-Robinson equation of state are used to describe the molecular diffusion,multi-component adsorption,and gas properties,respectively.In relation to geomechanics,a path-dependent constitutive law is applied for the hydraulic fracture deformation hysteresis.The finite volume method(FVM)and the stabilized extended finite element method(XFEM)are applied to discretize the flow and geomechanics equations,respectively.We then solve the coupled model using the fixed-stress split iterative method.Finally,we verify the presented method using several numerical examples,and apply it to investigate the effect of hydraulic fracture deformation hysteresis on CO_(2)huff-n-puff performance in a 3D shale gas reservoir.Numerical results show that hydraulic fracture deformation hysteresis has some negative effects on CO_(2)huff-n-puff performance.The effects are sensitive to the initial conductivity of hydraulic fracture,production pressure,starting time of huff-n-puff,injection pressure,and huff-n-puff cycle number.

Differences in respiration components and their dominant regulating factors across three alpine grasslands on the Qinghai−Tibet Plateau

Greenhouse gases(GHGs)emissions from high-cold terrestrial ecosystems underlain by permafrost on the Qinghai–Tibet Plateau(QTP)have received widespread attention.However,the dominant factors regulating ecosystem respiration(Re)and its components(soil respiration Rs and heterotrophic respiration Rh)and how the differences in carbon emissions from different ecotypes and seasons remain are still unclear.We conducted a 2-year field investigation(August 2018 to October 2020)and applied the structural equation model(SEM)to clarify the changes in the factors controlling the respiration components during different seasons.The results indicate that the R_(e)and its controlling factors in three alpine grassland ecosystems(alpine steppe,alpine meadow,and swamp meadow)vary with seasons.Furthermore,autotrophic respiration(Ra)contributes the most to the seasonal changes in R_(e).The R_(e)gradually increases in the early growing season and rapidly decreases in the late growing season.Rh remains relatively stable during the year.Under these seasonal variations in the respiration components,the dominant factors controlling R_(e)in the nongrowing season are the temperature of the atmosphere–soil interface(heat flux,atmospheric temperature,and soil temperature at 5 cm depth)and microbial activity(microbial carbon and pH)with the variable importance projections>1.5.During the growing season,the dominant factors regulating R_(e),Rs,and Rh are the soil temperature with a standardized direct effect(SDE)of 0.424,soil nutrient conditions(total nitrogen and pH)with SDEs of 0.570–0.614,and microbial activity(microbial carbon)with a SDE of 0.591,respectively.In addition,meteorological conditions have an important impact on the respiration components during the growing season.Specifically,the atmospheric vapor pressure is the dominant factor regulating the three respiration components(standardized total effects=0.44−0.53,p<0.001).The optimal soil water contents during the growing season(water content at which R_(e)reaches the maximum)are 10%in the alpine steppe,13%–15%in the alpine meadow,and 40%–43%in the swamp meadow,respectively.The effect of the soil water content on R_(e)is more important in arid ecosystems(alpine steppe and alpine meadow)than in wet ecosystem(swamp meadow).The alleviation of water limitations in arid ecosystems may potentially increase R_(e).

Cytotoxic phenazine and antiallergic phenoxazine alkaloids from an arctic Nocardiopsis dassonvillei SCSIO 502F

Microbes well-adapted to the Arctic Ocean are promising for producing novel compounds,due to their fancy strategies for adaptation and being under-investigated.Two new phenazine alkaloids(1 and 2)and one new phenoxa-zine(3)were isolated from Nocardiopsis dassonvillei 502F,a strain originally isolated from Arctic deep-sea sediments.AntiSMASH analysis of the genome of Nocardiopsis dassonvillei 502F revealed the presence of 16 putative biosynthetic gene clusters(BGCs),including a phenazine BGC.Most of the isolated compounds were evaluated for their antibacterial,antiallergic,and cytotoxic activities.Among them,compounds 4 and 5 exhibited potent in vitro cytotoxic activities against osteosarcoma cell line 143B with IC_(50) values 0.16 and 20.0μM,respectively.Besides,the results of antiallergic activities of compounds 6-8 exhibited inhibitory activities with IC_(50) values of 10.88±3.05,38.88±3.29,and 2.44±0.17μg/mL,respectively(IC_(50)91.6μM for the positive control loratadine).

Coarsening behavior of（Ni,Co）2Si particles in Cu-Ni-Co-Si alloy during aging treatment

The coarsening behavior of(Ni,Co)2Si particles in Cu-Ni-Co-Si alloy was investigated by experimental observations and coarsening kinetics calculations when aged at 450,500,550 and 600℃ for different durations.The results show that the critical particle radius for coherence mismatch is found to be 10.3 nm,and particles larger than 25 nm are generally semi-coherent.The relationship of(Ni,Co)2Si particles size and aging time follows Lifshitz,Slyosov and Wagner(LSW) theory.The particle size distributions fit well to the LSW theoretical distribution.The activation energy for(Ni,Co)2Si coarsening is accurately determined to be(216.21 ± 5.18)kJ mol-1 when considering the effect of temperature on the solution concentrations in matrix.The coarsening of(Ni,Co)2Si particles in Cu-Ni-Co-Si alloy is controlled by diffusion of Ni,Co and Si in Cu matrix.The growth of particles for long durations suggests that vacancies can be trapped within the structure for long time despite their mobility.

西藏三种庭院生产体系的能值评价（英文）

目的:利用能值方法评价西藏三种庭院生产体系的生产效率、环境效益、可持续性以及经济效益。创新点:利用能值方法,首次对近年流行的新型农牧一体化生产模式("玉米田养鹅"),以及西藏常规庭院生产体系"豌豆–小麦轮作"和"常规玉米连作"进行生态与生产效益的全面评价,明确适宜西藏可持续发展的庭院生产技术体系。方法:以两年(2012和2013)作为时间单元,记录期间各庭院生产体系物质的投入和产出。各生产体系中所有投入和产出的物质与各物质相对的转化系数即单位能值价值(UEV)相乘转换为太阳能值(sej),各物质的UEV统一全球驱动能值在15.20×10^(24) sej/year的基准上。利用"可新比例"划分各投入物质的可更新和不可更新的部分,并计算相应的能值指标(能值产出率、能值自给率、环境负载率、可持续性指标以及农产品安全指标等),从而通过能值指标和经济效益的分析来评价各庭院生产体系的生态与经济效益。结论:本研究中"玉米田养鹅"具有卓越的生态–经济效益,"豌豆–小麦轮作"次之,而"常规玉米连作"可持续性低且环境负载较大。