北京农户叶类蔬菜营销渠道绩效评价

评价北京农户的叶类蔬菜渠道绩效时,首先建立相应评价指标体系;其次通过层次分析法建立多阶层次分析模型并计算影响绩效的各因素指标权重,同时基于三角白化权函数的灰色评估方法,评估渠道各层次指标,得到相应渠道绩效的等级和综合评价值。定量评价结论是:“农户 + 企业或合作社”模式的渠道绩效最高,其次是“农户 + 产地集贸市场”和“农户 + 产地收购商”。“农户 + 批发市场”模式的渠道绩效最低,不适于农户进行叶类蔬菜的销售。

中国管理研究的理论贡献

本文在回顾池太岚教授文章的基础上,进一步分析了中国管理研究如何做出相应的理论贡献。我们认为,中国制度环境下的动态性和历史情境下的独特性都使中国管理研究具备了形成理论贡献的基础。理论贡献是对我们已知或未知的管理问题,尤其是因果关系,进行探索并不断地累积新的知识。单纯地使用中国数据验证某种理论,或者是创立一个只在中国独有情境下适用的解释都不足以成为充分的理论贡献。本文继而指出了理论贡献的三个层次:指导性战略(orienting strategy)、个体理论(unit theory)和理论研究纲领(theoretical research program),并分析了不同层次理论贡献的差异。由于理论研究纲领探讨的是理论与理论间的关系,在这个层次上分析不同理论的联系更有助于做出理论贡献,使之成为一个努力的方向。在此基础上,本文讨论了五种理论关系,并逐一指出不同理论贡献的形式。最后,本文结合中国企业实践探讨了中国管理实践向西方学习的历史过程。

Immunosuppression and phenotypic plasticity in an atlas of human hepatocholangiocarcinoma

Background:Hepatocholangiocarcinoma(H-ChC)has the clinicopathological features of both hepatocellular carcinoma(HCC)and intrahepatic cholangiocarcinoma(iCCA)and is a more aggressive subtype of primary hepatic carcinoma than HCC or iCCA.Methods:We sequenced 91,112 single-cell transcriptomes from 16 human samples to elucidate the molecular mechanisms underlying the coexistence of HCC and iCCA components in H-ChC.Results:We observed two molecular subtypes of H-ChC at the whole-transcriptome level(CHP and CIP),where a metabolically active tumour cell subpopulation enriched in CHP was characterized by a cellular pre-differentiation property.To define the heterogeneity of tumours and their associated microenvironments,we observe greater tumour diversity in H-ChC than HCC and iCCA.H-ChC exhibits weaker immune cell infiltration and greater CD8+exhausted T cell(Tex)dysfunction than HCC and iCCA.Then we defined two broad cell states of 6,852 CD8+Tex cells:GZMK+CD8+Tex cells and terminal CD8+Tex cells.GZMK+CD8+Tex cells exhibited higher infiltration of after treatment in H-ChC,the effector scores and expression of the immune checkpoints of them greatly increased after immunotherapy,which indicated that H-ChC might be more sensitive than HCC or iCCA to immunotherapy.Conclusions:In this paper,H-ChC was explored,hoping to contribute to the study of mixed tumours in other cancers.

近十年国际K-12领域机器人教育研究最新进展及启示--基于系统性文献综述法

为厘清国际近十年(2010-2019年) K-12领域机器人教育研究的最新进展,本研究采用系统性文献综述法,选取Web of Science、ScienceDirect、ERIC、Wiley数据库的19篇高质量实证研究论文进行统计分析,发现目前机器人教育主要面对小学生开展小样本、短周期的研究,研究多采用实验与准实验设计,结合问卷调查、测试、访谈、观察等多种方法从多角度分析数据,基于此得出以下结论:STEM领域是国际机器人教育实证研究的热门主题,英语、地理、阅读等非STEM领域逐渐受到重视;机器人在促进学生学业课程表现、提高元认知和人际交往能力方面具有积极促进作用,而在改善STEM态度、培养STEM动机与兴趣方面仍需进一步研究证实;机器人教育研究的复杂性、新兴技术的接受度和易用性以及机器人课程与师资培训等是现存的问题。最后,探讨了研究对机器人教学实践和科学研究带来的启示,以期促进我国机器人教育的发展。

Downstaging and resection of hepatocellular carcinoma in patients with extrahepatic metastases after stereotactic therapy

Background:A combination of tyrosine kinase inhibitors(TKIs)and anti-PD-1 antibodies with local regional therapy has elicited yield substantial clinical benefits in patients who have hepatocellular carcinoma(HCC)with extrahepatic metastases.Using this treatment strategy to convert HCC patients with extrahepatic metastases from unresectable to resectable has not yet been reported.Methods:Consecutive hepatocellular carcinoma patients with extrahepatic metastases who received first-line therapy with a combination of TKIs and anti-PD-1 antibodies and at least one local regional therapy were analysed.Results:Nine patients with localized disease who received first-line systemic therapy were enrolled.At baseline,all of them had oligometastatic disease,namely,Barcelona Clinic Liver Cancer stage C(or Chinese Liver Cancer stage IIIB).The most common treatment administered was lenvatinib plus anti-PD-1 antibody and transarterial chemoembolization,and the median time span from systemic therapy to surgery was 3.2(IQR,2.8-6.2)months.Three patients achieved a pathological complete response.Six patients underwent laparoscopic surgery,and the other 3 patients underwent open surgery.After a median follow-up of 10.2(IQR,8.6-20.0)months,7 patients survived without disease recurrence,and 2 experienced tumour recurrence.All patients had any-grade AEs,and 55.6%of the patients experienced grade 3 AEs.Fatigue was the most common AE,followed by elevated aminotransferase levels and hypertension.Conclusions:Stereotactic therapy is a feasible conversion therapy for HCC patients with extrahepatic metastases to become resectable.This is the first study to analyse therapeutic outcomes of patients receiving these therapies for HCC with extrahepatic metastases.

Sb_(2)WO_(6)/BiOBr 2D nanocomposite S-scheme photocatalyst for NO removal

Photocatalysis technology is an efficient method for removing nitrogen oxides at low concentrations.Herein,dimension-matched Sb_(2)WO_(6)/BiOBr photocatalysts were synthesized at room temperature via precipitation-deposition way.Under visible light irradiation,the as-obtained Sb_(2)WO_(6)/Bi OBr photocatalysts showed enhanced photocatalytic performance compare with the pure Sb_(2)WO_(6) and BiOBr for removal of NO.The optimal ratio for photocatalytic performance of Sb_(2)WO_(6)/BiOBr composite was found to be 30 wt.%of Sb_(2)WO_(6),which showed excellent recycling property even after 5 runs.Moreover,in situ DRIFT was carried out to reveal the time-dependent evolution of reaction intermediates during photocatalytic NO oxidation.The probable photocatalytic mechanism was considered based on the active species capture experiments.The enhanced photocatalytic performance for the Sb_(2)WO_(6)/BiOBr composite photocatalyst perhaps is attributed to the interaction between BiOBr and Sb2WO6 and S-scheme charge transfer path.

Effects of parental empathy and emotion regulation on social competence and emotional/behavioral problems of school‐age children

Importance Parents take the lead in parent–child interactions and their emotion regulation ability and empathy during parenting may be associated with children’s emotional/behavioral problems.However,the specific mechanisms underlying these associations remain unclear.Objective The present study aimed to explore the effect of parental empathy and emotional regulation on social competence and emotional/behavioral problems in school‐age children.Methods A questionnaire‐based survey was conducted with 274 parents of 8–11‐year‐old children using Achenbach’s Child Behavior Checklist,the Emotion Regulation Questionnaire,and the Questionnaire of Cognitive and Affective Empathy.Results Children with emotional/behavioral problems(n=37)had relatively lower social competence than children in a matched control group(n=37).Compared with the parents of children in the control group,parents of children with emotional/behavioral problems had significantly lower cognitive empathy scores,mainly manifested by low perspective‐taking and online simulation abilities.Mediation analysis showed that parental cognitive empathy had an indirect effect on children’s emotional/behavioral problems through children’s social competence.Interpretation Parental empathy may have a subtle influence on the social competence of school‐aged children,which further affects the severity of children’s emotional/behavioral problems.

SUSTAINABLE NITROGEN MANAGEMENT INDEX: DEFINITION, GLOBAL ASSESSMENT AND POTENTIAL IMPROVEMENTS

To represent the sustainability of nitrogen management in the Sustainable Development Goals indicator framework,this paper proposes a sustainable nitrogen management index(SNMI).This index combines the performance in N crop yield and N use efficiency(NUE),thereby accounting for the need for both food production and environmental protection.Applying SNMI to countries around the world,the results showed improvement in the overall sustainability of crop N management over the past four decades,but this improvement has been mainly achieved by crop yield increase,while global NUE has improved only slightly.SNMI values vary largely among countries,and this variation has increased since the 1970s,implying different levels of success,even failure,in improving N management for countries around the world.In the standard SNMI assessment,the reference NUE was defined as 1.0(considered an ideal NUE)and the reference yield was defined as 90 kg·ha^(−1)·yr^(−1) N(considering a globally averaged yield target for meeting food demand in 2050).A sensitivity test that replaced the reference NUE of 1.0 with more realistic NUE targets of 0.8 or 0.9 showed overall reduction in SNMI values(i.e.,improved performance),but little change in the ranking among countries.In another test that replaced the universal reference yield with region-specific attainable yield,SNMI values declined(i.e.,improved performance)for most countries in Africa and West Asia,whereas they increased for many countries in Europe and South America.The index can be improved by further investigation of approaches for setting region-specific yield targets and high-quality data on crop yield potentials.Overall,SNMI offers promise for a simple and transparent approach to assess progress of countries toward sustainable N management with a single indicator.

Design of front-end electronics based on a programmable transimpedance amplifier for an HIAF beam intensity detector

Background The beam intensity of the High Intensity Heavy-ion Accelerator Facility(HIAF)is converted into current sig-nals by beam intensity detectors and then processed by front-end electronics.The performance of the front-end electronics affects the measurement accuracy of the accelerator.Purpose To design front-end electronics to readout the current signals from a beam intensity detector.Methods A programmable transimpedance amplifier(TIA)converts current signals into voltage signals and amplify the signals.An analog-to-digital converter(ADC)converts analog signals into digital signals under the control of ZYNQ7015.Results and conclusion An integrated front-end electronics system was designed and verified.The electronics could collect and process current signals from 40 pA to 4 mA.The system had a higher dynamic range than traditional beam intensity measuring electronics.

HIRFL cooling water-monitoring system design and construct

Background HIRFL is a heavy ion accelerator built by the Institute of Modern Physics,Chinese Academy of Sciences,which constitutes a total length of over 900 m by the SFC,SSC,CSRm,CSRe and so on.It bears a lot of research task of the country,so to ensure its safe operation is very important.Purpose Cool-water system is a key part in HIRFL,and the parameters of the cool-water system need to be monitored before an accident occurs.Methods This article describes three aspects of the system,from the water leakage detection,pressure monitoring,to the water-level monitoring.A complete monitor system was designed and constructed,including the hardware structure;the data transfer mode,as well as specific control program.C++,FLASH and SCADA are used in the monitoring system.Results Fault alarm was performed timely and accurately by the monitoring system,and many accidents were avoided.Conclusion Water system monitoring is an important part of the accelerator control system.It will also play a major role in the construction of large-scale scientific device named HIAF in the further.

Control system design for new electronic cooler of HIRFL-CSRm

Introduction In this paper,we detail the architecture,design,and testing of an accurate and usable electronic cooler control system for the cooling storage main ring at the Heavy Ion Research Facility,Lanzhou,China(HIRFL-CSRm),and present the results of its use.Purpose A control system must manage devices with a high degree of accuracy to satisfy various physical requirements,and to ensure the accuracy of the data acquisition and control characteristics.Methods and materials The software for the system,based on the C++,was developed following the model-view-controller architecture pattern.On the hardware side,an I-7017R module was adopted for analog-to-digital conversion and an I-7065D module for electronic delay.The communication protocol was analyzed,discussed,and implemented.Results The control system was then tested with the 12C3+carbon beam at HIRFL-CSRm.The fast reaction time and high-precision data processing exhibited during beam tuning verified the stability and maintainability of the proposed control system.