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家企混同、保险保障与创业存活

保险研究 2024年第1期 3-20页

作者：石晓军杜宝瑞秦国庆中国人民大学财政金融学院、中国财政金融政策研究中心中国人民大学财政金融学院西北农林科技大学经济管理学院

创业存活比创业涌现更重要,中国小微企业存活水平低是导致“消失的中等企业”问题的重要原因,是阻碍创新型经济发展的关键掣肘。本文从“家企混同”的独特视角出发,构建了“家庭资产-创业企业-家庭保险”的资产组合理论模型,得到了家庭... 详细信息

创业存活比创业涌现更重要,中国小微企业存活水平低是导致“消失的中等企业”问题的重要原因,是阻碍创新型经济发展的关键掣肘。本文从“家企混同”的独特视角出发,构建了“家庭资产-创业企业-家庭保险”的资产组合理论模型,得到了家庭保险提升创业存活的一系列可检验假设。进一步,使用中国家庭金融调查(CHFS)小微企业主样本并融合创业政策数据、淘宝村数据、数字金融指数进行实证检验。经验证据显示,家庭保险能显著提升创业存活,且该结论具有稳健性,在考虑了内生性问题后依旧成立;提升效应因保险属性、行业要素弹性、所处区域的不同而存在异质性;家庭保险对存活企业资产规模和员工数量具有正向影响,有助于存活企业迈向中等企业之路;家庭保险与国家创业政策及数字金融具有协同效应。从作用机制来看,一方面,家庭保险能够抑制“家产企用”所产生的连带风险,从而提升创业存活;另一方面,家庭保险能够抑制“家事殃企”所引发的风险溢出,从而提升创业存活。

关键词：创业存活小微企业家庭保险家企混同

西南不同类型紫色土pH变化、重金属累积与潜在生态风险评估

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环境科学 2024年第4期45卷 2440-2449页

作者：张海琳张雨王顶谢军张跃强张宇亭王洁石孝均西南大学资源环境学院重庆400715 重庆三峡库区土壤质量国家野外科学观测研究站重庆400716

施肥在作物增产方面的优势已得到广泛认可,但施肥对西南不同类型紫色土重金属累积与潜在生态风险的长期影响与作用机制尚不清楚.基于连续13a玉米-白菜轮作长期定位试验,采集单施化肥(NPK)、单施有机肥(M)、有机无机配施(NPKM)和不施肥对... 详细信息

施肥在作物增产方面的优势已得到广泛认可,但施肥对西南不同类型紫色土重金属累积与潜在生态风险的长期影响与作用机制尚不清楚.基于连续13a玉米-白菜轮作长期定位试验,采集单施化肥(NPK)、单施有机肥(M)、有机无机配施(NPKM)和不施肥对照(CK)这4个处理的酸性、中性和钙质紫色土,测定各处理土壤理化指标和耕层土壤中Cu、Zn、Cd、Ni、Pb和Cr全量,通过单因子污染指数(Pi)分别计算内梅罗综合污染指数(PN)和潜在生态风险指数(RI),评估长期施肥后土壤重金属污染特征和生态风险,进一步通过偏最小二乘路径模型(PLS-PM)解析土壤理化指标变量与重金属综合污染指数和潜在生态风险的关系.结果表明,土壤理化指标和重金属全量在不同施肥方式和土壤类型下差异显著(P <0.05),且施肥方式的影响程度高于土壤类型.相较于NPK处理,NPKM和M处理土壤有机碳(SOC)、有效钾(AK)和有效磷(AP)含量平均增幅达62.53%~236.07%、105%~505.71%和444.92%~1 269.95%;各施肥处理显著改变酸性和中性紫色土pH,NPK处理下显著降低1.58和1.87,NPKM和M处理下平均上升0.61~1.70.长期施肥后3种不同类型紫色土重金属全量均有提高,NPKM和M处理土壤重金属全量的平均增幅(93.63%和96.39%)高于NPK处理(51.79%).长期施用有机肥后PN更高,其中钙质紫色土M处理PN最高,达中等危害等级,且酸性和中性紫色土中各处理RI高于钙质紫色土,重金属Cd和Pb的污染程度和生态风险更高;对理化因子、PN和RI进行冗余分析结果表明,AP、ΔpH(各施肥处理相较于初始土壤pH变化量)和NO_(3)--N分别解释了方差变异的57.7%、11.2%和9.7%,达到显著水平;PLS-PM分析结果表明,长期施肥通过提高土壤AP和加剧pH变化影响重金属累积导致潜在生态风险增加.研究结果可为紫色土农田养分管理与重金属污染防治提供理论依据.

关键词：不同类型紫色土 pH变化土壤重金属污染生态风险偏最小二乘路径模型(PLS-PM)

论《金瓶梅词话》饮食叙事的时空特征及其小说史意义

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三峡大学学报（人文社会科学版） 2024年第1期46卷 19-26,115页

作者：史小军吉琳暨南大学文学院广东广州510632

《金瓶梅词话》饮食叙事的时空特征比较明显,一方面,兰陵笑笑生刻画了以自然地理条件为基础的特色饮食物象,时令性与地域性特点突出;另一方面,书中的饮食场景描写深入而细致,展现了西门庆等人的性格特征、生活状态以及世俗人情等多方面... 详细信息

《金瓶梅词话》饮食叙事的时空特征比较明显,一方面,兰陵笑笑生刻画了以自然地理条件为基础的特色饮食物象,时令性与地域性特点突出;另一方面,书中的饮食场景描写深入而细致,展现了西门庆等人的性格特征、生活状态以及世俗人情等多方面的内容。从小说史角度来看,世情小说《金瓶梅词话》的饮食叙事具有开创性意义,在饮食物象选择与场景构建方面对《林兰香》《红楼梦》等作品也有着启迪作用。

关键词：《金瓶梅词话》饮食叙事时空特征小说史意义

Exploring multiple equilibria for symmetric 2×2 CES/LES pure exchange economies

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Applied Mathematics(A Journal of Chinese Universities) 2010年第2期25卷 137-154页

作者： shi xiao-jun ZHANG Shun-ming School of Economics and Management Beijing University of Aeronautics and Astronautics Beijing 100191 China China Financial Policy Research Center Renmin University of China Beijing 100872 China

This paper explores the existence of 3 equilibria for symmetric 2-individual 2-good CES/LES pure exchange economies. For certain parameterizations in the economies, we show analytically that there are no more than 3 equilibria. We generalize our analytical results of existence of 3 equilibria for a wide range of parameterizations. Then we provide examples of 3 equilibria and parameter zones of 3 equilibria for CES and CES/LES economies.

关键词： Multiple equilibria Cobb-Douglas utility function CES/LES utility function.

Effect of organic matter and pH on mercury release from soils

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Journal of Environmental Sciences 2007年第11期19卷 1349-1354页

作者： YANG Yong-kui ZHANG Cheng shi xiao-jun LIN Zao WANG Ding-yong College of Resources and Environment Southwest University Chongqing 400716 China Chongqing Key Lab of Agricultural Resources and Environment Chongqing 400716 China

An investigation was conducted on the effect of organic matter （OM） and pH on mercury （Hg） release from soils. Hg release flux was measured using the dynamic flux chamber （DFC） combined with the Lumex multifunctional mercury analyzer in both laboratory experiment and field monitoring. The results showed that Hg emission from the OM-added soils was apparently low because of the high affinity of OM to Hg, resulting in the reverse order as the amount of OM addition. Meanwhile, Hg release flux from different pH value soils exhibited the same trend for both Hg^2＋ and Hg2^2＋ treatment, increasing the Hg flux with pH value of soils increasing. The trend of Hg release in the pH dependence experiment has been well in agreement with that from the field test. In addition, Hg release seemed to be related to its species in the soil, the flux from Hg^2＋-added soil was obviously higher than that of Hg2^2＋-added soil by the laboratory experiment.

关键词： mercury organic matter pH release flux

有机替代比例对奉节脐橙产量、品质及环境代价的影响

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中国土壤与肥料 2024年第4期 53-63页

作者：李栋邓丹丹张丽君周鹏赵敬坤王昱桁王洁石孝均张跃强西南大学资源环境学院重庆400715 西南大学长江经济带农业绿色发展研究中心重庆400716 重庆市奉节县农业技术服务中心重庆404699 重庆市农业技术推广总站重庆401122 西南大学西南山地生态农业国培基地重庆400716 国家紫色土肥力与肥料效益监测站重庆400716

通过主成分分析和综合得分来评判不同比例有机肥替代化肥对柑橘产量和品质的影响,同时探究有机肥替代在减少柑橘生产周期碳排放方面的潜力,为其科学减肥、合理增施有机肥和柑橘增产增效提供理论依据。于2018—2019年在奉节柑橘主产区进... 详细信息

通过主成分分析和综合得分来评判不同比例有机肥替代化肥对柑橘产量和品质的影响,同时探究有机肥替代在减少柑橘生产周期碳排放方面的潜力,为其科学减肥、合理增施有机肥和柑橘增产增效提供理论依据。于2018—2019年在奉节柑橘主产区进行了为期两年的田间试验,设置农户常规施肥(FP)、优化施肥(OPT)、优化施肥+有机替代氮肥20%(OPT+N20)、优化施肥+有机替代氮肥30%(OPT+N30)、优化施肥+有机替代氮肥50%(OPT+N50)5个处理,比较不同处理之间对脐橙果实产量、品质及橘园土壤肥力和环境代价的影响。结果表明,(1)与FP相比,优化施肥和有机无机配施处理能够提高脐橙产量和改善果实品质,2018年各处理间在产量上没有显著差异,2019年OPT较FP产量显著提高22.3%,OPT+N20、OPT+N30、OPT+N50产量较FP分别增产27.3%、28.3%、34.1%,同时有机无机配施较FP能够显著降低果实可滴定酸含量,提高果实可食率、可溶性固形物含量和固酸比,还可以改善果皮亮度和色泽。(2)有机无机配施较FP可明显提高土壤pH,增加土壤有效养分,维持土壤养分平衡。(3)优化施肥和有机无机配施较FP可显著降低温室气体排放强度和提高经济效益,有机无机配施处理碳足迹较FP分别提高44.20%、48.10%和59.23%,产投比分别提高63.64%、51.82%和39.70%。(4)通过对脐橙产量、果实品质等因素综合分析,各处理得分从大到小排序为OPT+N30>OPT+N50>OPT+N20>OPT>FP,即各有机无机配施的肥效响应优于FP处理,其中优化施肥配合有机肥替代氮肥30%时对果实品质提升效果最优,化肥投入的减少和有机肥的施用能够显著减少脐橙在生产生命周期中碳排放的同时提高经济效益。因此,在优化施肥的基础上配施有机肥可以提高脐橙产量、品质,减少果园碳排放。

关键词：有机替代产量品质碳排放碳足迹

Systematic study of the synthesis of heavy and superheavy nuclei in 48Ca-induced fusion-evaporation reactions

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Nuclear Science and Techniques 2024年第7期35卷 157-172页

作者： shi-Hao Zhu Tian-Liang Zhao xiao-jun Bao Department of Physics Collaborative Innovation Center for Quantum EffectsKey Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of EducationHunan Normal UniversityChangsha410081China School of Nuclear Science and Technology Lanzhou UniversityLanzhou730000China School of Physics Xi’an Jiaotong UniversityXi’an710049China

We systematically studied the evaporation residue cross sections of ^(48)Ca-induced reactions on lanthanide and actinide target nuclei under the Dinuclear System(DNS)model framework to check the reliability and applicability of the *** produce new proton-rich Fl and Lv isotopes through hot fusion reactions in the superheavy element region with Z≥104,we utilized the reactions ^(48)Ca+^(236,238,239) Pu and ^(48)Ca+^(242,243,244,250) ***,owing to the detection limit of available equipment(0.1 pb),only 283Fl and 287−289Lv,which have the maximum evaporation residue cross section values of 0.149,0.130,9.522,and 0.309 pb,respectively,can be ***,to produce neutron-deficient isotopes of actinides near the proton drip line with Z=93−100,we attempted to generate the new isotopes(224−227Pu,228−232,237Cm)using the reactions ^(48)Ca+180,182,183 W and ^(48)Ca+^(184,186,187,192) *** maximum evaporation residue cross section values are 0.07,0.06,0.26,and 0.30 nb for the former set of reactions,and 1.96 pb,5.73 pb,12.16 pb,19.39 pb,54.79 pb,and 6.45 nb for the latter,*** results are expected to provide new information for the future synthesis of unknown neutron-deficient isotopes.

关键词： Dinuclear system(DNS)model Evaporation residue cross section Neutron-deficient isotopes

Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China

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Water Science and Engineering 2024年第1期17卷 83-91页

作者： jun-jian Sun Jia-yue shi Qi Zhang xiao-tao shi jun-jun Tan PowerChina Huadong Engineering Corporation Limited Hangzhou 311122China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang 443002China

To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in *** Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest ***,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream *** and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two *** results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish *** the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream *** species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of ***,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the *** findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF.

关键词： Vertical slot fishway Nature-like fishway Aguatic ecological survey Fishwaymonitoring Statistical analysis

Nitrogen Use Efficiency as Affected by Phosphorus and Potassium in Long-Term Rice and Wheat Experiments

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Journal of Integrative Agriculture 2014年第3期13卷 588-596页

作者： DUAN Ying-hua shi xiao-jun LI Shuang-lai SUN Xi-fa HE Xin-hua Key Laboratory of Crop Nutrition and Fertilization Ministry of Agriculture/Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences College of Resources and Environment Southwest Agricultural University Institute of Plant Protection and Soil Science Hubei Academy of Agricultural Sciences Soil and Fertilizer Institute Sichuan Academy of Agricultural Sciences School of Plant Biology University of Western Australia

Improving nitrogen use efficiency （NUE） and decreasing N loss are critical to sustainable agriculture. The objective of this research was to investigate the effect of various fertilization regimes on yield, NUE, N agronomic efficiency （NAE） and N loss in long-term （16- or 24-yr） experiments carried out at three rice-wheat rotation sites （Chongqing, Suining and Wuchang） in subtropical China. Three treatments were examined： sole chemical N, N＋phosphorus （NP）, and NP＋potassium （NPK） fertilizations. Grain yields at three sites were significantly increased by 9.3-81.6% （rice） and 54.5-93.8% （wheat） under NP compared with N alone, 1.7-9.8% （rice） and 0-17.6% （wheat） with NPK compared with NP. Compared to NP, NUE significantly increased for wheat at Chongqing （9.3%） and Wuchang （11.8%）, but not at Suining, China. No changes in NUE were observed in rice between NP and NPK at all three sites. The rice-wheat rotation＇s NAE was 3.3 kg kg1 higher under NPK than under NP at Chongqing, while NAE was similar for NP and NPK at Suining and Wuchang. We estimated that an uptake increase of 1.0 kg N hal would increase 40 kg rice and 30 kg wheat ha-1. Nitrogen loss/input ratios were -60, -40 or -30% under N, NP or NPK at three sites, indicating significant decrease of N loss by P or PK additions. We attribute part of the increase in NUE soil N accumulation which significantly increased by 25-55 kg ha-1 yr1 under NPK at three sites, whereas by 35 kg ha-1 yr-1 under NP at Chongqing only. This paper illustrates that apply P and K to wheat, and reduce K application to rice is an effective nutrient management strategy for both the NUE improvement and N losses reduction in China.

关键词： apparent nitrogen balance grain yield nitrogen agronomic efficiency nitrogen loss soil nitrogen accumulation