This study aimed to analyze the quality differences of sauced beef with aged brine and quantitative marinating methods by evaluating sensory characteristics, color, shear force, texture, moisture distribution, taste nucleotides, and free amino acids. Results showed that quantitative marinated beef received a higher score in sensory evaluation than aged brine marinated beef. Additionally, quantitative marinated beef had better color, lower shear force and hardness compared to aged brine marinated beef (P<0.05). It also had a higher moisture content and more even moisture distribution. The quantitative marinating method resulted in higher levels of 5′-AMP, 5′-IMP, and 5′-GMP in the beef sauce, which enhanced its umami intensity (P<0.05). Moreover, the total free amino acid content was higher in quantitative marinated beef (475.60 mg/100 g) than aged brine marinated beef (274.66 mg/100 g). These findings suggested that the use of quantitative marinating method can significantly improve the quality of marinated beef products and promote the industry's advancement.

为研究不同冷却方式对酱牛肉品质的影响,分析冷风隧道、自然冷却和真空冷却条件下酱牛肉冷却速率、冷却损失率、菌落总数、色泽、剪切力、风味等指标变化,通过扫描、透射电子显微镜观察不同冷却方式下酱牛肉的肌纤维横向和纵向收缩情况.结果表明:3种冷却方式中,真空冷却处理酱牛肉冷却速率最快、肉色较为鲜艳,但冷却损失率和剪切力也最大,扫描、透射电镜观察结果表明,真空冷却加速了水分损失和肌纤维结构收缩;冷风隧道和自然冷却处理酱牛肉的初始菌落总数分别为2.35、2.75(lg(CFU/g)),显著高于真空冷却酱牛肉的1.85(lg(CFU/g))(P＜0.05);3种冷却方式处理酱牛肉风味品质无明显差异.因此,真空冷却可提高酱牛肉冷却速率,降低颜色劣变,延长产品货架期,但水分损失相对较大,嫩度下降,在酱牛肉工业化加工应用中需综合考虑.

扩大农业农村投资是实施乡村振兴战略、打赢脱贫攻坚战和全面建成小康社会的重要支撑.自2019年以来我国农业农村投资增速明显下滑,2020年初新冠肺炎疫情更对农业农村投资产生较大冲击.本文在分析我国农业农村投资现状的基础上,剖析造成农业农村投资下滑的主要原因,提出扩大农业农村有效投资的政策建议.研究认为,今后一段时期农业农村投资重点要聚焦现代农业设施、农村基础设施和公共服务、农业农村新型基础设施三大领域,加快推动农业农村投资立法,创新多元主体参与的投融资机制,深化农村土地制度改革,健全风险预警与应对机制,建立乡村振兴投入绩效评价体系.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">为完善农村宅基地利用管理政策及盘活利用农村闲置宅基地和闲置住宅提供支撑,采用文献分析与归纳概括等方法,通过对国内农村宅基地盘活利用研究进展进行系统总结和梳理,并提出未来农村宅基地盘活利用研究若干重点方向。结果表明:1)现有研究主要从农村宅基地利用现状、农村宅基地盘活利用的影响因素、农村宅基地盘活利用的模式、农村宅基地盘活利用的路径及农村宅基地盘活利用的实践样态等方面开展;2)已有研究主要采用了农户问卷调查方法、统计分析与计量分析方法、典型案例研究方法及其他相关研究方法。基于已有研究进行评述,并结合现有研究的不足提出了未来重点研究方向,包括:1)农村宅基地利用定量测度和问题诊断研究;2)农村宅基地盘活利用的基础理论问题研究;3)典型地域农村宅基地盘活利用模式提炼研究;4)农村宅基地盘活利用的整体制度设计研究。</span>

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">使用2013—2015年农业产业化国家重点龙头企业数据,测度中国各地级市农业企业全要素生产率,并进行空间比较,在此基础上,并就影响中国农业企业全要素生产率的相关因素进行分析。结果显示:1)整体来看,2013—2015年中国农业企业全要素生产率变动幅度不大;2)从各省份来看,农业企业全要素生产率差异较为明显,仅有个别省份全要素生产率呈现递增趋势;从各地市来看,各地市农业企业全要素生产率空间差异大,但是各地市农业全要素生产率排名变化不大,全要素生产率处于中高水平以上的企业不多;3)从影响中国农业企业全要素生产率的因素来看,研发投入、要素密集度和企业规模对中国农业企业全要素生产率的影响为正,企业出口并未对农业企业全要素生产率起到推进作用。</span>

[目的]在乡村振兴战略全面实施的背景下,产业振兴是关键,农业"新六产"作为产业升级的新理念,具有重要的理论价值与战略意义.[方法]根据农业产业振兴战略实施效果与"六次产业"的研究成果,探索农业"新六产"的理论逻辑与形成路径.[结果]目前,农业"新六产"的研究尚属起步阶段,主要集中在概念解构、 发展现状、 发展问题与发展模式的案例分析,缺少理论体系的构建与案例的理论归纳.研究基于农业"新六产"发展的4个阶段,提出由产业联动层、 发展模式层与新型业态层3个模块构建的农业"新六产"理论架构;在此基础上,为新型业态层中物流终端型等5类业态设计了形成路径与逻辑图组.[结论]理论与路径的研究成果可以为传统的产业融合模式寻求突破,为乡村振兴战略的落实提供有力的支撑,具体包括平衡利益群体、 强化产业结构、 判断产业融合模式可行性、 保障农产品质量安全4个方向.在进一步研究中,农业"新六产"可以从新业态理论拓展、 综合型业态战略实施与业态评价方法等维度深入探索.

新冠肺炎疫情在全球加速蔓延,对世界经济、国际农产品市场与贸易产生重大影响,主要表现为世界经济增速大幅下降并陷入衰退;全球农产品供需将从供应相对充足转向供不应求;国际农产品价格将止跌回升,甚至出现大幅上涨;全球农产品贸易将因限制性措施严重受阻,贸易规模显著下降;中国也因全球疫情蔓延而遭受巨大冲击.因此,本文建议加大国内农业生产支持力度、确保国内主要农产品供应,加快大宗农产品进口步伐,积极应对贸易限制措施,有效开展农业对外援助、深化粮食安全国际合作.

本文运用偏离—份额Esteban模型,对1996 ～2015年中国31个省(市、自治区)的劳动生产率优势变动进行比较研究,结果显示:各省份劳动生产率呈现上升趋势,且差异越来越明显,内部劳动生产率是影响劳动生产率的主要因素,各省份产业部门竞争力对劳动生产率的影响相对较大;不同产业部门劳动生产率优势存在明显差异,第一产业相对较低,其优势地区主要集中在中西部地区,第二、第三产业相对较高,其优势地区主要集中在东部地区.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">中国企业"出口—生产率悖论"逐步引起学者重视,但相关研究大多针对制造业或工业企业。本文基于2013²015年1126家国家级农业产业化重点龙头企业的数据,验证中国农业企业是否存在"出口—生产率悖论",并对"出口—生产率悖论"存在与否给出解释。研究结论表明:（1）中国农业企业存在"出口—生产率悖论",但农业出口企业与农业非出口企业的生产率均值差异不明显。除畜牧类企业外,其它类型企业均存在"出口—生产率悖论";（2）与其它行业不同,加工贸易企业或外资企业的存在并不是中国农业企业存在"出口—生产率悖论"的主要原因;（3）出口密集度、要素密集度和企业促销成为中国农业企业"出口—生产率悖论"存在的关键原因;（4）国内市场分割对中国农业企业是否存在"出口—生产率悖论"影响并不明显,但国内市场分割刺激了低生产率农业企业的出口。</span>

Azoxystrobin and picoxystrobin are two primary strobilurin fungicides used worldwide. This study was conducted to test their effects on embryonic development and the activity of several enzyme in the zebrafish (Danio rerio). After fish eggs were separately exposed to azoxystrobin and picoxystrobin from 24 to 144 h post fertilization (hpf), the mortality, hatching, and teratogenetic rates were measured. Additionally, effects of azoxystrobin and picoxystrobin on activities of three important antioxidant enzymes [catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD)] and two primary detoxification enzymes [carboxylesterase (CarE) and glutathione S-transferase (GST)] and malondialdehyde (MDA) content in zebrafish larvae (96 h) and livers of adult zebrafish of both sexes were also assessed for potential toxicity mechanisms. Based on the embryonic development test results, the mortality, hatching, and teratogenetic rates of eggs treated with azoxystrobin and picoxystrobin all showed significant dose- and time-dependent effects, and the 144-h LC50 values of azoxystrobin and picoxystrobin were 1174.9 and 213.8 mu g L-1, respectively. In the larval zebrafish (96 h) test, activities of CAT, POD, CarE, and GST and MDA content in azoxystrobin and picoxystrobin-treated zebrafish larvae increased significantly with concentrations of the pesticides compared with those in the control. We further revealed that azoxystrobin and picoxystrobin exposure both caused significant oxidative stress in adult fish livers and the changes differed between the sexes. Our results indicated that picoxystrobin led to higher embryonic development toxicity and oxidative stress than azoxystrobin in zebrafish and the male zebrafish liver had stronger ability to detoxify than that of the females. (C) 2018 Elsevier Ltd. All rights reserved.

分析了国际粮食市场的整体环境,并结合具体国家案例,说明一国实现国家粮食安全的重要性.维护一国粮食安全要有"端牢饭碗"的战略意识,勇于承担"端牢饭碗"的战略责任,始终保持"端牢饭碗"的战略定力.提出具体政策建议:一是贸易谈判中顶住贸易压力,适度拓展外部空间;二是建立农业投入长效机制,适度拓展外部空间;三是提高劳动力生产率.

: This paper summarizes the development of various utilization models for returning livestock and poultry manure to farmlands. It analyzes the problems affecting the industrial development of livestock and poultry manure recycling in China, discusses developmental strategies for the next step in this process. In past years, important progress has been made in exploring utilization models for returning livestock and poultry manure to farmlands, and in identifying suitable parameters for the livestock-carrying capacity of such lands, both at home and abroad. However, problems remain, such as nutrient imbalance after combining planting and livestock systems, large nutrient losses, and a lack of reasonable principles for manure application on farmlands. In future, studies should focus on the environmentally friendly return of manure to farmlands and introduce the concept of nutrient management after combining planting and livestock systems. Techniques should be introduced for the collection, storage, and processing of manure; for the return of the manure to farmlands; for reasonable manure application; and for balancing the nitrogen and phosphorus nutrients in order to reduce non-point-source pollution; among other aspects. In addition, policies for the efficient recycling of livestock and poultry manure should be promoted.

The acute toxicity and safety of four strobilurin fungicides on Trichogramma confusum were evaluated in this study. Dry film residue method was followed to determine the acute toxicity of four strobilurin fungicides and their safety were also assessed. The LR50 of picoxystrobin technical and kresoxim-methyl technical to T. confusum were 2.66×10-4 and 7.32×10-4 mg a.i.·cm-2 respectively, which is higher acute intrinsic toxicity, with high risks;whereas both pyraclostrobin technical and azoxystrobin technical had a lower intrinsic toxicity with LR50 of 3.01×10-3 and 3.47×10-3 mg a.i.·cm-2, both moderate risks. However, among four strobilurin fungicide formulations, picoxys-trobin SC gave the highest intrinsic toxicity with LR50 of 5.02×10-5 mg a.i.·cm-2, extremely high risk; followed by pyraclostrobin SC and EC with LR50 of 3.78×10-3 and 5.80×10-3 mg a.i.·cm-2, both moderate risks. The lowest intrin-sic toxicity was observed in azoxystrobin WG and SC, kresoxim-methyl WG with LR50 of>4.0×10-2 mg a.i.·cm-2, all low risks. Some strobilurin fungicides, especially picoxystrobin formulations had a high risk on Trichogramma. Thus, it is suggested that we should avoid applying these fungicides during releasing Trichogramma in the field.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">本文通过构建世界八区域两部门CGE模型,并利用2002年和2010年中国区域投入产出表数据,研究了贸易成本对中国各地区农产品贸易增长的影响。研究发现:（1）中国农产品贸易成本存在显著的地区差异,但差异总体呈下降趋势;（2）贸易成本对中国各地区农产品贸易增长存在显著的负向效应,该效应在中国西北、西南和华中地区的表现较为明显;（3）贸易成本主要影响双边农产品贸易,而对第三方农产品贸易的影响并不大;（4）在其他条件不变的情况下,贸易成本下降至运输成本对中国区际农产品贸易和农产品对外贸易增长的贡献分别为35.79%和39.87%;（5）农产品对外贸易成本下降扩大了农产品贸易逆差,区际农产品贸易成本下降则缩小了农产品贸易逆差。</span>

Intensive dairy farms have developed rapidly in China over the last three decades, which have produced a lot of manure nutrients. However, due to the decoupling of crop-animal systems and poor manure management, large loss of nutrients from manure has led to serious environmental pollution. There is an urgent need to define an integrated manure management plan, which requires a quantitative understanding of nutrient balance and budget in a mixed crop-animal system. In this study, we reported a typical manure processing model so called "solid-liquid separation - compost+oxidation pond - manure application" from a dairy farm, and developed a comprehensive manure nutrient management plan using the data collection from farm investigation, soil, solid and liquid manure sampling and parameters collection from literatures. The results showed that dairy excretion N and P were 204 and 33 t/a with the breeding stock number of 2978 dairy cattle, respectively. After manure collection and processing, the N and P amounts of manure nutrients were 126 and 27 t/a, which could be available for crop use. Manure management of lactating dairy cattle and young dairy cattle were different, therefore the amount of their manure nutrients supply were quantified, respectively. The collection rate of manure N and P nutrient was 131 and 23 t/a in the lactating dairy cattle house, respectively. The manure from flood flushing system was treated by solid-liquid separation; therein the solid part of manure after solid-liquid separation could be composted as organic fertilizer applied to the field. At the same time, the liquid part could be treated by the oxidation pond as liquid manure to be returned to the field. The rate of manure N and P nutrient from lactating dairy cattle house was eventually 107 and 22 t/a, respectively. The young dairy cattle was mainly raised outdoor. Most of urine would be leaked and evaporated on the non-concrete ground, and the solid feces were collected regularly on a dry manure basis. Therefore, the amounts of solid manure N and P nutrient collected from young dairy cattle were 23 and 5 t/a, respectively. Finally, the amounts of N and P nutrient from young dairy cattle's solid manure composted were 19 and 5 t/a, respectively. Based on crop nutrient requirements and soil nutrient supply, considering the ratio of manure to inorganic fertilizer (50%) and current manure nutrient use efficiency (30%), the amounts of manure N and P that could be applied to arable land were 727.6 and 131.2 t/a with the land area of 1473 hm2, respectively, which were greater than the amounts of available manure nutrients from the dairy farm under different N and P indices. Among them, total application rates of manure N and P nutrient for silage corn, grain corn, alfalfa, and apricot were 287 and 61.1, 213.8 and 22.2, and 226.0 and 47.7, 0.8 and 0.2 t/a, separately. Therefore, the land carrying capacity of manure N and P nutrient is sufficient in this typical mixed crop-dairy farm. Manure application management plan in the mixed crop-dairy farm shows that, 19000 and 14000 t organic fertilizer can be applied to the farmland, and 100% of organic fertilizer produced from dairy farms can be eliminated based on N and P application rules. A total of 1.40 and 2.53 million m3 waste water can be used as fertilizer in the dairy farm, which is 5.6 and 9.8 times the current amount of waste water based on N and P application rules, respectively. The implementation of comprehensive manure nutrient management plan can make full use of manure nutrient resources for crop growth and reduce the direct discharge of manure nutrient to the environment, thus ensuring long-term sustainable production in the mixed crop-dairy farms.

文章利用8省1047个农户样本调研数据,构建Logit模型就农户市场预判能力及其影响因素进行实证分析,研究结论如下,第一,农户市场预判能力相对较弱,价格预测与实际吻合度在70％以上的农户仅占样本总量的18.53％,中部和东部地区的农户市场预判能力高于西部地区;第二,养殖经历、养殖年限、多样化的信息渠道、政府培训、金融借贷对农户市场预判能力影响为正;第三,养殖合同、同行竞争关系、鸡蛋销售难易程度、培训次数对农户市场预判能力影响为负.根据研究结论,文章提出政府应及时发布农产品市场监测信息、加强农户培训、调动农户主观能动性等措施.

采用半静态法测定了4种甲氧基丙烯酸酯类杀菌剂原药及制剂对斑马鱼(Brachydonio rerio)急性毒性.结果表明,以实测浓度计,250 g·L-1嘧菌酯悬浮剂对斑马鱼的96 h半数致死浓度(LC50)值为0.539 mg·L-1,急性毒性为高毒,95％嘧菌酯原药和50％嘧菌酯水分散粒剂对斑马鱼的LC50(96 h)值分别为1.09和1.21 mg·L-1,急性毒性均为中毒;98％啶氧菌酯原药和22.5％的啶氧菌酯悬浮剂对斑马鱼的LC50(96 h)值分别为0.0974和0.0972 mg·L-1,急性毒性均为剧毒;95％吡唑醚菌酯原药、15％吡唑醚菌酯悬浮剂和250 g·L-1吡唑醚菌酯乳油对斑马鱼的LC50(96 h)值为0.0613、0.0549和0.0487 mg·L-1,急性毒性均为剧毒;95％醚菌酯原药和50％醚菌酯水分散粒剂对斑马鱼的LC50(96 h)值分别为0.468和0.702 mg·L-1,急性毒性均为高毒.这4种甲氧基丙烯酸酯类杀菌剂对斑马鱼均有较高风险,会对其他水生生物也存在潜在的风险.

基于2000-2013年统计数据对安徽省各城市城镇化协调水平进行测度,不仅考虑传统类型的城镇化,而且考虑城乡统筹和生态环境等.结果显示:①安徽省城镇化协调度处于上升趋势,但协调度并不高.②传统类型的城镇化协调度呈现出上升趋势,其大小依次为土地、经济、人口和社会城镇化;2006年之前,城乡统筹和生态环境城镇化协调度高于传统类型的城镇化,之后年份前者下降明显,且滞后于后者.③安徽省各城市城镇化协调度差异并不明显,但具体类型的城镇化协调度差异明显;从地理分布来看,皖北地区城市的人口城镇化、社会城镇化协调度高于其他地区,皖南地区城市的土地城镇化、经济城镇化协调度高于其他地区.

农民工由农村进入城市、由农业部门进入非农业部门就业,必然经过工作搜寻阶段.本文利用2014年上海市松江区、苏州市和南京市等地的378份农民工调研数据,就人力资本对农民工工作搜寻方式的影响进行分析,研究结果表明:依赖亲戚或朋友等社会关系寻找工作仍是农民工首次工作搜寻的主要方式,通过人才市场的方式工作搜寻成为农民工目前工作搜寻的主要方式;人力资本对农民工工作搜寻方式的影响显著,受教育水平高、受过职业教育的农民工倾向于自己寻找工作;受过职业教育的农民工不会轻易改变工作搜寻方式,专业技术培训使得农民工工作搜寻方式发生变化;此外,年龄是影响农民工工作搜寻的重要因素.加强农民工人力资本投资,完善劳动力市场中介组织,有效促进农民工流动是推动经济快速转型、和谐发展的关键所在.

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">根据2014年对江苏、上海和湖南等地实际调研数据,构建Logit模型,就工作环境和工作强度对农民工工作流动的影响进行分析,本研究分两步进行,首先分析工作环境和工作强度对农民工外出务工的影响,在此基础上分析其对农民工工作流动的影响。结果显示:1)就业于发达城市的农民工外出务工意愿强,工作流动意愿弱。2)工作环境越差,农民工外出务工意愿和工作流动意愿均越强。3)工作强度对农民工外出务工意愿的影响为正,工作强度越大,外出务工意愿越强;但工作强度对农民工工作流动意愿的影响并不显著。本研究同样考察了其他因素对农民工工作流动的影响,其中婚姻和受教育水平对农民工工作流动的影响显著。</span>