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旱区弃收田放牧群体发病特点及防治措施
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作者 闫立军 马敬伟 《吉林畜牧兽医》 2002年第1期26-26,共1页
食草型动物饲养管理离不开放牧,这是提高经济效益的最佳途经.不同畜种、不同季节、不同草质、不同地势,科学的放好牧,就能使畜只增膘复壮,公畜能配种,母畜能按时发情,妊娠母畜能按时产仔,各项生产性能都有提高.
关键词 旱区弃收田放牧 饲料中毒 食用型动物 群体发病 发病特点 症状 防治
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人口流失状态下农村林果产品的弃收现象思考
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作者 王显 《农业经济》 北大核心 2021年第11期142-144,共3页
当前,我国农村林果产品的弃收现象普遍存在,已成当今农村亟待解决的问题。人口流失是农村林果产品弃收的根本原因。在人口流失状态下,治理农村林果产品弃收现象,可采取以下措施:抓紧研发适合山地和老人的林果产品采收工具,提高林果产品... 当前,我国农村林果产品的弃收现象普遍存在,已成当今农村亟待解决的问题。人口流失是农村林果产品弃收的根本原因。在人口流失状态下,治理农村林果产品弃收现象,可采取以下措施:抓紧研发适合山地和老人的林果产品采收工具,提高林果产品采收效率;鼓励以林果产品为原料产业研发,增加林果产品需求,提升林果业收益;支持林果业规模化、集约化建设,打造林果产品地方知名品牌;农村青年积极利用新媒体,利用直播带货等途径带动林果产品销售;解除城镇居民购买农村土地和房屋限制,引导城市资金、技术和人口流向农村。 展开更多
关键词 人口流失 农村 林果产品 弃收
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海底管道收弃管作业分析 被引量:18
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作者 戴英杰 宋甲宗 冯刚 《海洋工程》 CSCD 2000年第3期75-78,共4页
为保证海洋管道在收弃管作业过程中不发生屈服 ,利用样条函数配点法分析了管道的变形 ,利用线性积分法分析了缆索的收放和受力 ,以图表的形式给出了管道和缆索的受力和变形、铺管船的运动以及 A/
关键词 管作业 样条函数 加权残数法 海底管道
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深水S型铺管收弃管作业分析 被引量:3
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作者 龚顺风 徐普 +2 位作者 钟文军 何宁 燕晖 《浙江大学学报(工学版)》 EI CAS CSCD 北大核心 2013年第11期1904-1910,共7页
为研究深水S型铺管收弃管(A/R)作业过程管道的形态与受力特性,运用刚悬链线理论建立管道静平衡微分方程,结合缆索受力与铺管船移动,给出迭代求解两阶段作业过程管道与缆索形态的数值计算方法,并开发收弃管作业计算分析程序,模拟2 000m... 为研究深水S型铺管收弃管(A/R)作业过程管道的形态与受力特性,运用刚悬链线理论建立管道静平衡微分方程,结合缆索受力与铺管船移动,给出迭代求解两阶段作业过程管道与缆索形态的数值计算方法,并开发收弃管作业计算分析程序,模拟2 000m水深弃管操作过程.结果表明,第1阶段,铺管船需要向前移动,以使A/R绞车施加的张力保持不变,管道形态变得平缓,管道内张力逐步增加而弯矩减小;第2阶段,铺管船静止,A/R绞车施加的张力需要逐步减小,管道形态变陡,管道内张力减小而弯矩迅速增加.与铺管专业软件OFFPIPE计算得到的结果吻合较好,验证了计算分析程序的有效性和实用性,从而可为实际深水管道铺设设计提供理论依据. 展开更多
关键词 海底管道 S型铺管 管作业 缆索 刚悬链线理论
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实物期权理论在农业生产经营决策中的应用——对农户种植蔬菜弃收现象诠释 被引量:1
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作者 李红艳 《价格理论与实践》 北大核心 2019年第4期96-99,共4页
近年来,蔬菜价格波动加剧,引发社会关注。价格过低可能导致出现蔬菜弃收现象,这不仅是菜农的损失,更是资源的浪费。本文分析了农产品生产者在农业生产经营过程中不同阶段的投入决策行为,构建其保留价格的决定模型,并利用理论分析结果对... 近年来,蔬菜价格波动加剧,引发社会关注。价格过低可能导致出现蔬菜弃收现象,这不仅是菜农的损失,更是资源的浪费。本文分析了农产品生产者在农业生产经营过程中不同阶段的投入决策行为,构建其保留价格的决定模型,并利用理论分析结果对产地弃收现象进行经济学解释。结论表明:物流运输成本高和不耐储存的特征限制了蔬菜供给在时空上的分散配置,使蔬菜生产波动大部分传导为供给波动,进而引发供需失衡和价格波动。与此同时,物流运输成本、储藏成本和收割环节成本又推高了农户的预期保留价格。当市场价格(或预期市场价格)低于农户的保留价格(或预期保留价格)时,农户就会选择弃收。因此,应从物流成本、机械化收割蔬菜、降低储藏成本方面减少蔬菜弃收现象。 展开更多
关键词 蔬菜价格波动 实物期权 保留价格 二叉树模型 蔬菜弃收
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南荻秸秆厌氧发酵产物含磷量对旱作红壤磷有效性的影响
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作者 苏露涯 魏晓梦 +2 位作者 邓扬悟 葛体达 刘勇 《植物营养与肥料学报》 CAS CSCD 北大核心 2023年第7期1333-1342,共10页
【目的】洞庭湖区南荻(Triarrhena lutarioriparia)秸秆生物量大,富含磷素,每年大量秸秆废弃于水体带来巨大的环境压力。研究南荻秸秆发酵产物对旱作红壤磷有效性的影响,以期为南荻资源化利用提供理论依据。【方法】试验采用室内培养法... 【目的】洞庭湖区南荻(Triarrhena lutarioriparia)秸秆生物量大,富含磷素,每年大量秸秆废弃于水体带来巨大的环境压力。研究南荻秸秆发酵产物对旱作红壤磷有效性的影响,以期为南荻资源化利用提供理论依据。【方法】试验采用室内培养法,供试土壤为红壤。供试南荻秸秆发酵物有高磷含量(4.23 g/kg)和低磷含量(2.98 g/kg)两个产品,通过厌氧发酵过程中分别接种植物乳杆菌发酵(In1)和黑曲霉菌(In4)获得,以不添加秸秆发酵物作为对照(CK),在25℃恒温培养70天。在培养的第7、20、40、70天进行破坏性采样,分析土壤全磷、Olsen-P、pH、磷库组成和土壤酶活性。【结果】在70天的培养周期中,In1处理的土壤Olsen-P均显著高于CK处理,在培养第7天最为显著,而In4处理的土壤Olsen-P含量与CK无显著差异,除培养第40天时显著低于CK。In1和In4处理土壤中可溶性磷含量均较CK增加,但In4处理显著降低了有机酸交换态磷(疏松吸附态磷),是土壤Olsen-P含量降低的主要原因。南荻秸秆发酵产物显著增加了土壤磷酸酶活性,且In1处理高于In4处理。Pearson相关分析显示,土壤Olsen-P和疏松吸附态磷库与有机碳含量和磷酸酶活性呈显著正相关,说明秸秆发酵物添加对土壤磷吸附性能的影响是In1处理提高土壤磷有效性的重要原因。【结论】南荻秸秆厌氧发酵物进行肥料化利用,可提高旱作红壤的磷肥有效性,含磷量高的发酵物的效果更好。因此,选择可浓缩秸秆磷的发酵菌剂,生产含磷量高的秸秆发酵物,是高效利用南荻秸秆资源的有效途径。 展开更多
关键词 弃收南荻 发酵 旱地红壤 磷有效性 土壤磷分级 土壤酶活性
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后稷“三弃三收”新论——来自神话学的阐释
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作者 刘勤 《清华大学学报(哲学社会科学版)》 CSSCI 北大核心 2022年第5期85-93,209,210,共11页
《诗经·大雅·生民》中常被学人提及的后稷被“弃”,实为后稷被“寘”。“寘”字保留了十分丰富的仪式和神话内涵。因此,所谓的“三弃三收”,实为“三寘三收”。“三寘三收”的情节源自远古地母崇拜的仪式和神话——血祭沃土... 《诗经·大雅·生民》中常被学人提及的后稷被“弃”,实为后稷被“寘”。“寘”字保留了十分丰富的仪式和神话内涵。因此,所谓的“三弃三收”,实为“三寘三收”。“三寘三收”的情节源自远古地母崇拜的仪式和神话——血祭沃土。不过,在《诗经·大雅·生民》的文本中,就已经文明化了。进而,发展到春秋战国时期,人们已经不能理解“三寘三收”情节的仪式和神话内涵,亦为适应新的时代思想(如人治、德化、中央集权等),遂将被“寘”简单化为被“弃”,由此而产生了后稷“弃”之名。到西汉,通过司马迁的进一步整合和阐释,“三弃三收”的说法遂基本定型。随后,世人便遵循这一脉络纷纷用后世的道德观念、合理性去解释后稷被弃之由,离真相愈加遥远。 展开更多
关键词 后稷 稷神 地母 血祭沃土
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Evaluating the treatment of E-waste──a case study of discarded refrigerators 被引量:1
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作者 DENG Jian-jun WEN Xue-feng ZHAO Yue-min 《Journal of China University of Mining and Technology》 EI 2008年第3期454-458,共5页
Disassembly and recycling of E-waste creates a series of environmental problems. The selection of a technologically reliable, environmentally friendly, economically affordable and socially acceptable recycling technol... Disassembly and recycling of E-waste creates a series of environmental problems. The selection of a technologically reliable, environmentally friendly, economically affordable and socially acceptable recycling technology for E-waste is a significant question. This study establishes a Monte-Carlo mathematical model of cost minimization, given the constraints of environmentally sound handling of the e-waste, in the context of Crystal Ball risk assessment and evaluation software. By following the streams of the different treatment processes, which consist of various technologies including disassembly, recycling and disposal, the econom-ics of various possibilities were identified and the optimal recycling technology proposed. The key factors of the proposed scenarios were determined by using sensitivity analysis. The results of this study show that, for discarded refrigerators, the operating life span plays the key role. The model supports maintenance and resale of the short lived refrigerators. For the longer lived refrigerators material recycling is recommended by the model. Sensitivity analysis shows that purchase cost, plastic sale price, condenser sale price and disassembly costs are the main effects. This study provides a significant technical support for policy making in E-waste management. 展开更多
关键词 E-WASTE end-of-life refrigerator RECYCLING Monte-carlo method sensitivity analysis
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Economical Analysis and Optimization of Recovery Processing Policies about Discarded Product 被引量:1
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作者 XieJiaping KongLingcheng ChenRongqiu 《Ecological Economy》 2005年第2期44-51,共8页
On the foundation of analyzing the closed loop logistics chain of product with multi-lifecycle, the connotation of environmental value is set forth, recurring to such conceptions as supply chain and value chain. The p... On the foundation of analyzing the closed loop logistics chain of product with multi-lifecycle, the connotation of environmental value is set forth, recurring to such conceptions as supply chain and value chain. The plotting rules about disassembly tree are discussed in detail. The reachable matrix R of components’ disas- sembly is introduced into distinguishing if disassembly is needed, in combination with disassembly-deciding vector X. Furthermore, the arithmetic of disassembly cost is put forward. And the cost-benefits of components’ reusing, materials’ recycling, safety disposing are dissertated based on the activity-based costing. Then the 0-1 goal-programming model on product recovery processing is established, with components’ demotion calculated. In addition, taking the PC’s recovery processing for example, we put it into application. 展开更多
关键词 discarded product DISASSEMBLY RECOVERY 0-1 Programming goal programming.
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Pesticide Packaging Waste Management Model for Thailand 被引量:2
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作者 Vanvlmol Pataraslrlwong Panompom Wongpan +1 位作者 Roongnapa Korpraditskul Lawan Jeerapong 《Journal of Environmental Science and Engineering(B)》 2013年第1期1-6,共6页
Pesticide packaging waste in Thailand has recently been valued as a kind of commercial product. Selling empty pesticide packaging to reuse/recycling business has been increased in all over the country. Subject to the ... Pesticide packaging waste in Thailand has recently been valued as a kind of commercial product. Selling empty pesticide packaging to reuse/recycling business has been increased in all over the country. Subject to the resource conservation and global climate change, this could be defined as sustainable or green consumption for the most beneficial use of natural resources. However, on the point of environmental and public health, this is the way to disperse harmfulness of pesticide into non-target areas. Human and environmental health risk of exposure due to pesticide residue in such packaging waste could be a co-incident. This paper was aimed to determine a practical model for pesticide packaging waste management appropriate for Thailand based on the context of country's circumstances and the best practices reported around the world. Establishing some necessary components has been proposed, i.e. multiple rinse method applied by farmers conscientiously, central collecting site driven by local community, waste recovery program offered by pesticide production enterprises, and sanitary glass bottle washing plant registration and regulations launched by the government. In conclusion, governmental initiative and all stakeholders including in pesticide packaging waste supply chain should be encouraged to contribute their participation towards sustainable management. 展开更多
关键词 PESTICIDE packaging waste DISPOSAL REUSE recycle.
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Thoughts on e-waste recycling
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作者 Yinhe BU 《International English Education Research》 2014年第4期103-105,共3页
This paper summarizes the situation of e-waste recycling in China, points out several key problems, identify the causes and draw lessons and experiences abroad about e-waste management, propose systematic suggestions ... This paper summarizes the situation of e-waste recycling in China, points out several key problems, identify the causes and draw lessons and experiences abroad about e-waste management, propose systematic suggestions from the production side, the recovery side, consumers side, government departments and thelegislation. 展开更多
关键词 e-waste recycling ISSUES CAUSES systematic recommendation
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Fixed-bed-column Studies for Methylene Blue Removal and Recovery by Untreated Coffee Residues
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作者 Odysseas Kopsidas 《Journal of Environmental Science and Engineering(B)》 2016年第9期412-418,共7页
This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the ... This paper contributes to the Industrial Ecology Concept by using a common urban solid waste, i.e., coffee residues, to clean industrial wastewaters polluted by basic dyes, e.g., Methylene Blue. For the data from the continuous fixed-bed column system, two common models, namely (a) Bohart and Adams and (b) Clark were implemented. The Bohart and Adams capacity was up to N = 46,166 mg.L-1 or q0 = 104.5 mg.g-1 for bed-depth 15 cm, initial dye concentration 800 mg.g-1 and flow rate 20 mL.min-1. The results revealed that the Methylene Blue is fairly adsorbed on coffee residues. Consequently, this process can be applied as a low cost technique for cleaning basic dyes from the aquatic environment. 展开更多
关键词 Adsorption DESORPTION COLUMN methylene blue coffee residues.
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Redox behavior of indium in molten chlorides
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作者 Liang XU Yan-hang XIONG +5 位作者 Jin-wei MENG Jia-bao WANG Zhong-sheng HUA Yong-pan TIAN Jing-lin YOU Zhuo ZHAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2021年第5期1496-1505,共10页
An electrochemical study on the redox behavior of indium in the eutectic LiCl-KCl system at 450 ℃ was carried out with the transient techniques of cyclic voltammetry and chronopotentiometry on an inert molybdenum ele... An electrochemical study on the redox behavior of indium in the eutectic LiCl-KCl system at 450 ℃ was carried out with the transient techniques of cyclic voltammetry and chronopotentiometry on an inert molybdenum electrode. The reduction of In(Ⅲ) was found to be a two-step process involving In(Ⅲ)/In(Ⅰ) and In(Ⅰ)/In couples at the potentials of about-0.4 and-0.8 V versus Ag/AgCl, respectively. The redox mechanism was further confirmed by the theoretical evaluation of the number of transferred electrons based on cyclic voltammetry and characterizations of the precipitates generated by the potentiostatic electrolysis. The diffusion coefficients of indium ions in the eutectic LiCl-KCl melt at 450 ℃ were estimated by cyclic voltammetry and chronopotentiometry. The results obtained through the two methods are in fair agreement, delivering an average diffusion coefficient of approximately 1.8×10^(-5)cm^(2)/s for In(Ⅲ), and 1.4×10^(-4)cm^(2)/s for In(Ⅰ). 展开更多
关键词 indium ions redox behavior eutectic LiCl−KCl melt end-of-life LCDs resources recycling
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