多自由度剑麻收割机的设计与仿真制造

剑麻是一种广泛使用的硬质纤维的主要来源,被广泛的运用到各种行业,需求极大;但其收割现以手工为主,且因剑麻自身带有刺,加大了收割的难度,降低了效率。为解决剑麻的纯手工收割收割困难以及效率低的问题,提出一种多自由度剑麻收割机的机械,并申请了国家发明专利,得到授权。本文将运用UG、Sdams以及Mat Leb对该机械进行改进设计与仿真分析,并试制实物机械进行试验。试验结果表明:该机实现了剑麻收割的半自动化并提高剑麻收割的效率,可满足现行各行各业对剑麻的需求量。     

浙江省农村能源结构及主要污染物排放量估算

通过2009—2014年浙江省农村能源的使用情况，计算各类能源的SO2，NOX及TSP（Total suspended particulate）污染物排放量及其贡献度。研究表明:浙江省农村能源结构处于传统能源占主导地位的阶段，对于新型能源的普及与利用仍有待发展；从SO2、NOX、TSP的排放量和贡献度来看，煤炭贡献了94.3%的SO2、86.6%的NOX以及39.8%的TSP排放量，柴薪主要对TSP排放量贡献了25.7%，秸秆对TSP排放量贡献率为34.5%，但对NOX和SO2贡献率很低，分别为8.9%和2.4%。优化能源结构，使用替代煤的清洁能源，对煤炭进行较完全的脱硫处理，是降低SO2、NOX排放量的有效措施；改变秸秆的利用方式，通过先进的转化技术，将秸秆转化为高品位燃料是降低TSP、NOX排放量的有效措施。      

哈尔滨群力新区绿地生态规划设计建议

在分析群力新区绿地景观格局的基础上,针对提出的问题,对群力新区绿地系统进行生态规划,确立了"一轴、两廊、三纵、五片、六核"的绿地布局。确定近期、中期、远期绿地规划绿地率指标分别为19%、25%、33%,绿化覆盖率分别为24%、30%、40%,人均公园绿地为8.5、10.0、12.0m2。规划公园绿地为研究区绿地系统的核心绿地景观,均衡分布各个公园绿地的位置与规模,提高绿地景观均匀性。大幅增加附属绿地面积,注重各类斑块等级的运用,增加绿地斑块之间的联系性,降低附属绿地破碎化程度。生产、防护绿地要确保分别达到绿地指标的完成,尽可能的多采用大中型斑块和大型斑块,能更好的发挥其生产、防护的作用。规划湿地公园填补其它绿地类型的缺失,丰富了研究区绿地景观的多样性。     

行株距配置对烟田微生态环境、烤烟光合特性及产值的影响

为了探索适宜武陵山区烟叶生产的最佳栽培行株距配置,采用田间试验,研究了烤烟不同行株距搭配对烟田微生态环境、烤烟光合特性及烟叶产值的影响。结果表明:(1)适宜的行株距配置能为烟株创造良好的烟田微生态环境;(2)行距0.12 m、株距0.40 m配置和行距0.12 m、株距0.60 m配置的叶片净光合速率最大,行距0.11 m、株距0.40 m配置和行距0.11 m、株距0.50 m配置的胞间CO2浓度较高,行距0.12 m、株距0.40 m配置的叶片蒸腾速率显著高于其他处理,行距0.11 m、株距0.60 m配置的蒸汽压亏缺显著高于其他处理;(3)从产量和产值上看,行距0.12 m、株距0.40 m配置表现较优,且其上等烟比例和均价都较高。综合分析,武陵山区烟叶适宜的栽培行株距配置为行距0.12 m,株距0.40 m。     

清洁发展机制(CDM)对中国农村沼气工程经济性影响

按中国农村户用沼气池的不同适用对象分类对其运行成本分别进行了研究,并分析了其不同的温室气体减排效果以及在清洁发展机制(CDM)下出售这些减排权(CERs)可以带来的额外经济效益,对改善沼气工程直接经济效益的措施进行了讨论。结果表明:沼气工程直接经济效益不高,在清洁发展机制(CDM)下通过出售减排权(CERs),经济性可得到改善。沼气项目对于燃煤的农户将具有市场竞争力和投资吸引力。     

Using ecological indicators in the context of an ecosystem approach to fisheries for data-limited fisheries

The tenets of ecosystem approach to fisheries (EAF) now occupy centre stage in our efforts to maintain the sustainability of fisheries and rebuild marine ecosystems. The paper discusses how an EAF can be adopted for data limited fisheries and uses the northern South China Sea fishery as an example to demonstrate the selection and use of indicators for determining the states of the fishery and its relevant ecosystem to provide advice on management. Implementing EAF management requires indicators and models that address the impact of fishing across entire ecological communities and determine management actions to be taken to achieve the preset objectives according to decision rules. Data limited fisheries necessarily have limited resources for data collection and scientific studies and therefore could not support complex models. To overcome the data limitation and absence of modelling support, simple indicators have to be used to assess the current state and monitor changes of the fishery and its ecosystem. Such indicators should: (1) be observable and understandable by all stakeholders, (2) be based on easily obtainable and reliable data, (3) adequately reflect the condition of the resource, and (4) have associated reference values and responsive management measures. The paper also reviews the recent development and use of indicators and harvest strategies in both conventional and EAF management to better understand the differences and to shed light on the challenges of EAF, in particular for data limited fisheries.     

Evaluation of the Ability of GroBiotic®‐A to Enhance Growth,Muscle Composition,Immune Responses,and Resistance Against Aeromonas hydrophila in Nile tilapia,Oreochromis niloticus

This study was conducted to evaluate the potential of graded levels of GroBiotic^®‐A to improve performance of Nile tilapia, Oreochromis niloticus, fed a 29% crude protein (CP) diet. A 29% CP diet was formulated and supplemented with 0, 0.4, 0.8, and 1.2% GroBiotic^®‐A and compared to performance of fish fed a 33% CP diet. Enhanced weight gain and feed efficiency were generally observed in fish fed the diets supplemented with GroBiotic^®‐A compared to the 29% CP diet. No significant differences in these responses were observed between fish fed diets supplemented with GroBiotic^®‐A compared to those fed the 33% CP diet. Supplementation of 0.8 and 1.2% GroBiotic^®‐A induced significantly lower condition factor and hepatosomatic index compared to fish fed the 29% CP diet, but those values were similar to that of fish fed the 33% CP diet. GroBiotic^®‐A supplementation and protein reduction had no effect on the viscerosomatic index of fish or moisture, lipid, and protein content of muscle samples. However, muscle ash increased significantly with protein reduction (29% CP diet), but GroBiotic^®‐A supplementation (0.8 and 1.2%) reduced muscle ash content. Activities of catalase and superoxide dismutase were markedly reduced in fish fed GroBiotic^®‐A (0.8 and 1.2%) compared to those fed the control diet. GroBiotic^®‐A supplementation also induced significantly higher neutrophil oxidative radical production compared to fish fed the 29% CP diet, but no significant difference was observed in comparison with the 33% CP diet. After 8 wk of feeding, exposure to Aeromonas hydrophila for 3 wk resulted in 40% (0.4, 0.8% GroBiotic^®‐A) and 27% (1.2% GroBiotic^®‐A) mortality and reduced signs of disease, while 47% mortality was observed in fish fed the 29% CP diet. Based on the result of this study, it is concluded that 0.8 and 1.2% GroBiotic^®‐A positively influenced growth performance and feed efficiency of tilapia fed diets containing 29% crude protein to levels comparable to fish fed the 33% CP diet. GroBiotic^®‐A supplementation also significantly increased neutrophil oxidative radical production as well as resistance to Ae. hydrophila infection.     

The innovation effect of low-carbon technology transfer from the perspective of carbon emission reduction demand: A case study of the Yangtze River Economic Belt in China

Reducing carbon emissions is the only way to solve the global climate problem, which obviously requires the joint efforts of all regions. From the perspective of carbon emission reduction demand, this research obtains the data of low-carbon patents and CO₂ emissions from 2000 to 2019, and then explores the innovation effect of low-carbon technology transfer in the Yangtze River Economic Belt (YREB). We draw the following conclusions: (1) Low-carbon technology transfer has a positive impact on low-carbon technology innovation. However, a large number of low-carbon technology transfers are concentrated between developed regions in the YREB at present. (2) No matter from the perspective of total amount or efficiency, carbon emission reduction demand can play positive moderating role in the process of exerting the innovation effect of low-carbon technology transfer, indicating that the transfer of low-carbon technologies to regions with high demand is efficient. (3) The moderating effect of carbon emission reduction demand in different regions has regional heterogeneity. Carbon emissions per unit of GDP plays a greater role in moderating the innovation effect of low-carbon technology transfer in the eastern region, while CO₂ emissions plays a greater role in the central and western regions. Therefore, we propose to strengthen the transfer of low-carbon technologies between developed and less-developed regions, and adopt differentiation strategies according to the actual situation of each region. Our research has deepened the understanding of environmental economic geography on the innovation effect of low-carbon technology transfer, and has reference significance for global low-carbon technology cooperation.     

Human capital agglomeration,institutional barriers,and internal migration in China

This paper investigates how human capital agglomeration interplays with institutional factors to affect migration destination choice in China. Over the last decades, China has experienced massive internal migration, substantial human capital investment, and the relaxation of its hukou system, thus providing us with a valuable opportunity to examine the role of human capital externality in migration choice. Based on rich data on province-to-province migration flows for different education and hukou groups, we find that migrants in China, especially highly educated and urban-to-urban migrants, have a strong preference to move to provinces with a high agglomeration of human capital. Further examination reveals that low-skilled migrants in China are less likely to benefit from human capital agglomeration because of their lower ability to overcome hukou restrictions. Our findings raise the concern that labor migration under the skill-biased hukou system would enlarge China's regional disparities in human capital and economic development.