中国农业技术应用的宏观取向与农户技术采用行为诱导

综合分析表明，中国农业技术应用的宏观取向是可持续农业技术，然而，现实情况显示出，我国农户总体上表现出的技术采用偏好与国家的宏观技术取向存在着较大差异，缩小差异是可持续农业发展的必然要求。本文着重分析了中国农业技术应用的宏观取向，农户技术采用偏好，以及二者差异的原因，并根据农户采用行为规律，提出了缩小这上差异的诱导措施。     

Effect of copper on the adsorption of p-nitrophenol onto soils

The effect of copper on adsorption of p-nitrophenol on two typical Chinese soils was investigated using a batch-equilibration method. Adsorption experiments were carried out when both copper and p-nitrophenol were adsorbed simultaneously, and when copper was previously adsorbed on soils. It was observed that adsorption of p-nitrophenol decreased with increasing copper concentrations thereby indicating a competition between copper and p-nitrophenol for occupying the adsorption sites on soils. Moisture increased the hydrated sphere and the acidity of water surrounding the cation, which further reduced the adsorption of p-nitrophenol. Fourier transform infrared spectroscopy study provided the direct evidence for the coordination of p-nitrophenol sorbed by soils with metal cation in n-hexane system. It was observed that the perturbations included a red shift of the nu(asym) (NO) band, a concomitant blue-shift of the nu(sym) (NO) band and a blue-shift of C-N band when compared with the infrared spectra obtained from water solution.     

城市天然气工程环境风险评价

结合广州、深圳、东莞、佛山等城市的天然气工程情况,对城市天然气工程的环境风险评价进行了讨论,并采用穆尔哈斯(Moorhowse)和普里恰特(Prichard)提出的热辐射预测模式和爆炸冲击波预测模式对城市天然气工程进行了风险评价.结果表明,如果发生天然气泄漏并引起火灾,假设在10 min以内,城市门站、调压站和城市高中压管道的火球对建筑物和设备的严重损害范围( A 级)最远距离分别为35.8 m、18.0 m和28.7 m,爆炸冲击波严重损害范围( C1 级)分别为距事故处54.8 m、27.8 m和44.4 m.最后从城市门站、调压站选址及输气管道选线、安全防范距离、作业过程中的风险控制与管理以及事故应急对策四方面提出了风险事故的防范措施与对策.     

利用百合(Lilium davidii)根尖细胞的微核细胞率作为环境监测指标的探讨

首次报道了利用百合根尖细胞微核细胞率作为环境监测指标的可行性和优越性。实验证明,百合根尖比蚕豆根尖细胞的微核细胞率更敏感。     

滤料的脉冲清灰效果评价指标的有效性分析

研究分析了袋式除尘器脉冲喷吹清灰效果的相关评价指标的有效性问题。结果表明:同一清灰装置,滤布的压差峰值、最大反向加速度和冲量密度与清灰效果是一致的;不同的清灰装置,冲量密度与清灰效果是一致的,而压差峰值和最大反向加速度与清灰效果则不再一致。因此,同一清灰系统,压差峰值、最大反向加速度及冲量密度均可用于评价其清灰效果,而不同的清灰系统,则只能用冲量密度来评价。     

信息量模型在地质灾害调查与区划中的应用研究

以浙江省仙居县地质灾害调查与区划项目为例,在分析当地实际地质情况的基础上结合信息论原理,对仙居县进行了基于多因素分析的地质灾害预测区划。经分析计算．得出的区划结果基本符合仙居县的实际情况。故用信息量模型进行地质灾害区划是可行的。     

液压支架薄煤层采煤工作面风流流动规律研究

分别对北宿煤矿以装备液压支架和单体支柱为主的14710和1667薄煤层采煤工作面风流场进行了现场测定研究,结果显示,装备液压支架后,工作面的风流流动规律发生了较大变化,百米风阻值及向采空区的漏风率均大幅度提高。     

干燥条件下高硫煤低温氧化特性研究

为进一步揭示不同环境条件下高硫煤的低温氧化特性,选取含硫量较低、自燃倾向性较高的褐煤,向其添加不同比例的FeS2,配制成含量分别为3%,5%,7%的混合高硫煤样,利用中国矿业大学自行研制的煤氧化模拟试验系统,测试分析干燥混合煤样在低温氧化过程中,交叉温度和指标气体CO产生量体积的变化。试验结果表明,在低温干燥的条件下,随着FeS2含量的增加,煤样的氧化特性受到抑制:交叉点温度升高;指标气体CO产生量在相同温度时体积降低。因此,在高硫煤层自燃火灾防治过程中,应尽量控制煤层周围环境的干燥度。     

Reconsideration on the effect of nitrogen on mixed culture polyhydroxyalkanoate production toward high organic loading enrichment history

Effect of nitrogen on mixed culture PHA production was reconsidered. Enrichment history of PHA accumulating culture was discussed. Higher PHA content and biomass growth were achieved in presence of nitrogen. Enrichment strategy toward higher PHA accumulation was investigated. Microbial community succession in PHA accumulation phase was investigated. In most of the operating strategies for mixed microbial cultures polyhydroxyalkanoate (PHA) production, moderate organic loads and low nitrogen concentrations are used, however, the real waste streams contain variable concentrations of carbon and nitrogen. To evaluate the effect of enrichment history on PHA producer and production the various carbon and nitrogen levels were utilized during the accumulation phase. Different operating strategies were applied in three sequencing batch reactors (SBRs) subjected to aerobic dynamic feeding. The maximum PHA production of the enriched cultures under nutrient excess, limitation and starvation (Cmol/Nmol ratio of 8, 40 and ∞, respectively) was evaluated in batch assays. A higher PHA content and biomass growth were achieved in the nutrients presence in comparison to the nutrient starvation condition. The cultures from the SBR treated under short sludge retention time, high organic loading rate, short cycle length (SBR#3) and nutrient excess reached the maximum PHA content (54.9%) and biomass increase (38.9%). Under nutrient limitation, the negative biomass growth was observed under nutrient starvation because of the sampling loss. The succession of microbial communities in SBRs and batch assays was analyzed using terminal restriction fragment length polymorphism. The SBR#3 had the best overall PHA production performance considering its high PHA content and productivity in all nutrient content, it indicates that nitrogen has a substantial impact on PHA yield especially when high organic loading rate enrichment history is involved.     

Deep learning of grasping detection for a robot used in sorting construction and demolition waste

Journal of Material Cycles and Waste Management - The traditional construction and demolition waste (CDW) treatment process adopts the method of crushing and screening after mixing and combines the...