农地整治权属调整中农户认知对行为响应的作用机制--基于改进TPB及多群组SEM

农地整治权属调整是实现农业规模化和现代化的重要手段,而农户有效参与是推动权属调整的内在动力,研究农地整治权属调整中农户认知对其行为响应的作用机制,有助于高效引导农户参与权属调整,并为制定农地整治权属调整的政策提供科学依据。基于改进计划行为理论和湖北省11个县(市、区)1044份农户抽样调查数据,采用多群组结构方程模型探究了农地整治权属调整中不同类型农户认知对其行为响应的作用机制。结果表明:农地整治权属调整中农户行为逻辑符合改进计划行为理论,农户的行为态度、主观规范、知觉行为控制交互影响行为意愿,进而转换为行为响应,政府支持在行为意愿和行为响应之间起到部分中介作用。总体上,农户行为响应是"自发性""诱发性"和"约束性"三重行动逻辑的结合,且"自发性"占主导地位。多群组结构方程估计结果表明,纯农型与兼业Ⅰ型农户的行为响应受到"自发性""诱发性"和"约束性"三重影响,兼业Ⅱ型农户受到"自发性"和"诱发性"双重影响,非农型农户仅受到"诱发性"单一影响。因此,为引导农户积极参与农地整治权属调整,应该分别针对各类农户相应地提高其参与的"自发性"和"诱发性",降低"约束性",充分发挥农村社会经济组织的作用,将四种不同类型农户的利益需求统筹考虑,降低权属调整过程中利益协调难度。     

预腐蚀铝合金材料裂纹萌生寿命评估

铝合金在航空工业中广泛应用,因此对于铝合金构件的寿命评估很重要。利用扫描电子显微镜(SEM)原位观测技术,研究了预腐蚀铝合金试件在循环应力作用下的疲劳裂纹萌生和扩展行为。结果表明腐蚀坑对于裂纹萌生扩展行为具有强烈的影响。基于局部应变法,提出了一种预测带有腐蚀损伤的铝合金疲劳裂纹萌生寿命的评估公式。     

Ce-MCM-22分子筛的合成与吸附动力学研究

采用静态水热晶化法,以硅溶胶为硅源、六亚甲基亚胺(HMI)为模板剂,通过掺杂Ce合成了具有MWW层状结构的Ce-MCM-22分子筛。并利用粉末X-射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)等方法对其进行了表征,对其进行了吸附动力学的研究。研究表明,Ce-MCM-22吸附动力方程拟一级方程为y=-0.028 1x-0.136,R2=0.983 4。Ce-MCM-22吸附动力方程拟二级方程为y=0.465 7x+1.2005,R2=0.999 5,说明拟二级反应模型更能真实地反映分子筛吸附亚甲蓝溶液的反应机理。     

城市污染河道沉积物AVS与重金属生物毒性研究

采集珠江三角洲典型城市污染河道佛山水道表层沉积物和上覆水样品,测定了沉积物AVS,Eh,SEM_Pb,SEM_Cd,SEM_Cu,SEM_Zn,SEM_Ni,SEM_Cr,及上覆水Eh,DO.同步进行了底栖动物调查,结合调查结果分析了城市污染河道沉积物AVS与重金属生物毒性的关系.主要研究SEM-AVS判据在判断城市重污染河道重金属生物有效性方面的作用.所测AVS最大值为69.579 μmol/g,最小值为0.339 μmol/g,均值为20.283 μmol/g;各采样站位∑SEM₅（SEM_Pb,SEM_Cd,SEM_Cu,SEM_Zn,SEM_Ni之和）最大值为23.067 μmol/g,最小值为1.062 μmol/g;底栖动物种类和数量均较少,且基本为耐污种,优势种为水丝蚓.13个采样站位中,∑SEM₅-AVS<0的有9个,MDS分析结果显示：这9个站位中的7个底栖动物群落结构相似程度高.这表明重污染河道沉积物重金属的生物毒性与SEM-AVS的值关系密切,SEM-AVS判据在判断重污染区域重金属的生物毒性方面具有较大作用;同时说明重污染河流重金属生物毒性比较复杂,不能完全由SEM-AVS解释.     

两种粒径氧化镍纳米颗粒对小球藻(Chlorella vulgaris)的生物毒性

采用藻类生物毒性测试方法(OECD201)研究了两种粒径氧化镍(NiO)纳米颗粒对小球藻(Chlorella vulgaris)的生物毒性.发现纳米颗粒的毒性与其尺度有关,7 nm NiO的毒性大于20 nm NiO,二者72 h EC50分别为18.01和74.64mgNiO/L.利用扫描电子显微镜(SEM)观察了对...     

太湖沉积物酸可挥发性硫化物分布特征及重金属生物有效性评价

对太湖4个湖区沉积物的酸可挥发性硫化物（AVS）和同步可提取重金属（SEM）的水平和垂直分布特征进行了研究,并对沉积物重金属的潜在生态风险进行初步评价.结果表明,氧化还原电位（Eh）与AVS和SEM含量均无显著相关性;表层沉积物中AVS含量分布在研究区差异较大,变异系数达134.28%;∑SEM含量波动较小,变异系数为...     

优化的甘蔗皮渣吸附居室甲醛

为了研究优化后的甘蔗皮渣吸附居室中的甲醛,本研究通过3种方法处理材料进行吸附甲醛对比,得出简便高效的碱热烫处理,并针对其热烫时间(X1)、pH值(X2)、水浴锅温度(X3)和水浴时间(X4)设置正交实验,得出热烫时间30 min、pH=11、水浴锅温度80℃、水浴时间2.5 h,甘蔗皮渣对甲醛吸附率可达27.91%。通过与活性炭、硅藻纯吸附效果比较,经F检验得出优化处理甘蔗皮渣与硅藻纯吸附效果相当,均极显著优于活性炭。电镜观测出优化甘蔗皮渣与活性炭、硅藻纯同具粗糙、皱褶、疏松多孔结构;傅里叶红外光谱分析出C≡C等基团在甲醛吸附中起主要作用。     

Determinants of workers’ attitude toward low-carbon technology adoption: empirical evidence from Chinese firms

As the main contribution of China’s carbon emissions, low-carbon production in industrial firms becomes an inevitable choice, and industrial firm employees’ attitudes on low-carbon new technology directly influence the results of low-carbon production. Based on the Unified Theory of Acceptance and Use of Technology model, structural equation modeling was used to analyze the main factors influencing firm staff to accept low-carbon new technology. The study reveals that the employee’s social impact, performance expectation, effort expectations and convenient conditions, and employee characteristics are all main factors affecting their acceptance attitudes on low-carbon new technology. And social influence has the largest effect on employees’ acceptance attitudes toward low-carbon new technology. Accordingly, relevant policy recommendations are put forward for the future research direction.     

Structural equation model of the influence of noise annoyance on miners’ unsafe behavior in coal mines

Miners' unsafe behavior (UB) is the main cause of coal mine accidents. Previous research has suggested that excessive noise in tunnels impacts miners' temperaments and safe production behavior. To explore the influence of noise on UB, four different dimensions of noise annoyance were identified: cognitive, emotional, communication, and physical mechanism annoyance. The coal mine noise annoyance scale, miners' unsafe behavior intention (UBI) scale, and miners’ UB scale were developed according to different dimensions. In the first survey, a total of 200 questionnaires were distributed in the two coal mines, and 193 valid questionnaires were recovered. Exploratory factor analysis was conducted, and invalid items were removed according to the analysis results to form the final scale. Then, 500 final scales were distributed in two Chinese coal mines, and 482 valid questionnaires were collected. Confirmatory factor analysis was conducted by collating the data of the second questionnaire. Based upon the structural equation model (SEM), the SEM of the influence of noise annoyance degree on UB and the path analysis with latent variable path analysis with the latent variables (PA-LVs) mediating model of the effect of UBI on UB were established, and the path coefficients with fitting data of the model were analyzed. The results indicated that the four dimensions of coal mine noise annoyance had a strong positive impact on UB, which was reduced by less noise annoyance. In addition, the Bootstrap method was used to verify the mediating method among the four dimensions of noise annoyance, cognitive annoyance, emotional annoyance, with communication annoyance indirectly affecting UB through UBI. The research results provide theoretical support for reducing the UB of miners and improving coal mine safety levels.     

电沉积处理含镉废水的性能研究

电沉积含镉废水考察溶液的不同初始p H、镉的不同初始浓度、电流密度及金属配合物对电沉积效果的影响,利用SEM和XRD对沉积物的表面形貌和物相成分进行分析,研究沉积物金属的存在形式。实验结果表明,p H在1.5~3.5时,溶液中镉的去除效果达到99.3%;一级动力学常数随着初始镉溶液浓度增加而变大;当电流密度为4.46 m A/cm2进行90 min电沉积时反应速率较快且沉积量最大;氨水与镉形成的配合物可以促进电沉积镉的反应速率;对电沉积后的沉积物进行扫描电镜(SEM)和X-射线衍射(XRD)测试。SEM表明,沉积物呈现树枝状的纳米结构。XRD表明,沉积物主要成分为氢氧化镉和镉。