地球自转速率年代际周期分量的时变特性

利用日长的年均值序列计算了1800～2002年间地球自转速率的年代际周期分量的参数，用小波变换方法分析了主要的年代际周期分量随时间的变化，发现它们均具有时变的特征。文章认为，在研究地球自转与地球物理现象和自然灾害现象的关系时，应特别注意地球自转变化的周期分量的时变性。     

利用生物转轴技术处理现河首站采油废水

针对胜利油田现河首站采油废水排放口的污染现状,提出了利用生物转轴技术处理采油废水。研究结果表明:现河首站采油废水污染严重且达标治理难度极大,采用传统物化处理工艺已不能使其处理达标。生物转轴技术具有技术上先进可行,处理效率高,处理成本低,可操作性强等多种优势,可使采油废水达标排放。     

煤矿安全从业人员工作满意感与应激水平、自我效能感的关系

运用问卷法,以43名国有煤矿安全从业人员为研究对象,探讨了在煤矿这一特定环境下的工作人员其工作满意感、应激水平和自我效能感的关系。结果发现应激水平能负向预测工作满意感,自我效能感不仅能正向预测工作满意感,还能调节应激水平对工作满意感的影响,较高的自我效能感能使应激水平对工作满意感的负效应转为正效应。根据笔者研究结果,提出了减少工作应激刺激、提供培训提高员工自我效能感、制定合理的人员安置和促进员工发展的人事制度,以增强员工的工作满意感的建议。     

Modelling impacts of alternative farming management practices on greenhouse gas emissions from a winter wheat–maize rotation system in China

Agricultural production plays an important role in affecting atmospheric greenhouse gas concentrations. Field measurements were conducted in Quzhou County, Hebei Province in the North China Plains to quantify carbon dioxide (CO₂) and nitrous oxide (N₂O) emissions from a winter wheat–maize rotation field, a common cropping system across the Chinese agricultural regions. The observed flux data in conjunction with the local climate, soil and management information were utilized to test a process-based model, Denitrification–Decomposition or DNDC, for its applicability for the cropping system. The validated DNDC was then used for predicting impacts of three management alternatives (i.e., no-till, increased crop residue incorporation and reduced fertilizer application rate) on CO₂ and N₂O emissions from the target field. Results from the simulations indicated that (1) CO₂ emissions were significantly affected by temperature, initial SOC, tillage method, and quantity and quality of the organic matter added in the soils; (2) increases in temperature, initial SOC, total fertilizer N input, and manure amendment substantially increased N₂O emissions; and (3) temperature, initial SOC, tillage, and quantity and quality of the organic matter added in the soil all had significant effects on global warming. Finally, five 50-year scenarios were simulated with DNDC to predict their long-term impacts on crop yield, soil C dynamics, nitrate leaching losses, and N₂O emissions. The modelled results suggested that implementation of manure amendment or crop residue incorporation instead of increased fertilizer application rates would more efficiently mitigate GHG emissions from the tested agro-ecosystem. The multi-impacts provided a sound basis for comprehensive assessments on the management alternatives.     

某石化企业化验岗位工人苯系物接触现状调查

为了解某石化企业化验岗位工人与苯系物接触现状,对该企业6个化验岗位进行了苯系物职业危害因素检测。结果表明：化工厂一工段油品室、乙烯化验车间、乙烯质检中心油品组苯超标严重。通过综合分析,对今后该企业化验岗位苯系物危害因素治理提出了建议。     

氮肥水平对不同土壤N2O排放的影响

摘要：鉴于N2O排放量占施用氮肥量的比例即N2O排放系数还有很大不确定性,室外盆栽试验于2002~2003年在南京农业大学实施,选取3个供试土壤,各土壤设置对照和低、中、高氮肥水平,全年施尿素量 (以N计) 分别为334 kg/hm2、670 kg/ hm2、1004 kg/hm2。结果表明,水稻生长季,各个土壤的N2O累积排放量与其对照相比的增加量在低、中、高氮肥水平间无明显差异;而小麦生长季,随氮肥施用量增加,各个土壤的N2O累积排放量与其对照相比的增加量在3种氮肥水平之间的差异显著。整个稻麦轮作系统,随氮肥用量的增加明显促进麦田N2O的排放。无论水稻或小麦生长季,对照3个土壤的N2O累积排放量并无显著差异,F土壤（江苏溧水）,G土壤（江苏涟水）和H土壤（江苏农科院）的N2O累积排放量,在水稻生长季分别为168mg/m2、127 mg/m2和146 mg/m2;小麦生长季,分别为134 mg/m2、124 mg/m2和168 mg/m2。在施氮肥后,3个土壤的N2O排放量出现差异,如在中氮水平下,小麦生长季,F土壤、G土壤和H土壤N2O累积排放量分别为976 mg/m2、744 mg/m2和626 mg/m2。稻麦轮作生长季内,在低氮与中氮两个水平下,不同土壤间N2O排放系数存在显著差异。以一个稻麦轮作周期为时间尺度,F土壤,G土壤和H土壤总的N2O排放系数分别为1.1%±0.23%, 0.75%±0.17%和1.01%±0.11%,表明不同土壤对N2O排放系数的影响不同。     

Are “job hoppers” trapped in hedonic treadmills? Effects of career orientations on newcomers' attitude trajectories

Joining a new organization to change jobs is an influential event in an employee's career. Thus, inter-organizational job changes have sparked growing scholarly interest, especially in the temporal dynamics involved in detaching from organizations and adapting to new ones. While it is widely accepted that employees adapt differently to job changes, the influence of employees' career orientations on changes in job attitudes has not yet been considered. This is surprising given that a key difference between self-centered and organization-centered career orientations is a positive attitude toward job changes. Building on hedonic adaptation, we examined how career orientations influence changes in job satisfaction and turnover intention throughout a job change. We compared self-centered and organization-centered employees using random coefficient modeling on two longitudinal data sets with voluntary job changers. Our results illustrate that self-centered career orientations foster a stronger decline in job satisfaction with the new employer, as well as a larger increase in turnover intention, than organization-centered career orientations. In contrast, employees with organization-centered career orientations experienced an upward trend in job satisfaction toward the end of the first year. Our findings offer important implications for research on the determinants of job attitude trajectories when individuals join a new organization.     

体力疲劳对建筑工人不安全行为的影响效应研究

为降低建筑安全事故发生的概率,从建筑工人的不安全行为入手,构建体力疲劳与不安全行为理论影响模型,通过结构方程模型(structural equation model, SEM)与层次回归法实证检验二者间的影响关系。研究结果表明：体力疲劳直接正向影响建筑工人不安全行为,且通过工作倦怠作为中介因素间接影响建筑工人不安全行为;而心理资本反向调节体力疲劳与工作倦怠的关系。研究结果揭示体力疲劳与不安全行为的中介调节机制,丰富和完善二者的间接及整体关系,有助于管理者有效防控建筑工人的不安全行为。     

控释掺混肥对麦玉轮作体系作物产量和温室气体排放的影响

为探究控释掺混肥一次性施肥对华北平原麦玉（冬小麦和夏玉米）轮作体系作物产量和温室气体排放的影响,于2020~2022年在德州市现代农业科技园区开展田间试验.冬小麦和夏玉米均设不施氮对照（CK）、农户习惯施氮（FFP）、优化施氮（OPT）、CRU1（包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为5∶5和3∶7）、CRU2（包膜尿素与普通尿素在冬小麦和夏玉米上的掺混比例分别为7∶3和5∶5）共5个处理.对比分析了不同处理的作物产量、氮肥利用效率、施肥经济效益和温室气体排放的差异.结果表明,施氮可显著提高麦玉轮作系统单季和周年作物产量（P<0.05）.与FFP相比,CRU1和CRU2处理的夏玉米、冬小麦和周年产量分别提高了0.4%~5.6%、-5.4%~4.1%和-1.1%~3.9%（P>0.05）;氮肥吸收利用率、氮肥农学利用率和氮肥偏生产力分别提高了-8.6%~43.4%、2.05~6.24 kg·kg^-1和4.24~10.13 kg·kg^-1;周年净收益提高了0.2%~6.3%.施氮显著增加了麦玉轮作体系的土壤N₂O和CO₂的周年排放（P<0.05）,但对CH₄周年排放没有影响（第1年FFP处理除外）.CRU1和CRU2处理的土壤N₂O周年排放总量较FFP处理显著降低了23.4%~30.2%（P<0.05）.施氮显著增加了麦玉轮作体系的周年全球增温潜势（GWP）（P<0.05）,但各施氮处理通过提高作物产量降低了温室气体排放强度.与FFP相比,CRU1和CRU2处理的周年GWP降低了9.6%~11.5%（P<0.05）,周年温室气体排放强度（GHGI）降低了11.2%~13.8%（P>0.05）.综上所述,一次性减量施用控释掺混肥在减少氮肥和人工投入、提高作物产量、经济效益和降低温室气体排放方面具有积极作用,是促进华北平原粮食作物清洁生产的有效氮肥管理措施.     

不同立地管理措施对2代杉木人工林某些土壤性质的影响

在29a生1代杉木林采伐迹地上用5种林地处理方式进行2代杉木人工林营造,并研究处理后3a土壤体积质量、pH值、有机质的变化.结果表明BL3BM0(收获树干和树皮、加倍采伐剩余物)处理方式对降低土壤体积质量和提高土壤pH值的作用最大,是最佳的立地管理措施,而BL0BM0(收获地上所有有机质)处理的作用正相反,增加土壤体积质量和降低土壤pH值的幅度最大,对土壤肥力的维持最为不利.火烧采伐剩余处理并非最差的立地管理方式.