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741.
A signal-amplified mercury sensing biosensor with desired sensitivity was developed through firstly using the GFP mutant with fluorescence increasing response towards Hg2+ as the reporter module. The developed biosensor showed response for Hg2+ in a relatively wide range of 1–10,000 nmol/L, and the detection limit was improved one or two orders of magnitude in comparison with most metal-sensing biosensors in similar constructs. In addition, the biosensor could distinguish Hg2+ easily from multiple metal ions and displayed strong adaptability to extensive pH conditions (pH 4.0–10.0). More importantly, the developed biosensor was able to provide an initial assessment of Hg2+ spiked in the environmental water with the recoveries between 85.70% and 112.50%. The signal-amplified strategy performed by the modified reporter module will be widely applicable to many other whole-cell biosensors, meeting the practical requirements with sufficient sensing performance.  相似文献   
742.
Circular economy (CE) focuses on resource-productivity and eco-efficiency improvement in a comprehensive way, especially on the industrial structure optimization of new technology development and application, equipment renewal and management renovation. The leather industry on the one side boosts the local economic development, on the other side however leads to the tremendous environment pollution and biological chains destruction. The CE model has been implemented as a new way of raw materials, water and energy consumption reduction in the leather industry. Reduce, Reuse, Recycle and Recover of the tannery effluents have been discussed in detail according to the different operation processes. The successful treatment approaches with analysis in the aspects such as wastewater, solid waste, sulfide, Chemical Oxygen Demand (COD), ammonium salt, chloride and chrome of the leather tannery with CE model provide guidance for the sustainable development of leather industry in the future.  相似文献   
743.
744.

The association between co-exposure to multiple metals and renal function is poorly understood. We aimed to evaluate the individual and joint effects of metal exposure on renal function in this study. We performed a cross-sectional study including 5828 participants in Guangxi, China, in 2019. Urine concentrations of 17 metals were detected by inductively coupled plasma mass spectrometry (ICP-MS). Logistic regression model and restricted cubic spline (RCS) were applied to investigate the association of individual metal exposure with renal dysfunction. Weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) were used to assess the co-exposure effects of the metals. Participants with the highest quartile of urinary Cu were at 1.84-fold (95% confidence interval (CI): 1.20–2.87) increased risk of renal dysfunction compared with the lowest quartile. The highest quartiles of urinary Sr, Cs, V, Ba, and Se were associated with 0.27-fold (95% CI: 0.17–0.43), 0.33 (95% CI: 0.19–0.53), 0.41 (95% CI: 0.25–0.65), 0.58 (95% CI: 0.36–0.90), and 0.33 (95% CI: 0.19–0.56) decreased risk of renal dysfunction compared with their lowest quartile, respectively. Furthermore, urinary Ba and Cu were non-linearly correlated with renal dysfunction. The WQS analysis showed that mixed metal exposure was inversely associated with renal dysfunction (OR = 0.47, 95% CI: 0.35–0.62), and Sr accounted for the largest weight (52.2%), followed by Cs (32.3%) in the association. Moreover, we observed a potential interaction between Cu, Cs, and Ba for renal dysfunction in BKMR model. Exposure to Se, Sr, Cs, V, and Ba is associated with decreased risk of renal dysfunction, whereas an increased risk is associated with Cu exposure. Co-exposure to these metals is negatively associated with renal dysfunction, and Sr and Cs are the main contributors to the associations.

  相似文献   
745.
按照应力、疲劳、锈蚀、腐蚀等失效原理,结合由于雷击所造成的具体事故案例,对避雷针(网)进行失效分析。同时,从“人机环”本质安全化的角度,提出了预防、预控、预测的对策。  相似文献   
746.
747.
We investigated the ecophysiology (physiological ecology) of plant succession within a coastal wetland community. The photosynthetic characteristics of six plants were studied; Scirpus mariqueter and Carex scabrifolia in early successional communities, Phragmites communis and Tamarix chinensis in mid successional communities, and Salix matsudana and Imperata cylindrica in later successional communities. Environmental factors were concurrently determined for each community. Relationships between photosynthetic and environmental factors were analyzed by path analysis, and the dependence of photosynthesis on particular environmental factors was shown to vary between plants in the differing successional communities. Ability to cope with irradiation appears to be one of the most important factors influencing plant succession. The increasing stratification of plant communities following colonization of new coastal land necessitates differing physiological strategies and photosynthetic dynamics in the later colonizing plants.  相似文献   
748.
加勒比松1a生幼林氮磷钾不同配比的追肥试验表明,追肥后6a,肥效都极显著;其中以第2a的效果最显著,最大树高、胸径、材积分别比不追肥增加39.1%~52.6%、45.4%~109.3%和34.1%~405.6%;6a后肥效下降,但追肥仍比不追肥的树高、胸径、材积增长8.7%~20%、10.9%~17.9%、31.5%~54.7%。氮磷钾配合施用的效果最佳,施氮磷而缺钾有负效应。当氮磷钾相同配比(N30P30K30)时有特殊的低效应。  相似文献   
749.
战晓  高宝玉  刘斌  许春华  岳钦艳 《环境科学》2010,31(5):1198-1205
选用2种无机高分子混凝剂聚合氯化铁(PFC)和聚合氯化铝(PAC)处理黄河水,考察了混凝剂的投加量对浊度、UV254、DOC和高锰酸盐指数的去除效果,并结合混凝出水的Zeta电位分析其混凝机制.选择粉末活性炭与混凝联用,研究了混凝剂和吸附剂投加量以及二者的投加顺序对有机物去除效果的影响,并对混凝吸附后出水进行加氯消毒,考察水中残余氯随时间的变化.结果表明,2种混凝剂均有较高的浊度去除率(﹥90%).PAC对UV254、高锰酸盐指数和DOC的去除率分别为29.2%、26.1%和27.9%;PFC对三者的去除率分别为32.3%、23.3%和32.9%.PAC在混凝过程中,电中和作用占主导地位;PFC在混凝过程中,吸附架桥和电中和同时发挥作用.混凝-吸附联用处理黄河水样时,有机物的去除率随混凝剂和吸附剂投加量的增加而升高.先混凝后吸附工艺对UV254和DOC的去除效果优于先吸附后混凝工艺.先使用PAC混凝后吸附对UV254和DOC的去除率分别为95.2%和99.9%;对于PFC,先混凝后吸附对UV254和DOC的去除率分别为90.1%和99.9%.但是先投加粉末活性炭能提高矾花的沉降性能,且处理出水在保持持续消毒效果方面优于前者.  相似文献   
750.
微量金属强化餐厨垃圾厌氧消化优化条件研究   总被引:1,自引:0,他引:1  
采用L9(34)正交试验,研究了CoCl2·6H2O、FeCl2 ·4H2O及NiCl2·6H2O投加量对餐厨垃圾厌氧消化总固体(TS)、挥发性固体(VS)和COD减量及累积产气量的影响,确定了三因素的主次顺序及最优工艺条件.结果表明,当CoCl2·6H2O、FeCl2·4H2O及NiCl2·6H2O的投加量分别为0.1 mg/(L·d)、1 mg/(L·d)和0.4 mg/(L·d)时,餐厨垃圾厌氧消化减量及产气效果均最优.在此条件下,经过25 d单相厌氧消化,餐厨垃圾厌氧消化TS、VS、COD的去除率及累积产气量分别达到46.04%、61.02%、58.24%和27 433 mL/L,比不投加微量金属的处理分别高16.98%、28.12%、27.84%和48.63%.Co、Fe和Ni的投加量对餐厨垃圾厌氧消化TS、VS和COD去除率及累积产气量均有显著影响,其中Co的影响达到极显著水平;Co、Fe和Ni对餐厨垃圾厌氧消化减量及产气效率影响的主次顺序及显著性从大到小均为Co、Ni、Fe.  相似文献   
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