Nickel carcinogenesis mechanism: cell cycle dysregulation

Environmental Science and Pollution Research - Nickel (Ni) is a widely distributed metal in the environment and an important pollutant due to its widespread industrial applications. Ni has various...     

Characteristics of colloids and their affinity for heavy metals in road runoff with different traffic in Beijing,China

The characteristics of colloids in urban road runoff with different traffic in Beijing, China, such as concentration, particle size, chemical property, and affinity for heavy metals were determined. The concentration of colloids was high, and an evident first flush effect was found in the runoff of road with heavy traffic. A large portion of colloids were distributed in the range of 1–10 μm. Traffic activity, rainfall intensity, and time of sample collection would not change the size distribution of colloids in the road runoff. The chemical property of colloids in the road runoff would be influenced by the soil erosion nearby green space, causing the content of organic colloids was high. The correlation coefficient between the concentration of colloids in colloidal fractions and the concentration of heavy metals (Cu, Zn, Cd, Pb, Fe, and Mn) in the road runoff with different traffic decreased with the same sequence from 0.02–0.2 μm, 0.2–0.45 μm, 0.45–1 μm, to 1–10 μm, suggesting that the heavy metals had stronger affinity for the colloids with small size. The concentration of Cu, Pb, and Zn exhibited significant correlations with the concentration of organic colloids in the road runoff. More aggregated spherical particles were found in the TEM image of the road runoff with heavy traffic. Zeta potentials and RMV data showed that the colloids with smaller size and the colloids in the road runoff with lighter traffic were much more stable.

     

劳动争议仲裁管辖探析

劳动争议发生后,需要向劳动争议仲裁委员会申请仲裁的,究竟应向哪一级、哪一个劳动仲裁委员会申请仲裁;各级争议仲裁委员会、同级仲裁委员会处理劳动争议案件的分工和权限如何确定,这就涉及到劳动争议仲裁管辖的问题.     

Studies on catalytic reduction of nitrate in groundwater

Catalytic reduction of nitrate in groundwater by sodium formate over the catalyst was investigated. Pd-Cu/γ-Al₂O₃ catalyst was prepared by impregnation and characterized by brunauer-emmett-teller (BET), inductive coupled plasma (ICP), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX). It was found that total nitrogen was effectively removed from the nitrate solution (100 mg/L) and the removal efficiency was 87%. The catalytic activity was affected by pH, catalyst amount used, concentration of sodium formate, and initial concentration of nitrate. As sodium formate was used as reductant, precise control in the initial pH was needed. Excessively high or low initial pH (7.0 or 3.0) reduced catalytic activity. At initial pH of 4.5, catalytic activity was enhanced by reducing the amount of catalyst, while concentrations of sodium formate increased with a considerable decrease in N₂ selectivity. In which case, catalytic reduction followed the first order kinetics.     

膜分离技术处理高浓度味精废水试验研究

利用膜分离技术，将高浓度味精废水分离为数量不等的滤过水和浓缩水，浓缩水可再次开发利用，滤过水可直接进行生化处理，使外排废水达到国家规定标准。     

飞机字符显示的编码方式

着重论述了各类单个字符及显示格式的编码方式，有些编码方式在实际应用中已得证实，有些仍待研究解决。只有不断探索，才能在“人－机－环”系统中，使飞行员和“机器”能有效而可靠地工作，即“人的特性”与“机器”能有效配合，更好地发挥飞行员的技术和战术水平。由此国军标也将随着科学技术的进步而更加充实、完善、先进、合理。     

Effects of environmental contaminants on fertility and reproductive health

Recent research indicates that the human infertility rate is increasing. Although various reasons have been hypothesized for the growing infertility rate, environmental contaminants are potentially important causal agents associated with this change. Chemical contaminants are widespread throughout our environment and human exposure is virtually unavoidable. The overall contribution of environmental exposure to infertility is unknown, but studies involving occupational exposure, together with results from animal experiments, suggest that environmental contaminants may adversely affect fertility. We reviewed the adverse effects of environmental exposure on fertility and related reproductive outcomes. Environmental contaminants covered in this review include heavy metals, organic solvents, pesticides and endocrine disrupting chemicals. It is hoped that this review will highlight the need for further research in this area.     

地膜覆盖和施氮对菜地CO2通量的影响

为了探讨地膜覆盖和不同施氮处理对菜地生态系统CO₂净交换通量（Net CO₂ Ecosystem Exchange,简称NEE）、生态系统呼吸通量（Ecosystem Respiration,简称ER）及总初级生产力（Gross Primary Productivity,简称GPP）的影响,以辣椒-萝卜轮作菜地为研究对象,采用静态明/暗箱-气相色谱法,进行了为期1 a（2014年5月-2015年4月）的田间原位观测.试验设置8个处理,分别为常规无氮（CN0）、覆膜无氮（MN0）、常规低氮（CN1）、覆膜低氮（MN1）、常规中氮（CN2）、覆膜中氮（MN2）、常规高氮（CN3）、覆膜高氮（MN3）.结果表明,辣椒季累积NEE最大值分别为CN3和MN3处理下的-30.96和-29.83 t·hm^-2,累积ER排放量最大值分别为CN1和MN1处理下的40.18和39.16 t·hm^-2,累积GPP最大值分别为CN3和MN3处理下的70.60和68.61 t·hm^-2;萝卜季累积NEE最大值分别为CN3和MN3处理下的-22.25和-24.88 t·hm^-2,累积ER排放量最大值分别为CN2和MN2处理下的17.00和19.43 t·hm^-2,累积GPP最大值分别为CN3和MN3处理下的37.92和43.80 t·hm^-2.在两个生长季中,覆膜及覆膜和施氮的交互作用只对辣椒季中ER有显著影响,对于NEE和GPP均无显著影响（p>0.05）;施氮显著提高了菜地生态系统NEE和GPP而降低了辣椒季ER（p<0.05）,并且这种增加或降低效应随着施氮量的提高而逐渐增强.本研究中菜地呈现碳汇并随着施氮水平的提高碳汇逐渐增强,而覆膜对CO₂固定无显著影响,表明常规高氮的农田管理措施能够提高西南地区代表性的辣椒-萝卜轮作菜地的固碳潜力,对该地区农田生态系统碳的源/汇功能具有一定的参考意义.     

Mechanochemical synthesis of MAPbBr3/carbon sphere composites for boosting carrier-involved superoxide species

Lead halide perovskites MAPbX₃ (MA = CH₃NH₃ or Cs; X = I, Br, Cl) are well considered to be potential candidates for photocatalytic reaction due to its excellent photoelectrical properties, but they still suffer from the low charge separation efficiency and slow catalytic reaction dynamics. To tackle the drawbacks, herein, MAPbBr₃/carbon sphere (CS) composite photocatalysts using glucose as the carbon source were elaborately designed and fabricated via a dry mechanochemical grinding process. The interfacial interaction Pb-O-C chemical bonds were constructed between MAPbBr₃ and the carbon sphere surface containing organic functional groups. By optimizing the content of CSs, the enhanced photocatalytic degradation kinetic rate of Malachite Green (MG) pollutants (92% within 20 min) for MAPbBr₃/CS_x (x = 17 wt.%) is about 3.6-fold of that for pristine MAPbBr₃, which is attributed to the corporative adsorption and enhanced carrier transportation and separation of MAPbBr₃/CS_x. Furthermore, the possible degradation mechanism was proposed on basis of the electrochemical, mass spectrometry and optical characterization results. Owing to the robust interfacial interaction, effective electron extraction rate (k_et = 4.6 × 10⁷ sec^?1) from MAPbBr₃ to CS can be established, which driven oxygen activation where superoxide radicals (?O₂^?) played an important role in MG degradation. It is expected that mechanochemistry strategy may provide a new route to design efficient lead halide perovskite-carbon or metal oxide or sulfide composite photocatalysts.     

群众路线指导下高职课堂教学改革研究

针对高职课堂教学中出现的重理论教学、轻实践教学、忽视学生学习需求的多样性和个体差异性等现实问题,以党的群众路线为指导,提出高职课堂教学改革应遵循"以学生需求为根本、以课堂教学质量为基础"的基本原则,坚持走学生路线,学会站在学生的立场看问题的教学方法,大力倡导"相信学生,依靠学生,从学生中来,到学生中去"的基本教学途径,努力提高学生对教学工作的认可度、满意度,争取更加良好的课堂教学效果。