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排序方式: 共有552条查询结果,搜索用时 31 毫秒
71.
Zhongkai Xie Hongyun Luo Shengjie Xu Longhua Li Weidong Shi 《Advanced functional materials》2024,34(17):2313886
Photoreduction carbon dioxide (CO2) and water (H2O) into valuable chemicals is a huge potential to mitigate immoderate CO2 emissions and energy crisis. To date, tremendous attention is concentrated on the improvement of independent CO2 reduction or H2O oxidation behaviors. However, the simultaneous control of efficient electron and hole utilization is still a huge challenge due to the complex cascade redox reactions. Here, a proton turnover exists in the whole CO2 photoreduction process is discovered, which is defined as the pivot to concatenate the hole and electron behaviors. As a demonstration of the concept, the efficient activated hydrogen (*H) production centers of copper (Cu) and rapid hydrogenation centers of nickel (Ni) are coupled by an alloying strategy, and the proton turnover behaviors could be directly determined by adjustment of the molar ratios of CuxNiy. Moreover, Cu3Ni1–TiO2 exhibits the highest electron selectivity of 93.7% for methane (CH4) production with a rate of 175.9 µmol g−1 h−1, while Cu1Ni5–TiO2 reaches up to the highest carbon monoxide (CO) electron selectivity and generation rate at 84.4% and 164.6 µmol g−1 h−1, respectively. Consequently, the experimental and theoretical analysis all clarify the predominate proton turnover effect during the overall CO2 photoreduction process, which directly determines the categories and generated efficiency of C-based products by regulating variable reaction pathways. Therefore, the revelation of the proton turnover pivot could broaden the new sights by bidirectional optimization of dynamics during the overall CO2 photoreduction system, which favors the efficient, selective, and stable photocatalytic CO2 reduction with H2O. 相似文献
72.
机场航站楼行李处理系统是航站楼建设的核心部分之一,其设计尤为重要.而行李分拣系统的设计又是行李处理系统设计的关键,在规划建设过程中,要结合机场的定位、旅客吞吐量、土建条件、投资、运营特点等进行多方面综合考虑;翻盘分拣系统作为一种应用成熟的分拣技术,不仅适用于机场新建航站楼的建设,也能很好地适应到机场旧航站楼的改造.文中研究行李处理系统的分拣模式以及影响行李分拣系统设计的因素,引入国内某机场航站楼的行李处理系统作为案例进行分析,为机场运营方以及行李系统设计方在选择机场行李分拣系统上提供理性的依据. 相似文献
73.
Anayat Bhat Shuang Li Daniel Hammler Martin J. Winterhalder Andreas Marx Andreas Zumbusch 《International journal of molecular sciences》2021,22(16)
The hydrolysis of nucleotides is of paramount importance as an energy source for cellular processes. In addition, the transfer of phosphates from nucleotides onto proteins is important as a post-translational protein modification. Monitoring the enzymatic turnover of nucleotides therefore offers great potential as a tool to follow enzymatic activity. While a number of fluorescence sensors are known, so far, there are no methods available for the real-time monitoring of ATP hydrolysis inside live cells. We present the synthesis and application of a novel fluorogenic adenosine 5′-tetraphosphate (Ap4) analog suited for this task. Upon enzymatic hydrolysis, the molecule displays an increase in fluorescence intensity, which provides a readout of its turnover. We demonstrate how this can be used for monitoring cellular processes involving Ap4 hydrolysis. To this end, we visualized the enzymatic activity in live cells using confocal fluorescence microscopy of the Ap4 analog. Our results demonstrate that the Ap4 analog is hydrolyzed in lysosomes. We show that this approach is suited to visualize the lysosome distribution profiles within the live cell and discuss how it can be employed to gather information regarding autophagic flux. 相似文献
74.
应收账款是企业流动资产的重要组成部分,企业必须加强对应收账款的管理与控制,才能保证这部分资产的安全完整.本文对应收账款管理不善的原因、危害以及如何加强应收账款内部控制进行了阐述,为企业降低风险、加速资金周转提出了可行性建议. 相似文献
75.
Abstract and Key Results
相似文献
– | ▪ The present study empirically investigates employee reward preferences in the cross-national context using a sample drawn from 60 companies in two culturally distinct countries, Finland and China (Hong Kong). |
– | ▪ The results underscore the benefits of adopting a total reward management approach which includes a mix of financial and non-financial rewards. |
– | ▪ We found that a fuller appreciation of reward preferences entails consideration of employee characteristics and other contextual factors beyond culture. |
76.
鲫鱼卵唾液酸糖蛋白对去卵巢大鼠骨质疏松症的改善作用 总被引:1,自引:0,他引:1
目的:从鲫鱼卵中提取唾液酸糖蛋白,研究其对去卵巢大鼠骨质疏松症的改善作用,并探究其作用机理。方法:采用切除大鼠双侧卵巢的方法建立骨质疏松症大鼠模型,灌胃鲫鱼卵唾液酸糖蛋白(400 mg/(kg·d))90 d后,分别检测大鼠尿液骨吸收指标(脱氧吡啶啉、钙、磷)、血清骨吸收指标(抗酒石酸酸性磷酸酶、组织蛋白酶K)、血清骨生成指标(骨源性碱性磷酸酶、骨钙素、Ⅰ型前胶原羧基端前肽)以及血清骨保护素(osteoprotegerin,OPG)、核因子κB受体活化因子(receptor activator for nuclear factor-κB,RANK)、核因子κB受体活化因子配体(receptor activator for nuclear factor-κB ligand,RANKL)含量。结果:鲫鱼卵唾液酸糖蛋白能显著降低骨质疏松症大鼠尿液脱氧吡啶啉(P<0.01)、钙(P<0.01)、磷(P<0.01)含量和血清抗酒石酸酸性磷酸酶(P<0.01)、组织蛋白酶K(P<0.01)活性,防止大鼠骨吸收;显著降低血清骨源性碱性磷酸酶(P<0.01)活性和骨钙素(P<0.01)、Ⅰ型前胶原羧基端前肽(P<0.01)含量,抑制大鼠高骨转换速率;显著上调OPG(P<0.01)含量,下调RANKL(P<0.01)含量,降低RANKL/OPG比值,抑制破骨细胞增殖分化,降低骨吸收。结论:鲫鱼卵唾液酸糖蛋白具有改善去卵巢大鼠骨质疏松症的作用,其作用机理可能与下调RANKL/OPG比值有关。 相似文献
77.
C.J. Mitchell R.F. DSouza A.C. Fanning S.D. Poppitt D. Cameron-Smith 《Journal of dairy science》2017,100(6):4230-4234
Whey protein concentrate (WPC) is a high-quality dairy ingredient that is often included in formulated food products designed to stimulate muscle anabolism. Whey protein concentrate can be affected by UHT processing, and its sensory properties are not compatible with some formulated food products. Microparticulated WPC (mWPC) is a novel ingredient that is resistant to heat treatment and has enhanced sensory properties. When 16 healthy middle-aged men consumed 20 g of either WPC or mWPC, both proteins increased plasma essential AA and leucine concentrations with no detectable difference in curve kinetics. Myofibrillar protein synthesis was increased in both groups for 90 min after ingestion with no difference between groups. Ingestion of mWPC resulted in a muscle anabolic response that was equivalent to that of WPC over the full 210-min measurement period. Formulated products incorporating mWPC or standard WPC would provoke equivalent anabolic responses. 相似文献
78.
京唐炼钢厂的定位是打造高效低成本洁净钢生产平台。高效、低成本与洁净钢这3个基本理念并非相互独立、互不相连,而是相互依存、共同发展。结合京唐炼钢厂实际情况,通过采用六西格玛的方法对京唐炼钢厂钢包周转周期进行改善。结果表明,通过压缩生产组织节奏,同时在转炉出毕至精炼环节取消部分钢种的炉后取样测温操作,可提高物流速度,钢包周转周期缩短了11.7min,其中转炉出毕至连铸开浇的时间从80降低至75min;在目前班产30炉、钢包周转周期为201.4min情况下,合适的钢包周转数量为13个;优化RH合金化过程,并严格控制钢包周转数量(不超过13个),转炉出毕至连铸开浇的时间从75降低至70min。 相似文献
79.
80.
职业高原是个体职业发展中的停滞阶段。为了了解其影响因素,本研究从个人、家庭和组织三个方面分别选取了成就动机,家庭-工作冲突和工作支持三个变量作为职业高原的前因变量,将离职倾向作为职业高原的后果变量,运用结构方程和层次回归的方法对问卷调查数据进行分析。结果发现:成就动机、家庭-工作冲突和工作支持都会显著影响内容高原和层级高原;内容高原会显著增加离职倾向,年龄对层级高原与离职倾向的关系具有负向调节作用。可见,个人的职业发展受到个人、家庭和组织三个方面的影响,而且年龄会影响到个人对自己职业发展的定位。 相似文献