悬索桥复合除湿系统可行性分析

在悬索桥防腐方面,高湿环境是导致桥梁腐蚀的主要因素,为解决复杂环境下悬索桥除湿系统适应性差的问题,文章提出了悬索桥冷凝与转轮复合除湿系统,通过数学建模,研究冷凝除湿与转轮除湿的工况适应性,同时对除湿系统进行了可行性分析,提出了悬索桥复合除湿系统的控制策略,为悬索桥防腐除湿提供了新的方案。研究结果对悬索桥防腐应用具有一定的指导意义。

Mg量影响的纳米片负载Pt-In催化异丁烷脱氢性能

采用一步法在Al_(2)O_(3)表面原位生长一系列Mg含量不同的超薄水滑石纳米片,并采用分步浸渍复原法逐步引入助剂In和活性组分Pt,进一步通过焙烧和还原处理制备了负载Pt-In双金属催化剂PtIn/HTR-x(x=0.05,0.1,0.15,0.2 mol·L^(-1))。探究了催化剂及其前体的结构、物化性能与异丁烷直接脱氢性能之间的关系。结果表明,制备母液中Mg^(2+)浓度会影响纳米片厚度,进而影响催化剂结构、还原能力、表面化学状态、表面酸性和脱氢性能。当Mg^(2+)浓度为0.15 mol·L^(-1)时,催化剂获得最佳脱氢性能,其中异丁烯产率高达58%。催化剂PtIn/HTR-0.15优异的活性、选择性、稳定性及良好的抗积炭性能与催化剂高的比表面积、低的强酸量和酸强度、强的金属载体相互作用以及高的表面In^(3+)/In^(0)原子比有关。

阿拉善左旗5.8级地震前地脉动信号特征分析

本文针对2015年4月15日发生在南北地震带北端的阿拉善左旗5.8级地震,利用乌海台、东升庙台、石嘴山台的连续数字地震波形资料,采用快速傅里叶变换对三个台站的2015年4月1日00时—4月15日23时波形数据进行分析,并持续跟踪0~0.25 Hz包络幅值极大值的变化形态。结果显示:(1)在5.8级地震前,震中附近的乌海地震台、东升庙地震台、石嘴山地震台记录的地震波形均出现频谱向低频偏移的现象;(2)三个台站出现低频异常的包络幅值极大值跟踪形态不一致,其中只有乌海台在震前出现明显的持续不稳定异常,异常持续时间约120h;(3)三个台站距离震中由近及远包络幅值极大值的跟踪形态差异明显。

活动断裂围界地块差分运动与强震趋势

在全球板块构造理论中,活动断裂围界地块间的差分运动是板内地壳变形的一个重要特征。在围界地块的活动断裂上,伴随或触发强震发生以响应块体差分运动所积累的能量释放,是地块间差分运动保持平衡的必然自然现象。本文以青藏高原东北缘活动断裂围界地块差分运动和强震资料为基础,进一步阐述上述结论性认识。该区域活动地块有川滇菱形块体、华南块体、巴颜喀拉块体、柴达木块体和岷山块体。

Studies on Catalytic Conversion of Ethylene

FCC dry gas contains a large amount of ethylene. It is used by most of the refineries in China as fuel or simply burned in atmosphere. Few refineries make good use of the dry gas, so the precious ethylene resource in the dry gas is wasted. In this article, the possibility of catalytic conversion of ethylene to C3, C4, and some high molecular weight hydrocarbons in a fixed bed micro-reactor using LTB-1 catalyst, with pure ethylene as feedstock was studied. Effects of reaction temperature, reaction pressure, and feedstock flow rate, on the conversion of ethylene and the distribution of products were investigated to determine the proper reaction parameters to be used in practice. Good results indicate that this study may provide a new way of using the ethylene resource in the FCC dry gas.

Effect of acid density of HZSM-5 on the oligomerization of ethylene in FCC dry gas

The oligomerization of ethylene in FCC dry gas over HZSM-5 catalyst with different Si/A12 ratios was studied. The effect of acid density of catalyst on the oligomerization of ethylene was discussed. By increasing the acid density of catalyst, ethylene conversion showed a linear increase, while the yields of olefins decreased when the acid density of catalyst exceeded 0.14mmolNH3/g owing to a promotion of hydrogen transfer reaction. Through comparing the average distance between acid sites on catalyst with kinetic diameters of olefins, it was found that the dimerization of ethylene was not restrained by the sparse distribution of acid sites, while the hydrogen transfer reaction of C3 and C4 olefins was limited. On these bases, a conclusion is proposed that the dimerization of ethylene proceeded via Eley-Rideal mechanism, while the hydrogen transfer reaction of C3 and C4 olefins followed the Langmuir-Hinshelwood mechanism.

Inhibition of corneal neovascularization by topical application of nintedanib in rabbit models

AIM:To evaluate the potential efficacy and mechanisms of nintedanib in corneal neovascularization(NV)in rabbit models.METHODS:Corneal NV was induced using 1 mol/L Na OH.Rabbits(n=21)were randomized to 3 groups:Group 1 were treated with 0.9%NaCl,Group 2 with Avastin(5 mg/mL),and Group 3 with nintedanib(1 mg/mL).All treatments star ted 1 d af ter alkaline burns and were topically performed 3 times a day for 2 wk.Photographs were taken on a slit lamp microscope on day 7 and 14.The NV area,the length of the vascularization and angiogenesis index(AI)were used to evaluate the corneal NV.On day 14,the immunohistochemical(IHC)studies of the cornea were examined.Western blot was performed to test the expression levels of vascular endothelial growth factor(VEGF),Akt,p-Akt,P38,p-P38,MMP-2 and MMP-9.RESULTS:The corneal NV area,vessel length and AI in Group 3 were significantly lower than Group 2,with both being lower than Group 1.IHC staining showed that VEGF was significantly overexpressed in the epithelium and stroma of cornea following alkaline burns.In contrast,the level of VEGF was significantly suppressed in both Group 2 and Group 3.Western blot results further confirmed that,compared with Group 1,Group 3 had significantly reduced expressions of VEGF,Akt,p-Akt,p-P38,MMP-2,and MMP-9 in corneal tissues.Trends of lower levels of MMP-2,AKT,and p-AKT in Group 3 than Group 2 were identified.CONCLUSION:Nintedanib and Avastin can effectively inhibit corneal NV,with P38 MAPK and AKT signaling pathways being possibly involved.Nintedanib seems more effective than Avastin and has the potential to be a novel therapy for preventing corneal NV.

Comsol模拟金属离子浓度对电镀铜锌合金的影响

以酒石酸钾钠体系电镀铜锌合金为对象,建立三维电镀模型,根据实际工艺参数设置边界条件,采用Comsol多物理场软件对电解液中离子的扩散过程进行数值模拟,以研究金属离子浓度对阴阳极间电解质浓度及阴极边界镀层厚度的影响,最终为电镀铜锌合金的仿真研究提供理论分析基础及为工艺的优化提供理论依据。

Evaluation of Natural Radioactivity in Marine Sand Deposits from Offshore China

Natural radioactivity is very important for the assessment of the marine sand property and usability. By using gamma spectrometry, the concentration of the natural radionuclides 226Ra, 232Th and 40K have been measured in marine sand deposits from Liaodong Bay (LDB), North Yellow Sea (NYS), Zhoushan area (ZS), Taiwan Shoal (TS) and Pearl River Mouth (PR), offshore China, which are potential marine sand mining areas. The radiation activity equivalent (Raeq), indoor gamma absorbed dose rate (DR), annual effective dose (HR), alpha index (Ia), gamma index (Ig), external radiation hazard index (Hex), internal radiation hazard index (Hin), representative level index (RLI), excess lifetime cancer risk (ELCR) and annual gonadal dose equivalent (AGDE) associated with the natural radionuclides are calculated to assess the radiation hazard of the natural radioactivity in the marine sands offshore China. From the analysis, it is found that these marine sands are safe for the constructions. The Pearson correlation coefficient reveals that the 226Ra distribution in the marine sands offshore China is controlled by the variation of the 40K concentration. Principal component analysis (PCA) yields a two-component representation of the entire data from the marine sands, wherein 98.22% of the total variance is explained. Our results provide good baseline data to expand the database of radioactivity of building materials in China and all over the world.

Analysis of Drought Characteristics in the Inland Areas of Shandong Province from 1960 to 2013

Drought is one of the major meteorological disasters affecting the climate in China.In this paper,the interannual variation and seasonal distribution changes of drought at different time scales were analyzed with the standardized precipitation index( SPI) as the drought evaluation criterion to the precipitation data of the 5 meteorological stations of Jinan,Tai'an,Yiyuan,Shen County and Yanzhou from 1960 to 2013.The results showed that:(1) the frequency of drought was low in spring and summer in inland areas of Shandong Province,while autumn had frequent occurrences of moderate drought,and winter had frequent occurrences of heavy and severe droughts.(2) In the 1960 s,1980 s and early 21^(st) century,the number of droughts increased significantly,and the SPI values showed a significant decrease.(3) The 3-month time scale range was wide,during which the frequency of occurrence was high.The trend of SPI changes at the 12-month time scale was affected by the accumulation of antecedent precipitation,and the change was slow.The research results can provide a scientific reference for arid climate analysis and water resources management in agriculture and production in inland areas of Shandong Province.

Study on Spatial Variation Characteristics of Air Pollutants in Typical Cities of Shandong Province

Air pollution has become the most concerned regional environmental problem in China at present.According to the data of typical cities in Shandong Province from January,2014 to December,2015,the air quality status,pollution status and spatial variation characteristics of air pollutants were classified and analyzed,thereby providing a scientific basis for air pollution control.The conclusions of this study are as follows:(1) PM_(2.5) was the most important atmospheric pollutant in Shandong Province;(2) Qingdao had the best air quality with a good air quality rate of 73.7%,while Jinan had the worst air quality with a good air quality rate only of 31.3%; and(3) the days with heavy pollution were mainly concentrated in winter,mainly due to coal-fired heating in winter.

悬索桥主缆联合除湿系统设计与实验研究

悬索桥主缆防腐效果对悬索桥使用寿命起着关键性作用。本文针对悬索桥主缆传统转轮除湿系统高温高湿工况下除湿能效差和再生能耗高的缺点,结合悬索桥主缆除湿需求和工程实际,提出了将冷凝除湿与转轮除湿结合的联合除湿系统,同时引入分离式热管充分利用冷凝热。本文通过实验对两种除湿系统的除湿能效和节能水平进行对比分析,研究表明:在进风温度26~34℃、相对湿度60%~80%工况下联合除湿系统的出风相对湿度均低于25%。相同工况下联合除湿系统除湿量、除湿率和单位功率除湿量均高于转轮除湿系统。在温度34℃、相对湿度80%工况下,联合除湿系统除湿量最高为10.12 g/kg,单位功率最大为0.89 kg/kW·h。在温度26℃、相对湿度60%工况下,联合除湿系统除湿率最高为64%。相较于传统转轮除湿系统,采用分离式热管的联合除湿系统节能率随着温度和含湿量的增加,呈现上升趋势,在温度30℃、相对湿度80%工况下,系统节能率最大为8.32%。

Surface promotion of copper nanoparticles with alumina clusters derived from layered double hydroxide accelerates CO_(2)reduction to ethylene in membrane electrode assemblies

Electrochemical CO_(2)reduction has the vast potential to neutralize CO_(2)emission and valorizes this greenhouse gas into chemicals and fuels under mild conditions.Its commercial realization hinges on catalyst innovation as well as device engineering for enabling reactions at industrially relevant conditions.Copper has been widely examined for the selective production of multicarbon chemicals particularly ethylene,while there is still a substantial gap between the expected and the attainable.In this work,we report that the surface promotion of copper with alumina clusters is a viable strategy to enhance its electrocatalytic performance.AlOx-promoted Cu catalyst is derived from Cu-Al layered double hydroxide nanosheets after alkali etching and cathodic conversion.It can catalyze CO_(2)to ethylene and multicarbon products with great selectivity and stability far superior to pristine copper in both an H-cell and a zero-gap membrane electrode assembly(MEA)electrolyzer.The surface promotion effect is understood via computational simulations showing that alumina clusters can stabilize key reaction intermediates(*COOH and*OCCOH)along the reaction pathway.

AIFM1 variants associated with auditory neuropathy spectrum disorder cause apoptosis due to impaired apoptosis-inducing factor dimerization

Auditory neuropathy spectrum disorder(ANSD)represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function,but with the preservation of outer hair cell function.ANSD represents up to 15%of individuals with hearing impairments.Through mutation screening,bioinformatic analysis and expression studies,we have previously identified several apoptosis-inducing factor(AIF)mitochondria-associated 1(AIFM1)variants in ANSD families and in some other sporadic cases.Here,to elucidate the pathogenic mechanisms underlying each AIFM1 variant,we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats(CRISPR)/CRISPR-associated protein 9(Cas9)system and constructed AIF-wild type(WT)and AIF-mutant(mut)(p.T260A,p.R422W,and p.R451Q)stable transfection cell lines.We then analyzed AIF structure,coenzyme-binding affinity,apoptosis,and other aspects.Results revealed that these variants resulted in impaired dimerization,compromising AIF function.The reduction reaction of AIF variants had proceeded slower than that of AIF-WT.The average levels of AIF dimerization in AIF variant cells were only 34.5%-49.7%of that of AIF-WT cells,resulting in caspase-independent apoptosis.The average percentage of apoptotic cells in the variants was 12.3%-17.9%,which was significantly higher than that(6.9%-7.4%)in controls.However,nicotinamide adenine dinucleotide(NADH)treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells.Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD,and introduce NADH as a potential drug for ANSD treatment.Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.

悬索桥主缆用复合除湿系统性能分析

对悬索桥主缆用复合除湿系统进行了数值研究,分析了蒸发温度和再生温度对系统性能的影响,计算了夏季工况下的运行能耗。结果表明:蒸发温度与除湿能耗比(SMER)存在优化关系。进风工况35℃,85%,蒸发温度22℃时,SMER达到最大值2.12 kg/(kW·h),应控制系统的蒸发温度为22℃。提高再生温度可以增加除湿量,但会导致SMER降低。复合除湿系统夏季平均运行能耗为3902.7 kW·h,与悬索桥传统转轮除湿系统相比,节能率为70%,具有良好的节能潜力和应用前景。

CO electroreduction:What can we learn from its parent reaction,CO_(2) electroreduction?

The CO electroreduction reaction(CORR)represents an important piece of the decarbonization puzzle and is heavily inspired by research on the CO_(2) electroreduction reaction(CO_(2)RR).Compared to its parent reaction,CORR circumvents the(bi)carbonate issue that plagues CO_(2)RR,potentially enabling greater stability and selectivity toward C2þproducts,particularly oxygenates.Despite its unique potential,CORR still suffers from unsatisfactory performance.In this perspective article,we aim to provide a concise and informative overview of CORR and its close connection with CO_(2)RR.We start by briefly presenting the two reactions’similarities and differences,then discussing several catalyst design strategies.This is followed by highlights of the latest results on device integration and engineering.Finally,we offer our thoughts about possible future research opportunities that could render this technology a practical reality.

大学生创新创业项目的选择——以蟾皮画为例

创新创业是基于创新基础上的创业活动。大学生创新创业训练项目的实施能够使大学生的创新意识得以实现,创业能力得到锻炼。大学生创业能否成功,很大程度上取决于项目的选择。创新性是项目选择的核心要素,创新支持创业,创业升华创新。蟾皮作为全新的装饰画制作材料首次出现在大众的视野内,将蟾皮通过剪刻等传统手法加工结合现代元素制作而成的蟾皮画为国内首创。该文以蟾皮画为例,从市场需求、创新性、寓意及创业成本的角度探讨了蟾皮画作为大学生创新创业项目的优势。

Effects of applying lactic acid bacteria to the fermentation on a mixture of corn steep liquor and air-dried rice straw

This study was to determine the fermentation quality of a mixture of corn steep liquor(CSL)(178 g/kg wet basis) and air-dried rice straw(356 g/kg wet basis) after being treated with inoculants of different types of lactic acid bacteria(LAB). The treatments included the addition of no LAB additive(control),which was deionized water; homo-fermentative LAB alone(^(ho)LAB), which was Lactobacillus plantarum alone), and a mixture of homo-fermentative and hetero-fermentative LAB(^(he+ho)LAB), which were L. plantarum, Lactobacillus casei, and Lactobacillus buchneri. The results showed that the inoculation of the mixture of CSL and air-dried rice straw with ^(he+ho)LAB significantly increased the concentration of acetic acid and lactic acid compared with the control(P < 0.05). The addition of ^(he+ho)LAB effectively inhibited the growth of yeast in the silage. The concentration of total lactic acid bacteria in the ^(he+ho)LAB-treated silage was significant higher than those obtained in other groups(P < 0.05). The duration of the aerobic stability of the silages increased from 56 h to >372 h. The control group was the first to spoil, whereas the silage treated with ^(he+ho)LAB remained stable throughout the 372 h period of monitoring. The results demonstrated that the ^(he+ho)LAB could effectively improve the fermentation quality and aerobic stability of the silage.

Assessing the relative role of climate change and human activities in desertification of North China from 1981 to 2010

Desertification is a severe environmental problem induced by both climate change and human activities.This study assessed the relative contribution of climate change,human activities,and different climatic and anthropogenic factors in desertification reversion and expansion of North China from 1981 to 2010.The results showed that the desertification of North China had changed significantly over the past 30 years;desertification reversion and expansion covered an area of 750,464 km^2, and the spatial distribution of these regions exhibited considerable heterogeneity.For desertification reversion, climate change and human activity accounted for 22.6% and 26%,respectively of total reverted land.Wind speed reduction and the improvement ofhydrothermal conditions were the most important climatic factors for desertification reversion in the arid region of Northwest China (ARNC) and the Three-River Headwaters region (TRHR),and the reduction in grassland use intensity was the most important anthropogenic factor related to desertification reversion in Inner Mongolia and regions along the Great Wall (IMGW). For desertification expansion,the relative role of climate change was more obvious,which was mainly attributed to the continuous reduction in precipitation in eastern IMGW, and the increase in grassland use intensity was the main factor underlying regional human-induced desertification expansion.

Prediction of instantaneous driving safety in emergency scenarios based on connected vehicle basic safety messages

Purpose–Basic safety message(BSM)is a core subset of standard protocols for connected vehicle system to transmit related safety information via vehicle-to-vehicle(V2V)and vehicle-to-infrastructure(V2I).Although some safety prototypes of connected vehicle have been proposed with effective strategies,few of them are fully evaluated in terms of the significance of BSM messages on performance of safety applications when in emergency.Design/methodology/approach–To address this problem,a data fusion method is proposed to capture the vehicle crash risk by extracting critical information from raw BSMs data,such as driver volition,vehicle speed,hard accelerations and braking.Thereafter,a classification model based on information-entropy and variable precision rough set(VPRS)is used for assessing the instantaneous driving safety by fusing the BSMs data fromfield test,and predicting the vehicle crash risk level with the driver emergency maneuvers in the next short term.Findings–Thefindings and implications are discussed for developing an improved warning and driving assistant system by using BSMs messages.Originality/value–Thefindings of this study are relevant to incorporation of alerts,warnings and control assists in V2V applications of connected vehicles.Such applications can help drivers identify situations where surrounding drivers are volatile,and they may avoid dangers by taking defensive actions.