竹格填料与PVC填料在冷却塔中的节能效率与环境影响研究

本研究针对电厂冷却塔领域的能源成本及水资源短缺等问题,系统分析了新兴竹格淋水填料的节能效率及对环境影响等特性,并与市场占有率最高的PVC填料进行了对比。结果发现,竹格填料的阻力性能优于PVC填料,而热力性能较差;在6个月实际应用试验中,使用竹格填料的电厂,比使用PVC填料节约529.2 t标煤;生命周期评价结果显示,PVC填料的能源需求总量(CED)为3420 MJ,竹格填料的能源需求总量仅为561 MJ,比PVC填料减少6倍;从环境影响指数(BEES)看,PVC填料替换为竹格填料后,各主要影响指标降低了1.5~10.5倍不等。结果表明,竹格填料是替换PVC填料的良好选择,具有很好的推广价值。

Comparative growth, dry matter accumulation and photosynthetic rate of seven species of Eucalypt in response to phosphorus supply

Plantations of eucalypts as short-rotation tree crops are rapidly expanding in tropical and sub-tropical regions, including southern China, where the soils are acidic and available phosphorus （P） is limited. We investigated seedling growth, dry matter accumulation, and the dynamics of photosynthetic rate and chlorophyll content of seven Eucalyptus spe- cies/hybrids （E. dunnii, E. grandis, E. grandis x E. camaldulensis, E. urophylla x E. camaldulensis, E. urophylla x E. tereticornis, E. grandis x E. tereticornis, E. urophylla x E. grandis） in response to different levels of P supply （0, 6, 12 and 18 mg-kg-l KH2PO4）. The photosynthetic rate and the chlorophyll content significantly declined as the P supply declined in almost a linear fashion for all species as the P stress period extended. In the absence of P supply, height growth of seedlings of all species was significantly impaired, while root collar diameter growth and whole plant dry matter accumulation was not affected by the level of P supply in most of the species. Significant inter-species variations in growth, dry matter accumulation and photosynthetic rate in response to P supply were detected. Eucalyptus dunnii had the lowest growth perform- ance across all levels of P supply while E. urophylla x E. tereticornis showed superior growth performance. From a practical point of view, E. urophylla x E. tereticornis is suggested as a candidate hybrid for planting on slightly P-deficient sites in southern China while E. dunnii, being a slow-growing species, is not suitable for short-rotation plantation. On plantation sites where severe P deficiency exists, P fertilization needs to be considered to boost rapid growth of seedlings so as to meet the man- agement objectives of short-rotation plantation.

Morphological plasticity and phosphorus uptake mechanisms of hybrid Eucalyptus roots under spatially heterogeneous phosphorus stress

In this study, we subjected the root systems of eight Eucalyptus hybrids currently cultivated in southern China to heterogeneous phosphorus stress to provide a scientific basis for the selection of a highly phosphorus-efficient Eucalyptus variety. When the ability of these hybrids to locate phosphorus under different experimental conditions (phosphorus supply in a homogeneous or heterogeneous manner vs. no phosphorus supply) was compared, the main growth characteristics of Eucalyptus, such as plant height, diameter, dry mass, and phosphorus content, significantly improved when the phosphorus supply was increased from no phosphorus or heterogeneous phosphorus (half of the phosphorus amount) to homogeneous phosphorus. Across these three conditions, the growth traits of different Eucalyptus hybrids differed significantly, indicating different adaptabilities of the hybrids to various phosphorus conditions. The growth traits of the aboveground tissues of Eucalyptus under different phosphorus conditions were largely influenced by the morphology of the underground root system. In addition, the root morphology of Eucalyptus under heterogeneous phosphorus treatment suggested that there were two mechanisms for locating nutrients. Eucalyptus hybrids such as Urophylla 3229, Grandis 9, Guanglin 3, 201-2, and Dunn produced more roots proximal to the phosphorus supply; the other hybrids, Urophylla 3216, Grandis 5, and Guanglin 9, relied mainly on the growth of roots opposite the phosphorus supply to obtain adequate nutrients for growth. With these two strategies, a wide range of nutrients was obtained, root distribution was greater, more soil volume was covered, the contact area of the roots with soil phosphorus was increased, and the uptake of phosphorus by the root system was increased. These results demonstrate that Eucalyptus relies on changes to morphological characteristics of the root system to increase accessibility to phosphorus resources.

Boosting electrocatalytic hydrogen generation by a renewable porous wood membrane decorated with Fe-doped NiP alloys

Porous biomass electrodes have emerged as a critical material for electrocatalytic hydrogen evolution reaction(HER).However,most approaches for synthesizing porous electrodes from biomass require high energy consumption,which is resulted from the smash of biomass and the undergoing of serial assembly.Herein,a self-supported wood-derived"breathable"membrane is utilized directly as electrodes for highefficient HER via an assembly of Fe-doped NiP alloys.The well-designed hierarchical porous structures in natural wood membrane(NWM)are unusually beneficial for electrolytes accessibility and hydrogen gas removal.The obtained wood-derived membrane exhibits a high electrocatalytic activity and good cycling durability in acidic and alkaline electrolytes.Remarkably,the Fe_(0.074) NiP alloys/NWM electrode affords a large current density of 100 m A cm^(-2) at extremely low overpotentials of 168 mV in acidic electrolyte and174 m V in alkaline electrolyte.Density functional theory calculations unveil that the Fe atom doped in NiP alloys can create much more charge accumulation around Fe and Ni active sites,which helps decrease the △GH_(*)and △G_(H2O)and significantly promote the HER process.This new insight will promote further explorations of economic,high-efficient,and biodegradable wood-derived electrocatalysts for HER.

Analysis of infection and prognosis of extensively drug resistant Acinetobacter baumannii in ICU

Objective:To investigate the infection of patients in the ICU with extensively drug-resistant Acinetobacter baumannii(XDRAB)and analyse the effect of tigecycline therapy for XDRAB.Methods:Seventy-one patients admitted to the ICU with XDRAB infection from January 2013 to July 2017 were divided into the tigecycline group(combination therapy with 50 mg tigecycline and 0.1 g minocycline every 12 hours)or the control group(no tigecycline treatment).Patient data,including age,sex,history of malignant tumour,body temperature,APACHE Ⅱ score,ALT,AST,GGT,TB,ALB,TBIL,DBIL,IBIL,BUN,Cr,absolute neutrophil count,procalcitonin(PCT),site positive for XDRAB infection,length of stay,and prognosis,were collected and compared between the two groups.Binary logistic regression was used to analyse the prognostic risk factors for XDRAB.Results:A total of 61.6% of the patients infected with XDRAB had multiple sites of XDRAB colonization.The cure rate achieved in the tigecycline group was higher than that of the control group(70.7%vs 41.9%).Multivariate analysis showed that older age,a high level of PCT after treatment and the absence of tigecycline treatment were poor prognostic factors for XDRAB infection.Conclusion:Combination therapy with tigecycline and minocycline is effective for XDRAB infection and reduces the cost of treatment.Combined therapy with tigecycline is a predictor of good prognosis for patients infected with XDRAB,whereas older age and increased PCT levels after treatment are predictors of poor prognosis.

单细胞分辨率下出生后猪肝脏的动态发育

肝脏作为代谢和免疫的重要器官,对其在出生后单细胞分辨率下的发育过程了解甚少.为此,本项目综合应用单核转录组以及单细胞转录组测序技术研究了猪出生后4个重要发育阶段(30,42,150,730天)肝脏的84824个细胞,鉴定到23种细胞类型,包括3种稀有细胞类型:浆细胞样树突状细胞、CAVIN3+IGF2+内皮细胞以及EBF1+成纤维细胞,并通过多重荧光免疫组化实验进行了验证.发育轨迹和基因调控网络分析揭示了33个与肝细胞发育和功能相关的转录因子编码基因,包括调节肝脏代谢的NFIL3.本文表征了肝脏内皮细胞的时空异质性,鉴定并验证了亮氨酸拉链蛋白2(LUZP2)是新的成年肝窦内皮细胞特异的转录因子.发现淋巴系免疫细胞(NK和T细胞)从出生后30天开始即主导了猪肝脏免疫系统.作者进一步鉴定到一簇肝脏组织驻留的NK细胞,该簇细胞呈现出病毒防御功能且在730天仍保持增殖特征.跨物种比较分析表明,与小鼠相比,猪肝脏驻留的NK细胞与人类表现出更保守的转录因子表达模式.本研究构建了迄今最为全面的出生后肝脏单细胞发育图谱并且阐释了其4个年龄阶段代谢和免疫的变化.

Developmental dynamics of the single nucleus regulatory landscape of pig hippocampus

The hippocampus is a brain region associated with memory,learning and spatial navigation,its aging-related dysfunction is a common sign of Alzheimer’s disease.Pig is a good model for human neurodegenerative disease,but our understanding of the regulatory program of the pig hippocampus and its cross-species conservation in humans remains limited.Here,we profiled chromatin accessibility in 33,409 high-quality nuclei and gene expression in 8,122 high-quality nuclei of the pig hippocampus at four postnatal stages.We identified 510,908 accessible chromatin regions(ACRs)in 12 major cell types,among which progenitor cells such as neuroblasts and oligodendrocyte progenitor cells showed a dynamic decrease from early to later developmental stages.We revealed significant enrichment of transposable elements in cell type-specific ACRs,particularly in neuroblasts.We identified oligodendrocytes as the most prominent cell type with the greatest number of genes that showed significant changes during the development.We identified ACRs and key transcription factors underlying the trajectory of neurogenesis(such as POU3F3 and EGR1)and oligodendrocyte differentiation(RXRA and FOXO6).We examined 27 Alzheimer’s disease-related genes in our data and found that 15 showed cell type-specific activity(TREM2,RIN3 and CLU),and 15 genes displayed age-associated dynamic activity(BIN1,RABEP1 and APOE).We intersected our data with human genome-wide association study results to detect neurological disease-associated cell types.The present study provides a single nucleusaccessible chromatin landscape of the pig hippocampus at different developmental stages and is helpful for the exploration of pigs as a biomedical model in human neurodegenerative diseases.

Microplastics pollution:Economic loss and actions needed

Microplastics originate from plastic bottles of water and soft drink,plastic bags,tire wear,plastic agricultural mulches and 3D printing[1,2].These small fragments of wastes being 1μm to 5 mm pollute the environment and threaten human health and ecosystem services including crops and others,leading to economic losses[1–3].It is predicted that by 2030,plastic productions will be leading environmental pollution in terms of carbon footprint and toxic chemicals[4],making U.S.the world’s largest plastic waste generator[5].Based on reports from the United Nations Environment Assembly(UNEA)and the United Nations Environmental Program(UNEP),plastics in the environment annually burden the global economy by$19 billion,causing concerns for long-term ecological sustainability and the Global Goals[6].It is reported that about 8.3 billion tons of plastic waste have been created,leading to 4.9 billion tons discarded through landfilling globally[7],causing a yearly financial loss of more than$13 billion[8].

In-Situ Chemosynthesis of ZnO Nanoparticles to Endow Wood with Antibacterial and UV-Resistance Properties

Hybrid wood materials have attracted considerable attention because they have combined advantages of both wood and inorganic compounds. This work investigated the microstructural morphology, thermal stability, ultraviolet（UV） stability, and antibacterial property of composites made from wood/ZnO hybrid materials through a facile in-situ chemosynthesis methods. The X-ray diffraction（XRD） and thermogravimetric analysis（TGA） results indicated that the synthesized ZnO particles had an average grain size of about 10.8 nm. The scanning electron microscopy（SEM） observations showed that ZnO nanoflowers self-assembled with nanosheets were presented in wood cell lumens and increased with increasing Zn^（2＋）concentrations. ZnO nanoparticles were also generated in the wood cell wall, which was confirmed by the results of energy-dispersive spectroscopy（EDS）. The TGA tests also indicated that the thermal stability of wood/ZnO hybrid materials was improved after the formation of ZnO inorganic particles. Finally, the results of antibacterial efficacy tests and UV resistance tests revealed that ZnO nanoparticles showed a promising future as antimicrobial agents against Escherichia coli（E.coli） and UV resistance agents for wood protection.

Land cover change and multiple remotely sensed datasets consistency in China

Introduction:Although numerous land cover datasets can act as references for understanding land cover change in China,the inconsistencies between the datasets can also provide understanding.Previous studies on the consistency between land cover datasets have mostly focused on land cover type consistencies and have ignored data consistencies in land cover change.Outcomes:Therefore,we aim to analyse the consistencies in land cover changes through likelihood assessment methods.We compared the spatiotemporal changes in forest,grassland,cropland,and bare land in the Climate Change Initiative land cover dataset(CCI-LC),Moderateresolution Resolution Imaging Spectroradiometer land cover dataset(MCD12Q1),China’s National Land Use and Cover Change(CNLUCC),Globeland30 and Global Land Cover Fine Surface Covering 30(GLC-FCS30)datasets in 2010.The results showed that the percentages and changes in each land cover type in MCD12Q1 were different from those in the other datasets.Discussion:For example,the proportion of grassland in MCD12Q1 was the highest,reaching 48.04%.The places with high consistency were the places where the land cover types were concentrated,and the bare land had the highest consistency.However,the consistency of China’s land cover change was quite low,and the percentage of low consistency was more than 87%from 2000-2018.Comparison of the data with the global artificial impervious area(GAIA)and Hansen-Global Forest Change(Hansen-GFC)datasets showed that the percentage of high construction gain consistency(38.83%)was higher than the forest change consistency,and the percentage forest loss high consistency(8.85%)was lower than the forest gain high consistency(12.76%).Conclusion:The results not only provide a basis for the use of land cover datasets but also give a clearer understanding of the pattern of land cover changes.

Biochar aerogel-based electrocatalyst towards efficient oxygen evolution in acidic media

The controllable synthesis of oxygen evolution reaction(OER)electrocatalyst is an urgent need to advance the develop-ment of sustainable energy conversion and storage.However,the OER efficiency in acidic media is seriously hindered by slow reaction kinetics.The traditional acidic OER electrocatalysts are more prone to be oxidized and corroded as results of unstable carrier structures and variable electronic states of active species.Herein,a high-performing biochar aerogel(BA)based electrocatalyst were realistically designed and synthetized via joint utilization of the terrestrial lignin and seaweed polysaccharide as carbon sources.Originating from the induction effect of"egg-box"structure in alginate and the self-template effect of lignosulfonate,the BA decorated with Ru/RuS_(2)particles was synthesized triumphantly.The as-synthesized electrocatalyst required a low overpotential of 228 mV to attain 10 mA cm^(−2)in 0.5 M H_(2)SO_(4)and exhibited a good stability for over 12,000 s.The good activity was strongly dependent on the assembled unique two-dimensional/three-dimensional(2D/3D)channels in carbon aerogels.Notably,the numerous defective sites at carbon could strongly interact with the Ru/RuS_(2)heterojunction for remarkably enhancing the catalytic activity and stability of whole catalytic system in acidic media.This work puts forward a novel and effective strategy towards the enhancement of the acidic OER process by rational regu-lations of the BA and the coupling effect in micro-interface.