Recent advancement and future challenges of photothermal catalysis for VOCs elimination:From catalyst design to applications

Photothermal catalysis realizes the synergistic effect of solar energy and thermochemistry,which also has the potential to improve the reaction rate and optimize the selectivity.In this review,the research progress of photothermal catalytic removal of volatile organic compounds(VOCs)by nano-catalysts in recent years is systematically reviewed.First,the fundamentals of photothermal catalysis and the fabrication of catalysts are described,and the design strategy of optimizing photothermal catalysis performance is proposed.Second,the performance for VOC degradation with photothermal catalysis is evaluated and compared for the batch and continuous systems.Particularly,the catalytic mechanism of VOC oxidation is systematically introduced based on experimental and theoretical study.Finally,the future limitations and challenges have been discussed,and potential research directions and priorities are highlighted.A broad view of recent photothermal catalyst fabrication,applications,challenges,and prospects can be systemically provided by this review.

Endeavors on the development of efficient and sustainable supported metal catalysts for chemical synthesis on solid-liquid interfaces

Supported metal catalysts,particularly for precious metals,have gained increasing attention in green synthetic chemistry.They can make metal-catalyzed organic synthesis more sustainable and economical due to easy separation of product with less metal residue,as well as reusability of the high-cost catalysts.Although great effort has been spent,the precise catalytic mechanism of supported metal-catalyzed reactions has not been clearly elucidated and the development of efficient and stable recyclable catalysts remains challenging.This highlight reveals a“molecular fence”metal stabilization strategy and discloses the metal evolution in Pd-catalyzed C-C bond formation reactions using Nheterocyclic carbene(NHC)-functionalized hypercrosslinked polymer support,wherein the polymeric skeleton isolates or confines the metal species involved in the catalytic reactions,and NHC captures free low-valent metal species in solution and stabilizes them on the support via strong metal-support coordination interaction.This strategy creates a novel route for the development of supported metal catalysts with high stability and provides insights into the reaction mechanism of heterogeneous catalysis.

Strumal Carcinoid of the Ovary: A Report of Two Cases

We describe two cases of strumal carcinoid of ovary, which is an extremely rare ovarian germ cell tumor composed of an intimate mixture of thyroid and carcinoid tissues. The first case involved a 63-year-old woman, who presented with a 1-month history of abdominal distension and unintentional weight loss (5 kg). Abdominal and chest computed tomography revealed right ovarian tumor and bilateral pleural effusion. Her thyroid-stimulating hormone level was slightly lower 0.475 μIU/mL (normal range: 0.55 - 4.78 μIU/mL);however, the levels of FT3 and FT4 were normal. Intraoperatively, the right ovary was enlarged (8.0 cm × 7.0 cm), with a smooth surface and intact capsule. Bilateral salpingo-oophorectomy with a total abdominal hysterectomy and an appendectomy was performed. The second case was a 54-year-old woman, in whom pelvic mass was recognized 2 months before. Intraoperatively, the left ovary was dumbbell-shaped (20.0 cm × 9.0 cm × 9.0 cm) and connected to two masses (9.0 cm × 8.0 cm and 8.0 cm × 7.0 cm, respectively). Her thyroid function test was normal (0.70 μIU/mL). Total abdominal hysterectomy, partial omentectomy, and pelvic adhesion lysis were performed. In both patients, intraoperative frozen section suggested strumal carcinoid of the ovary (stage IA). Ovarian strumal carcinoid should be included in a differential diagnosis of adnexal masses. The prognosis is considered good.

PPh_(3)衍生准多孔有机笼在Rh/PPh_(3)体系催化氢甲酰化反应中的应用:增强活性和选择性及可回收利用

多孔有机笼(POCs)由英国利物浦大学的Cooper教授在2009年首次合成,这种多孔小分子材料的出现具有两方面重要意义:(1)开拓了多孔材料领域的一个全新分支,改变了人们对多孔材料的传统认知;(2)由于POCs材料由离散的小分子堆积而成,可溶解于一些常用的有机溶剂中,因此其在材料制备方面具有很好的“溶液成型”性能,该优势是三维延伸网状多孔材料所不具备的.POCs本质上是一种“中心带孔”的有机小分子,由刚性有机分子砌块收敛堆叠而成,其特殊结构在气体吸附与分离等方面表现出很好的应用前景.不同于传统空间延伸网状框架材料(如金属-有机框架材料和共价有机框架材料)及多孔有机聚合物(POPs)材料,POCs是一种在大多数有机溶剂中可溶解的小分子材料,因此在均相催化领域也有很好的应用前景.作为最为经典的有机配体,三苯基膦(PPh_(3))在金属有机化学和均相催化领域应用十分广泛,如目前均相催化工业应用最成功的典范之一氢甲酰化反应,大多数情况下使用的是PPh_(3)与Rh形成的络合物催化剂.本文首先将PPh_(3)进行醛基官能团化,通过醛基和氨基的收敛缩合形成POCs材料,合成了基于PPh_(3)配体的准多孔有机笼(POC-DICP),利用得到的多孔有机笼制备出类Rh/PPh_(3)均相催化体系的Rh/POC-DICP络合催化体系,并将其应用于氢甲酰化反应.相比于经典的Rh/PPh_(3)均相催化体系,该Rh/POC-DICP催化体系在氢甲酰化反应中不仅展示出了更高的活性和目标产物醛的选择性(醛的化学选择性为97%,醛的正异构比为1.89),而且可以很方便地从均相反应体系中沉淀回收(通过调整溶剂体系极性).在氢甲酰化反应中,Rh/POC-DICP体系显示出了良好的底物适用性,在己烯、庚烯、辛烯和苯乙烯的氢甲酰化反应中均表现出良好的催化活性和醛选择性,同时催化剂回收使用4次,未见催化性能明显下降.X射线单晶衍射、同步辐射及DFT计算等结果表明,Rh/POC-DICP催化体系在氢甲酰化反应中具有较高活性和选择性的原因是POC-DICP多孔有机笼分子的有利的空间咬合角(123.88o)和P原子上相对的缺电子效应.本文设计合成的PPh_(3)衍生的多孔有机笼不仅拓宽了多孔有机笼材料在催化领域的应用,而且为新型配体及络合催化剂的设计、合成及修饰提供了新的思路.

Behavior of rare earth elements in granitic profiles, eastern Tibetan Plateau, China

Rare earth elements(REEs) can record geologic and geochemical processes. We studied two granitic regolith profiles from different climatic zones in eastern Tibetan Plateau and found that(1)∑ RREEs ranged from119.65 to 275.33 mg/kg in profile ND and5.11–474.55 mg/kg in profile GTC, with average values of205.79 and 161 mg/kg, respectively. ∑RREEs was higher in accumulation horizon and semi-regolith;(2) Influenced by climate, the fractionation of light and heavy REEs(LREEs and HREEs) varied during weathering. The ratio of LREEs/HREEs in pedosphere was higher than semi-regolith in tropical profile;(3) A negative Eu anomaly in both profiles was the result of bedrock weathering. A positive Ce anomaly was observed in all layers of profile ND, and only in the upper 100 cm of profile GTC. This indicates that redox conditions along the regolith profile varied considerably with climate.(4) Normalized by chondrite,LREEs accumulated much more than HREEs; REE distribution curves were right-leaning with a V-type Eu anomaly in both profiles.

A functional hyperbranched binder enabling ultra-stable sulfur cathode for high-performance lithium-sulfur battery

Binders are of vital importance in stabilizing the cathodes to enhance the cycling stability of lithiumsulfur(Li-S) batteries. However, conventional binders are typically confronted with the drawback of inability for adsorbing lithium polysulfide(Li PS), thus resulting in severe active material losing and rapid capacity fading. Herein, a novel water-soluble hyperbranched poly(amidoamine)(HPAA) binder with controllable hyperbranched molecular structure and abundant amino end groups for Li-S battery is designed and fabricated, which can improve efficient adsorption for Li PS and stability of the sulfur cathodes. Besides, the strong intermolecular hydrogen bonds in HPAA binder can contribute to the structural stability of S cathode and integration of the conductive paths. Therefore, the Li-S battery with this functional binder exhibits excellent cycle performance with a capacity retention of 91% after 200 cycles at 0.1 C.Even at a high sulfur loading of 5.3 mg cm-2, a specific capacity of 601 mA h g-1 can also be achieved.Density functional theory(DFT) calculation further demonstrates that the enhanced electrochemical stability derives from the high binding energy between amino groups and LiP S and the wide electrochemical window(6.87 e V) of HPAA molecule. Based on the above all, this functional polymer will lighten a new species of binders for eco-friendly sulfur cathodes and significantly promote the practical applications of high-performance Li-S batteries.

Soil organic carbon dynamics study bias deduced from isotopic fractionation in corn plant

Carbon stable isotope techniques were extensively employed to trace the dynamics of soil organic carbon(SOC)across a land-use change involving a shift to vegetation with different photosynthetic pathways.Based on the isotopic mass balance equation,relative contributions of new versus old SOC,and SOC turnover rate in corn fields were evaluated world-wide.However,most previous research had not analyzed corn debris left in the field,instead using an average corn plant δ^(13)C value or a measured value to calculate the proportion of corn-derived SOC,either of which could bias results.This paper carried out a detailed analysis of isotopic fractionation in corn plants and deduced the maximum possible bias of SOC dynamics study.The results show approximately 3‰ isotopic fractionation from top to bottom of the corn leaf.The ^(13)C enrichment sequence in corn plant was tassel﹥stalk or cob﹥root﹥leaves.Individual parts accounting for the total dry mass of corn returned distinct values.Consequently,the average δ^(13)C value of corn does not represent the actual isotopic composition of corn debris.Furthermore,we deduced that the greater the fractionation in corn plant,the greater the possible bias.To alleviate bias of SOC dynamics study,we suggest two measures:analyze isotopic compositions and proportions of each part of the corn and determine which parts of the corn plant are left in the field and incorporated into SOC.

The influence of climate and topography on chemical weathering of granitic regoliths in the monsoon region of China

Exploring the relationship between weathering and erosion is essential for understanding the evolution of landscapes and formation of soil under the influence of climate, tectonics, and topography. We measured the bulk chemistry of regoliths and calculated their weathering rates and intensity in three locations in China: Inner Mongolia in the mid-temperate semi-humid zone; Jiangxi Province, in the mid-subtropical humid zone; and Hainan Province, in the tropical humid zone. These profiles exhibited increased weathering with increasing temperature and precipitation.The low-gradient profile exhibited stronger weathering of saprolite than of soil, whereas the high-gradient profile showed a more constant weathering pattern. The regolith in the cold climate was the product of easily weatherable minerals, whereas weathering of K-feldspar and even secondary minerals occurred in hot and humid climates. The weathering of subtropical profiles was both supply-and kinetic-limited, controlled by weathering and erosion. The tropical profile experienced supply-limited weathering,indicating slow erosion and an intense weathering profile;the mid-temperate profile was not classifiable due to weak erosion and weathering. Long-term weathering fluxes of these profiles show that Si, Na, and K(or Mg) represent thebulk of the mass lost through weathering. This study underscores that weathering of granitic regolith is controlled by both climatic conditions and landscape.

Rational construction of multiple hollow silicalite-1 zeolite with enhanced quasi acidity for robust vapor-phase Beckmann rearrangement

Developing efficient and stable zeolites for vapor-phase Beckmann rearrangement of cyclohexanone oxime is still a great challenge to realizeε-caprolactam(CPL)green production.In this work,the hierarchical porous silicalite-1 zeolites with multiple hollow structure(S-1-M)are explored by in-situ desilication−recrystallization post-treatment of spongy highway-like zeolites(S-1-S),which are synthesized through silanization synthesis of conventional bulky silicalite-1(S-1).Compared to S-1,S-1-M achieves superior catalytic performance,with improving the CPL selectivity from 85.7%to 94.1%and prolonging the catalyst lifetime from 74 to 126 h at a weight hourly space velocity(WHSV)of 6 h^(−1).Comprehensive physiochemical studies demonstrate that the highly dispersed intracrystalline cavities within S-1-M endow greater mass diffusion and better quasi acidity inducing by the enhanced H-bonds among abundant H-bonded silanols,which is cooperatively responsible for its superior catalytic performance.

The initial exploration for ^(26)Al chronology in deep-sea ferromanganese crust

Background The deep-sea ferromanganese crust(DSFC)is a natural archive for recording the history of the Earth’s evolution,as one of the most common authigenic assemblages in marine sediments.Although the depositional age dating using meteoric ^(10)Be has been successfully used in the study on the chronology of DSFC,the research on ^(26)Al has not seen relevant reports in this aspect due to the influence of factors such as measurement sensitivity and ^(26)Al in situ production.Method The first exploration for ^(26)Al chronology in DSFC was carried out by using accelerator mass spectrometry(AMS)measurements of ^(10)Be and ^(26)Al,and the comparison of relationship between isotopic ratios and concentrations of Al and Be.Results The growth rates of G.R=(1.44±0.09)mm/Ma,(3.58±0.29)mm/Ma,(1.52±0.10)mm/Ma and(2.93±0.14)mm/Ma are derived using ^(10)Be/^(9)Be,^(26)Al/^(27)Al ratios,^(10)Be and ^(26)Al concentrations,respectively.Conclusion The ^(26)Al chronological methods have been explored based on a DSFC sample and encouraging results were obtained.The results are preliminary and insufficient;some information is still needed to explain the difference between ^(26)Al and ^(10)Be chronology.

MOFs衍生金属氧化物及其复合材料在锂离子电池负极材料中的应用

锂离子电池作为比能量最高的二次电池,广泛用于便携电子设备、新能源汽车和大规模储能电站等领域。目前商用锂离子电池正面临着一些技术瓶颈,如能量密度低和使用寿命短等。关于锂离子电池负极材料的报道有很多,但大多无法克服锂化前后巨大的体积膨胀、电极材料粉末化和电极阻抗大等缺点。金属-有机骨架衍生金属氧化物及其复合材料因具有低而平的充放电电位平台、高容量和稳定的循环性能等优点,被广泛应用于锂离子电池。本文将从单金属氧化物、双金属氧化物、双组分金属氧化物复合材料和金属氧化物/碳复合材料四个模块进行综述,总结其合成方法、形貌与电化学性能之间的关系,并展望其未来发展的机遇与挑战。

Heterogeneous lamellar-edged Fe-Ni(OH)_(2)/Ni_(3)S_(2)nanoarray for efficient and stable seawater oxidation

Development of efficient non-precious catalysts for seawater electrolysis is of great significance but challenging due to the sluggish kinetics of oxygen evolution reaction(OER)and the impairment of chlorine electrochemistry at anode.Herein,we report a heterostructure of Ni_(3)S_(2)nanoarray with secondary Fe-Ni(OH)_(2)lamellar edges that exposes abundant active sites towards seawater oxidation.The resultant Fe-Ni(OH)_(2)/Ni_(3)S_(2)nanoarray works directly as a free-standing anodic electrode in alkaline artificial seawater.It only requires an overpotential of 269 mV to afford a current density of 10 mA·cm^(-2)and the Tafel slope is as low as 46 m V·dec^(-1).The 27-hour chronopotentiometry operated at high current density of 100 mA·cm^(-2)shows negligible deterioration,suggesting good stability of the Fe-Ni(OH)_(2)/Ni_(3)S_(2)@NF electrode.Faraday efficiency for oxygen evolution is up to〜95%,revealing decent selectivity of the catalyst in saline water.Such desirable catalytic performance could be benefitted from the introduction of Fe activator and the heterostructure that offers massive active and selective sites.The density functional theory(DFT)calculations indicate that the OER has lower theoretical overpotential than Cl_(2) evolution reaction in Fe sites,which is contrary to that of Ni sites.The experimental and theoretical study provides a strong support for the rational design of high-performance Fe-based electrodes for industrial seawater electrolysis.

The long-term denudation rate of granitic regolith in Qinhuangdao, North China determined from the in situ depth profile of the cosmogenic nuclides ^(26)Al and ^(10)Be

This study quantifies the surface denudation rate of granitic regolith via the application of the in situ cosmogenic26 Al and10Be depth profile in China. The concentration ranges of26 Al and10Be in the quartz along the*3-m granitic regolith profile in Qinhuangdao are(4.9–23.1) 9 105and(2.3–36.6) 9 104atoms/g, respectively. With the exception of the surface sample, both26 Al and10Be concentrations decrease exponentially with sample depth. The Chi-square best-fitting results revealed a total denudation rate of *9 m/Ma averaged over a 103–105a timescale, which is lower than the values observed in global granitic outcrops. Compared with global datasets, the flat terrain due to the lack of tectonic activities is most likely the dominant factor that controls the local denudation process.The surface sample offsets from the theoretical cosmogenic nuclide distribution implies that the denudation rate from river basin sediment could be overestimated because of the bioturbation in the surficial soil layer.

Synthesis and kinetics investigation of meso-microporous Cu-SAPO-34 catalysts for the selective catalytic reduction of NO with ammonia

A series of meso-microporous Cu-SAPO-34 catalysts were successfully synthesized by a one-pot hydrothermal crystallization method, and these catalysts exhibited excellent NH3-SCR performance at low temperature. Their structure and physic chemical properties were characterized by means of X-ray diffraction patterns （XRD）, Scanning electron microscopy （SEM）, Transmission electron microscopy （TEM）, N2 sorption-desorption, nuclear magnetic resonance （NMR）, Inductively Coupled Plasma-Atomic Emission spectrometer （ICP-AES）, X-ray absorption spectroscopy （XPS）, Temperature-programmed desorption of ammonia （NH3-TPD）, Ultraviolet visible diffuse reflectance spectroscopy （UV-Vis DRS） and Temperature programmed reduction （TPR）. The analysis results indicate that the high activities of Cu-SAPO-34 catalysts could be attributed to the enhancement of redox property, the formation of mesopores and the more acid sites. Furthermore, the kinetic results verify that the formation of mesopores remarkably reduces diffusion resistance and then improves the accessibility of reactants to catalytically active sites. The 1.0-Cu-SAPO-34 catalyst exhibited the high NO conversion （〉90%） among the wide activity temperature window in the range of 150- 425℃.

基于类肽等级自组装结构仿生纳米材料:合成,表征和应用

类肽(或N-取代甘氨酸)具有合成效率高、化学稳定性强、抗酶水解及生物相容性好等优点,是一类潜在的可自定义序列的生物仿生聚合物.通过调节类肽的侧链化学,可以精确地控制类肽序列并实现侧链的多样性.基于以上类肽分子独特的优势,在过去的几年里,研究者设计和合成了大量的双亲性类肽作为基本的结构单元,通过自下而上的分子自组装作用构建了结构可控和具有特定功能的仿生纳米材料.本文从以下三个方面综述了我们在类肽自组装领域取得的一些成果.首先,概述了以云母和硅片为无机基底辅助类肽自组装.将原子力显微镜原位成像技术和单分子力谱技术相结合,可实时观察类肽分子在表面的组装过程并直接测定类肽分子与基底间的相互作用,揭示基底表面对类肽自组装的影响.其次,介绍了类肽分子在溶液中自组装成纳米管和具有自修复功能的纳米薄膜.最后,综述了基于类肽自组装纳米材料的应用,包括以类肽自组装纳米材料为催化模板构建纳米仿生催化剂和作为细胞内输送物质的载体等.

Honeycomb-like g-C_(3)N_(4)/CeO_(2)-x nanosheets obtained via one step hydrothermal-roasting for efficient and stable Cr(Ⅵ) photo-reduction

Graphitic carbon nitride(g-C_(3)N_(4))-based materials are regarded as one of the most potential photocatalysts for utilizing solar energy.In this work,we reported a facile one step in-situ hydrothermal-roasting method for preparing honeycomb-like g-C_(3)N_(4)/CeO_(2) nanosheets with abundant oxygen vacancies(g-C_(3)N_(4)/CeO_(2)-x).The hydrothermal-roasting and incomplete-sealed state can(i)generate an in-situ reducing atmosphere(CO,N2,NH3) to tune the concentration of oxygen vacancies in CeO_(2);(ii) beneficial to prevent continuous growth of g-C_(3)N_(4) and results in honeycomb-like g-C_(3)N_(4)/CeO_(2)-x hybrid nanosheets.What is more,the g-C_(3)N_(4)/CeO_(2)-x photocatalyst exhibited extended photoresponse range,increased specific surface area and obviously enhanced separation efficiency of photogenerated electron-hole pairs.As a proof-of-concept application,the optimized g-C_(3)N_(4)/CeO_(2)-xnanosheets could achieve 98% removal efficiency for Cr(Ⅵ) under visible light irradiation(λ≥420 nm)within 2.5 h,which is significantly better than those of pure g-C_(3)N_(4) and CeO_(2).This work provides a new idea for more rationally designing and constructing g-C_(3)N_(4)-based catalysts for efficient extended photochemical application.

China is initiating the Aquatic 10-100-1,000 Genomics Program

On June 17 of 2016,a group of scientists from Chinese Academy of Fishery Sciences(CAFS)and Shenzhen BGI Fisheries Sci&Tech Co.Ltd.(BGI Fisheries)met together in Shenzhen,China to launch a novel project,the China Aquatic 10-100-1,000 Genomics Program,to conduct molecular breeding of^10 aquaculture species and sequence genomes of^100 and transcriptomes of^1,000 aquatic species.The main objective of this project is to build

Deciphering non-steady landscape evolution by in-situ cosmogenic nuclide depth profile

In-situ cosmogenic nuclide s are receiving growing attention in surface Earth system science in which the steady-state denudation is an important assumption for estimating the surface denudation of long-lived(103-106 years)surfaces.However,distinguishing steady-state denudation and deciphering a reliable denudation rate from non-steady state denudation region are difficult.Recent depth profile models for investigating the denudation rate,exposure age and inheritance are widely used for sediment and regolith of steady-state denudation region.Here we present in-situ co smogenic nuclides^(10)Be and^(26)Al from two typical granite regolithes from Jixian in Tianjin and Tengchong in Yunnan to model non-steady landscape evolution process by using steady state(Model 1)and non-steady state(Model 2,continuous exposure;Model 3 a,changed denudation rate;Model 3 b,abrupt denudation event)models.The results of steady state model show that both regolithes are in non-steady state.^(10)Be non-steady state models of Jixian regolith reveal that the surface has likely experienced a denudation rate change or an abrupt denudation event during the past several millennia,resulting in a non-steady state.The similar Model 3 a and 3 b denudation rates of 14.6-12.9^(+9.4)and 14.7-14.7^(+9.0)mmkyr^(-1),respectively,might demonstrate the long-term denudation rate rather than the exaggerated rate s of 39.0-2.3^(+2.6)and 39.0-2.4+^(2.5)mm kyr^(-1)calculated by assuming steady-state denudation and ignoring inheritance.The non-steady state model results of Tengchong regolith suggest that the surface has likely experienced a strong denudation about 157 ka(^(10)Be)or 127 ka(^(26)Al)ago.This timing is basically consistent with the termination of the MIS 6(TII:130 ka)and the climate change events in the Tibetan Plateau,suggesting a strong surface landscape denudation during the transition from glacial to interglacial.The compiling of basin-wide denudation rates in the Tibetan Plateau shows a good positive correlation with the regional tectonic activity,indicating that the denudation rate derived from non-steady state region with strong tectonic activity is likely to be overestimated by assuming steady state.We suggest that a combination of steady state and non-steady state depth profile models should be used to quantify denudation rate and exposure age more accurately and effectively in strong tectonic activity or climate change regions.

Reversible conductivity recovery of highly sensitive flexible devices by water vapor

With decreasing size of integrated circuits in wearable electronic devices,the circuit is more susceptible to aging or fracture problem,subsequently decreasing the transmission efficiency of electricity.Micro-healing represents a good approach to solve this problem.Herein,we report a water vapor method to repair microfiber-based electrodes by precise positioning and rapid healing at their original fracture sites.To realize this micro-level conducting healing,we utilize a bimaterial composed of polymeric microfibers as healing agents and electrically conductive species on its surface.This composite electrode shows a high-performance conductivity,great transparency,and ultra-flexibility.The transmittance of our electrode could reach up to 88 and 90%with a sheet resistance of 1 and 2.8Ωsq^(−1),respectively,which might be the best performance among Au-based materials as we know.Moreover,after tensile failure,water vapor is introduced to mediate heat transfer for the healing process,and within seconds the network electrode could be healed along with recovering of its resistance.The recovering process could be attributed to the combination of adhesion force and capillary force at this bimaterial interface.Finally,this functional network is fabricated as a wearable pressure/strain sensing device.It shows excellent stretchability and mechanical durability upon 1000 cycles.