Extending the solid solution range of sodium ferric pyrophosphate:Off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)as a novel cathode for sodium‐ion batteries

Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.

A miniaturized spin-exchange relaxation-free atomic magnetometer based on uniform light field

We experimentally study the dynamic characteristics of a miniaturized spin-exchange relaxation-free(SERF) magnetometer based on uniform light field. The ceramic ferrule is used to expand the Gaussian beam to improve light intensity uniformity, while the volume of the sensor is also reduced. This scheme makes the magnetometer have better sensitivity when the detected light intensity is less than 3.16 m W/cm^(2) at 120℃. When the temperature rises to 150℃ the sensitivity under the action of uniform light field is 18.5 f T/Hz^(1/2). The bandwidth of the sensor remains at the original level and meets application needs. The proposed structure improves transverse polarization uniformity within the miniaturized sensor, which is ideal for the magnetoencephalography and magnetocardiography imaging systems.

Tin dioxide buffer layer-assisted efficiency and stability of wide-bandgap inverted perovskite solar cells

Inverted perovskite solar cells(IPSCs) have attracted tremendous research interest in recent years due to their applications in perovskite/silicon tandem solar cells. However, further performance improvements and long-term stability issues are the main obstacles that deeply hinder the development of devices. Herein, we demonstrate a facile atomic layer deposition(ALD) processed tin dioxide(SnO2) as an additional buffer layer for efficient and stable wide-bandgap IPSCs. The additional buffer layer increases the shunt resistance and reduces the reverse current saturation density, resulting in the enhancement of efficiency from 19.23% to 21.13%. The target device with a bandgap of 1.63 eV obtains open-circuit voltage of 1.19 V, short circuit current density of 21.86 mA/cm^(2), and fill factor of 81.07%. More importantly, the compact and stable SnO_(2) film invests the IPSCs with superhydrophobicity, thus significantly enhancing the moisture resistance. Eventually, the target device can maintain 90% of its initial efficiency after 600 h storage in ambient conditions with relative humidity of 20%–40% without encapsulation. The ALD-processed SnO_(2) provides a promising way to boost the efficiency and stability of IPSCs, and a great potential for perovskite-based tandem solar cells in the near future.

Composite electron transport layer for efficient N-I-P type monolithic perovskite/silicon tandem solar cells with high open-circuit voltage

Perovskite/silicon tandem solar cells(PSTSCs) have exhibited huge technological potential for breaking the Shockley-Queisser limit of single-junction solar cells. The efficiency of P-I-N type PSTSCs has surpassed the single-junction limit, while the performance of N-I-P type PSTSCs is far below the theoretical value. Here, we developed a composite electron transport layer for N-I-P type monolithic PSTSCs with enhanced open-circuit voltage(VOC) and power conversion efficiency(PCE). Lithium chloride(Li Cl) was added into the tin oxide(SnO_(2)) precursor solution, which simultaneously passivated the defects and increased the electron injection driving force at the electron transfer layer(ETL)/perovskite interface.Eventually, we achieved monolithic PSTSCs with an efficiency of 25.42% and V_(OC) of 1.92 V, which is the highest PCE and VOCin N-I-P type perovskite/Si tandem devices. This work on interface engineering for improving the PCE of monolithic PSTSCs may bring a new hot point about perovskite-based tandem devices.

Tumor-targeting intravenous lipid emulsion of paclitaxel:Characteristics,stability,toxicity,and toxicokinetics

Lipid nanoemulsions are promising nanodrug delivery carriers that can improve the efficacy and safety of paclitaxel(PTX).However,no intravenous lipid emulsion of PTX has been approved for clinical treatment,and systemic safety profiles have not yet been reported.Here we outline the development of a PTXloaded tumor-targeting intravenous lipid emulsion(PTX Emul)and describe its characteristics,colloidal stability,and systemic safety profiles in terms of acute toxicity,long-term toxicity,and toxicokinetics.We also compare PTX Emul with conventional PTX injection.Results showed that PTX Emul exhibited an ideal average particle size(approximately 160 nm)with narrow size distribution and robust colloidal stability under different conditions.Hypersensitivity reaction and hemolysis tests revealed that PTX Emul did not induce hypersensitivity reactions and had no hemolytic potential.In addition,where the alleviated systemic toxicity of PTX Emul may be attributed to the altered toxicokinetic characteristics in beagle dogs,including the decreased AUC and increased plasma clearance and volume of distribution,PTX Emul alleviated acute and long-term toxicity as evidenced by the enhanced the median lethal dose and approximate lethal dose,moderate body weight change,decreased bone marrow suppression and organ toxicity compared with those under PTX injection at the same dose.A fundamental understanding of the systemic safety profiles,high tumor-targeting efficiency,and superior antitumor activity in vivo of PTX Emul can provide powerful evidence of its therapeutic potential as a future treatment for breast cancer.

Multi-Body Dynamics Modeling and Simulation Analysis of a Vehicle Suspension Based on Graph Theory

Multi-body dynamics,relative coordinates and graph theory are combined to analyze the structure of a vehicle suspension.The dynamic equations of the left front suspension system are derived for modeling.First,The pure tire theory model is used as the input criteria of the suspension multibody system dynamic model in order to simulate the suspension K&C characteristics test.Then,it is important to verify the accuracy of this model by comparing and analyzing the experimental data and simulation results.The results show that the model has high precision and can predict the performance of the vehicle.It also provides a new solution for the vehicle dynamic modeling.

Mo_(3)Nb_(14)O_(44): A New Li^(+) Container for High-Performance Electrochemical Energy Storage

Intercalating Nb-based oxides are promising anode compounds for lithiumion batteries since they have both good safety and large capacities.However,the research in this field is still limited.Here,Mo_(3)Nb_(14)O_(44)with a large theoretical capacity of 398 mAh g^(–1)(Mo^(64)←→Mo^(4+)and Nb^(5+)←→Nb^(3+))is exploited as a new Nb-based oxide anode compound,and Mo_(3)Nb_(14)O_(44)micron-sized particles(Mo_(3)Nb_(14)O_(44)-M)and Mo3Nb14O44 nanowires(Mo_(3)Nb_(14)O_(44)-N)are demonstrated.Mo3Nb14O44 owns a tetragonal shear ReO_(3)crystal structure(high-symmetric 14 space group)constructed by 4×4×∞(Mo,Nb)O_(6)octahedron blocks linked by Mo O4 tetrahedra,forming an A–B–A layered structure with a large interlayer spacing.This interesting structure allows fast Li+storage within the interlayers and significant intercalation-pseudocapacitive behavior,leading to the high rate performance of Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N with a large 10 C versus 0.1 C capacity retention percentage of 38.1/54.2%.Mo_(3)Nb_(14)O_(44)-M/Mo_(3)Nb_(14)O_(44)-N further exhibits a safe operating potential of 1.72/1.68 V,large reversible capacity of 323/321 m Ah g^(–1)at 0.1 C,high initial coulombic efficiency of 92.2/90.0%,and good cycling stability with 71.8/75.8%capacity retention after 1000 cycles at10 C.Additionally,a Li Mn_(2)O_(4)/Mo_(3)Nb_(14)O_(44)-N full cell also performs well.Therefore,Mo_(3)Nb_(14)O_(44)holds great promise as a fast-charging,safe,largecapacity,high-efficient,and long-life Li^(+)anode container.

用于光催化能量转换的Z-型异质结的研究进展

受植物光合作用的启发,研究者发展了多种模拟光合作用体系用于光分解水、二氧化碳光还原和氮光固定以生产"太阳燃料"(如氢气、甲烷和氨气),以期缓解当前的能源短缺和环境污染。尽管基于人造半导体材料的光合作用是一种潜在、理想的以"太阳燃料"的化学键形式存储太阳能的方法,但是构筑能够在规模和成本方面与化石燃料竞争的生产"太阳燃料"的人工光合作用体系仍然存在巨大的挑战。因此,开发低成本的高效光催化剂对于促进人工光合作用的三种主要光催化过程(光俘获、电荷产生与分离,以及表面/界面催化反应)具有重要的意义。在已研究的各类光催化剂中,Z-型异质结复合体系不仅可以提高光俘获能力和显著抑制电荷载流子复合,而且还可通过保持光激发电子/空穴的强还原/氧化能力来促进表面/界面催化反应,因而受到广泛关注。将太阳能转化为化学能的Z-型纳米异质结的研究证明这些异质结在提高生产"太阳燃料"的光催化反应体系的整体效率方面的重要性。该综述主要介绍了Z-型异质结的发展历史和直接Z-型异质结相较于传统II型异质结、液相Z-型和全固态Z-型异质结的优势,并阐述了两步激发Z-型光催化体系的反应机理和途径。然后,从材料组成角度重点介绍了近5年来不同类型Z-型纳米结构材料(无机,有机和无机-有机复合材料)在光催化能源转换领域的应用,以及提高Z-型纳米结构材料光催化性能的各种调控/工程策略(如扩展光谱吸收区、促进电荷转移/分离和表面化学改性等)。此外,还讨论了Z-型光催化机理的表征方法与策略(如金属负载法、牺牲试剂测试法、自由基捕集实验、原位X-射线光电子能谱、光催化还原实验、Kelvin探针力显微镜、表面光电压光谱、瞬态吸收光谱及理论计算等)及光催化性能的评价方法和标准。最后,介绍了Z-型异质结光催化体系目前面临的挑战和发展方向。我们希望该综述能为光催化体系的性能突破方向提供新的认识,并为新型Z-型光催化材料的设计和构筑提供指导。

首轮“双一流”建设政策执行的现实困境与破解之道——基于史密斯政策执行过程模型的分析

政策的有序执行是确保政策目标得以实现的关键。基于史密斯政策执行过程模型,全面审视首轮“双一流”建设的政策执行过程,发现在理想化政策、执行机构、目标群体、政策环境四个维度,其分别面临政策本体内在限制导致政策执行力度减弱、机构执行能力不足致使政策执行效率降低、目标群体认知偏差造成政策执行阻力增大和政策环境建设乏力引致政策执行基础薄弱等现实困境。在新一轮“双一流”政策的后续调整与执行过程中,须从优化制度顶层设计,提高政策执行力度;强化机构执行能力,健全政策执行机制;提升目标群体认知,增强其政策参与意愿;改善政策执行环境,夯实政策执行基础等方面找准出路,以持续促进“双一流”建设政策落实、稳固推动“三步走”战略目标实现。

Three-dimensionally ordered macroporous CeO_2/Al_2O_3-supported Au nanoparticle catalysts: Effects of CeO_2 nanolayers on catalytic activity in soot oxidation

A series of catalysts consisting of three‐dimensionally ordered macroporous(3DOM)x‐CeO2/Al2O3‐supported Au nanoparticles(x=2,10,20,and40wt%)were successfully synthesized using a reduction‐deposition method.These catalysts were characterized using scanning electron microscopy,the Brunauer‐Emmett‐Teller method,X‐ray diffraction,transmission electron microscopy,ultraviolet‐visible spectroscopy,and temperature‐programmed reduction by H2.Au nanoparticles of mean particle size5nm were well dispersed and supported on the inner walls of uniform macropores.The3DOM structure improved the contact efficiency between soot and the catalyst.An Al‐Ce‐O solid solution was formed in the multilayer support,i.e.,x‐CeO2/Al2O3,by the incorporation of Al3+ions into the CeO2lattice,which resulted in the creation of extrinsic oxygen vacancies.Strong interactions between the metal(Au)and the support(Ce)increased the amount of active oxygen species,and this promoted soot oxidation.The catalytic performance in soot combustion was evaluated using a temperature‐programmed oxidation technique.The presence of CeO2nanolayers in the3DOM Au/x‐CeO2/Al2O3catalysts clearly improved the catalytic activities in soot oxidation.Among the prepared catalysts,3DOM Au/20%CeO2/Al2O3showed high catalytic activity and stability in diesel soot oxidation.

I/P interface modification for stable and efficient perovskite solar cells

Interface engineering has played an increasingly essential role in the development of perovskite solar cells(PSCs).Herein,we adopted an effective and simple one-step interface passivation method on a FA-based perovskite to fabricate efficient and stable planar PSCs.The surface defects are reduced by the perovskite interface passivation layer incorporated between the hole transport and perovskite absorber layers,and then non-radiative recombination is suppressed while interfacial carrier extraction is enhanced.The passivated planar PSCs demonstrates 20.83%power conversion efficiency(PCE),which is caused by the simultaneous enhancement of the fill factor and open-circuit voltage.In addition,the device also shows great ambient and thermal stability.It retains 94%of its original PCE after 1000 h under ambient air without encapsulation as well as90%of its initial efficiency after 400 h under continuous heating at 65°C with encapsulation.This research provides a strategy for the development of efficient and stable PSCs.

Effect of yttrium on catalytic performance of Y-doped TiO_(2) catalysts for propane dehydrogenation

Defective bulk catalysts based on TiO_(2) have superior catalytic performance for propane dehydrogenation(PDH).The oxygen vacancy concentration and the number of active sites on the catalyst surface can be effectively tuned by doping metal in TiO_(2).Herein,yttrium(Y)-doped titanium dioxide(nY/TiO_(x))catalysts were in-situ synthesized via the coprecipitation method to study the effect of rare earth metal Y doping on the structure of TiO_(2) and the catalytic performance for PDH.Experimental results demonstrate that Ydoped TiO_(2) exhibits higher catalytic activity,propylene selectivity and stability than bare TiO_(2).Full characterizations with X-ray diffraction(XRD),high-resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS),infrared spectroscopy of pyridine adsorption(Py-IR),temperature-programmed desorption of ammonia(NH_(3)-TPD),H_(2) temperature-programmed reduction(H_2-TPR),and Raman techniques on these catalysts reveal that Y^(3+)can enter TiO_(2) lattice,and the lattice stability of the catalyst can be enhanced by replacing Ti^(4+)to form Y-O-Ti structure.Meanwhile,the introduction of an appropriate amount of Y can obviously promote the PDH reaction by adjusting the acidity of the catalyst,improving the release capacity of TiO_(2) lattice oxygen and increasing the formation of active centers.Nevertheless,excessive Y doping will lead to pore clogging,and the exposure of active sites will be reduced,resulting in the degradation of catalytic performance.

Z-scheme photocatalyst based on porphyrin derivative decorated few-layer BiVO4 nanosheets for efficient visible-light-driven overall water splitting

It is highly desirable to simulate natural photosynthesis by using sunlight to drive the overall water splitting without using external bias and sacrificial agent.Herein,few-layer monoclinic BiVO4 nanosheets(BVNS)with a thickness of(∼)4.3 nm,exposed(010)facets and abundant oxygen vacancies are fabricated using graphene oxide dots as templating reagent.After decorating with asymmetric chromium porphyrin derivative bearing one benzoic acid and three phenyls as meso-position substituents(chromium-5-(4-carboxyphenyl)-10,15,20-triphenylporphrin,CrmTPP)and PtOx cocatalyst,the obtained two-dimensional(2D)hybrid nanocomposite(BVNS/CrmTPP/Pt)with an optimal component ratio delivers a robust overall water splitting performance with a relatively high apparent quantum yield(8.67%)at 400 nm monochromatic light.The ultrathin structure and widely distributed oxygen vacancies on the exposed(010)facets of BVNS not only endow strong and intimate contact with the decorated CrmTPP molecules to promote a two-step excitation Z-scheme charge transfer mechanism for preserving the high redox ability of the photogenerated charge carriers,but also alleviate their recombination,and thus causing the robust overall water splitting performance of the 2D hybrid nanocomposites.The present results provide a novel strategy to construct highly efficient artificial photosynthetic system for overall water splitting.

Suppressed recombination for monolithic inorganic perovskite/silicon tandem solar cells with an approximate efficiency of 23%

Potentially temperature-resistant inorganic perovskite/silicon tandem solar cells(TSCs)are promising devices for boosting efficiency past the single-junction silicon limit.However,undesirable non-radiative recombination generally leads to a significant voltage deficit.Here,we introduce an effective strategy using nickel iodide,an inorganic halide salt,to passivate iodine vacancies and suppress non-radiative recombination.NiI_(2)-treated CsPbI_(3-x)Br_(x) inor-ganic perovskite solar cells with a 1.80 eV bandgap exhibited an efficiency of 19.53%and a voltage of 1.36 V,corresponding to a voltage deficit of 0.44 V.Importantly,the treated device demonstrated excellent operational stability,maintaining 95.7%of its initial efficiency after maximum power point tracking for 300 h under continuous illumination in a N_(2) atmosphere.By combining this inorganic perovskite top cell with a narrower bandgap silicon bottom cell,we for the first time achieved monolithic inorganic perovskite/silicon TSCs,which exhibited an effi-ciency of 22.95%with an open-circuit voltage of 2.04 V.This work provides a promising strategy for using inorganic passivation materials to achieve efficient and stable solar cells.

In situ grown TiN/N-TiO_(2)composite for enhanced photocatalytic H_(2)evolution activity

Titanium nitride(TiN)decorated N-doped titania(N-TiO_(2))composite(TiN/N-TiO_(2))is fabricated via an in situ nitridation using a hydrothermally synthesized TiO_(2)and melamine(MA)as raw materials.After the optimization of the reaction condition,the resultant TiN/NTiO_(2)composite delivers a hydrogen evolution activity of up to 703μmol/h under the full spectrum irradiation of Xelamp,which is approximately 2.6 and 32.0 times more than that of TiO_(2)and TiN alone,respectively.To explore the underlying photocatalytic mechanism,the crystal phase,morphology,light absorption,energy band structure,element composition,and electrochemical behavior of the composite material are characterized and analyzed.The results indicate that the superior activity is mainly caused by the in situ formation of plasmonic TiN and N-TiO_(2)with intimate interface contact,which not only extends the spectral response range,but also accelerates the transfer and separation of the photoexcited hot charge carrier of TiN.The present study provides a fascinating approach to in situ forming nonmetallic plasmonic material/N-doped TiO_(2)composite photocatalysts for high-efficiency water splitting.