水铁矿负载甘蔗渣吸附磷酸根开放性综合化学实验

采用原位沉淀法制备了对磷酸根有较好吸附性能的水铁矿负载甘蔗渣复合吸附剂。通过扫描电镜-X射线能谱仪(SEM-EDS)、X射线衍射光谱(XRD)、傅里叶变换红外光谱(FTIR)、Zeta电位等手段对负载甘蔗渣吸附剂进行了表征,同时考查了水铁矿负载甘蔗渣吸附剂对磷酸根吸附的行为和机理。结果表明负载后的甘蔗渣对磷酸根的吸附量提高显著,吸附可在30 min内达到平衡,等温吸附线符合Langmuir模型,动力学曲线符合准二级模型,负载吸附剂对废水中磷的去除率高达99.8%。该研究可作为工业分析、应用化学、环境工程等专业高年级的综合化学实验,有利于提升学生的研究兴趣,培养学生将理论知识运用于实际的能力,激发学生的创新能力。

Energy-information trade-off induces continuous and discontinuous phase transitions in lateral predictive coding

Lateral predictive coding is a recurrent neural network that creates energy-efficient internal representations by exploiting statistical regularity in sensory inputs.Here,we analytically investigate the trade-off between information robustness and energy in a linear model of lateral predictive coding and numerically minimize a free energy quantity.We observed several phase transitions in the synaptic weight matrix,particularly a continuous transition that breaks reciprocity and permutation symmetry and builds cyclic dominance and a discontinuous transition with the associated sudden emergence of tight balance between excitatory and inhibitory interactions.The optimal network follows an ideal gas law over an extended temperature range and saturates the efficiency upper bound of energy use.These results provide theoretical insights into the emergence and evolution of complex internal models in predictive processing systems.

Reversibly sensitizing-storing-releasing ^(1)O_(2) within a single platinum(Ⅱ)-acetylide-based metallacycle molecule via laser power modulation

Tumor hypoxia severely limits the therapeutic efficacy of photodynamic therapy(PDT) for solid tumors,which is highly dependent on tissue oxygen concentration.In this study,we developed a platinum(Ⅱ)-acetylide-based metallacycle compound bearing six 1,4-dimethylnaphthalenes(DMN) groups,and controlled the photodynamic and photothermal effects of the compound by adjusting the power of 730 nm laser to achieve reversible sensitization,storage and release of 1~O_(2) within a single molecule.The compound formed nanoparticles by self-assembly and exhibited good water solubility and biocompatibility.Under laser irradiation,the strong spin-orbit coupling of platinum atoms in the metallacycle facilitated 1~O_(2) generation.The produced 1~O_(2) was captured by the DMN carriers and transported into the hypoxic tumor,where 1~O_(2) release was triggered owing to the good photothermal effect of the extended conjugation of the metallacycle.During therapy,the metallacycle serving as a photosensitizer,1~O_(2) carrier,and photothermal reagent,achieved the synergistic therapy of PDT/PTT,demonstrating the versatility of the metallacycle.This study proposes a new strategy to develop phototherapy agents that are suitable for hypoxic tumors.

Phosphorous-doped carbon nanotube/reduced graphene oxide aerogel cathode enabled by pseudocapacitance for high energy and power zinc-ion hybrid capacitors

The design and development of energy storage device with high energy/power density has become a research hotspot.Zinc-ion hybrid capacitors(ZHCs)are considered as one of the most promising candidates.However,the application of ZHCs is hindered by their low energy density at high power density due to the unsatisfactory cathode material.In this study,a novel 3D phosphorus-doped carbon nanotube/reduced graphene oxide(P-CNT/rGO)aerogel cathode is synthesized through a synergistic modification strategy of CNT insertion and P doping modification combined with 3D porous design.The as-obtained P-CNT/rGO aerogel cathode manifests significantly increased surface aera,expanded interlayer spacing,and enhanced pseudocapacitance behavior,thus leading to significantly enhanced specific capacitance and superb ions transport performance.The as-assembled ZHC based on P-CNT/rGO cathode delivers a superior energy density of 42.2 Wh/kg at an extreme-high power density of 80 kW/kg and excellent cycle life.In-depth kinetic analyses are undertaken to prove the enhanced pseudocapacitance behavior and exceptional power output capability of ZHCs.Furthermore,the reaction mechanism of physical and chemical adsorption/desorption of electrolyte ions on the P-CNT/rGO cathode is revealed by systematic ex-situ characterizations.This work can provide a valuable reference for developing advanced graphene-based cathode for high energy/power density ZHCs.

Photothermally Responsive Conjugated Polymeric Singlet Oxygen Carrier for Phase Change-Controlled and Sustainable Phototherapy for Hypoxic Tumor

Hypoxia significantly compromises the therapeutic performance of photodynamic therapy(PDT)owing to the oxygen level which plays a key role in the production of singlet oxygen(^(1)O_(2)).Herein,the photothermally responsive phase change materials(PCM)are used to encapsulate 1,4-dimethylnaphthalene-functionalized platinum(II)-acetylide conjugated polymer(CP1)with intense nearinfrared(NIR)absorption to prepare new ^(1)O_(2) nanocarriers(CP1-NCs).The 1,4-dimethylnaphthalene moieties in CP1-NCs can trap the ^(1)O_(2) produced from CP1 under irradiation and form a stable endoperoxide.Then,the endoperoxide undergoes cycloreversion to controllably release ^(1)O_(2) via the NIR light-triggered photothermal effect of CP1 and controllable phase change of PCM,which can be used for oxygen-independent PDT for hypoxic tumor.Furthermore,the in vivo luminescence imagingguided synergistic PDT and photothermal therapy showed better efficiency in tumor ablation.The smart design shows the potent promise of CP1-NCs in PCM-controlled and sustainable phototherapy under tumor hypoxic microenvironment,providing new insights for constructing oxygen-independent precise cancer phototherapeutic platform.

Large effective aperture metalens based on optical sparse aperture system

We present a kind of large effective aperture metalens based on an optical sparse aperture(OSA) system. Each subaperture of the system is a metalens, which is comprised of just a thin Au film with patterned subwavelength rectangular annular arrays on a Si O2 substrate and has a numerical aperture of 0.46 with a diameter of 21.6 μm.Ring6 design was selected to enlarge the effective aperture and enhance the spatial resolution. Compared with the absent mid-frequency and high-frequency modulation transfer function of individual metalens, Ring6 can offer a full-frequency band and show a better restored image quality by using Tikhonov regularization.

新型花束状磷酸钴作为超高倍率和稳定的混合超级电容器电池型正极材料

红磷由于资源丰富、化学稳定性好、环境友好等优点有利于工业化.然而,低的电子导电性和大的体积膨胀限制了其在储能方面的应用.本工作首次以红磷作为磷源,利用一步水热法制备了一种新型的花束状Co_(3)(HPO_(4))_(2)(OH)_(2),将其作为混合超级电容器的正极材料时展现出大的比容量(在1 A g^(−1)时的比容量为119.2 mA h g^(−1))、极好的倍率性能(在100 A g^(−1)时的比容量为83.6 mA h g^(−1))和出色的电化学稳定性(在10 A g^(−1)下5000次循环后的容量保持率为92%).此外,以Co_(3)(HPO_(4))_(2)-(OH)_(2)作为正极和多孔碳作为负极组装出的新型混合超级电容器表现出高达44.6 W h kg^(−1)的能量密度和高达33.75 kW kg^(−1)的功率密度,以及出色的循环性能(在3 A g^(−1)下10,000次循环后的容量保持率为91.8%).该研究不仅开发了一种新型高性能的电池型正极材料,而且为红磷在储能领域的商业化应用提供了新的思路.