•The pyridine-including half-salamo-like ligands HL1 and HL2 have been developed successfully.•Two first Co(III) complexes, Co(L1)(N3)2 (1), and Co(L2)(N3)2 (2) were synthesized and ascertained ...structurally.•The complexes 1 and 2 are unusual salamo-like Co(III) complexes with variable valence. This situation has never reported in the previous salamo-based complexes.
Two structurally novel Co(III) complexes have been successfully constructed from the pyridine-including half-salamo-like ligands (HL1 and HL2), namely as Co(L1)(N3)2 (1) and Co(L2)(N3)2 (2). The structural features of complexes 1 and 2 have been confirmed by means of single crystal X-ray diffraction experiment. The structural studies revealed that complexes 1 and 2 have similar structures. The characterization of the two ligands and their Co(III) complexes was ascertained by means of infrared spectra, ultraviolet spectra and Hirshfeld surfaces analyses. In addition, compared with the ligands HL1 and HL2, the fluorescence intensities of the corresponding complexes 1 and 2 decreased significantly. When Co(II) salt was gradually added to the ligand solution, the intensity of the fluorescence emission peak decreased with the continuous addition of Co(II) salt until this trend stopped, which indicates that the introduction of Co(II) ion leads to the charge transfer from the ligand to Co(III) ion.
Two structurally novel Co(III) complexes have been successfully constructed from the pyridine-including half-salamo-like ligands (HL1 and HL2), namely as Co(L1)(N3)2 (1) and Co(L2)(N3)2 (2). The characterization of the two ligands and their Co(III) complexes was ascertained by means of infrared spectra, ultraviolet spectra, X-ray crystallography, fluorescence spectra and Hirshfeld surfaces analyses. Display omitted
Achieving on-chip optical signal isolation is a fundamental difficulty in integrated photonics. The need to overcome this difficulty is becoming increasingly urgent, especially with the emergence of ...silicon nano-photonics, which promises to create on-chip optical systems at an unprecedented scale of integration. Until now, there have been no techniques that provide complete on-chip signal isolation using materials or processes that are fundamentally compatible with silicon CMOS processes. Based on the effects of photonic transitions, we show here that a linear, broadband and non-reciprocal isolation can be accomplished by spatial-temporal refractive index modulations that simultaneously impart frequency and wavevector shifts during the photonic transition process. We further show that a non-reciprocal effect can be accomplished in dynamically modulated micrometre-scale ring-resonator structures. This work demonstrates that on-chip isolation can be accomplished with dynamic photonic structures in standard material systems that are widely used for integrated optoelectronic applications.
MXene, as a novel two-dimensional (2D) material, has unique inherent features such as lightweight, flexibility, high electrical conductivity, customizable surface chemistry, and facile solution ...processability. However, utilizing MXene (Ti3C2T x ) films for long-term electromagnetic interference (EMI) shielding poses challenges, as they are susceptible to chemical deterioration through oxidation into TiO2. In this work, an ultrathin heterogeneous film of Ti3C2T x MXene integrated with multiwalled carbon nanotubes supporting MoS2 clusters (MXene/MWCNT@MoS2) was developed. The heterogeneous film with 15 wt % of MWCNT@MoS2 clusters exhibited improved EMI shielding performance such as the highest EMI shielding effectiveness of 50 dB and the specific shielding effectiveness of 20,355 dB cm2 g –1, mainly attributed to the excellent electrical conductivity, distinctive porous structure, and multiple interfacial interactions. The heterogeneous films underwent extended exposure to a moisture environment (35 days), and their structural stability and EMI shielding performance were enhanced by the integration of MWCNT@MoS2 clusters. As a result, the engineered heterostructure of multilayered hybrid films holds promise as a viable option for improving the EMI shielding effectiveness and stability of Ti3C2T x MXene.
This paper examines the role of social capital, embedded in kinship-based clans, in disaster relief during China's Great Famine (1958–1961). Using a county-year panel and a difference-in-differences ...strategy, we find that the rise in the mortality rate during the famine years is significantly less in counties with a higher clan density. Analysis using a nationally representative household survey corroborates this finding. Investigation of potential mechanisms suggests that social capital's impact on famine may have operated through enabling collective action against excessive government procurement. These results provide evidence that societal forces can ameliorate damages caused by faulty government policies in times of crisis.
•We study the role of social capital in disaster relief during China's Great Famine.•We measure social capital using the density of family clans in rural China.•Death toll was smaller in counties with higher clan density.•Rural residents from communities with more clans report fewer hunger experiences.•Clans helped organize villagers against state expropriation, thus saving lives.
ABSTRACT
Over the past few years, wide-field time-domain surveys such as Zwicky Transient Facility and Optical Gravitational Lensing Experiment have led to discoveries of various types of interesting ...short-period stellar variables, such as ultracompact eclipsing binary white dwarfs (WDs), rapidly rotating magnetized WDs, transitional cataclysmic variables between hydrogen-rich and helium accretion, and blue large-amplitude pulsators (BLAPs), which greatly enrich our understandings of stellar physics under some extreme conditions. In this paper, we report the first-2-yr discoveries of short-period variables (i.e. P < 2 h) by the Tsinghua University–Ma Huateng Telescopes for Survey (TMTS). TMTS is a multitube telescope system with a field of view up to 18 deg2, which started to monitor the Large Sky Area Multi-object Fiber Spectroscopic Telescope (LAMOST) sky areas since 2020 and generated uninterrupted minute-cadence light curves for about 10 million sources within 2 yr. Adopting the Lomb–Scargle periodogram with period-dependent thresholds for the maximum powers, we identify over 1100 sources that exhibit a variation period shorter than 2 h. Compiling the light curves with the Gaia magnitudes and colours, LAMOST spectral parameters, International Variable Star Index classifications, and archived observations from other prevailing time-domain survey missions, we identified 1076 as δ Scuti stars, which allows us to study their populations and physical properties in the short-period regime. The other 31 sources include BLAPs, subdwarf B variables, pulsating WDs, ultracompact/short-period eclipsing/ellipsoidal binaries, cataclysmic variables below the period gap, etc., which are highly interesting and worthy of follow-up investigations.
Radiotherapy efficacy was greatly limited by hypoxia and overexpression of glutathione (GSH) in the tumor microenvironment (TME), which maintained the immunosuppressive microenvironment and promoted ...DNA repair. In this work, 4T1 cell membrane-coated Bi2–x Mn x O3 nanospheres have been achieved via a facile protocol, which showed enhanced therapeutic efficacy for a combination of radiotherapy and immunotherapy. Bi2–x Mn x O3 nanospheres showed appreciable performance in generating O2 in situ and depleting GSH to amplify DNA damage and remodel the tumor immunosuppressive microenvironment, thus enhancing radiotherapy efficacy. Cancer cell membrane-coated Bi2–x Mn x O3 nanospheres (T@BM) prolonged blood circulation time and enriched the accumulation of the materials in the tumor. Meanwhile, the released Mn2+ could activate STING pathway-induced immunotherapy, resulting in the immune infiltration of CD8+ T cells on in situ mammary tumors and the inhibition of pulmonary nodules. As a result, approximately 1.9-fold recruitment of CD8+ T cells and 4.0-fold transformation of mature DC cells were observed compared with the phosphate-buffered saline (PBS) group on mammary tumors (in situ). In particular, the number of pulmonary nodules significantly decreased and the proliferation of pulmonary metastatic lesions was substantially inhibited, which provided a longer survival period. Therefore, T@BM exhibited great potential for the treatment of 4T1 tumors in situ and lung metastasis.
Day–night photocatalysts that can persistently generate reactive oxygen species (ROS) after ceasing light attracted intensive attention in diverse fields. However, current strategies of combining a ...photocatalyst and an energy storage material can hardly fulfill the demands, especially in size. We herein present a one-phase sub-5 nm day–night photocatalyst via simply doping Nd, Tm, or Er into YVO4:Eu3+ nanoparticles, efficiently producing ROS in both day and night modes. We demonstrate that the rare earth ions acted as a ROS generator, and Eu3+ and defects contributed to the long persistency. Furthermore, the ultrasmall size led to remarkable bacterial uptake and bactericidal efficacy. Our finding suggests an alternative mechanism of day–night photocatalysts that could be ultrasmall and thus may shed light on disinfection and other applications.
In recent years, ATP has emerged as an anionic biocomponent for the design of dynamic and stimuli-responsive supramolecular assemblies. Herein, we present ATP-enhanced Förster resonance energy ...transfer (FRET) in the coassemblies of pyrene-imidazolium amphiphiles with pyrene acting as an excellent donor for the coembedded acceptor dyes to generate tunable multiluminescent materials in aqueous solutions and in polymer and solid films. We achieved high energy transfer efficiency up to 95% even at a donor/acceptor (D/A) ratio of 100:1. By a simple variation of the D/A ratio, emission covering almost the whole range of the visible spectrum from blue to red including white light was obtained in solution and in solid and polymer films. Furthermore, the systems exhibited FRET ON/OFF features controlled by various stimuli such as temperature, pH, and metal ions. Most notably, a ratiometric and linear luminescence response to temperature and pH was observed. The stimuli-responsive tunable solid-state emission was further exploited in encryption–decryption applications.
Light can be coupled into propagating electromagnetic surface waves at a metal-dielectric interface known as surface plasmon polaritons (SPPs). This process has traditionally faced challenges in the ...polarization sensitivity of the coupling efficiency and in controlling the directionality of the SPPs. We designed and demonstrated plasmonic couplers that overcome these limits using polarization-sensitive apertures in a gold film. Our devices enable polarization-controlled tunable directional coupling with polarization-invariant total conversion efficiency and preserve the incident polarization information. Both bidirectional and unidirectional launching of SPPs are demonstrated. The design is further applied to circular structures that create radially convergent and divergent SPPs, illustrating that this concept can be extended to a broad range of applications.
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