A novel rare-earth free narrow-band green-emitting Mn2+ doped ZnB2O4 phosphor was synthesized. The phosphor can be excited by blue light and emit bright green light. Besides, the phosphor also ...performs outstanding thermal stability and excellent cathodoluminescence properties.
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•A novel narrow-band green-emitting Mn2+ doped ZnB2O4 phosphor was synthesized.•The phosphor has a broad excitation, which can match well with blue LED chips.•The phosphor emits green light under blue light or electron beam excitation.•The phosphor has excellent thermal and color stability, high color purity.
A novel rare-earth free narrow-band green-emitting Mn2+ doped ZnB2O4 phosphor has been synthesized successfully through solid-state method, and the photoluminescence and cathodoluminescence properties of samples were investigated in detail. The phosphor can emit bright green light peaking at 541 nm with FWHM about 41 nm under both UV and blue light excitation. The broad excitation ranges from 235 nm to 535 nm, especially the strongest excitation locates in blue region, which indicates that the phosphor can match well with not only UV LED chips but also blue LED chips. The temperature-dependent PL properties show that the phosphor has good thermal stability and outstanding color stability. From the CL spectra, it is obvious that the phosphor also exhibits intense green emission with high color purity and good color stability under low-voltage excitation, and the results indicate that the phosphor owns high saturation voltage and saturation current. In view of the outstanding performance in the PL and CL, the ZnB2O4:Mn2+ can be considered to apply in both LED and FED devices.
Exosomes are small membrane-bound vesicular particles generated by most cells for intercellular communication and regulation. During biogenesis, specific lipids, RNAs, proteins, and carbohydrates are ...enriched and packaged into the vesicles so that the exosomal contents reflect not only the source but also the physiological conditions of the parental cells. These exosomes transport materials or signals to the target cells for diverse physiological purposes. Our study focused on the exosomes derived from M1-polarized, proinflammatory macrophages for the possibility of using M1 exosomes as an immunopotentiator for a cancer vaccine. The M1 exosomes displayed a tropism toward lymph nodes after subcutaneous injection, primarily taken up by the local macrophages and dendritic cells, and they induced the release of a pool of Th1 cytokines. We found that M1, but not M2, exosomes enhanced activity of lipid calcium phosphate (LCP) nanoparticle-encapsulated Trp2 vaccine, and they induced a stronger antigen-specific cytotoxic T cell response. The M1 exosomes proved to be a more potent immunopotentiator than CpG oligonucleotide when used with LCP nanoparticle vaccine in a melanoma growth inhibition study. Thus, our study indicated that exosomes derived from M1-polarized macrophages could be used as a vaccine adjuvant.
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Exosomes are small membrane-bound vesicular particles generated by most cells. Exosomes derived from M1-polarized macrophages enhanced anti-tumor activity of lipid calcium phosphate (LCP) nanoparticle-encapsulated Trp2 vaccine, and they induced a stronger antigen-specific cytotoxic T cell response, indicating that exosomes from M1-polarized macrophages could be used as a vaccine adjuvant.
A variety of Eu3+-activated BaZrGe3O9 phosphors was synthesized via solid-state reaction. The phase formation of BaZrGe3O9:Eu3+ samples was verified by powder X-ray diffraction analysis, while ...Rietveld refinement method was used to confirm the crystal structure. The electronic structure and characteristic photoluminescence as well as cathodoluminescence properties were researched in detail. The samples show strong absorption at 394 nm, which matches well with the commercial near-ultraviolet chips. Under 394 nm excitation, the phosphors exhibit the characteristic emissions of Eu3+ ions consistent with the 5D0–7FJ transitions. Then we investigated the thermal stability detailedly. The temperature-dependent photoluminescence emission spectra suggest that the obtained phosphors have favorable thermal stability. A white light-emitting diode (WLED) lamp with low correlated color temperature and good color render index was fabricated with blue-emitting BaMgAl10O17:Eu2+, green-emitting Sr2SiO4:Eu2+ (commercial), and red-emitting BaZrGe3O9:Eu3+ phosphors in near-ultraviolet light-emitting diodes (λmax = 395 nm) as well. Furthermore, the phosphor also exhibits red emission with high resistance and high current saturation under low voltage electron bombardment. It has better degradation resistance than the commercial Y2O3:Eu phosphor. All the results manifest that the Ba0.88Eu0.08ZrGe3O9 phosphor can be an eligible red-emitting phosphor candidate for WLEDs and field-emission displays.
Over the past two decades, the Chinese domestic security apparatus has expanded dramatically. “Stability maintenance” operations have become a top priority for local Chinese authorities. We argue ...that this trend goes back to the early 1990s, when central Party authorities adopted new governance models that differed dramatically from those of the 1980s. They increased the bureaucratic rank of public security chiefs within the Party apparatus, expanded the reach of the Party political-legal apparatus into a broader range of governance issues, and altered cadre evaluation standards to increase the sensitivity of local authorities to social unrest. We show that the origin of these changes lies in a policy response to the developments of 1989–1991, namely the Tiananmen democracy movement and the collapse of communist political systems in Eastern Europe. Over the past twenty years, these practices have developed into an extensive stability maintenance apparatus, whereby local governance is increasingly oriented around the need to respond to social unrest, whether through concession or repression. Chinese authorities now appear to be rethinking these developments, but the direction of reform remains unclear. 在过去的 20 多年中, 中国的国内维稳体系经历了大幅的扩展, 维护社会稳定成为地方政府工作的重中之重。我们提出这一趋势源于 90 年代初期党中央采取的一系列有别于 80 年代的治理模式。这一模式提高了公安部门领导在整个官僚体系中的地位, 扩大了党的政法系统对一系列治理领域的影响, 以及将社会稳定纳入到了地方干部考核体制中。我们认为这些变化是政府对 1989 至 1991 年间的事件--即天安门民主运动和东欧共产党政权的倒台--的政策回应。经过 20 多年的发展, 这些政策已经促成了一个庞大的维稳体系。在这一体系中, 地方治理的重心日益围绕着如何应对社会抗争进行, 或是妥协或是镇压。中国政府正在重新考量这一体系, 但改革的方向尚不明朗。
In 2011, Gogotsi et al. discovered a new type of two‐dimensional transition metal carbides and nitrides, called MXenes, which have become a dazzling new star in the energy storage industry. ...MXenes are endowed with a series of fascinating properties due to their unique structures and tunable surface chemical functional groups. The application of MXenes in electrochemical energy storage has attracted special attention, especially showing great potential in supercapacitor applications. Compared with other materials, MXenes have high mechanical flexibility, high energy density, and good electrochemical performance, so they are especially suitable as electrode materials for supercapacitors. However, similar to other 2D materials, due to the strong van der Waals forces, MXene layers inevitably undergo stacking agglomeration, resulting in severe loss of electrochemically active sites. If the self‐stacking of MXenes layers can be effectively suppressed, their electrochemical performance will be enhanced. Structural optimization of MXenes and composite doping of MXenes with other materials are two strategies with significant effects. This review summarizes recent advances in MXene synthesis, fundamental properties, and composite materials, focusing on the latest electrochemical performance of MXene‐based electrodes/devices, and puts forward the challenges and new opportunities that MXenes face in this emerging energy storage field.
MXene is a bright new star in the field of energy storage, and the application of MXene in supercapacitors has received special attention. This study summarizes the latest progress in MXene synthesis, basic properties, and composite materials, focusing on MXene‐based electrodes/devices and the latest electrochemical performance. It presents challenges and new opportunities for MXene in this future energy storage field.
A series of novel red emission Mg3Ga2GeO8 (MGG):Mn4+ phosphors under near-UV (NUV) excitation are synthesized successfully by traditional high-temperature solid-state reaction. The structure of ...Mg3Ga2GeO8 is investigated by high-resolution transmission electron microscopy, scanning electron microscopy, and powder X-ray diffraction (XRD) Rietveld refinement. It has one octahedral site and one tetrahedral site in the crystal structure. According to XRD and photoluminescence (PL) property analysis, Mn4+ can occupy an octahedral (Mg2+/Ga3+) site. The PL properties are investigated by diffuse-reflectance, emission, excitation, and temperature-dependent spectroscopy and decay curves. It can emit red light peaking at 659 nm under NUV excitation. The critical quenching concentration of Mn4+ was about 0.5 mol %. The concentration quenching mechanism could be a d–d interaction for the Mn4+ center. The CIE chromaticity coordinates and full-width at half-maximum are (0.295, 0.677) and 24 nm, respectively. It demonstrated that MGG:Mn4+ has high color purity. The PL intensity of MGG:0.5% Mn4+ drops to 72% when the temperature is raised up to 150 °C. Furthermore, MGG:0.5% Mn4+ exhibits outstanding quantum efficiency (64.7%). By tuning of the weight ratio of blue, green, and red phosphors, the fabricated white-light-emitting diodes using a 405 nm GaN NUV chip combined with a blend of blue phosphor BAM:Eu2+, green phosphor Sr2SiO4:Eu2+, and red-emitting phosphor MGG:Mn4+ driven by 40 mA current can get white light with chromaticity coordinates (0.316, 0.375) and CCT = 3340 K. This demonstrates that MGG:Mn4+ is a potential red phosphor matching NUV LED chips to get white light.
Under what conditions would authoritarian rulers be interested in the rule of law? What type of rule of law exists in authoritarian regimes? How do authoritarian rulers promote the rule of law ...without threatening their grip on power? Tying the Autocrat's Hands answers these questions by examining legal reforms in China. Yuhua Wang develops a demand-side theory arguing that authoritarian rulers will respect the rule of law when they need the cooperation of organized interest groups that control valuable and mobile assets but are not politically connected. He also defines the rule of law that exists in authoritarian regimes as a partial form of the rule of law, in which judicial fairness is respected in the commercial realm but not in the political realm. Tying the Autocrat's Hands demonstrates that the rule of law is better enforced in regions with a large number of foreign investors but less so in regions heavily invested in by Chinese investors.
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Sound hybrid joint was achieved with a sufficient mixture of 6061-T6 aluminum (Al) alloy and polyether ether ketone (PEEK) via friction stir lap welding (FSLW) by a tapered thread pin ...with the triple facets. The larger length ratio between the Al anchor and the rotating pin reached approximately 0.8 at low welding speeds due to the dynamic flow induced by the triple facets. The mechanical interlocking and adhesive bonding attributed to the high-quality joining. Increasing welding speed resulted in the reduction of the adhesion area and the decrease in the size of the Al anchor, deteriorating the mechanical interlocking. A high-quality with the maximum shear bond strength of 20 MPa was achieved through the big Al anchor with a high hardness value. The tapered thread pin with the triple facets has feasible and potential to FSLW of metal and polymer in terms of enhancing mechanical interlocking.
Broadband near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) have many prospective applications in areas related to food inspection, health management, plant growth, and night ...vision, because NIR phosphors are critical components of the corresponding devices. Given the wide‐ranging applicability of the material, this study is designed to comprehensively evaluate a series of novel NIR phosphors: BaMgGaxAl10–xO17:Cr3+ (x = 0, 1, 2, 3). The ultra‐low‐temperature (4 K) fluorescence spectroscopy and decay curve results confirm that Cr3+ occupies the four lattice sites of Al3+ in the matrix. Additionally, the introduction of Ga3+ increases the full‐width at half‐maximum (FWHM) of the NIR spectrum from 100 to 300 nm without affecting the fluorescence efficiency; it also considerably increases spectral coverage. An experiment to evaluate the applicability of the novel NIR phosphors reveals that the sunlight‐converting film prepared by applying the material combination of BaMgGa3Al7O17:0.02Cr3+ is able to effectively promote the growth of Chlorella. In addition, the NIR pc‐LED with a BaMgGa3Al7O17:0.2Cr3+ basis and 395‐nm LED chip has been proven to be an excellent candidate for applications in NIR spectral detection and night‐vision technology.
A near‐infrared broadband emission phosphor with ultra‐wide response range has been successfully developed and optimized. Its application potential in plant growth, near‐infrared spectroscopy, and night vision technology has been successfully tapped.
Summary Background Many patients with psoriasis develop psoriatic arthritis, a chronic inflammatory disease that afflicts peripheral synovial, axial, and entheseal structures. The fully human ...monoclonal antibody ustekinumab is an efficacious treatment for moderate-to-severe plaque psoriasis. We did a randomised, placebo-controlled, phase 3 trial to assess the safety and efficacy of ustekinumab in patients with active psoriatic arthritis. Methods In this phase 3, multicentre, double-blind, placebo-controlled trial at 104 sites in Europe, North America, and Asia-Pacific, adults with active psoriatic arthritis (≥5 tender and ≥5 swollen joints, C-reactive protein ≥3·0 mg/L) were randomly assigned (1:1:1, by dynamic central randomisation based on an algorithm implemented by an interactive voice–web response system) to 45 mg ustekinumab, 90 mg ustekinumab, or placebo at week 0, week 4, and every 12 weeks thereafter. At week 16, patients with less than 5% improvement in both tender and swollen joint counts entered masked early-escape and were given 45 mg ustekinumab (if in the placebo group) or 90 mg ustekinumab (if in the 45 mg group). At week 24, all remaining patients in the placebo group received ustekinumab 45 mg, which they continued at week 28 and every 12 weeks thereafter. Our primary endpoint was 20% or greater improvement in American College of Rheumatology (ACR20) criteria at week 24. This trial is registered with ClinicalTrials.gov ( NCT01009086 ) and EudraCT (2009-012264-14). Findings Between Nov 30, 2009, and March 30, 2011, 615 patients were randomly assigned—206 to placebo, 205 to 45 mg ustekinumab, and 204 to 90 mg ustekinumab. More ustekinumab-treated (87 of 205 42·4% in the 45 mg group and 101 of 204 49·5% in the 90 mg group) than placebo-treated (47 of 206 22·8%) patients achieved ACR20 at week 24 (p<0·0001 for both comparisons); responses were maintained at week 52. At week 16, proportions of patients with adverse events were similar in the ustekinumab and placebo groups (171 of 409 41·8% vs 86 of 205 42·0%). Interpretation Ustekinumab significantly improved active psoriatic arthritis compared with placebo, and might offer an alternative therapeutic mechanism of action to approved biological treatments. Funding Janssen Research & Development.
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