The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon ...The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.展开更多
<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room t...<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range. </div>展开更多
Robust quantum cascade laser(QCL)enduring high temperature continuous-wave(CW)operation is of critical importance for some applications.We report on the realization of lattice-matched InGaAs/InAlAs/InP QCL materials g...Robust quantum cascade laser(QCL)enduring high temperature continuous-wave(CW)operation is of critical importance for some applications.We report on the realization of lattice-matched InGaAs/InAlAs/InP QCL materials grown by metal-organic chemical vapor deposition(MOCVD).High interface quality structures designed for light emission at 8.5μm are achieved by optimizing and precise controlling of growth conditions.A CW output power of 1.04 W at 288 K was obtained from a 4 mm-long and 10μm-wide coated laser.Corresponding maximum wall-plug efficiency and threshold current density were 7.1%and 1.18 kA/cm2,respectively.The device can operate in CW mode up to 408 K with an output power of 160 mW.展开更多
This study investigates the influences of boreal summer intraseasonal oscillation(BSISO), which originates from the equatorial Indian Ocean and prevails over the Indo-Pacific region, on precipitation over Southeast Ch...This study investigates the influences of boreal summer intraseasonal oscillation(BSISO), which originates from the equatorial Indian Ocean and prevails over the Indo-Pacific region, on precipitation over Southeast China, including South China and Yangtze River Valley. The results indicate that the BSISO-related precipitation anomalies are remarkably different between early summer(May–June) and late summer(July–August). The BSISO-related precipitation anomalies tend to appear more northward in late summer in comparison with early summer. Accordingly, the BSISO is significantly related to precipitation anomalies over South China during many phases in early summer but related to very weak anomalies during all the phases in late summer. Such northward shifts of precipitation anomalies from early summer to late summer are clearest during phases 4 and 7, when the lower-tropospheric anticyclonic and cyclonic circulation anomalies dominate over the subtropical western North Pacific, respectively. Finally, we explain the differences between early and late summers through the seasonal northward migration of climatological equivalent potential temperature gradient, which is located in the South China during early summer but migrates northward to the YRV during late summer.展开更多
Tributyltin（TBT）,a biocide used in antifouling paints,has shown strong teratogenic effects on Xenopus tropicalis embryos at environmentally relevant concentrations.X.tropicalis embryos were exposed to 50,100 and 200...Tributyltin（TBT）,a biocide used in antifouling paints,has shown strong teratogenic effects on Xenopus tropicalis embryos at environmentally relevant concentrations.X.tropicalis embryos were exposed to 50,100 and 200 ng/L tributyltin chloride for 72 hr.The histological changes were further observed on abnormal eyes,enlarged trunks,enlarged proctodaeums and absence of fins induced by TBT.The lens and the retinal layers of abnormal eyes were slightly or barely differentiated,and that the pigment epithelium was neither continuous nor smooth.The abdomens were full of undifferentiated gut tissue with yolk-rich inclusions in the tadpoles with enlarged trunks.The proctodaeums formed a bump-like or columnar structure.The mass of yolk-rich cells occupied the lumen,blocked the opening and even turned inside out of the proctodaeum.Both the ventral and dorsal fins in trunks and tails became narrow or even disappeared totally.Our results suggest that great changes of histology took place corresponding to the unique phenotypes.The gut tissue was poorly differentiated,which led to the failed elongation of the guts and subsequently the enlarged trunks.The enlarged proctodaeums were due to the undifferentiation of inner layer,the expansion of outer epidermal part and the absence of fins around them.In brief,the histological observations provided insights into the reason of the unique external malformations in some degree.展开更多
Heteropolyacid nanoparticles(NPs)were supported on Cs-modified three-dimensionally ordered macroporous(3DOM)SiO2 and used as the catalyst for the oxidation of methacrolein(MAL)to methacrylic acid(MAA).Hydrothermal tre...Heteropolyacid nanoparticles(NPs)were supported on Cs-modified three-dimensionally ordered macroporous(3DOM)SiO2 and used as the catalyst for the oxidation of methacrolein(MAL)to methacrylic acid(MAA).Hydrothermal treatment and incipient wetness impregnation were employed respectively for the Cs-modification.It was found that hydrothermal Cs-modification of 3DOM SiO2 promoted the dispersion of the supported heteropolyacid,which showed an average particle size of 5.2 nm,much smaller than that(17.6 nm)on the Csmodified 3DOM SiO2 prepared by incipient wetness impregnation.The effects of hydrothermal treatment on the structure and catalytic performance of the catalyst were investigated.Results showed that the ion exchange between Cs+and the surface silanol groups on 3DOM SiO2 was promoted with the increase of the hydrothermal temperature.Meanwhile,Cs-modification helped the heteropolyacid to retain intact Keggin structure,inhibiting the formation of MoO3.Highly dispersed heteropolyacid NPs with enhanced structural stability exhibited excellent selectivity to MAA in the oxidation of MAL.展开更多
Sharing the advantages of high optical power,high efficiency and design flexibility in a compact size,quantum cascade lasers(QCLs)are excellent mid-to-far infrared laser sources for gas sensing,infrared spectroscopic,...Sharing the advantages of high optical power,high efficiency and design flexibility in a compact size,quantum cascade lasers(QCLs)are excellent mid-to-far infrared laser sources for gas sensing,infrared spectroscopic,medical diagnosis,and defense applications.Metalorganic chemical vapor deposition(MOCVD)is an important technology for growing high quality semiconductor materials,and has achieved great success in the semiconductor industry due to its advantages of high efficiency,short maintenance cycles,and high stability and repeatability.The utilization of MOCVD for the growth of QCL materials holds a significant meaning for promoting the large batch production and industrial application of QCL devices.This review summarizes the recent progress of QCLs grown by MOCVD.Material quality and the structure design together determine the device performance.Research progress on the performance improvement of MOCVD-grown QCLs based on the optimization of material quality and active region structure are mainly reviewed.展开更多
We demonstrated a scheme of phase-locked terahertz quantum cascade lasers(THz QCLs)array,with a single-mode pulse power of 108 mW at 13 K.The device utilizes a Talbot cavity to achieve phase locking among five ridge l...We demonstrated a scheme of phase-locked terahertz quantum cascade lasers(THz QCLs)array,with a single-mode pulse power of 108 mW at 13 K.The device utilizes a Talbot cavity to achieve phase locking among five ridge lasers with first-order buried distributed feedback(DFB)grating,resulting in nearly five times amplification of the single-mode power.Due to the optimum length of Talbot cavity depends on wavelength,the combination of Talbot cavity with the DFB grating leads to better power amplification than the combination with multimode Fabry-Perot(F-P)cavities.The Talbot cavity facet reflects light back to the ridge array direction and achieves self-imaging in the array,enabling phase-locked operation of ridges.We set the spacing between adjacent elements to be 220μm,much larger than the free-space wavelength,ensuring the operation of the fundamental supermode throughout the laser's dynamic range and obtaining a high-brightness far-field distribution.This scheme provides a new approach for enhancing the single-mode power of THz QCLs.展开更多
In this work,we demonstrated high-power quantum cascade laser(QCL)arrays lasing at λ~5μm by employing an optimized coupled-ridge waveguide(CRW)structure.Five-element QCL arrays were simulated and fabricated through ...In this work,we demonstrated high-power quantum cascade laser(QCL)arrays lasing at λ~5μm by employing an optimized coupled-ridge waveguide(CRW)structure.Five-element QCL arrays were simulated and fabricated through a two-step etching method to extend the CRW structure to a mid-wave infrared regime.A lateral far-field with the main peak near a diffraction-limited intensity curve of about 10°was observed by properly designing a geometric shape of the ridges and interspaces.By introducing a buried 2nd-order distributed feedback(DFB)grating,substrate emission with a radiation power above 1 W at 25℃ is achieved.Single longitudinal mode operation is obtained by changing the temperature of the heatsink with a good linear wavelength tuning coefficient of -0.2 cm^(-1)/K.展开更多
For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with th...For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with that of an ordinary sampled grating laser with an emission wavelength of approximately 8.6μm,when the periodicities within both the base grating and the sample grating are kept constant.Under this condition,an improvement in the continuous tuning capability of the QCL array is ensured.The ASG structure is fabricated in holographic exposure and optical photolithography,thereby enhancing its flexibility,repeatability,and cost-effectiveness.The wavelength modulation capability of the two channels of the grating is insensitive to the variations in channel size,assuming that the overall waveguide width remains constant.The output wavelength can be tailored freely within a certain range by adjusting the width of the ridge and the material of the cladding layer.展开更多
The Three Gorges Project, also known as the Yangtze River Three Gorges Water Control Project, is located in Yichang, Hubei Province, China. The dam is one of the largest hydropower stations in the world, with an eleva...The Three Gorges Project, also known as the Yangtze River Three Gorges Water Control Project, is located in Yichang, Hubei Province, China. The dam is one of the largest hydropower stations in the world, with an elevation of 185 meters and a water storage elevation of 175 meters.展开更多
In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages ...In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range.展开更多
The purpose of this study is to clarify the significance of postoperative radiotherapy for N2 lung cancer.This study aimed to investigate the effect of postoperative radiotherapy on the survival and prognosis of patie...The purpose of this study is to clarify the significance of postoperative radiotherapy for N2 lung cancer.This study aimed to investigate the effect of postoperative radiotherapy on the survival and prognosis of patients with N2 lung cancer.Data from 12,000 patients with N2 lung cancer were extracted from the Surveillance,Epidemiology,and End Results database(2004-2012).Age at disease onset and 5-year survival rates were calculated.Survival curves were plotted using the Kaplan-Meier method.The univariate log-rank test was performed.Multivariate Cox regression were used to examine factors affecting survival.Patients’median age was 67 years(mean 66.46±10.03).The 5-year survival rate was 12.55%.Univariate analysis revealed age,sex,pathology,and treatment regimen as factors affecting prognosis.In multivariate analysis,when compared to postoperative chemotherapy,postoperative chemoradiotherapy was better associated with survival benefits(hazard ratio[HR]=0.85,95%confidence interval[CI]:0.813-0.898,P<0.001).Propensity score matching revealed that patients who had received postoperative chemoradiotherapy had a better prognosis than did patients who had received postoperative chemotherapy(HR=0.869,95%CI:0.817-0.925,P<0.001).Female patients and patients aged<65 years had a better prognosis than did their counterparts.Patients with adenocarcinoma had a better prognosis than did patients with squamous cell carcinoma.Moreover,prognosis worsened with increasing disease T stage.Patients who had received postoperative chemoradiotherapy had a better prognosis than did patients who had received postoperative chemotherapy.Postoperative radiotherapy was an independent prognostic factor in this patient group.展开更多
Bidens pilosa, a globally invasive Asteraceae plant, threatens both natural and agro-ecological habitats. Species distribution models (SDMs) are a valuable tool for predicting invasion potential, often exclusively bas...Bidens pilosa, a globally invasive Asteraceae plant, threatens both natural and agro-ecological habitats. Species distribution models (SDMs) are a valuable tool for predicting invasion potential, often exclusively based on climate variables. Here, we aimed to predict the current and future global distribution of B. pilosa by integrating climatic, human-induced and biodiversity factors, all of which are critical for accurate projections. Our more comprehensive results showed that climate conditions were the main driver of B. pilosa’s current distribution, with an expanded suitable area compared to previous studies, especially in eastern China and the Sichuan Basin. Incorporating human-induced factors significantly reduced predicted suitable areas, reflecting the species’ association with disturbed environments shaped by human activities. Biodiversity factors further refined habitat suitability, as areas with high phylogenetic richness were identified as potential hotspots for invasion due to competitive or facilitative interactions. Future predictions, based on solely available climate data, suggested a high risk of habitat expansions in Asia, Europe and North America. Niche dynamic analyses revealed that introduced populations occupied a distinct environmental niche space compared to native populations, due to adapting to altered climatic and anthropogenic conditions. This ecological niche divergence is likely driving the increased invasion risk in the introduced range. Our study underscores the complex interactions between climate conditions, biodiversity and human activity in shaping the spread of B. pilosa. SDMs integrating climatic, biotic variables and human-influenced factors, together with updated occurrence data improve predictions of invasion spread and help guide targeted management.展开更多
Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and s...Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and submicrocrystals/nanocrystals inside.How to effectively combine the advantages of both relaxor ferroelectric ceramics and glass-ceramics is of great significance for the development of new dielectric materials with high energy storage performance.In this work,we firstly prepared BaO-SrO-Bi_(2)O_(3)-Na_(2)0-TiO_(2)-Al_(2)O_(3)-SiO_(2)(abbreviated as GS)glass powders,and then fabricated(Ba_(0.3)Sr_(0.7))_(0.5)(Bi_(0.5)Na_(0.5))_(0.5)TiO_(3)+x wt%GS ceramic composites(abbreviated as BSo.sBNT-xGS,x=0,2,6,10,14,16,and 18).Submicrocrystals/nanocrystals with a similar composition to BSo.sBNT were crystalized from the glass,ensuring the formation of uniform core-shell structure in BSo.sBNT-xGS relaxor ferroelectric ceramic/glass-ceramic composites.When the addition amount of GS was 14 wt%,the composite possessed both high&r(>3200 at 1 kHz)and high E,(~170 kV/cm)at room temperature,and their recoverable energy storage density and efficiency were Wrec=2.1 J/cm’and n=65.2%,respectively.The BSo.sBNT-14GS composite also had several attractive properties such as good temperature,frequency,cycle stability,and fast charge-discharge speed.This work provides insights into the relaxor ceramic/glass-ceramic composites for pulsed power capacitors and sheds light on the utilization of the hybrid systems.展开更多
The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the ...The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the corresponding E3 ligases and deubiquitinating enzymes(DUBs)remain elusive.Here,we found that the K63-linked polyubiquitin chains loaded on MAVS can be directly recognized by RIG-I to initiate RIG-I-mediated MAVS aggregation with the prerequisite of the CARDRIG-I-CARDMAVS interaction.Interestingly,many K63-linked polyubiquitin chains attach to MAVS via an unanchored linkage.We identified Ube2N as a major ubiquitin-conjugating enzyme for MAVS and revealed that Ube2N cooperates with the E3 ligase Riplet and TRIM31 to promote the unanchored K63-linked polyubiquitination of MAVS.In addition,we identified USP10 as a direct DUB that removes unanchored K63-linked polyubiquitin chains from MAVS.Consistently,USP10 attenuates RIG-I-mediated MAVS aggregation and the production of type I interferon.Mice with a deficiency in USP10 show more potent resistance to RNA virus infection.Our work proposes a previously unknown mechanism for the activation of the RLR signaling cascade triggered by MAVS-attached unanchored K63-linked polyubiquitin chains and establishes the DUB USP10 and the E2:E3 pair Ube2N-Riplet/TRIM31 as a specific regulatory system for the unanchored K63-linked ubiquitination and aggregation of MAVS upon viral infection.展开更多
InAs-based interband cascade lasers(ICLs)with InAs plasmon waveguides or InAs/AlSb superlattice(SL)waveguides were demonstrated at emission wavelengths below 4.1μm.The threshold current densities of the lasers with S...InAs-based interband cascade lasers(ICLs)with InAs plasmon waveguides or InAs/AlSb superlattice(SL)waveguides were demonstrated at emission wavelengths below 4.1μm.The threshold current densities of the lasers with SL waveguides were 37 A/cm;at 77 K in continuous wave mode.The operation temperature of these lasers reached room temperature in pulsed mode.Compared with the thick InAs n++plasmon cladding layer,the InAs/AlSb superlattice cladding layers have greater advantages for ICLs with wavelengths less than 4μm even in InAs based ICLs because in the short-wavelength region they have a higher confinement factor than InAs plasmon waveguides.展开更多
Immune checkpoint inhibitors(ICIs)have demonstrated unparalleled clinical responses and revolutionized the paradigm of tumor treatment,while substantial patients remain unresponsive or develop resistance to ICIs as a ...Immune checkpoint inhibitors(ICIs)have demonstrated unparalleled clinical responses and revolutionized the paradigm of tumor treatment,while substantial patients remain unresponsive or develop resistance to ICIs as a single agent,which is traceable to cellular metabolic dysfunction.Although dysregulated metabolism has long been adjudged as a hallmark of tumor,it is now increasingly accepted that metabolic reprogramming is not exclusive to tumor cells but is also characteristic of immunocytes.Correspondingly,people used to pay more attention to the effect of tumor cell metabolism on immunocytes,but in practice immunocytes interact intimately with their own metabolic function in a way that has never been realized before during their activation and differentiation,which opens up a whole new frontier called immunometabolism.The metabolic intervention for tumor-infiltrating immunocytes could offer fresh opportunities to break the resistance and ameliorate existing ICI immunotherapy,whose crux might be to ascertain synergistic combinations of metabolic intervention with ICIs to reap synergic benefits and facilitate an adjusted anti-tumor immune response.Herein,we elaborate potential mechanisms underlying immunotherapy resistance from a novel dimension of metabolic reprogramming in diverse tumor-infiltrating immunocytes,and related metabolic intervention in the hope of offering a reference for targeting metabolic vulnerabilities to circumvent immunotherapeutic resistance.展开更多
We demonstrate a broad area（400 μm） high power quantum cascade laser（QCL）. A total peak power of 62 W operating at room temperature is achieved at λ~ 4.7 μm. The temperature dependence of the peak power charact...We demonstrate a broad area（400 μm） high power quantum cascade laser（QCL）. A total peak power of 62 W operating at room temperature is achieved at λ~ 4.7 μm. The temperature dependence of the peak power characteristic is given in the experiment, and also the temperature of the active zone is simulated by a finite-elementmethod（FEM）. We find that the interface roughness of the active core has a great effect on the temperature of the active zone and can be enormously improved using the solid source molecular beam epitaxy（MBE） growth system.展开更多
High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavel...High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavelength confinement of the waveguide structure,direct beam brightness upscaling with device area remains elusive due to several mode competition and external optical lens is normally used to enhance the THz beam brightness.Here,we propose a metallic THz photonic crystal resonator with a phase-engineered design for single mode surface emission over a broad area.The quantum cascade surface-emitting laser is capable of delivering an output peak power over 185 mW with a narrow beam divergence of 4.4°×4.4°at 3.88 THz.A high beam brightness of 1.6×10^(7)W sr^(-1)m^(-2)with near-diffraction-limited M2 factors of 1.4 in both vertical and lateral directions is achieved from a large device area of 1.6×1.6 mm^(2)without using any optical lenses.The adjustable phase shift between the lattices enables a stable and high-intensity surface emission over a broad device area,which makes it an ideal light extractor for large-scale THz emitters.Our research paves the way to high brightness solid-state THz lasers and facilitates new applications in standoff THz imaging,detection,and diagnosis.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.12494604,12393834,12393831,62274014,6223501662335015)the National Key R&D Program of China (Grant No.2024YFA1208900)。
文摘The development of quantum materials for single-photon emission is crucial for the advancement of quantum information technology.Although significant advancements have been witnessed in recent years for single-photon sources in the near-infrared band(λ∼700–1000 nm),several challenges have yet to be addressed for ideal single-photon emission at the telecommunication band.In this study,we present a droplet-epitaxy strategy for O-band to C-band single-photon source-based semiconductor quantum dots(QDs)using metal-organic vaporphase epitaxy(MOVPE).By investigating the growth conditions of the epitaxial process,we have successfully synthesized InAs/InP QDs with narrow emission lines spanning a broad spectral range of λ∼1200–1600 nm.The morphological and optical properties of the samples were characterized using atomic force microscopy and microphotoluminescence spectroscopy.The recorded single-photon purity of a plain QD structure reaches g^((2))(0)=0.16,with a radiative recombination lifetime as short as 1.5 ns.This work provides a crucial platform for future research on integrated microcavity enhancement techniques and coupled QDs with other quantum photonics in the telecom bands,offering significant prospects for quantum network applications.
文摘<div style="text-align:justify;"> In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range. </div>
基金The authors would thank Ping Liang and Ying Hu for their help with device fabrication.This work was supported by the National Key Research and Development Program of China(Grant No.2020YFB0408401)in part by the National Natural Science Foundation of China(Grant Nos.61991430,61774146,61790583,61734006,61835011,61674144,61774150,61805168)+1 种基金in part by Beijing Municipal Science&Technology Commission(Grant No.Z201100004020006)in part by the Key Projects of the Chinese Academy of Sciences(Grant Nos.2018147,YJKYYQ20190002,QYZDJ-SSW-JSC027,XDB43000000,ZDKYYQ20200006).
文摘Robust quantum cascade laser(QCL)enduring high temperature continuous-wave(CW)operation is of critical importance for some applications.We report on the realization of lattice-matched InGaAs/InAlAs/InP QCL materials grown by metal-organic chemical vapor deposition(MOCVD).High interface quality structures designed for light emission at 8.5μm are achieved by optimizing and precise controlling of growth conditions.A CW output power of 1.04 W at 288 K was obtained from a 4 mm-long and 10μm-wide coated laser.Corresponding maximum wall-plug efficiency and threshold current density were 7.1%and 1.18 kA/cm2,respectively.The device can operate in CW mode up to 408 K with an output power of 160 mW.
基金supported by the National Natural Science Foundation of China (Grant No. 41721004)。
文摘This study investigates the influences of boreal summer intraseasonal oscillation(BSISO), which originates from the equatorial Indian Ocean and prevails over the Indo-Pacific region, on precipitation over Southeast China, including South China and Yangtze River Valley. The results indicate that the BSISO-related precipitation anomalies are remarkably different between early summer(May–June) and late summer(July–August). The BSISO-related precipitation anomalies tend to appear more northward in late summer in comparison with early summer. Accordingly, the BSISO is significantly related to precipitation anomalies over South China during many phases in early summer but related to very weak anomalies during all the phases in late summer. Such northward shifts of precipitation anomalies from early summer to late summer are clearest during phases 4 and 7, when the lower-tropospheric anticyclonic and cyclonic circulation anomalies dominate over the subtropical western North Pacific, respectively. Finally, we explain the differences between early and late summers through the seasonal northward migration of climatological equivalent potential temperature gradient, which is located in the South China during early summer but migrates northward to the YRV during late summer.
基金supported by the National Natural Science Foundation of China (No. 20877023,20507007)
文摘Tributyltin（TBT）,a biocide used in antifouling paints,has shown strong teratogenic effects on Xenopus tropicalis embryos at environmentally relevant concentrations.X.tropicalis embryos were exposed to 50,100 and 200 ng/L tributyltin chloride for 72 hr.The histological changes were further observed on abnormal eyes,enlarged trunks,enlarged proctodaeums and absence of fins induced by TBT.The lens and the retinal layers of abnormal eyes were slightly or barely differentiated,and that the pigment epithelium was neither continuous nor smooth.The abdomens were full of undifferentiated gut tissue with yolk-rich inclusions in the tadpoles with enlarged trunks.The proctodaeums formed a bump-like or columnar structure.The mass of yolk-rich cells occupied the lumen,blocked the opening and even turned inside out of the proctodaeum.Both the ventral and dorsal fins in trunks and tails became narrow or even disappeared totally.Our results suggest that great changes of histology took place corresponding to the unique phenotypes.The gut tissue was poorly differentiated,which led to the failed elongation of the guts and subsequently the enlarged trunks.The enlarged proctodaeums were due to the undifferentiation of inner layer,the expansion of outer epidermal part and the absence of fins around them.In brief,the histological observations provided insights into the reason of the unique external malformations in some degree.
基金financially supported by the National Natural Science Foundation of China(21206179)the Natural Science Foundation of Shandong Province(ZR2018MB033)。
文摘Heteropolyacid nanoparticles(NPs)were supported on Cs-modified three-dimensionally ordered macroporous(3DOM)SiO2 and used as the catalyst for the oxidation of methacrolein(MAL)to methacrylic acid(MAA).Hydrothermal treatment and incipient wetness impregnation were employed respectively for the Cs-modification.It was found that hydrothermal Cs-modification of 3DOM SiO2 promoted the dispersion of the supported heteropolyacid,which showed an average particle size of 5.2 nm,much smaller than that(17.6 nm)on the Csmodified 3DOM SiO2 prepared by incipient wetness impregnation.The effects of hydrothermal treatment on the structure and catalytic performance of the catalyst were investigated.Results showed that the ion exchange between Cs+and the surface silanol groups on 3DOM SiO2 was promoted with the increase of the hydrothermal temperature.Meanwhile,Cs-modification helped the heteropolyacid to retain intact Keggin structure,inhibiting the formation of MoO3.Highly dispersed heteropolyacid NPs with enhanced structural stability exhibited excellent selectivity to MAA in the oxidation of MAL.
基金supported by National Key Research and Development Program of China (Grant No.2021YFB3201900)National Natural Science Foundation of China (Grant Nos.61991430,62235016)+1 种基金Youth Innovation Promotion Association of CAS (Grant Nos.2022112,Y2022046)Key projects of the Chinese Academy of Sciences (Grant No.XDB43000000)。
文摘Sharing the advantages of high optical power,high efficiency and design flexibility in a compact size,quantum cascade lasers(QCLs)are excellent mid-to-far infrared laser sources for gas sensing,infrared spectroscopic,medical diagnosis,and defense applications.Metalorganic chemical vapor deposition(MOCVD)is an important technology for growing high quality semiconductor materials,and has achieved great success in the semiconductor industry due to its advantages of high efficiency,short maintenance cycles,and high stability and repeatability.The utilization of MOCVD for the growth of QCL materials holds a significant meaning for promoting the large batch production and industrial application of QCL devices.This review summarizes the recent progress of QCLs grown by MOCVD.Material quality and the structure design together determine the device performance.Research progress on the performance improvement of MOCVD-grown QCLs based on the optimization of material quality and active region structure are mainly reviewed.
基金funded by National Natural Science Foundation of China, grant numbers 62335006, 62274014, 62235016, 61734006, 61835011, 61991430funded by Key Program of the Chinese Academy of Sciences, grant numbers XDB43000000, QYZDJSSW-JSC027Beijing Municipal Science & Technology Commission, grant number Z221100002722018
文摘We demonstrated a scheme of phase-locked terahertz quantum cascade lasers(THz QCLs)array,with a single-mode pulse power of 108 mW at 13 K.The device utilizes a Talbot cavity to achieve phase locking among five ridge lasers with first-order buried distributed feedback(DFB)grating,resulting in nearly five times amplification of the single-mode power.Due to the optimum length of Talbot cavity depends on wavelength,the combination of Talbot cavity with the DFB grating leads to better power amplification than the combination with multimode Fabry-Perot(F-P)cavities.The Talbot cavity facet reflects light back to the ridge array direction and achieves self-imaging in the array,enabling phase-locked operation of ridges.We set the spacing between adjacent elements to be 220μm,much larger than the free-space wavelength,ensuring the operation of the fundamental supermode throughout the laser's dynamic range and obtaining a high-brightness far-field distribution.This scheme provides a new approach for enhancing the single-mode power of THz QCLs.
基金supported by National Basic Research Program of China(Grant Nos.2018YFA0209103,2018YFB2200504)in part by National Natural Science Foundation of China(Grant Nos.61991430,61774146,61790583,61734006,61835011,61674144,61774150,61805168)+1 种基金in part by Beijing Municipal Science&Technology Commission(Grant No.Z201100004020006)in part by the Key projects of the Chinese Academy of Sciences(Grant No.2018147,Grant No.YJKYYQ20190002,Grant No.QYZDJ-SSW-JSC027,Grant No.XDB43000000,Grant No.ZDKYYQ20200006).
文摘In this work,we demonstrated high-power quantum cascade laser(QCL)arrays lasing at λ~5μm by employing an optimized coupled-ridge waveguide(CRW)structure.Five-element QCL arrays were simulated and fabricated through a two-step etching method to extend the CRW structure to a mid-wave infrared regime.A lateral far-field with the main peak near a diffraction-limited intensity curve of about 10°was observed by properly designing a geometric shape of the ridges and interspaces.By introducing a buried 2nd-order distributed feedback(DFB)grating,substrate emission with a radiation power above 1 W at 25℃ is achieved.Single longitudinal mode operation is obtained by changing the temperature of the heatsink with a good linear wavelength tuning coefficient of -0.2 cm^(-1)/K.
基金Project supported by the National Basic Research Program of China (Grant No. 2021YFB3201900)in part by the National Natural Science Foundation of China (Grant Nos. 61991430, 61774146, 61790583,61627822, and 61774150)in part by the Key Projects of the Chinese Academy of Sciences (Grant Nos. 2018147, YJKYYQ20190002, QYZDJ-SSW-JSC027,XDB43000000)
文摘For mode selection in a quantum cascade laser(QCL),we demonstrate an anti-symmetric sampled grating(ASG).The wavelength of the-1-th mode of this laser has been blue-shifted more than 75 nm(~10 cm^(-1))compared with that of an ordinary sampled grating laser with an emission wavelength of approximately 8.6μm,when the periodicities within both the base grating and the sample grating are kept constant.Under this condition,an improvement in the continuous tuning capability of the QCL array is ensured.The ASG structure is fabricated in holographic exposure and optical photolithography,thereby enhancing its flexibility,repeatability,and cost-effectiveness.The wavelength modulation capability of the two channels of the grating is insensitive to the variations in channel size,assuming that the overall waveguide width remains constant.The output wavelength can be tailored freely within a certain range by adjusting the width of the ridge and the material of the cladding layer.
基金provided by the National Natural Science Foundation of China (No.41572336)。
文摘The Three Gorges Project, also known as the Yangtze River Three Gorges Water Control Project, is located in Yichang, Hubei Province, China. The dam is one of the largest hydropower stations in the world, with an elevation of 185 meters and a water storage elevation of 175 meters.
文摘In this paper, we report a single-mode Fabry-Pérot long wave infrared quantum cascade lasers based on the double phonon resonance active region design. For room temperature CW operation, the wafer with 35 stages was processed into buried heterostructure lasers. For a 4 mm long and 13 μm wide laser with high-reflectivity (HR) coating on the rear facet, continuous wave output power of 43 mW at 288 K and 5 mW at 303 K is obtained with threshold current densities of 2.17 and 2.7 kA/cm2. The lasing wavelength is around 10.5 μm. Single mode emission was observed for this particular device over the whole investigated current and temperature range.
基金Project of Hebei Medical Science Research Plan in 2021(20210831)National key research and development program of China(2018YFE0114100).
文摘The purpose of this study is to clarify the significance of postoperative radiotherapy for N2 lung cancer.This study aimed to investigate the effect of postoperative radiotherapy on the survival and prognosis of patients with N2 lung cancer.Data from 12,000 patients with N2 lung cancer were extracted from the Surveillance,Epidemiology,and End Results database(2004-2012).Age at disease onset and 5-year survival rates were calculated.Survival curves were plotted using the Kaplan-Meier method.The univariate log-rank test was performed.Multivariate Cox regression were used to examine factors affecting survival.Patients’median age was 67 years(mean 66.46±10.03).The 5-year survival rate was 12.55%.Univariate analysis revealed age,sex,pathology,and treatment regimen as factors affecting prognosis.In multivariate analysis,when compared to postoperative chemotherapy,postoperative chemoradiotherapy was better associated with survival benefits(hazard ratio[HR]=0.85,95%confidence interval[CI]:0.813-0.898,P<0.001).Propensity score matching revealed that patients who had received postoperative chemoradiotherapy had a better prognosis than did patients who had received postoperative chemotherapy(HR=0.869,95%CI:0.817-0.925,P<0.001).Female patients and patients aged<65 years had a better prognosis than did their counterparts.Patients with adenocarcinoma had a better prognosis than did patients with squamous cell carcinoma.Moreover,prognosis worsened with increasing disease T stage.Patients who had received postoperative chemoradiotherapy had a better prognosis than did patients who had received postoperative chemotherapy.Postoperative radiotherapy was an independent prognostic factor in this patient group.
基金funding through the National Natural Science Foundation of China (32201438)the Scientific Research of Huazhong Agricultural University (11042110026 and 2662023ZHPY002)+1 种基金Wuhan talent grant for fundingNational Natural Science Foundation of China (32071660)。
文摘Bidens pilosa, a globally invasive Asteraceae plant, threatens both natural and agro-ecological habitats. Species distribution models (SDMs) are a valuable tool for predicting invasion potential, often exclusively based on climate variables. Here, we aimed to predict the current and future global distribution of B. pilosa by integrating climatic, human-induced and biodiversity factors, all of which are critical for accurate projections. Our more comprehensive results showed that climate conditions were the main driver of B. pilosa’s current distribution, with an expanded suitable area compared to previous studies, especially in eastern China and the Sichuan Basin. Incorporating human-induced factors significantly reduced predicted suitable areas, reflecting the species’ association with disturbed environments shaped by human activities. Biodiversity factors further refined habitat suitability, as areas with high phylogenetic richness were identified as potential hotspots for invasion due to competitive or facilitative interactions. Future predictions, based on solely available climate data, suggested a high risk of habitat expansions in Asia, Europe and North America. Niche dynamic analyses revealed that introduced populations occupied a distinct environmental niche space compared to native populations, due to adapting to altered climatic and anthropogenic conditions. This ecological niche divergence is likely driving the increased invasion risk in the introduced range. Our study underscores the complex interactions between climate conditions, biodiversity and human activity in shaping the spread of B. pilosa. SDMs integrating climatic, biotic variables and human-influenced factors, together with updated occurrence data improve predictions of invasion spread and help guide targeted management.
基金supported by the National Natural Science Foundation of China(52267002)Natural Science Foundation of Jiangxi Province(20212ACB204010)+1 种基金Science&Technology Research Project of Jiangxi Provincial Education Department(GJJ211301)the Graduate Innovation Fund of Jiangxi Province(YC2021-S527).
文摘Relaxor ferroelectric ceramics have very high dielectric constant(e)but relatively low electrical breakdown strength(Eb),while glass-ceramics exhibit higher E,due to the more uniformly dispersed amorphous phases and submicrocrystals/nanocrystals inside.How to effectively combine the advantages of both relaxor ferroelectric ceramics and glass-ceramics is of great significance for the development of new dielectric materials with high energy storage performance.In this work,we firstly prepared BaO-SrO-Bi_(2)O_(3)-Na_(2)0-TiO_(2)-Al_(2)O_(3)-SiO_(2)(abbreviated as GS)glass powders,and then fabricated(Ba_(0.3)Sr_(0.7))_(0.5)(Bi_(0.5)Na_(0.5))_(0.5)TiO_(3)+x wt%GS ceramic composites(abbreviated as BSo.sBNT-xGS,x=0,2,6,10,14,16,and 18).Submicrocrystals/nanocrystals with a similar composition to BSo.sBNT were crystalized from the glass,ensuring the formation of uniform core-shell structure in BSo.sBNT-xGS relaxor ferroelectric ceramic/glass-ceramic composites.When the addition amount of GS was 14 wt%,the composite possessed both high&r(>3200 at 1 kHz)and high E,(~170 kV/cm)at room temperature,and their recoverable energy storage density and efficiency were Wrec=2.1 J/cm’and n=65.2%,respectively.The BSo.sBNT-14GS composite also had several attractive properties such as good temperature,frequency,cycle stability,and fast charge-discharge speed.This work provides insights into the relaxor ceramic/glass-ceramic composites for pulsed power capacitors and sheds light on the utilization of the hybrid systems.
基金supported by grants from the National Natural Science Foundation of China(31730026,81930039,32000633)National Key Research and Development Program(2021YFC2300603),Natural Science Foundation of Shandong Province(ZR2020QH136)China Postdoctoral Science Foundation(2020M682187),and Postdoctoral Innovation Project of Shandong Province(202002012).
文摘The adaptor molecule MAVS forms prion-like aggregates to govern the RIG-I-like receptor(RLR)signaling cascade.Lys63(K63)-linked polyubiquitination is critical for MAVS aggregation,yet the underlying mechanism and the corresponding E3 ligases and deubiquitinating enzymes(DUBs)remain elusive.Here,we found that the K63-linked polyubiquitin chains loaded on MAVS can be directly recognized by RIG-I to initiate RIG-I-mediated MAVS aggregation with the prerequisite of the CARDRIG-I-CARDMAVS interaction.Interestingly,many K63-linked polyubiquitin chains attach to MAVS via an unanchored linkage.We identified Ube2N as a major ubiquitin-conjugating enzyme for MAVS and revealed that Ube2N cooperates with the E3 ligase Riplet and TRIM31 to promote the unanchored K63-linked polyubiquitination of MAVS.In addition,we identified USP10 as a direct DUB that removes unanchored K63-linked polyubiquitin chains from MAVS.Consistently,USP10 attenuates RIG-I-mediated MAVS aggregation and the production of type I interferon.Mice with a deficiency in USP10 show more potent resistance to RNA virus infection.Our work proposes a previously unknown mechanism for the activation of the RLR signaling cascade triggered by MAVS-attached unanchored K63-linked polyubiquitin chains and establishes the DUB USP10 and the E2:E3 pair Ube2N-Riplet/TRIM31 as a specific regulatory system for the unanchored K63-linked ubiquitination and aggregation of MAVS upon viral infection.
基金Project supported by the National Natural Science Foundation of China(Nos.61790583,61774150,61774151)the National Basic Research Program of China(No.2014CB643903)
文摘InAs-based interband cascade lasers(ICLs)with InAs plasmon waveguides or InAs/AlSb superlattice(SL)waveguides were demonstrated at emission wavelengths below 4.1μm.The threshold current densities of the lasers with SL waveguides were 37 A/cm;at 77 K in continuous wave mode.The operation temperature of these lasers reached room temperature in pulsed mode.Compared with the thick InAs n++plasmon cladding layer,the InAs/AlSb superlattice cladding layers have greater advantages for ICLs with wavelengths less than 4μm even in InAs based ICLs because in the short-wavelength region they have a higher confinement factor than InAs plasmon waveguides.
基金supported by research grants from the National Natural Science Foundation of China(No.82272806)the Natural Science Foundation of Hunan Province for Excellent Young Scholars(No.2021JJ20088)Frontier Cross Research Project of Central South University(2023QYJC039)to Fang Wu.
文摘Immune checkpoint inhibitors(ICIs)have demonstrated unparalleled clinical responses and revolutionized the paradigm of tumor treatment,while substantial patients remain unresponsive or develop resistance to ICIs as a single agent,which is traceable to cellular metabolic dysfunction.Although dysregulated metabolism has long been adjudged as a hallmark of tumor,it is now increasingly accepted that metabolic reprogramming is not exclusive to tumor cells but is also characteristic of immunocytes.Correspondingly,people used to pay more attention to the effect of tumor cell metabolism on immunocytes,but in practice immunocytes interact intimately with their own metabolic function in a way that has never been realized before during their activation and differentiation,which opens up a whole new frontier called immunometabolism.The metabolic intervention for tumor-infiltrating immunocytes could offer fresh opportunities to break the resistance and ameliorate existing ICI immunotherapy,whose crux might be to ascertain synergistic combinations of metabolic intervention with ICIs to reap synergic benefits and facilitate an adjusted anti-tumor immune response.Herein,we elaborate potential mechanisms underlying immunotherapy resistance from a novel dimension of metabolic reprogramming in diverse tumor-infiltrating immunocytes,and related metabolic intervention in the hope of offering a reference for targeting metabolic vulnerabilities to circumvent immunotherapeutic resistance.
基金Project supported by the National Basic Research Program of China(No.2013CB632801)the National Key Research and Development Program(No.2016YFB0402303)+2 种基金the National Natural Science Foundation of China(Nos.61435014,61627822,61574136,61306058,61404131)the Key Projects of Chinese Academy of Sciences(No.ZDRW-XH-20164)the Beijing Natural Science Foundation(No.4162060)
文摘We demonstrate a broad area（400 μm） high power quantum cascade laser（QCL）. A total peak power of 62 W operating at room temperature is achieved at λ~ 4.7 μm. The temperature dependence of the peak power characteristic is given in the experiment, and also the temperature of the active zone is simulated by a finite-elementmethod（FEM）. We find that the interface roughness of the active core has a great effect on the temperature of the active zone and can be enormously improved using the solid source molecular beam epitaxy（MBE） growth system.
基金supported by the National Natural Science Foundation of China(62274014,62235016)Bejing Municipal Science&Technology Commission(Z221100002722018).
文摘High-power terahertz(THz)quantum cascade laser,as an emerging THz solid-state radiation source,is attracting attention for numerous applications including medicine,sensing,and communication.However,due to the subwavelength confinement of the waveguide structure,direct beam brightness upscaling with device area remains elusive due to several mode competition and external optical lens is normally used to enhance the THz beam brightness.Here,we propose a metallic THz photonic crystal resonator with a phase-engineered design for single mode surface emission over a broad area.The quantum cascade surface-emitting laser is capable of delivering an output peak power over 185 mW with a narrow beam divergence of 4.4°×4.4°at 3.88 THz.A high beam brightness of 1.6×10^(7)W sr^(-1)m^(-2)with near-diffraction-limited M2 factors of 1.4 in both vertical and lateral directions is achieved from a large device area of 1.6×1.6 mm^(2)without using any optical lenses.The adjustable phase shift between the lattices enables a stable and high-intensity surface emission over a broad device area,which makes it an ideal light extractor for large-scale THz emitters.Our research paves the way to high brightness solid-state THz lasers and facilitates new applications in standoff THz imaging,detection,and diagnosis.
