Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.A...Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.展开更多
Background and Aims:The poor outcomes of hepatocellular carcinoma(HCC)patients may be due to not only malignant tumors but also limited liver function.Therefore,as stated in major guidelines,only patients with relativ...Background and Aims:The poor outcomes of hepatocellular carcinoma(HCC)patients may be due to not only malignant tumors but also limited liver function.Therefore,as stated in major guidelines,only patients with relatively normal liver function(Child-Pugh A)would be referred for curative hepatectomy.Even so,the postsurgery survival rate of patients is still extremely poor.Direct curative resection may benefit most patients.This study aimed to improve the prognosis predicting accuracy of the Child-Pugh scoring system.Methods:This study included two cohorts:cohort A being composed of 613 HCC patients,with a 23-month median postsurgery follow-up time;and cohort B being composed of 554 tumor-free chronic liver disease patients.Kaplan-Meier test and Cox model were used for survival analysis.Independent-samples t test or one-way ANOVA was used to test the differences between different groups.Results:Serum prealbumin levels were found inversely correlated with worsening of flbrotic scores(r=-0.482,p<0.001).Lower levels of presurgery prealbumin was an independent factor of poor postsurgery prognosis in Child-Pugh A patients,with a hazard ratio of 0.731(p=0.001).By integrating prealbumin together with total bilirubin level,serum albumin concentration and prothrombin time,a modified liver disease prognosis scoring system was developed to define traditional Child-Pugh A HCC patients as Modified Child-Pugh MCP-1,MCP-2 and MCP-3,with median postsurgery overall survival times of 44.00,28.00 and 11.00 months respectively.Conclusions:Preoperative serum prealbumin is a valuable prognosis predicting biomarker for Child-Pugh A HCC patients who may be under consideration for curative resection.With serum prealbumin included as one of the parameters,the MCP scoring system might improve the postsurgery survival predicting accuracy for HCC patients.展开更多
The quality control processes for herbal medicines have been problematic. Flavonoids are the major active components of Huangqin Tang(HQT, a traditional Chinese medicine formula). In this study, we used a combinative ...The quality control processes for herbal medicines have been problematic. Flavonoids are the major active components of Huangqin Tang(HQT, a traditional Chinese medicine formula). In this study, we used a combinative method approach consisting of chromatographic fingerprinting(high performance liquid chromatography; HPLC), quantitative methods and a pharmacodynamic evaluation model to analyze the flavonoids of HQT obtained from different sources. Ten batches of HQT were analyzed by the HPLC fingerprinting method and 26 common peaks were detected, of which 23 peaks corresponded with the chemical profile of HQT. In addition, 11 major compounds were identified by LC–MS analysis(liquid chromatography–tandem mass spectrometer; LC–MS^n) and quantified by the HPLC quantitative method approach. The studied10 batches of HQT were found to be homogeneous in their composition with a similarity between 0.990 and1.000. The distribution of the 11 identified compounds was found to be very similar among the batches. Only slight pharmacodynamic differences were detected between the different batches, confirming the homogeneity of HQT. The results of this study prove that the combination of chromatographic fingerprinting and quantitative analysis can be readily used for comprehensive quality control of herbal medicines.展开更多
Background Preeclampsia （PE） is a multifactorial pregnancy complication.Maternal underlying condition and adverse factors both influence the pathogenesis of PE.Abnormal lipid metabolism as a maternal underlying dise...Background Preeclampsia （PE） is a multifactorial pregnancy complication.Maternal underlying condition and adverse factors both influence the pathogenesis of PE.Abnormal lipid metabolism as a maternal underlying disease may participate in the occurrence and development of PE.This study aimed to observe the effects of adverse factors on PE-like symptoms of pregnant mice with genetic abnormal lipid metabolism.Methods Apolipoprotein C-Ⅲ （ApoC3） transgenic mice with abnormal lipid metabolism were subcutaneously injected with L-arginine methyl ester （L-NAME） or normal saline （NS） daily starting at Day 7 or 16 of pregnancy （ApoC3＋L-NA and ApoC3＋NS groups）,and wild-type （WT） mice served as a control （WT＋L-NA and WT＋NS groups）.All mice were subdivided into early and late subgroups by injection time.The mean arterial pressure （MAP） and urinary protein were measured.Pregnancy outcomes,including fetal weight,placental weight,live birth rate,and fetal absorption rate,were analyzed.Pathologic changes in the placenta were observed by hematoxylin-eosin staining.One-way analysis of variance,t-test,and x2 test were used for statistical analysis.Results MAP significantly increased for ApoC3＋NS groups compared with WT＋NS groups （P 〈0.05）,without significant difference in urine protein.Following L-NAME injection,MAP and urinary protein significantly increased for ApoC3＋L-NA and WT＋L-NA compared with the corresponding NS groups （P 〈0.05）,and the increase for ApoC3＋L-NA was more obvious.Urinary protein levels in early ApoC3＋L-NA and WT＋L-NA significantly increased compared with the corresponding late groups （P 〈0.05）.Fetal absorption rate significantly increased and fetal and placental weights significantly decreased in early ApoC3＋L-NA and WT＋L-NA compared with the corresponding NS groups （P 〈0.05）,without significant difference in late ApoC3＋L-NA and WT＋L-NA groups.Fetal weight in early ApoC3＋L-NA was significantly lower than in early WT＋L-NA 展开更多
Unmanned Aerial Vehicles(UAVs)play a vital role in military warfare.In a variety of battlefield mission scenarios,UAVs are required to safely fly to designated locations without human intervention.Therefore,finding a ...Unmanned Aerial Vehicles(UAVs)play a vital role in military warfare.In a variety of battlefield mission scenarios,UAVs are required to safely fly to designated locations without human intervention.Therefore,finding a suitable method to solve the UAV Autonomous Motion Planning(AMP)problem can improve the success rate of UAV missions to a certain extent.In recent years,many studies have used Deep Reinforcement Learning(DRL)methods to address the AMP problem and have achieved good results.From the perspective of sampling,this paper designs a sampling method with double-screening,combines it with the Deep Deterministic Policy Gradient(DDPG)algorithm,and proposes the Relevant Experience Learning-DDPG(REL-DDPG)algorithm.The REL-DDPG algorithm uses a Prioritized Experience Replay(PER)mechanism to break the correlation of continuous experiences in the experience pool,finds the experiences most similar to the current state to learn according to the theory in human education,and expands the influence of the learning process on action selection at the current state.All experiments are applied in a complex unknown simulation environment constructed based on the parameters of a real UAV.The training experiments show that REL-DDPG improves the convergence speed and the convergence result compared to the state-of-the-art DDPG algorithm,while the testing experiments show the applicability of the algorithm and investigate the performance under different parameter conditions.展开更多
The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on orbit.Currently,there are few researches about the end-effector,and the existing end...The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on orbit.Currently,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical components.According to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are proposed.And the end-effector should accommodate the following misalignments of the mechanical interface.The translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,respectively.Seven end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed elementarily.The three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in detail.The capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS software.The results show that the misalignment tolerance capabilities of these two schemes could satisfy the requirement.And the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,respectively.And the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals end-effector.The end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and the space docking mechanism.展开更多
The Chinese Hα Solar Explorer(CHASE), dubbed “Xihe”—Goddess of the Sun, was launched on October 14, 2021 as the first solar space mission of China National Space Administration(CNSA). The CHASE mission is designed...The Chinese Hα Solar Explorer(CHASE), dubbed “Xihe”—Goddess of the Sun, was launched on October 14, 2021 as the first solar space mission of China National Space Administration(CNSA). The CHASE mission is designed to test a newly developed satellite platform and to acquire the spectroscopic observations in the Hα waveband. The Hα Imaging Spectrograph(HIS)is the scientific payload of the CHASE satellite. It consists of two observational modes: raster scanning mode and continuum imaging mode. The raster scanning mode obtains full-Sun or region-of-interest spectral images from 6559.7 to 6565.9 ? and from 6567.8 to 6570.6 ? with 0.024 ? pixel spectral resolution and 1 min temporal resolution. The continuum imaging mode obtains photospheric images in continuum around 6689 ? with the full width at half maximum of 13.4 ?. The CHASE mission will advance our understanding of the dynamics of solar activity in the photosphere and chromosphere. In this paper, we present an overview of the CHASE mission including the scientific objectives, HIS instrument overview, data calibration flow, and first results of on-orbit observations.展开更多
Artemisia annua is an anti-fever herbal medicine first described in traditional Chinese medicine 1,000 years ago.Artemisinin,the extract of A.annua,and its derivatives(dihydroartemisinin(DHA),artemether,and artesunate...Artemisia annua is an anti-fever herbal medicine first described in traditional Chinese medicine 1,000 years ago.Artemisinin,the extract of A.annua,and its derivatives(dihydroartemisinin(DHA),artemether,and artesunate)have been used for the treatment of malaria with substantial efficacy.Recently,DHA has also been tested for the treatment of lupus erythematosus,indicating that it may function to balance the immune response in immunocompromised individuals.In the present study,the regulatory effect of artemisinin on the murine immune system was systematically investigated in mice infected with two different protozoan parasites(Toxoplasma gondii and Plasmodium berghei).Our results revealed that the mouse spleen index significantly increased(spleen enlargement)in the healthy mice after DHA administration primarily due to the generation of an extra number of lymphocytes and CD8^+T lymphocytes in both the spleen and circulation.DHA could increase the proportion of T helper cells and CD8^+T cells,as well as decrease the number of splenic and circulatory B cells.Further,DHA could reduce the production of proinflammatory cytokines.Our study revealed that apart from their anti-parasitic activity,artemisinin and its derivatives can also actively modulate the immune system to directly benefit the host.展开更多
An ultrahigh-Q silicon racetrack resonator is proposed and demonstrated with uniform multimode silicon photonic waveguides.It consists of two multimode straight waveguides connected by two multimode waveguide bends(MW...An ultrahigh-Q silicon racetrack resonator is proposed and demonstrated with uniform multimode silicon photonic waveguides.It consists of two multimode straight waveguides connected by two multimode waveguide bends(MWBs).In particular,the MWBs are based on modified Euler curves,and a bent directional coupler is used to achieve the selective mode coupling for the fundamental mode and not exciting the higher-order mode in the racetrack.In this way,the fundamental mode is excited and propagates in the multimode racetrack resonator with ultralow loss and low intermode coupling.Meanwhile,it helps achieve a compact 180°bend to make a compact resonator with a maximized free spectral range(FSR).In this paper,for the chosen 1.6μm wide silicon photonic waveguide,the effective radius Reffof the designed 180°bend is as small as 29μm.The corresponding FSR is about 0.9 nm when choosing 260μm long straight waveguides in the racetrack.The present high-Q resonator is realized with a simple standard single-etching process provided by a multiproject wafer foundry.The fabricated device,which has a measured intrinsic Q-factor as high as 2.3×10~6,is the smallest silicon resonator with a>106Q-factor.展开更多
Based on the statistical data, we analyzed and evaluated the degree of coupling and coordination of the eco-economic system in Yanchi County for the period spanning from 1983 to 2014. The eco-economic system can be di...Based on the statistical data, we analyzed and evaluated the degree of coupling and coordination of the eco-economic system in Yanchi County for the period spanning from 1983 to 2014. The eco-economic system can be divided into socioeconomic and ecological sub-systems and their relationship can reveal the interaction state between the two sub-systems and help the local government to establish a coordinated development mode. An index system was constructed to assess the development of the two sub-systems before the evaluation of the degree of coupling and coordination. The principal component regression analysis was adopted to quantitatively assess the influences of natural, economic and social factors on the degree of coupling and coordination of the eco-economic system. Results showed that, from 1983 to 2014, the development trends of both sub-systems were increasing with the ecological sub-system having more fluctuations. The degree of coupling and coordination of the eco-economic system in the study area increased gradually from 1983 to 2014, but experienced five different development stages from the verge of disorder to favorable coordination. The development of the local social and economic conditions was the most important factor influencing the degree of coupling and coordination. The second most important factor was the financial support from the local government. In addition, the environment protection policies also played undeniable roles. Due to the diversity of the influence factors, the government should take comprehensive measures to promote the sustainable development of the eco-economic system.展开更多
Catalytic dehydrogenation of isobutane has recently received considerable attention because of the increasing demand for isobutene.In this study,the synergistic effect between Sn and K on PtSnK/γ-Al2O3 catalysts has ...Catalytic dehydrogenation of isobutane has recently received considerable attention because of the increasing demand for isobutene.In this study,the synergistic effect between Sn and K on PtSnK/γ-Al2O3 catalysts has been investigated by changing the content of Sn.It was found that with the presence of potassium,suitable addition of Sn could not only increase the metal dispersion,but also reduce the catalyst acidity.In these cases,the synergistic effect could also strengthen the interactions between the metal and support,which resulted in an increase in both catalytic activity and stability.In our experiments,Pt-0.6SnK/Al catalyst exhibited the lowest deactivation rate （12.4%） and showed a selectivity to isobutene higher than 94% at the isobutane conversion of about 45.3% after running the reaction for 6 h.However,with the excessive loading of Sn,surface property of active sites and the interactions between metal and support were changed.As a result,the initial optimal ratio between the metallic function and acid function would be destroyed,which was disadvantageous to the reaction.展开更多
Low-dose total body irradiation （LTBI） is used in the treatment of some cancers mainly for immune enhancement rather than cell killing. However, the mechanism underlying LTBI remains unknown. In this study, by analy...Low-dose total body irradiation （LTBI） is used in the treatment of some cancers mainly for immune enhancement rather than cell killing. However, the mechanism underlying LTBI remains unknown. In this study, by analyzing the immune patterns of lymphocytes, we found that the percentage and absolute number of CD4^＋CD25^＋Foxp3^＋ regulatory T cells are markedly decreased in naive mice following treatment with LTBI. On the contrary, the CD4^＋CD44^＋/CD8^＋CD44^＋ effector-memory T cells are greatly increased. Importantly, naive mice treated with dendritic cell-gp100 tumor vaccines under LTBI induced an enhancement of antigen-specific proliferation and cytotoxicity as well as interferon-γ, （IFN-γ） secretion against FIO melanoma tumor challenge, compared to treatment with either the tumor vaccine or LTBI alone. Consequently, the treatment resulted in a reduced tumor burden and prolonged mouse survival. Our data demonstrate that LTBI＇s enhancement of antitumor immunity was mainly associated with selectively decreasing the proportion and number of T regulatory cells, implying the potential application of the combination of LTBI and a tumor vaccine in antitumor therapy.展开更多
Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste,bright color,and high nutritional value.However,neither the regulatory mechanism controlling flavonoid bios...Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste,bright color,and high nutritional value.However,neither the regulatory mechanism controlling flavonoid biosynthesis in mulberry nor the molecular basis of different mulberry fruit colors is fully understood.Here,we report that a flavonoid homeostasis network comprising activation and feedback regulation mechanisms determines mulberry fruit color.In vitro and in vivo assays showed that MYBA-bHLH3-TTG1 regulates the biosynthesis of anthocyanins,while TT2L1 and TT2L2 work with bHLH3 or GL3 and form a MYB-bHLH-WD40(MBW)complex with TTG1 to regulate proanthocyanidin(PA)synthesis.Functional and expression analyses showed that bHLH3 is a key regulator of the regulatory network controlling mulberry fruit coloration and that MYB4 is activated by MBW complexes and participates in negative feedback control of the regulatory network to balance the accumulation of anthocyanins and proanthocyanidins.Our research demonstrates that the interaction between bHLH3 and MYB4 in the homeostasis regulatory network ensures that the fruits accumulate desirable flavonoids and that this network is stable in pigmentrich mulberry fruits.However,the abnormal expression of bHLH3 disrupts the balance of the network and redirects flavonoid metabolic flux in pale-colored fruits,resulting in differences in the levels and proportions of anthocyanins,flavones,and flavonols among differently colored mulberry fruits(red,yellow,and white).The results of our study reveal the molecular basis of the diversity of mulberry fruit colors.展开更多
A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexa...A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.展开更多
Trichosanthin(TCS),extracted from the Chinese medicinal herb Trichosanthes kirilowi,has shown promise for the inhibition of tumor growth.However,its immunomodulatory effect on tumor–host interaction remains unknown.I...Trichosanthin(TCS),extracted from the Chinese medicinal herb Trichosanthes kirilowi,has shown promise for the inhibition of tumor growth.However,its immunomodulatory effect on tumor–host interaction remains unknown.In this study,we focused on the effect of TCS on murine anti-tumor immune response in the 3LL Lewis lung carcinoma tumor model and explored the possible molecular pathways involved.In addition to inhibiting cell proliferation and inducing apoptosis in the 3LL tumor,TCS retarded tumor growth and prolonged mouse survival more significantly in C57BL/6 immunocompetent mice than in nude mice.This reflected the fact that the host immune system was involved in tumor eradication.Using FACS analysis,we found that TCS increased the percentage of effector T cells,particularly Interferon-gamma(IFN-c)producing CD41 and CD81 T cells from tumor-bearing mice.TCS also promoted the vigorous proliferation of antigen-specific effector T cells,markedly increased Th1 cytokine secretion and elicited more memory T cells in tumor-bearing mice,consequently enhancing the anti-tumor response and inducing immune protection.Furthermore,we found that TCS upregulated the expression of tumor suppressor in lung cancer 1(TSLC1)in 3LL tumor cells and the expression of its ligand,class I-restricted T cell-associated molecule(CRTAM),in effector T cells.Blocking TSLC1 expression with small interfering RNA(siRNA)significantly eliminated the effects of TCS on the proliferation and cytokine secretion of effector T cells,suggesting that TCS enhances anti-tumor immune response at least partially by boosting the interaction between TSLC1 and CRTAM.Collectively,our data demonstrate that TCS not only affects tumor cells directly,but also enhances anti-tumor immunity via the interaction between TSLC1 and CRTAM.These findings may lead to the development of a novel approach for tumor regression.展开更多
PtSnSr/HZSM-5 catalysts with different amounts of strontium were prepared by sequential impregnation method, and characterized by BET analysis, TEM, NH3-TPD, Hz-TPR, TPO and TG techniques. The results showed that the ...PtSnSr/HZSM-5 catalysts with different amounts of strontium were prepared by sequential impregnation method, and characterized by BET analysis, TEM, NH3-TPD, Hz-TPR, TPO and TG techniques. The results showed that the addition of strontium could modify the characteristics and properties of both acid function and metal function of Pt-Sn-based cata- lysts. In this case, PtSnSr/HZSM-5 catalyst with an appropriate amount of Sr （1.2%） showed higher catalytic activity and lower amount of coke deposits than PtSn/HZSM-5 catalyst. However, excessive loading of Sr could facilitate the reduction of Sn, which was unfavorable to the reaction. Afterwards, 1.0 m% of Na was added into the PtSnSr（1.2%）/HZSM-5 catalyst to improve the catalytic performance in propane dehydrogenation, and this catalyst displayed the best catalytic performance during our experiments. After having been subjected to reaction for 5 h, the PtSnNa（1.0%）Sr（1,2%）/HZSM-5 catalyst had achieved a higher than 95% selectivity towards propene along with a corresponding propane conversion rate of 32.2%.展开更多
Turbine blade is one of the critical components of aircraft engine.The performance of the engine depends on the shape and dimensions of components,but superalloy blade material cannot be easily machined.Although inves...Turbine blade is one of the critical components of aircraft engine.The performance of the engine depends on the shape and dimensions of components,but superalloy blade material cannot be easily machined.Although investment casting is an ideal process for such net-shape components,it requires an accurate determination of the casting-die profile.In this paper,a reversing design methodology for investment casting die using ProCAST is proposed.By combining the methods of simplifying grid files and quick sorting,the efficiency of sorting and matching can be largely improved.Further,the mould/die cavity anti-deformation system can be easily built.With ProCAST,the optimized die profile for investment casting can be established.展开更多
Advanced multispectral detection technologies have emerged as a significant threat to objects,necessitating the use of multiband camouflage.However,achieving effective camouflage and thermal management across the enti...Advanced multispectral detection technologies have emerged as a significant threat to objects,necessitating the use of multiband camouflage.However,achieving effective camouflage and thermal management across the entire infrared spectrum,especially the short-wave infrared(SWIR)band,remains challenging.This paper proposes a multilayer wavelength-selective emitter that achieves effective camouflage across the entire infrared spectrum,including the near-infrared(NIR),SWIR,mid-wave infrared(MWIR),and long-wave infrared(LWIR)bands,as well as the visible(VIS)band.Furthermore,the emitter enables radiative heat dissipation in two non-atmospheric windows(2.5-3μm and 5-8μm).The emitter’s properties are characterized by low emittance of 0.270/0.042/0.218 in the SWIR/MWIR/LWIR bands,and low reflectance of 0.129/0.281 in the VIS/NIR bands.Moreover,the high emittance of 0.742/0.473 in the two non-atmospheric windows ensures efficient radiative heat dissipation,which results in a temperature decrement of 14.4℃ compared to the Cr reference at 2000Wm^(−2) input power density.This work highlights the role of solar radiance in camouflage,and provides a comprehensive guideline for developing multiband camouflage compatible with radiative heat dissipation,from the visible to LWIR.展开更多
This study focuses on the physical and chemical properties of surficial lunar regolith(LR)samples returned from the Moon by the Chang’E-5(CE-5)mission.Insights regarding the effect of a new sampling geological site o...This study focuses on the physical and chemical properties of surficial lunar regolith(LR)samples returned from the Moon by the Chang’E-5(CE-5)mission.Insights regarding the effect of a new sampling geological site on the surficial lunar sample CE5 C0400 were illustrated using nondestructive techniques such as laser diffractometry coupled with image analysis,X-ray computed tomography,and field emission scanning electron microscopy equipped with energy dispersive spectroscopy,and Xray diffraction combined with Rietveld refinement.From the characterization analyses,the CE-5 sampling site in the northeastern Oceanus Procellarum on the Moon yields a unique collection of relatively regular-shaped and fine basalt-dominated particles.The median grain size D_(50) is(55.24±0.96)μm,falling within the relatively low end of the range of the Apollo lunar returned samples.The coefficient of uniformity C_(u)of 15.1 and the coefficient of curvature C_(c)of 1.7 could classify CE5 C0400 to be well-graded.The minerals in CE5 C0400 comprise approximately 44.5%pyroxene,30.4%plagioclase,3.6%olivine,and6.0%ilmenite.There is a relatively low content of approximately 15.5%glass phase in the CE-5 lunar sample.From the results,we deduce that the CE-5 LR structure could have mainly resulted from micrometeoroid impacts to achieve such a high level of maturity.展开更多
Deformation behavior of non-rigid airships in wind tunnel tests is studied by considering three factors, including internal pressure, flow velocity and angle of attack. Fiber Bragg grating strain sensors are used to m...Deformation behavior of non-rigid airships in wind tunnel tests is studied by considering three factors, including internal pressure, flow velocity and angle of attack. Fiber Bragg grating strain sensors are used to measure the deformation of non-rigid airships. Wind tunnel tests in the case of different flow velocities and angles of attack are conducted. The measurement results reveal that the airship deformation is in proportion to internal pressure. For the tensile region,the airship deformation is in proportion to flow velocity. Effects of angle of attack on structural deformation are more complicated and there is no clear relationship existing between airship deformation and angle of attack.展开更多
文摘Pulsed power technology,whereas the electrical energy stored in a relative long period is released in much shorter timescale,is an efficient method to create high energy density physics(HEDP)conditions in laboratory.Around the beginning of this century,China Academy of Engineering Physics(CAEP)began to build some experimental facilities for HEDP investigations,among which the Primary Test Stand(PTS),a multi-module pulsed power facility with a nominal current of 10 MA and a current rising time~90 ns,is an important achievement on the roadmap of the electro-magnetically driven inertial confinement fusion(ICF)researches.PTS is the first pulsed power facility beyond 10 TW in China.Therefore,all the technologies have to be demonstrated,and all the engineering issues have to be overcome.In this article,the research outline,key technologies and the preliminary HEDP experiments are reviewed.Prospects on HEDP research on PTS and pulsed power development for the next step are also discussed.
基金supported by the SZSM201612071the National S&T Major Project for Infectious Diseases(2017YFC0908100,2017ZX10302201,2017ZX10201201)the project from Beijing Municipal Science and Technology Commission(No.Z161100000116047)
文摘Background and Aims:The poor outcomes of hepatocellular carcinoma(HCC)patients may be due to not only malignant tumors but also limited liver function.Therefore,as stated in major guidelines,only patients with relatively normal liver function(Child-Pugh A)would be referred for curative hepatectomy.Even so,the postsurgery survival rate of patients is still extremely poor.Direct curative resection may benefit most patients.This study aimed to improve the prognosis predicting accuracy of the Child-Pugh scoring system.Methods:This study included two cohorts:cohort A being composed of 613 HCC patients,with a 23-month median postsurgery follow-up time;and cohort B being composed of 554 tumor-free chronic liver disease patients.Kaplan-Meier test and Cox model were used for survival analysis.Independent-samples t test or one-way ANOVA was used to test the differences between different groups.Results:Serum prealbumin levels were found inversely correlated with worsening of flbrotic scores(r=-0.482,p<0.001).Lower levels of presurgery prealbumin was an independent factor of poor postsurgery prognosis in Child-Pugh A patients,with a hazard ratio of 0.731(p=0.001).By integrating prealbumin together with total bilirubin level,serum albumin concentration and prothrombin time,a modified liver disease prognosis scoring system was developed to define traditional Child-Pugh A HCC patients as Modified Child-Pugh MCP-1,MCP-2 and MCP-3,with median postsurgery overall survival times of 44.00,28.00 and 11.00 months respectively.Conclusions:Preoperative serum prealbumin is a valuable prognosis predicting biomarker for Child-Pugh A HCC patients who may be under consideration for curative resection.With serum prealbumin included as one of the parameters,the MCP scoring system might improve the postsurgery survival predicting accuracy for HCC patients.
基金financially supported by the National Natural Science Foundation of China (Nos. 81273662 and 81473592)the Operational Expenses for Basic Research of China Academy of Chinese Medical Sciences (No. ZZ2014020)
文摘The quality control processes for herbal medicines have been problematic. Flavonoids are the major active components of Huangqin Tang(HQT, a traditional Chinese medicine formula). In this study, we used a combinative method approach consisting of chromatographic fingerprinting(high performance liquid chromatography; HPLC), quantitative methods and a pharmacodynamic evaluation model to analyze the flavonoids of HQT obtained from different sources. Ten batches of HQT were analyzed by the HPLC fingerprinting method and 26 common peaks were detected, of which 23 peaks corresponded with the chemical profile of HQT. In addition, 11 major compounds were identified by LC–MS analysis(liquid chromatography–tandem mass spectrometer; LC–MS^n) and quantified by the HPLC quantitative method approach. The studied10 batches of HQT were found to be homogeneous in their composition with a similarity between 0.990 and1.000. The distribution of the 11 identified compounds was found to be very similar among the batches. Only slight pharmacodynamic differences were detected between the different batches, confirming the homogeneity of HQT. The results of this study prove that the combination of chromatographic fingerprinting and quantitative analysis can be readily used for comprehensive quality control of herbal medicines.
基金his work was supported by a grant from the National Natural Science Foundation of China （No. 81370723） and the Specialized Research Fund for the Doctoral Program of Higher Education from the Ministry of Education of China （No. 20130001110111）.
文摘Background Preeclampsia （PE） is a multifactorial pregnancy complication.Maternal underlying condition and adverse factors both influence the pathogenesis of PE.Abnormal lipid metabolism as a maternal underlying disease may participate in the occurrence and development of PE.This study aimed to observe the effects of adverse factors on PE-like symptoms of pregnant mice with genetic abnormal lipid metabolism.Methods Apolipoprotein C-Ⅲ （ApoC3） transgenic mice with abnormal lipid metabolism were subcutaneously injected with L-arginine methyl ester （L-NAME） or normal saline （NS） daily starting at Day 7 or 16 of pregnancy （ApoC3＋L-NA and ApoC3＋NS groups）,and wild-type （WT） mice served as a control （WT＋L-NA and WT＋NS groups）.All mice were subdivided into early and late subgroups by injection time.The mean arterial pressure （MAP） and urinary protein were measured.Pregnancy outcomes,including fetal weight,placental weight,live birth rate,and fetal absorption rate,were analyzed.Pathologic changes in the placenta were observed by hematoxylin-eosin staining.One-way analysis of variance,t-test,and x2 test were used for statistical analysis.Results MAP significantly increased for ApoC3＋NS groups compared with WT＋NS groups （P 〈0.05）,without significant difference in urine protein.Following L-NAME injection,MAP and urinary protein significantly increased for ApoC3＋L-NA and WT＋L-NA compared with the corresponding NS groups （P 〈0.05）,and the increase for ApoC3＋L-NA was more obvious.Urinary protein levels in early ApoC3＋L-NA and WT＋L-NA significantly increased compared with the corresponding late groups （P 〈0.05）.Fetal absorption rate significantly increased and fetal and placental weights significantly decreased in early ApoC3＋L-NA and WT＋L-NA compared with the corresponding NS groups （P 〈0.05）,without significant difference in late ApoC3＋L-NA and WT＋L-NA groups.Fetal weight in early ApoC3＋L-NA was significantly lower than in early WT＋L-NA
基金co-supported by the National Natural Science Foundation of China(Nos.62003267,61573285)the Aeronautical Science Foundation of China(ASFC)(No.20175553027)Natural Science Basic Research Plan in Shaanxi Province of China(No.2020JQ-220)。
文摘Unmanned Aerial Vehicles(UAVs)play a vital role in military warfare.In a variety of battlefield mission scenarios,UAVs are required to safely fly to designated locations without human intervention.Therefore,finding a suitable method to solve the UAV Autonomous Motion Planning(AMP)problem can improve the success rate of UAV missions to a certain extent.In recent years,many studies have used Deep Reinforcement Learning(DRL)methods to address the AMP problem and have achieved good results.From the perspective of sampling,this paper designs a sampling method with double-screening,combines it with the Deep Deterministic Policy Gradient(DDPG)algorithm,and proposes the Relevant Experience Learning-DDPG(REL-DDPG)algorithm.The REL-DDPG algorithm uses a Prioritized Experience Replay(PER)mechanism to break the correlation of continuous experiences in the experience pool,finds the experiences most similar to the current state to learn according to the theory in human education,and expands the influence of the learning process on action selection at the current state.All experiments are applied in a complex unknown simulation environment constructed based on the parameters of a real UAV.The training experiments show that REL-DDPG improves the convergence speed and the convergence result compared to the state-of-the-art DDPG algorithm,while the testing experiments show the applicability of the algorithm and investigate the performance under different parameter conditions.
基金supported by National Hi-tech Research and Development Program of China(863 Program,Grant No. 2006AA04Z228)
文摘The end-effector of the large space manipulator is employed to assist the manipulator in handling and manipulating large payloads on orbit.Currently,there are few researches about the end-effector,and the existing end-effectors have some disadvantages,such as poor misalignment tolerance capability and complex mechanical components.According to the end positioning errors and the residual vibration characters of the large space manipulators,two basic performance requirements of the end-effector which include the capabilities of misalignment tolerance and soft capture are proposed.And the end-effector should accommodate the following misalignments of the mechanical interface.The translation misalignments in axial and radial directions and the angular misalignments in roll,pitch and yaw are ±100 mm,100 mm,±10°,±15°,±15°,respectively.Seven end-effector schemes are presented and the capabilities of misalignment tolerance and soft capture are analyzed elementarily.The three fingers-three petals end-effector and the steel cable-snared end-effector are the most feasible schemes among the seven schemes,and they are designed in detail.The capabilities of misalignment tolerance and soft capture are validated and evaluated,through the experiment on the micro-gravity simulating device and the dynamic analysis in ADAMS software.The results show that the misalignment tolerance capabilities of these two schemes could satisfy the requirement.And the translation misalignment tolerances in axial and radial directions and the angular misalignment tolerances in roll,pitch and yaw of the steel cable-snared end-effector are 30mm,15mm,6°,3° and 3° larger than those of the three fingers-three petals end-effector,respectively.And the contact force of the steel cable-snared end-effector is smaller and smoother than that of the three fingers-three petals end-effector.The end-effector schemes and research methods are beneficial to the developments of the large space manipulator end-effctor and the space docking mechanism.
基金supported by China National Space Administration(CNSA)。
文摘The Chinese Hα Solar Explorer(CHASE), dubbed “Xihe”—Goddess of the Sun, was launched on October 14, 2021 as the first solar space mission of China National Space Administration(CNSA). The CHASE mission is designed to test a newly developed satellite platform and to acquire the spectroscopic observations in the Hα waveband. The Hα Imaging Spectrograph(HIS)is the scientific payload of the CHASE satellite. It consists of two observational modes: raster scanning mode and continuum imaging mode. The raster scanning mode obtains full-Sun or region-of-interest spectral images from 6559.7 to 6565.9 ? and from 6567.8 to 6570.6 ? with 0.024 ? pixel spectral resolution and 1 min temporal resolution. The continuum imaging mode obtains photospheric images in continuum around 6689 ? with the full width at half maximum of 13.4 ?. The CHASE mission will advance our understanding of the dynamics of solar activity in the photosphere and chromosphere. In this paper, we present an overview of the CHASE mission including the scientific objectives, HIS instrument overview, data calibration flow, and first results of on-orbit observations.
基金supported by the National Key Research and Development Program of China(2017YFD0500400)the National Natural Science Foundation of China(81420108023,81772219)distinguished scientist grant from Shenyang Agricultural University。
文摘Artemisia annua is an anti-fever herbal medicine first described in traditional Chinese medicine 1,000 years ago.Artemisinin,the extract of A.annua,and its derivatives(dihydroartemisinin(DHA),artemether,and artesunate)have been used for the treatment of malaria with substantial efficacy.Recently,DHA has also been tested for the treatment of lupus erythematosus,indicating that it may function to balance the immune response in immunocompromised individuals.In the present study,the regulatory effect of artemisinin on the murine immune system was systematically investigated in mice infected with two different protozoan parasites(Toxoplasma gondii and Plasmodium berghei).Our results revealed that the mouse spleen index significantly increased(spleen enlargement)in the healthy mice after DHA administration primarily due to the generation of an extra number of lymphocytes and CD8^+T lymphocytes in both the spleen and circulation.DHA could increase the proportion of T helper cells and CD8^+T cells,as well as decrease the number of splenic and circulatory B cells.Further,DHA could reduce the production of proinflammatory cytokines.Our study revealed that apart from their anti-parasitic activity,artemisinin and its derivatives can also actively modulate the immune system to directly benefit the host.
基金National Major Research and Development Program(2018YFB2200200)China National Funds for Distinguished Young Scientists(61725503)+1 种基金National Natural Science Foundation of China(6191101294,91950205)Natural Science Foundation of Zhejiang Province(LD19F050001,LZ18F050001)。
文摘An ultrahigh-Q silicon racetrack resonator is proposed and demonstrated with uniform multimode silicon photonic waveguides.It consists of two multimode straight waveguides connected by two multimode waveguide bends(MWBs).In particular,the MWBs are based on modified Euler curves,and a bent directional coupler is used to achieve the selective mode coupling for the fundamental mode and not exciting the higher-order mode in the racetrack.In this way,the fundamental mode is excited and propagates in the multimode racetrack resonator with ultralow loss and low intermode coupling.Meanwhile,it helps achieve a compact 180°bend to make a compact resonator with a maximized free spectral range(FSR).In this paper,for the chosen 1.6μm wide silicon photonic waveguide,the effective radius Reffof the designed 180°bend is as small as 29μm.The corresponding FSR is about 0.9 nm when choosing 260μm long straight waveguides in the racetrack.The present high-Q resonator is realized with a simple standard single-etching process provided by a multiproject wafer foundry.The fabricated device,which has a measured intrinsic Q-factor as high as 2.3×10~6,is the smallest silicon resonator with a>106Q-factor.
基金supported by the National Natural Science Foundation of China(41471436,41601587)the National Science and Technology Support Program of China(2015BAC06B01)+1 种基金the National Key Research and Development Program of China(2016YFC0500909)the National Natural Science Foundation of China(41601587)
文摘Based on the statistical data, we analyzed and evaluated the degree of coupling and coordination of the eco-economic system in Yanchi County for the period spanning from 1983 to 2014. The eco-economic system can be divided into socioeconomic and ecological sub-systems and their relationship can reveal the interaction state between the two sub-systems and help the local government to establish a coordinated development mode. An index system was constructed to assess the development of the two sub-systems before the evaluation of the degree of coupling and coordination. The principal component regression analysis was adopted to quantitatively assess the influences of natural, economic and social factors on the degree of coupling and coordination of the eco-economic system. Results showed that, from 1983 to 2014, the development trends of both sub-systems were increasing with the ecological sub-system having more fluctuations. The degree of coupling and coordination of the eco-economic system in the study area increased gradually from 1983 to 2014, but experienced five different development stages from the verge of disorder to favorable coordination. The development of the local social and economic conditions was the most important factor influencing the degree of coupling and coordination. The second most important factor was the financial support from the local government. In addition, the environment protection policies also played undeniable roles. Due to the diversity of the influence factors, the government should take comprehensive measures to promote the sustainable development of the eco-economic system.
基金supported by the National Natural Science Foundation of China (21106017 and 50873026)Specialized Research Fund for the Doctoral Program of Higher Education of China (20100092120047)Production and Research Prospective Joint Research Project of Jiangsu Province of China (Grant No.BY2009153)
文摘Catalytic dehydrogenation of isobutane has recently received considerable attention because of the increasing demand for isobutene.In this study,the synergistic effect between Sn and K on PtSnK/γ-Al2O3 catalysts has been investigated by changing the content of Sn.It was found that with the presence of potassium,suitable addition of Sn could not only increase the metal dispersion,but also reduce the catalyst acidity.In these cases,the synergistic effect could also strengthen the interactions between the metal and support,which resulted in an increase in both catalytic activity and stability.In our experiments,Pt-0.6SnK/Al catalyst exhibited the lowest deactivation rate （12.4%） and showed a selectivity to isobutene higher than 94% at the isobutane conversion of about 45.3% after running the reaction for 6 h.However,with the excessive loading of Sn,surface property of active sites and the interactions between metal and support were changed.As a result,the initial optimal ratio between the metallic function and acid function would be destroyed,which was disadvantageous to the reaction.
文摘Low-dose total body irradiation （LTBI） is used in the treatment of some cancers mainly for immune enhancement rather than cell killing. However, the mechanism underlying LTBI remains unknown. In this study, by analyzing the immune patterns of lymphocytes, we found that the percentage and absolute number of CD4^＋CD25^＋Foxp3^＋ regulatory T cells are markedly decreased in naive mice following treatment with LTBI. On the contrary, the CD4^＋CD44^＋/CD8^＋CD44^＋ effector-memory T cells are greatly increased. Importantly, naive mice treated with dendritic cell-gp100 tumor vaccines under LTBI induced an enhancement of antigen-specific proliferation and cytotoxicity as well as interferon-γ, （IFN-γ） secretion against FIO melanoma tumor challenge, compared to treatment with either the tumor vaccine or LTBI alone. Consequently, the treatment resulted in a reduced tumor burden and prolonged mouse survival. Our data demonstrate that LTBI＇s enhancement of antitumor immunity was mainly associated with selectively decreasing the proportion and number of T regulatory cells, implying the potential application of the combination of LTBI and a tumor vaccine in antitumor therapy.
基金funded by the“111”Project(No.B12006)the National Key Research and Development Program(No.2018YFD1000602)+3 种基金the Special Fund for Agro-scientific Research in the Public Interest of China(No.201403064)the Natural Science Foundation of China(No.31572323)Fundamental Research Funds for the Central Universities(No.SW118040)the Chongqing Research Program of Basic Research and Frontier Technology(No.cstc2018jcyjAX0407).
文摘Mulberry fruits with high concentrations of anthocyanins are favored by consumers because of their good taste,bright color,and high nutritional value.However,neither the regulatory mechanism controlling flavonoid biosynthesis in mulberry nor the molecular basis of different mulberry fruit colors is fully understood.Here,we report that a flavonoid homeostasis network comprising activation and feedback regulation mechanisms determines mulberry fruit color.In vitro and in vivo assays showed that MYBA-bHLH3-TTG1 regulates the biosynthesis of anthocyanins,while TT2L1 and TT2L2 work with bHLH3 or GL3 and form a MYB-bHLH-WD40(MBW)complex with TTG1 to regulate proanthocyanidin(PA)synthesis.Functional and expression analyses showed that bHLH3 is a key regulator of the regulatory network controlling mulberry fruit coloration and that MYB4 is activated by MBW complexes and participates in negative feedback control of the regulatory network to balance the accumulation of anthocyanins and proanthocyanidins.Our research demonstrates that the interaction between bHLH3 and MYB4 in the homeostasis regulatory network ensures that the fruits accumulate desirable flavonoids and that this network is stable in pigmentrich mulberry fruits.However,the abnormal expression of bHLH3 disrupts the balance of the network and redirects flavonoid metabolic flux in pale-colored fruits,resulting in differences in the levels and proportions of anthocyanins,flavones,and flavonols among differently colored mulberry fruits(red,yellow,and white).The results of our study reveal the molecular basis of the diversity of mulberry fruit colors.
基金This work was financially supported by the National Natural Science Foundation of China （No. 21071079）, the Research Fund of the State Key Laboratory of Materials-Oriented Chemical Engineering （2009）, and the Young Teachers Fund of Nanjing University of Technology.
文摘A series of unique nanowire superstructures, Cu2O nanowire polyhedra, have been synthesized through a cost-effective hydrothermal route. Three types of nanowire polyhedra, namely octahedra, concave octahedra, and hexapods, were formed in high morphological yields （90%） by reducing cupric acetate with o-anisidine or o-phenetidine in the presence of carboxylic acids. The architectures of these Cu2O nanowire polyhedra were examined by electron microscopy, which revealed ordered, highly aligned CU2O nanowires within the polyhedral outlines. The growth of the Cu2O nanowire polyhedra is controlled by the orientation and growth rates of the nanowire branches which are adjusted by addition of carboxylic acids. Compared to the Cu2O samples reported in the recent literature, the Cu2O nanowire octahedra exhibit notably enhanced photocatalytic activities for dye degradation in the presence of H202 under visible light, probably due to the high-density charge carriers photoexcited from the branched nanowires with their special structures. Additionally, the discussion in the recent literature of the photocatalytic activity of Cu2O in the absence of H2O2 for direct photodegradation of dyes seems questionable.
基金the National Key Technologies R&D Program of China during the Eleventh Five-Year Plan Period(2009ZX10004-104 and 2009ZX09301-011)National Science Foundation of China(30872378 and 81072408)the Science and Technology Commission of Shanghai Municipality(10JC1401100)in China and National 973 Project(2010CB912603 and 2011CB910400)in China.We thank the editors of Editage Company for professional editing of the article.
文摘Trichosanthin(TCS),extracted from the Chinese medicinal herb Trichosanthes kirilowi,has shown promise for the inhibition of tumor growth.However,its immunomodulatory effect on tumor–host interaction remains unknown.In this study,we focused on the effect of TCS on murine anti-tumor immune response in the 3LL Lewis lung carcinoma tumor model and explored the possible molecular pathways involved.In addition to inhibiting cell proliferation and inducing apoptosis in the 3LL tumor,TCS retarded tumor growth and prolonged mouse survival more significantly in C57BL/6 immunocompetent mice than in nude mice.This reflected the fact that the host immune system was involved in tumor eradication.Using FACS analysis,we found that TCS increased the percentage of effector T cells,particularly Interferon-gamma(IFN-c)producing CD41 and CD81 T cells from tumor-bearing mice.TCS also promoted the vigorous proliferation of antigen-specific effector T cells,markedly increased Th1 cytokine secretion and elicited more memory T cells in tumor-bearing mice,consequently enhancing the anti-tumor response and inducing immune protection.Furthermore,we found that TCS upregulated the expression of tumor suppressor in lung cancer 1(TSLC1)in 3LL tumor cells and the expression of its ligand,class I-restricted T cell-associated molecule(CRTAM),in effector T cells.Blocking TSLC1 expression with small interfering RNA(siRNA)significantly eliminated the effects of TCS on the proliferation and cytokine secretion of effector T cells,suggesting that TCS enhances anti-tumor immune response at least partially by boosting the interaction between TSLC1 and CRTAM.Collectively,our data demonstrate that TCS not only affects tumor cells directly,but also enhances anti-tumor immunity via the interaction between TSLC1 and CRTAM.These findings may lead to the development of a novel approach for tumor regression.
基金The Production and Research Prospective Joint Research Project (BY2009153)The Science and Technology Support Program (BE2008129) of Jiangsu Province of Chinathe National Nature Science Foundation of China (50873026,21106017) for financial support
文摘PtSnSr/HZSM-5 catalysts with different amounts of strontium were prepared by sequential impregnation method, and characterized by BET analysis, TEM, NH3-TPD, Hz-TPR, TPO and TG techniques. The results showed that the addition of strontium could modify the characteristics and properties of both acid function and metal function of Pt-Sn-based cata- lysts. In this case, PtSnSr/HZSM-5 catalyst with an appropriate amount of Sr （1.2%） showed higher catalytic activity and lower amount of coke deposits than PtSn/HZSM-5 catalyst. However, excessive loading of Sr could facilitate the reduction of Sn, which was unfavorable to the reaction. Afterwards, 1.0 m% of Na was added into the PtSnSr（1.2%）/HZSM-5 catalyst to improve the catalytic performance in propane dehydrogenation, and this catalyst displayed the best catalytic performance during our experiments. After having been subjected to reaction for 5 h, the PtSnNa（1.0%）Sr（1,2%）/HZSM-5 catalyst had achieved a higher than 95% selectivity towards propene along with a corresponding propane conversion rate of 32.2%.
基金supported by National Key Technologies R&D Program under Grant No. 2006BAF04B02
文摘Turbine blade is one of the critical components of aircraft engine.The performance of the engine depends on the shape and dimensions of components,but superalloy blade material cannot be easily machined.Although investment casting is an ideal process for such net-shape components,it requires an accurate determination of the casting-die profile.In this paper,a reversing design methodology for investment casting die using ProCAST is proposed.By combining the methods of simplifying grid files and quick sorting,the efficiency of sorting and matching can be largely improved.Further,the mould/die cavity anti-deformation system can be easily built.With ProCAST,the optimized die profile for investment casting can be established.
基金This work was supported by the National Natural Science Foundation of China(Grant No.61975181).The authors thank Liying Chen from the State Key Laboratory of Modern Optical Instrumentation,Zhejiang University for help in the FTIR experiments.
文摘Advanced multispectral detection technologies have emerged as a significant threat to objects,necessitating the use of multiband camouflage.However,achieving effective camouflage and thermal management across the entire infrared spectrum,especially the short-wave infrared(SWIR)band,remains challenging.This paper proposes a multilayer wavelength-selective emitter that achieves effective camouflage across the entire infrared spectrum,including the near-infrared(NIR),SWIR,mid-wave infrared(MWIR),and long-wave infrared(LWIR)bands,as well as the visible(VIS)band.Furthermore,the emitter enables radiative heat dissipation in two non-atmospheric windows(2.5-3μm and 5-8μm).The emitter’s properties are characterized by low emittance of 0.270/0.042/0.218 in the SWIR/MWIR/LWIR bands,and low reflectance of 0.129/0.281 in the VIS/NIR bands.Moreover,the high emittance of 0.742/0.473 in the two non-atmospheric windows ensures efficient radiative heat dissipation,which results in a temperature decrement of 14.4℃ compared to the Cr reference at 2000Wm^(−2) input power density.This work highlights the role of solar radiance in camouflage,and provides a comprehensive guideline for developing multiband camouflage compatible with radiative heat dissipation,from the visible to LWIR.
文摘This study focuses on the physical and chemical properties of surficial lunar regolith(LR)samples returned from the Moon by the Chang’E-5(CE-5)mission.Insights regarding the effect of a new sampling geological site on the surficial lunar sample CE5 C0400 were illustrated using nondestructive techniques such as laser diffractometry coupled with image analysis,X-ray computed tomography,and field emission scanning electron microscopy equipped with energy dispersive spectroscopy,and Xray diffraction combined with Rietveld refinement.From the characterization analyses,the CE-5 sampling site in the northeastern Oceanus Procellarum on the Moon yields a unique collection of relatively regular-shaped and fine basalt-dominated particles.The median grain size D_(50) is(55.24±0.96)μm,falling within the relatively low end of the range of the Apollo lunar returned samples.The coefficient of uniformity C_(u)of 15.1 and the coefficient of curvature C_(c)of 1.7 could classify CE5 C0400 to be well-graded.The minerals in CE5 C0400 comprise approximately 44.5%pyroxene,30.4%plagioclase,3.6%olivine,and6.0%ilmenite.There is a relatively low content of approximately 15.5%glass phase in the CE-5 lunar sample.From the results,we deduce that the CE-5 LR structure could have mainly resulted from micrometeoroid impacts to achieve such a high level of maturity.
基金supported by the National Natural Science Foundation of China(Nos.11472276,11332011 and 11502268)
文摘Deformation behavior of non-rigid airships in wind tunnel tests is studied by considering three factors, including internal pressure, flow velocity and angle of attack. Fiber Bragg grating strain sensors are used to measure the deformation of non-rigid airships. Wind tunnel tests in the case of different flow velocities and angles of attack are conducted. The measurement results reveal that the airship deformation is in proportion to internal pressure. For the tensile region,the airship deformation is in proportion to flow velocity. Effects of angle of attack on structural deformation are more complicated and there is no clear relationship existing between airship deformation and angle of attack.
