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A Plant Immune Receptor Degraded by Selective Autophagy
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作者 Fan Yang Athen N.Kimberlin +4 位作者 Christian G.Elowsky Yunfeng Liu Ariadna Gonzalez-Solis Edgar B.Cahoon James R.Alfano 《分子植物:英文版》 SCIE CAS CSCD 2019年第1期113-123,共11页
Plants recycle non-activated immune receptors to maintain a functional immune system.The Arabidopsis immune receptor kinase FLAGELLIN-SENSING 2 (FLS2)recognizes bacterial flagellin.However,the molecular mechanisms by ... Plants recycle non-activated immune receptors to maintain a functional immune system.The Arabidopsis immune receptor kinase FLAGELLIN-SENSING 2 (FLS2)recognizes bacterial flagellin.However,the molecular mechanisms by which non-activated FLS2 and other non-activated plant PRRs are recycled remain not well understood.Here,we provide evidence showing thatArabidopsis orosomucoid (ORM)proteins,which have been known to be negative regulators of sphingoUpid biosynthesis,act as selective autophagy receptors to mediate the degradation of FLS2.Arabidopsis plants overexpressing ORM 1 or ORM2 have undetectable or greatly diminished FLS2 accumulation,nearly lack FLS2 signaling,and are more susceptible to the bacterial pathogen Pseudomonas syringae.On the other hand,ORM1/2 RNAi plants and orml or orrn2 mutants generated by the CRISPR/Cas9-mediated gene editing have increased FLS2 accumulation and enhanced FLS2 signaling,and are more resistant to P.syringae.ORM proteins interact with FLS2 and the autophagy-related protein ATG8.Interestingly,overexpression of ORM1 or ORM2 in autophagydefective mutants showed FLS2 abundance that is comparable to that in wild-type plants.Moreover, FLS2 levels were not decreased in Arabidopsis plants overexpressing ORM1/2 derivatives that do not interact with ATGS.Taken together,these results suggest that selective autophagy functions in maintaining the homeostasis of a plant immune receptor and that beyond sphingolipid metabolic regulation ORM proteins can also act as selective autophagy receptors. 展开更多
关键词 Plant IMMUNITY SELECTIVE AUTOPHAGY pattern RECOGNITION RECEPTOR SELECTIVE AUTOPHAGY RECEPTORS
In uence of Particle Size on Laser Absorption and Scanning Track Formation Mechanisms of Pure Tungsten Powder During Selective Laser Melting 预览
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作者 Jiayao Zhang Dongdong Gu +4 位作者 Ying Yang Hongmei Zhang Hongyu Chen Donghuai Dai Kaijie Lin 《工程(英文)》 2019年第4期736-745,共10页
A three-dimensional laser absorption model based on ray tracing was established to describe the coupled interaction of a laser beam with particles in the powder layers of pure tungsten(W)material processed by selectiv... A three-dimensional laser absorption model based on ray tracing was established to describe the coupled interaction of a laser beam with particles in the powder layers of pure tungsten(W)material processed by selective laser melting(SLM).The influence of particle size on the powder-to-laser absorptivity and underlying absorption behavior was investigated.An intrinsic relationship between the absorption,distribution of absorbed irradiance within the powder layers,and surface morphology and geometric characteristics(e.g.,contact angle,width and height of tracks,and remelted depth)of the laser scanning tracks is presented here.Simulation conclusions indicate that the absorptivity of the powder layers considerably exceeds the single powder particle value or the dense solid material value.With an increase in particle size,the powder layer absorbs less laser energy.The maximum absorptivity of theWpowder layers reached 0.6030 at the particle size of 5 lm.The distribution of laser irradiance on the particle surface was sensitive to particle size,azimuthal angle,and the position of the powder particles on the substrate.The maximum irradiance in the powder layers decreased from 1.117×10^–3 to 0.85×10^–3W·μm^-2 and the contour of the irradiance distribution in the center of the irradiated area gradually contracted when the particle size increased from 5 to 45 lm.An experimental study on the surface morphologies and cross-sectional geometric characteristics of SLM-fabricated W material was performed,and the experimental results validated the mechanisms of the powder-to-laser-absorption behavior that were obtained in simulations.This work provides a scientific basis for the application of the ray-tracing model to predict the wetting and spreading ability of melted tracks during SLM additive manufacturing in order to yield a sound laser processability. 展开更多
关键词 Selective laser melting(SLM) TUNGSTEN Ray-tracing model ABSORPTIVITY Laser scanning tracks
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Data Mining for Mesoscopic Simulation of Electron Beam Selective Melting 预览
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作者 Ya Qian Wentao Yan Feng Lin 《工程(英文)》 2019年第4期746-754,共9页
In the electron beam selective melting(EBSM)process,the quality of each deposited melt track has an effect on the properties of the manufactured component.However,the formation of the melt track is governed by various... In the electron beam selective melting(EBSM)process,the quality of each deposited melt track has an effect on the properties of the manufactured component.However,the formation of the melt track is governed by various physical phenomena and influenced by various process parameters,and the correlation of these parameters is complicated and difficult to establish experimentally.The mesoscopic modeling technique was recently introduced as a means of simulating the electron beam(EB)melting process and revealing the formation mechanisms of specific melt track morphologies.However,the correlation between the process parameters and the melt track features has not yet been quantitatively understood.This paper investigates the morphological features of the melt track from the results of mesoscopic simulation,while introducing key descriptive indexes such as melt track width and height in order to numerically assess the deposition quality.The effects of various processing parameters are also quantitatively investigated,and the correlation between the processing conditions and the melt track features is thereby derived.Finally,a simulation-driven optimization framework consisting of mesoscopic modeling and data mining is proposed,and its potential and limitations are discussed. 展开更多
关键词 Electron beam selective melting Mesoscopic modeling Data mining
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A Simple Strategy for Fabrication of In(OH)3/ZnIn2S4 Heterostructure as Visible-light-driven Photocatalyst for Selective Oxidation 预览
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作者 陈志鑫 《结构化学》 SCIE CAS CSCD 2019年第5期825-836,672共13页
The cubic In(OH)3/ZnIn2S4 heterostructures were successfully synthesized via a simple strategy of post-treatment of cubic ZnIn2S4(C-ZIS), and their structures and properties were characterized by X-ray diffraction(XRD... The cubic In(OH)3/ZnIn2S4 heterostructures were successfully synthesized via a simple strategy of post-treatment of cubic ZnIn2S4(C-ZIS), and their structures and properties were characterized by X-ray diffraction(XRD), UV-vis diffuse reflectance spectra(DRS), field emission scanning electron microscopy(FESEM) and transmission electron microscopy(TEM). According to the results, the tofu-like In(OH)3 semiconductor as a new crystal phase appeared in the matrix of C-ZIS and formed a In(OH)3/ZnIn2S4 heterostructure. Compared with pure C-ZIS, the heterostructure exhibits higher photocatalytic activity towards selective oxidation of benzyl alcohol under visible light. The In(OH)3/ZnIn2S4 heterostructure manifests the best and the highest photocatalytic performance via 18 h post-treatment, which achieved nearly 100% selectivity, 35.5%conversion and 34.5% yield. This is ascribed to the formation of In(OH)3/ZnIn2S4 heterostructure to promote the transfer of photogenerated electron-hole pairs and thus efficiently inhibits their recombination, leading to the longer lifetime of photo-induced carriers. Furthermore, a possible photocatalytic mechanism is proposed and discussed. Our current work could boost more interest in researching the semiconductor materials of ternary chalcogenides and enlarging the applications based on cubic ZnIn2S4 heterostructure as visible-light-driven photocatalyst. 展开更多
关键词 ZnIn2S4 In(OH)3 HETEROSTRUCTURE POST-TREATMENT SELECTIVE OXIDATION
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5种DPP-4抑制剂分子结构差异及药代动力学特性 预览
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作者 李春杏 纪立伟 《药品评价》 CAS 2019年第8期3-9,16共8页
二肽基肽酶-4(Dipeptidyl peptidase-4,DPP-4)抑制剂是近年上市的治疗2型糖尿病的新型口服降糖药,其作用机制独特,以葡萄糖依赖性促进胰岛B细胞分泌胰岛素,同时抑制胰岛α细胞分泌胰高血糖素,可有效降低血糖,减少低血糖发作,同时不增加... 二肽基肽酶-4(Dipeptidyl peptidase-4,DPP-4)抑制剂是近年上市的治疗2型糖尿病的新型口服降糖药,其作用机制独特,以葡萄糖依赖性促进胰岛B细胞分泌胰岛素,同时抑制胰岛α细胞分泌胰高血糖素,可有效降低血糖,减少低血糖发作,同时不增加体重,被临床广泛应用。本文将对常见的5种DPP-4抑制剂的化学结构、亲和力、选择性差异、药代动力学特性及特殊人群用药逐项进行分析,因为尽管都是口服小分子化合物,但其化学结构、对DPP-4的亲和力、选择性、吸收、分布、代谢和排泄等药代动力学特性各异,以便为临床合理用药提供参考。 展开更多
关键词 DPP-4抑制剂 化学结构 亲和力 选择性 药代动力学 肾功能不全 肝功能不全
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Study on Flue Gas Desulfurization Process with Selective SO2 Removal by N-formylmorpholine 预览
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作者 Long Jian Wang Jin +2 位作者 Fan Chen Yang Minglei Zhong Weimin 《中国炼油与石油化工:英文版》 SCIE CAS 2019年第2期85-94,共10页
Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a l... Absorptive separation for resource utilization by selective SO2 removal from flue gas is a potential method applicable in practice. A flue gas desulfurization process for SO2 utilization by selective absorption in a lab-scale absorption tower at atmospheric pressure using N-formylmorpholine (NFM) as the absorbent is developed to capture and concentrate the SO2 from flue gas, in which the CO2 content is several orders higher than that of SO2. The investigation of the effects of different operating conditions on the SO2 removal efficiency shows that the SO2 removal efficiency can be obviously enhanced by increasing NFM concentration, or decreasing the absorption temperature, the superficial gas velocity, the gas-liquid ratio, or the SO2 concentration in absorption solution. Under the optimum operating conditions (covering a temperature of 40 °C, a superficial gas velocity of <0.0165 m/s, a gas-liquid ratio of 200—250, a SO2 concentration in lean NFM solution of 0—10 mg/L, and a NFM concentration of 3 mol/L), the SO2 removal rate reaches over 99.5% while the absorption of CO2 is negligible. Similarly, the SO2 removal rate is as high as 99.5% obtained in consecutive absorption-desorption cycles. Desorption experiment results indicate that the absorption of sulfur dioxide is completely reversible and the release of SO2 from NFM is very easy and rapid at 104 °C. The absorption simulation result for desulfurization of flue gas vented from the industrial catalytic cracking regenerator shows that 98.0% of SO2 can be absorbed in the absorber and most of them are released in the desorber. The experimental and simulated results show that the desulfurization ability and regenerability of NFM solution is encouraging for the development of FGD process to capture the SO2 from flue gas. 展开更多
关键词 FLUE gas DESULFURIZATION SELECTIVE SO2 REMOVAL N-formylmorpholine ABSORPTION simulation
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Improved Corrosion Resistance of Selective Laser Melted Ti-5Cu Alloy Using Atomized Ti-5Cu Powder
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作者 Ying Han Hong-Rui Wang +2 位作者 Yun-Dong Cao Wen-Tao Hou Shu-Jun Li 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第8期1007-1014,共8页
The different types of metal powder used for selective laser melting(SLM) process would cause distinct corrosion behavior due to the uniformity of the obtained microstructure.The SLM-produced Ti–5Cu alloy using atomi... The different types of metal powder used for selective laser melting(SLM) process would cause distinct corrosion behavior due to the uniformity of the obtained microstructure.The SLM-produced Ti–5Cu alloy using atomized Ti–5Cu metal powder(SLMed Ti–5Cu) in this work reveals a relatively uniform microstructure with overwhelming acicular α/α′ phase and shows great advantages on corrosion resistance compared with the SLM-produced Ti–5Cu alloy using the mixture powder(SLMedM Ti–5Cu).The effect of the micro-galvanic cells decreases due to the undetectable Ti2Cu phase in the microstructure of the SLMed Ti–5Cu.An apparent passivation behavior was observed for SLMed Ti–5Cu instead of severe pitting phenomenon for the SLMed-M Ti–5Cu.The charge transfer resistance of SLMed Ti–5Cu in this work is 10.09 ± 2.63 MΩ cm2, which is significantly higher than that of SLMed-M Ti–5Cu(4.76 MΩ cm2).The above result indicates the atomized Ti–5Cu powder plays an important role in the formation of the uniform microstructure of SLMed product, thereby enhancing its corrosion resistance in Hank’s solution at 37 ℃. 展开更多
关键词 SELECTIVE LASER MELTING Corrosion behavior Uniform microstructure Ti-5Cu PASSIVATION Polarization resistance
Static coarsening behaviour of lamellar microstructure in selective laser melted Ti–6Al–4V
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作者 Sheng Cao Qiaodan Hu +9 位作者 Aijun Huang Zhuoer Chen Ming Sun Jiahua Zhang Chenxi Fu Qingbo Jia Chao Voon Samuel Lim Rodney R.Boyer Yi Yang Xinhua Wu 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第8期1578-1586,共9页
Static coarsening mechanism of selective laser melted(SLMed) Ti–6Al–4V with a lamellar microstructure was established at temperatures from 700℃ to 950℃. Microstructure evolution revealed that high heat treatment t... Static coarsening mechanism of selective laser melted(SLMed) Ti–6Al–4V with a lamellar microstructure was established at temperatures from 700℃ to 950℃. Microstructure evolution revealed that high heat treatment temperature facilitated martensite decomposition and promoted lamellae growth. At each temperature, the growth rate decreased with increasing holding time. The static coarsening behaviour of SLMed Ti–6Al–4V can be interpreted by Lifshitz, Slyozov, and Wagner(LSW) theory. The coarsening coefficient were 0.33, 0.33–0.4, 0.4–0.5 for 700–800℃, 900℃ and 950℃, respectively. This indicated the coarsening mechanism was bulk diffusion at 700–800℃, and a combination of bulk diffusion and interface reaction at 900℃ and 950℃ conditions. 展开更多
关键词 SELECTIVE LASER MELTING Ti–6Al–4V Microstructure Heat treatment
HDAC6 regulates lipid droplet turnover in response to nutrient deprivation via p62-mediated selective autophagy
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作者 Yan Yan Hao Wang +4 位作者 Chuanxian Wei Yuanhang Xiang Xuehong Liang Chung-Weng Phang Renjie Jiao 《遗传学报:英文版》 SCIE CAS CSCD 2019年第4期221-229,共9页
Autophagy has been evolved as one of the adaptive cellular processes in response to stresses such as nutrient deprivation. Various cellular cargos such as damaged organelles and protein aggregates can be selectively d... Autophagy has been evolved as one of the adaptive cellular processes in response to stresses such as nutrient deprivation. Various cellular cargos such as damaged organelles and protein aggregates can be selectively degraded through autophagy. Recently, the lipid storage organelle, lipid droplet(LD), has been reported to be the cargo of starvation-induced autophagy. However, it remains largely unknown how the autophagy machinery recognizes the LDs and whether it can selectively degrade LDs. In this study, we show that Drosophila histone deacetylase 6(dHDAC6), a key regulator of selective autophagy, is required for the LD turnover in the hepatocyte-like oenocytes in response to starvation. HDAC6 regulates LD turnover via p62/SQSTM1(sequestosome 1)-mediated aggresome formation, suggesting that the selective autophagy machinery is required for LD recognition and degradation. Furthermore, our results show that the loss of dHDAC6 causes steatosis in response to starvation. Our findings suggest that there is a potential link between selective autophagy and susceptible predisposition to lipid metabolism associated diseases in stress conditions. 展开更多
关键词 HDAC6 LIPID droplets METABOLIC ADAPTION DROSOPHILA p62/SQSTM1 Selective autophagy
Black fungus derived aerogel with double faced properties
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作者 Bixing Fang Lina Dong +8 位作者 Xingwei Ding YingZi Ren Zhongsheng Lv Kuan Liu Feng Zhang Wei Zhang Jianjian Deng Hongbo Xin Xiaolei Wang 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第6期1178-1181,共4页
Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbabil... Black fungus derived carbonaceous aerogel (BFA) was prepared via a convenient and energy efficient ultrasonic disposal process. The adsorption experiments of atmospheric pollutants demonstrated the superior adsorbability of black fungus aerogel on PM2.5, PM10 and formaldehyde. More importantly, black fungus aerogel (BFA) exhibited intriguing double-faced properties. We explored properties of each side of the black fungus from three aspects: water contact angle measurements, liquid selective absorption capacity and air pollutant adsorption abilities. The subsequent modification of ZnO nanosheets endowed the prepared black fungus aerogel with several valuable properties, including broad-spectrum antibacterial capability and high-efficient adsorption ability. These valuable characters implied the BFA to be a promising bacteriostat and cleaner for air and water pollution treatment. 展开更多
关键词 AEROGELS DOUBLE FACED PROPERTIES Liquid selective absorption Air and water pollution treatment Antibacterial
High mechanical strengths and ductility of stainless steel 304L fabricated using selective laser melting
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作者 Q.B. Nguyen Z. Zhu +3 位作者 F.L. Ng B.W. Chu S.M.L. Nai J. Wei 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第2期388-394,共7页
Achieving not only high mechanical strengths but also high ductility is recently established using an additive manufacturing technique called selective laser melting. In the present study, stainless steel 304 L fully ... Achieving not only high mechanical strengths but also high ductility is recently established using an additive manufacturing technique called selective laser melting. In the present study, stainless steel 304 L fully dense samples were successfully printed using the 3 D systems – ProX 300 printing machine. The ductility and tensile yield strength were almost two and three times higher compared to those of ASTM cast’s alloy. Honey comb like nano-cellular structure with different orientation was observed in the fine grains(~4μm) due to fast cooling rate. In addition, the formation of martensite phase in random grains is also a contributor to the strengths. Furthermore, negative residual stresses in the build and horizontal directions were detected and assisted further increase in the tensile strength. Fractography revealed the ductile feature of plastic deformation and the crack openings at unmelted particles or pores. 展开更多
关键词 ADDITIVE manufacturing STAINLESS steel POWDER Selective laser MELTING
Ultra‐low cost Ti powder for selective laser melting additive manufacturing and superior mechanical properties associated 预览
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作者 Yuhang Hou Bin Liu +5 位作者 Yong Liu Yinghao Zhou Tingting Song Qi Zhou Gang Sha Ming Yan 《光电进展(英文)》 2019年第5期10-17,共8页
One of the bottleneck issues for commercial scale-up of Ti additive manufacturing lies in high cost of raw material, i.e. the spherical Ti powder that is often made by gas atomization. In this study, we address this s... One of the bottleneck issues for commercial scale-up of Ti additive manufacturing lies in high cost of raw material, i.e. the spherical Ti powder that is often made by gas atomization. In this study, we address this significant issue by way of powder modification & ball milling processing, which shows that it is possible to produce printable Ti powders based on ultra- low cost, originally unprintable hydrogenation-dehydrogenation (HDH) Ti powder. It is also presented that the as-printed Ti using the modified powder exhibits outstanding mechanical properties, showing a combination of excellent fracture strength (~895 MPa) and high ductility (~19.0% elongation). 展开更多
关键词 selective laser melting POWDER modification hydrogenation-dehydrogenation (HDH) TI ball MILLING additive manufacturing
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Anisotropy in mechanical properties and corrosion resistance of 316L stainless steel fabricated by selective laser melting 预览
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作者 Xiao-qing Ni De-cheng Kong +5 位作者 Ying Wen Liang Zhang Wen-heng Wu Bei-bei He Lin Lu De-xiang Zhu 《矿物冶金与材料学报:英文版》 SCIE EI CAS CSCD 2019年第3期319-328,共10页
The corrosion behavior and mechanical properties of 316L stainless steel (SS) fabricated via selective laser melting (SLM) were clarified by potentiodynamic polarization measurements, immersion tests, and tensile expe... The corrosion behavior and mechanical properties of 316L stainless steel (SS) fabricated via selective laser melting (SLM) were clarified by potentiodynamic polarization measurements, immersion tests, and tensile experiments. The microstructural anisotropy of SLMed 316L SS was also investigated by electron back-scattered diffraction and transmission electron microscopy. The grain sizes of the SLMed 316L SS in the XOZ plane were smaller than those of the SLMed 316L SS in the XOY plane, and a greater number of low-angle boundaries were present in the XOY plane, resulting in lower elongation for the XOY plane than for the XOZ plane. The SLMed 316L was expected to exhibit higher strength but lower ductility than the wrought 316L, which was attributed to the high density of dislocations. The pitting potentials of the SLMed 316L samples were universally higher than those of the wrought sample in chloride solutions because of the annihilation of MnS or (Ca,Al)-oxides during the rapid solidification. However, the molten pool boundaries preferentially dissolved in aggressive solutions and the damage of the SLMed 316L in FeCl3 solution was more serious after long-term service, indicating poor durability. 展开更多
关键词 selective laser MELTING mechanical property corrosion resistance 316L STAINLESS steel ANISOTROPY MOLTEN POOL boundary
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Selective hydrogenation of acetylene on SiO2-supported Ni-Ga alloy and intermetallic compound 预览
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作者 Lei Wang Fengxu Li +1 位作者 Yanjun Chen Jixiang Chen 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第2期40-49,共10页
Ni/Si O2 and bimetallic NixGa/SiO2 catalysts with different Ni/Ga atomic ratios(x = 10~2) were investigated for the selective hydrogenation of acetylene.It was found that NixGa/SiO2 showed higher selectivity to ethyle... Ni/Si O2 and bimetallic NixGa/SiO2 catalysts with different Ni/Ga atomic ratios(x = 10~2) were investigated for the selective hydrogenation of acetylene.It was found that NixGa/SiO2 showed higher selectivity to ethylene than Ni/Si O2.This is attributed to the formation Ni-Ga alloy and Ni3 Ga intermetallic compound(IMC) where there was a charge transfer from Ga to Ni,which is favorable for reducing the adsorption strength and amount of ethylene on Ni atoms.As a result,the over-hydrogenation,the C–C bond hydrogenolysis and the polymerization were suppressed,and subsequently the selectivity to ethylene was enhanced.With the decrease of Ni/Ga atomic ratio,the activity and stability of the NixGa/SiO2 catalysts increased first and then decreased,while the ethylene selectivity tended to increase.Ni5 Ga/SiO2 exhibited the best performance.Under the conditions of 180 °C,0.1 MPa,and a reactant(1.0 vol% acetylene,5.0 vol% H2 and 94 vol% N2) with the space velocity of 36,000 m L h-1 g-1,the acetylene conversion maintained at 100% on Ni5 Ga/SiO2 during 120 h time on stream and the selectivity to ethylene was 75%~81%after reaction for 68 h.It was also found that the formation of Ni-Ga alloy and Ni3 Ga IMC suppressed the incorporation of carbon to form NiCx,subsequently enhancing the catalyst stability.Additionally,with increasing the Ga content,the catalyst acid amount and strength tended to increase,which promoted the polymerization and carbon deposition and so the catalyst deactivation. 展开更多
关键词 Selective hydrogenation ACETYLENE Ni-Ga ALLOY Ni3Ga INTERMETALLIC compound
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Control of wall thickness and surface morphology of tungsten thin wall parts by adjusting selective laser melting parameters
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作者 Yan-jun Xie Huai-chao Yang +3 位作者 Xue-bing Wang Lin Zhao Chun-jiang Kuang Wei Han 《钢铁研究学报:英文版》 SCIE EI CAS CSCD 2019年第2期182-190,共9页
The tungsten thin wall parts which were used as high-performance collimator devices were fabricated by optimizing selective laser melting laser parameters.The effect of laser power and scan rate on wall thickness and ... The tungsten thin wall parts which were used as high-performance collimator devices were fabricated by optimizing selective laser melting laser parameters.The effect of laser power and scan rate on wall thickness and surface morphology of tungsten山in wall parts was investigated,respectively.The results indicated that the wall thickness increased with the enhancemem in laser power as a linear relationship.On the contrary,the wall thickness decayed exponentially with the acceleration in laser sean rate.Meanwhile,the wall thickness of the parts fabricated by laser double-pass melting was ihinner than that fabricated by laser single-pass melting.In addition,mathematic models for selecting suitable laser power and laser sean rate to fabricate specified tungsten thin wall parts were proposed.Furthermore,the effects of laser parameters on the top surface roughness,adhesive parts and hot cracks were also discussed. 展开更多
关键词 Selective LASER MELTING TUNGSTEN LASER power SCAN rate THIN wall part Surface morphology
New aporphine alkaloids with selective cytotoxicity against glioma stem cells from Thalictrum foetidum
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作者 DING Cai-Feng DAI Zhi +2 位作者 YU Hao-Fei ZHAO Xu-Dong LUO Xiao-Dong 《中国天然药物:英文版》 SCIE CAS CSCD 2019年第9期698-706,共9页
Seven new isoquinoline alkaloids,9-(2’-formyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy dehydroaporphine(1),9-(2’-formyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy oxoaporphine(2),3-methoxy-2’-formyl oxo... Seven new isoquinoline alkaloids,9-(2’-formyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy dehydroaporphine(1),9-(2’-formyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy oxoaporphine(2),3-methoxy-2’-formyl oxohernandalin(3),(–)-9-(2’-methoxycarbonyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy aporphine(4),(–)-2’-methoxycarbonyl thaliadin(5),(–)-9-(2’-methoxyethyl-5’,6’-dimethoxyphenoxy)-1,2,3,10-tetramethoxy aporphine(6),(–)-3-methoxy hydroxyhernandalinol(7),together with six known isoquinoline alkaloids(8–13)were isolated from the roots of Thalictrum foetidum.Their structures were elucidated by extensive spectroscopic measurements.Compounds 1 and 2 showed significant selective cytotoxicity against glioma stem cells(GSC-3#and GSC-18#)with IC50 values ranging from 2.36 to 5.37μg·mL^–1. 展开更多
关键词 THALICTRUM foetidum APORPHINE ALKALOIDS SELECTIVE CYTOTOXICITY GLIOMA stem cells
Rural Migrant Workers' Welfare and Labor Protection in China under the Labor Contract Law 预览
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作者 杜鹏程 徐舒 吴明琴 《中国经济学人:英文版》 2019年第2期81-94,共14页
This paper employs difference-in-differences(DID)approach to evaluate the effects of China’s Labor Contract Law’s implementation on rural migrant workers’welfare.Our findings suggest that the Labor Contract Law has... This paper employs difference-in-differences(DID)approach to evaluate the effects of China’s Labor Contract Law’s implementation on rural migrant workers’welfare.Our findings suggest that the Labor Contract Law has reduced rural migrant workers’ working hours by 23%,and increased their social insurance coverage by 10% to 26%.This conclusion holds true after removal of sample selection bias and policy expectation factor.Further analysis reveals that Labor Contract Law’s welfare improvement effect was more significant for migrant workers in regions where workers had poor bargaining power.Other economic factors during the same period of time did not affect the law’s labor protection effect.Our findings give a clear answer to controversies over whether the Labor Contract Law can improve labor rights for underprivileged groups,and are of reference value for developing labor protection systems. 展开更多
关键词 LABOR PROTECTION MIGRANT workers’welfare SELECTIVE BIAS
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Efficient catalytic hydrogen generation by intermetallic platinum-lead nanostructures with highly tunable porous feature
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作者 Bin E Lingzheng Bu +2 位作者 Qi Shao Yujing Li Xiaoqing Huang 《科学通报:英文版》 SCIE EI CSCD 2019年第1期36-43,共8页
The water-gas shift (WGS)reaction is an essential industrial reaction for upgrading hydrogen (H2)by removing carbon monoxide (CO),while highly efficient platinum (Pt)-based catalysts for WGS with simultaneously high a... The water-gas shift (WGS)reaction is an essential industrial reaction for upgrading hydrogen (H2)by removing carbon monoxide (CO),while highly efficient platinum (Pt)-based catalysts for WGS with simultaneously high activity and stability are still yet to be developed due to the poisoning issue during the reaction.Herein,we report on the porous PtPb peanut nanocrystals (porous PtPb PNCs)and porous PtPb octahedron nanocrystals (porous PtPb ONCs)with controllable ratios of Pt/Pb as extremely active and stable catalysts towards WGS reaction.It exhibits the composition-dependent activity with porous PtPb PNCs-40/ZnO being the most active for WGS to H2,16.9 times higher than that of the commercial Pt/C.The porous PtPb PNCs-40/ZnO also display outstanding durability with barely activity decay and negligible structure and composition changes after ten successive reaction cycles.X-ray photoelectron spectroscopy (XPS)results reveal that the suitable binding energy of Pt 4f7/12 and the high ratio of Pt(0) to Pt(Ⅱ)in porous PtPb PNCs/Zn0 and porous PtPb ONCs/ZnO are crucial for the enhanced WGS activity. The CO stripping results indicate the optimized CO adsorption strength on the Pt surface ensure the excellent WGS activity and the outstanding durability.The present work demonstrates an important advance in tuning the porous metal nanomaterials as highly efficient and durable catalysts for catalysis, energy conversion and beyond. 展开更多
关键词 POROUS Selective ETCHING Hydrogen Pt-Pb Water-gas shift
Cracking Behavior in Additively Manufactured Pure Tungsten
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作者 Dian-Zheng Wang Kai-Lun Li +3 位作者 Chen-Fan Yu Jing Ma Wei Liu Zhi-Jian Shen 《金属学报:英文版》 SCIE EI CAS CSCD 2019年第1期127-135,共9页
In this study, near fully dense(96.5%) pure tungsten bulks were additively manufactured and the cracking behavior was investigated. A crack network with a spacing of ~100 lm was observed in the fabricated bulks. It wa... In this study, near fully dense(96.5%) pure tungsten bulks were additively manufactured and the cracking behavior was investigated. A crack network with a spacing of ~100 lm was observed in the fabricated bulks. It was observed that the laser scanning strategy, which could tailor the microstructure, affected the crack distribution pattern in fabricated tungsten.The calculated surface temperature difference(7300 K) was much higher than the cracking criterion(800 K) of tungsten,indicating that cracking is almost inevitable in laser additive manufacturing of tungsten. It could be concluded that crack network formed because the cracks emerged in every laser molten track and then interconnected in the layer-by-layer building process. 展开更多
关键词 TUNGSTEN SELECTIVE LASER MELTING CRACKING Microstructure
Selective Targeting of Perirhinal Cortex Projection to Hippocampal CA1 Interneurons
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作者 Xiang Li Yiding Li +1 位作者 Junhui Zhang Xiaohui Zhang 《神经科学通报:英文版》 SCIE CAS CSCD 2019年第4期763-765,共3页
Dear Editor,The perirhinal cortex (PER) is conceptually important in the recognition memory, especially in familiarity discrimination, whereas the hippocampus is important for association and recollection [1]. This no... Dear Editor,The perirhinal cortex (PER) is conceptually important in the recognition memory, especially in familiarity discrimination, whereas the hippocampus is important for association and recollection [1]. This notion is known as the dualprocess model of recognition memory. 展开更多
关键词 SELECTIVE TARGETING Perirhinal CORTEX CA1 INTERNEURONS
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