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EHTPB基黏结剂体系的低温固化

火炸药学报 2024年第2期47卷 152-158,I0003页

作者：王晨刘玉存余思禹刘洋君中北大学环境与安全工程学院山西太原030051 山西北方兴安化学工业有限公司山西太原030051

为了开发适用于PBX浇注炸药低温固化的黏结剂体系,选取环氧端羟基聚丁二烯(EHTPB)为黏结剂,用黏度增长法研究了添加二聚酸二异氰酸酯(DDI)、甲苯二异氰酸酯(TDI)、六亚甲基二异氰酸酯三聚体(HDI trimer)、异佛尔酮二异氰酸酯(IPDI)、二... 详细信息

为了开发适用于PBX浇注炸药低温固化的黏结剂体系,选取环氧端羟基聚丁二烯(EHTPB)为黏结剂,用黏度增长法研究了添加二聚酸二异氰酸酯(DDI)、甲苯二异氰酸酯(TDI)、六亚甲基二异氰酸酯三聚体(HDI trimer)、异佛尔酮二异氰酸酯(IPDI)、二苯基甲烷二异氰酸酯(MDI)5种固化剂在45℃条件下黏度随时间的变化规律;并在35℃下研究体系中添加不同催化剂羰基铜化合物(YKT)、二月桂酸二丁基锡(T12)、三亚乙基二胺(DABCO)、辛酸亚锡(T9)、三苯基铋(TPB)对EHTPB-DDI黏结剂体系的催化反应效果;采用恒温流变技术对EHTPB-DDI-YKT黏结剂体系的固化反应动力学进行了计算。结果表明,在45℃条件下DDI与IPDI的固化反应活性相近,可作为较为理想的固化剂;在35℃下催化剂对EHTPB-DDI固化反应速率的影响顺序为:T12>T9>DABCO>YKT>TPB,其中添加YKT时适用期为5.45 h,符合固化工艺要求;通过反应速率判断出EHTPB-DDI-YKT黏结剂体系固化反应为自催化反应,计算出该黏结剂体系的表观活化能为91.65 kJ/mol,反应级数为0.836。EHTPB-DDI-YKT黏结剂体系能够有效降低黏结剂体系的固化温度,实现EHTPB基PBX浇注炸药低温固化。

关键词：物理化学环氧端羟基聚丁二烯 EHTPB PBX 低温固化黏结剂固化剂 Kawakita方程

中国化阐释与现代性建构——略论朱立元对马克思主义文艺学的创新探索

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兰州文理学院学报（社会科学版） 2024年第3期40卷 12-16页

作者：刘阳军贵州民族大学文学院贵州贵阳550025

朱立元对马克思主义文艺学的创新探索,是其立足中国和世界现代语境而展开的一种文论现代性建构。这一探索可概括为两点:马克思主义文艺学体系建构和马克思主义文艺学中国化研究。其不仅坚定主张马克思主义文艺学体系要贯通生产到消费、... 详细信息

朱立元对马克思主义文艺学的创新探索,是其立足中国和世界现代语境而展开的一种文论现代性建构。这一探索可概括为两点:马克思主义文艺学体系建构和马克思主义文艺学中国化研究。其不仅坚定主张马克思主义文艺学体系要贯通生产到消费、创造到接受之完整过程,系统总结和反思马克思主义文艺学中国化成就和经验等,同时还突出了古今中外交流互鉴,尤其是马克思主义文艺学与中国社会现实和文艺现实、中华优秀传统文化相结合的历史逻辑和理论逻辑,从而也突出了马克思主义文艺学中国化乃是当代中国文艺学创新建构之根本途径。

关键词：朱立元马克思主义文艺学中国化阐释现代性建构

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A Novel Design of a Pre-separation Panel Structure to Protect Against the Impact of an Explosion in an Aircraft Plenum Chamber

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Acta Mechanica Solida Sinica 2024年第1期37卷 166-180页

作者： Zongxing liu Xiang yang jun liu School of Aeronautics Northwestern Polytechnical UniversityXi'an 710072China COMAC Shanghai Aircraft Design and Research Institute Shanghai 201210China

To reduce the damage of the pressurizing panel structure of a fuselage caused by an explosion at the“least risk bomb location”in an aircraft structure,a new pre-separation panel structure was designed to resist blast ***,the dynamic strain response and morphology of impact damage of the new pre-separation panel were measured in an impact damage ***,the commercial software LS-DYNA was used to calculate the propagation of the blast shock wave,and the results were compared with empirical equations to verify the rationality of the numerical calculation ***,the fluid–structure coupling method was used to calculate the damage process of the pre-separation panel structure under the impact of an explosion wave and an impact *** calculated results were in good agreement with the test results,which showed the rationality of the calculation method and the *** residual strength of the damaged pre-separation panel was significantly higher than that of the original damaged *** results show that the new pre-separation panel structure is reasonable and has certain significance for guiding the design of plenum chambers with strong resistance to implosion for aircraft fuselages.

关键词： Pre-separation panel structure Explosive response Residual strength Aircraft plenum chamber Least risk bomb location

Study on Function of Rare Earth During Producing Phosphate Fertilizer by Wet Process

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Journal of Rare Earths 2004年第z1期22卷 261-264页

作者： Wang Jiachen liu Xiangsheng yang jun Fan Yubin Wu Yanping Beijing General Research Instiutes for Nonferrous Metals 100088 BeijingChina National Rare Earth Center for Agriculture of China100088 BeijingChina Grirem Advanced Materials Co. Ltd. Beijing 100088China Beijing General Research Instiutes for Nonferrous Metals100088 BeijingChina National Rare Earth Center for Agriculture of China100088 BeijingChina Grirem Advanced Materials Co. Ltd. Beijing 100088China

The impacts of the Rare Earth (RE) on the contents of available Phosphorus (P) and the physical character of the calcium superphosphate produced by the wet process on the basis of simulating the consumption of concentrated sulphuric acid, the slurry concentration and the cure conditions in different wet process were studied in laboratory, and the results show that adding RE into different wet process does not raise available P, but changes its physical character,for example, the composite is loose and the color is offwhite.

关键词： rare earth phosphate fertilizer, wet process, physical characteristics, available P

Sharp bilinear decomposition for products of both anisotropic Hardy spaces and their dual spaces with its applications to endpoint boundedness of commutators

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Science China Mathematics 2024年第9期67卷 2091-2152页

作者： jun liu Dachun yang Mingdong Zhang School of Mathematics China University of Mining and TechnologyXuzhou 221116China Laboratory of Mathematics and Complex Systems(Ministry of Education of China) School of Mathematical SciencesBeijing Normal UniversityBeijing 100875China

Let a:=(a_(1),...,a_(n))2[1,∞)^(n),p∈(0,1),andα:=1/*** any x∈R^(n)and t∈[0,∞),letΦ_(p)(x,t):={t/1+(t[x]_(a)^(ν))^(1-p)if να■N,t/1+(t[x]_(a)^(ν))^(1-p)[log(e+|x|a)]^(p)if να∈N,let where [·]a:=1+|·|a,|·|a denotes the anisotropic quasi-homogeneous norm with respect to a,and ν:=a_(1)+…+a_(n).Let H_(a)^(p)(R^(n)),L_(a)^(a)(R^(n)),and H_(a)^(Φ_(p))(R^(n))be,respectively,the anisotropic Hardy space,the anisotropic Campanato space,and the anisotropic Musielak-Orlicz Hardy space associated with Φ_(p) on R^(n).In this article,via first establishing the wavelet characterization of anisotropic Campanato spaces,we prove that for any f∈H_(a)^(p)(R^(n))and g∈L_(a)^(a)(R^(n)),the product of f and g can be decomposed into S(f,g)+T(f,g) in the sense of tempered distributions,where S is a bilinear operator bounded from H_(a)^(p)(R^(n))*L_(a)^(a)(R^(Φ_(p))) to L^(1)(R^(n)) and T is a bilinear operator bounded from H_(a)^(p)(R^(n))*L_(a)^(a)(R^(n)) to H_(a)^(Φ_(p))(R^(n)) .Moreover,this bilinear decomposition is sharp in the dual sense that any y■H_(a)^(Φ_(p))(R^(n)) that fits into the above bilinear decomposition should satisfy(L^(1)(R^(n))+y)*=(L^(1)(R^(n)+H_(a)^(Φ_(p))(R^(n))*.As applications,for any non-constant b∈L_(a)^(a)(R^(n)) and any sublinear operator T satisfying some mild bounded assumptions,we find the largest subspace of H_(a)^(p)(R^(n)),denoted by H_(a,b)^(p)(R^(n)),such that the commutator [b,T] is bounded from H_(a,b)^(p)(R^(n))to L^(1)(R^(n)).In addition,when T is an anisotropic CalderónZygmund operator,the boundedness of [b,T] from H_(a,b)^(p)(R^(n))to L^(1)(R^(n))(or to H_(a)^(1)(R^(n)) is also *** key of their proofs is the wavelet characterization of function spaces under consideration.

关键词： anisotropic Euclidean space bilinear decomposition Hardy space Campanato space Musielak-Orlicz Hardy space commutator wavelet

Spatial distribution of shallow landslides caused by Typhoon Lekima in 2019 in Zhejiang Province, China

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Journal of Mountain Science 2024年第5期21卷 1564-1580页

作者： CUI Yulong yang liu XU Chong ZHENG jun School of Civil Engineering and Architecture Anhui University of Science and TechnologyHuainan 232001China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China Department of Civil Engineering Zhejiang UniversityHangzhou 310058China

In recent years, the coastal region of Southeast China has witnessed a significant increase in the frequency and intensity of extreme rainfall events associated with landfalling typhoons. The hilly and mountainous terrain of this area, combined with rapid rainfall accumulation, has led to a surge in flash floods and severe geological hazards. On August 10, 2019, Typhoon Lekima made landfall in Zhejiang Province, China, and its torrential rainfall triggered extensive landslides, resulting in substantial damage and economic losses. Utilizing high-resolution satellite images, we compiled a landslide inventory of the affected area, which comprises a total of 2,774 rainfallinduced landslides over an area of 2965 km2. The majority of these landslides were small to mediumsized and exhibited elongated, clustered patterns. Some landslides displayed characteristics of high-level initiation, obstructing or partially blocking rivers, leading to the formation of debris dams. We used the inventory to analyze the distribution pattern of the landslides and their relationship with topographical, geological, and hydrological factors. The results showed that landslide abundance was closely related to elevation, slope angle, faults, and road density. The landslides were predominantly located in hilly and low mountainous areas, with elevations ranging from 150 to 300 m, slopes of 20 to 30 degrees, and a NE-SE aspect. Notably, we observed the highest Landslide Number Density(LND) and Landslide Area Percentage(LAP) in the rhyolite region. Landslides were concentrated within approximately 4 km on either side of fault zones, with their size and frequency negatively correlated with distances to faults, roads, and river systems. Furthermore, under the influence of typhoons, regions with denser vegetation cover exhibited higher landslide density, reaching maximum values in shrubland areas. In areas experiencing significantly increased concentrated rainfall, landslide density also showed a corr

关键词： Typhoon rainfall Landslide characteristics Spatial distribution Southeast coastal region

Remarkable Wear Resistance in a Complex Concentrated Alloy with Nanohierarchical Architecture and Composition Undulation

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Research 2024年第1期2023卷 403-416页

作者： Yushan Geng Wenyuan Chen Hui Tan jun Cheng Shengyu Zhu jun yang Weimin liu State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000PR China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049PR China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264000PR China

Sustained wear damages on the sliding surfaces of alloys are generally the culprit responsible for the failure of various mechanical *** by high-entropy effects,here we deliberately deploy nanohierarchical architecture with composition undulation in a Ni50(AlNbTiV)_(50) complex concentrated alloy,which yields ultralow wear rate within the order of 10^(−7) to 10^(−6) mm^(3)/Nm between room temperature and 800℃.Such remarkable wear resistance heretofore represents one of the highest wear resistance reported for the bulk alloys or composites,and originates from the multi-type adaptive friction interface protection governed by intrinsically nano-coupled grains and *** cooperative heterostructure releases gradient frictional stress in stages upon wear at room temperature through the coexistence of multiple deformation pathways while activating a dense nanocrystalline glaze layer upon wear at 800℃ to minimize adhesive and oxidative *** work uncovers a practical avenue for tailoring wear properties with multicomponent heterostructures over a wide temperature range.

关键词： wear alloys friction

A 27 GHz,simple 2-bit 1×8 phased array

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Journal of Electronic Science and Technology 2024年第3期22卷 26-34页

作者： jun-Xian liu Yun-Ying Man Hao yang Peng yang School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

This study demonstrates a simple 2-bit phased array operating at 27 GHz that supports one-dimensional beam scanning with left-handed circular polarization(LHCP).The antenna is constructed using a compact four-layer printed circuit board(PCB)structure,consisting of a 90°phase shifter layer with microstrip structures,a ground(GND)layer,a direct current(DC)control layer,and a circularly polarized annular radiation patch layer with 1-bit phase *** on the proposed unit structure,a 1×8 array with half-wavelength inter-element spacing was designed and *** results show that the array achieves a peak gain of 10.23 dBi and is capable of beam scanning within±50°.

关键词： 27 GHz 2-bit P-i-n diodes Phased array Reconfigurable antennas

Strategies and opportunities of micro/nano delivery systems for targeted therapy of ulcerative colitis:Focus on underlying mechanisms and future perspectives

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Chinese Chemical Letters 2024年第2期35卷 118-130页

作者： Zihan liu Han liu Jialing Cheng Hongliang Wang Yanfang yang jun Ye Yuling liu State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijing 100050China Beijing Key Laboratory of Drug Delivery Technology and Novel Formulation Institute of Materia MedicaChinese Academy of Medical Sciences & Peking Union Medical CollegeBeijing 100050China

Ulcerative colitis(UC)is a common progressive inflammatory disease whose incidence has increased rapidly in recent years,and can develop into colorectal cancer in severe *** are currently no adequate or effective treatments for UC due to the fact that some patients have found suboptimal results after repeated administration,while others have experienced adverse *** the rapid development of nanotechnology,developing innovative colon-targeting platforms is essential to improving efficacy,reducing side effects,and improving patient *** this review,we summarize the pathophysiological characteristics of UC and the most recent status of numerous nanodrug delivery systems based on different targeting mechanisms in treating ***,intravenous,and rectal drug delivery nanoparticles targeting the colon are discussed,which can provide ideas for the design of colon-targeting nanoparticles for the treatment of colon diseases,especially for the treatment of *** but not least,we provide a glimpse into the future of colon-targeted delivery systems,as well as future advancements in the field.

关键词： Ulcerative colitis Physiological characteristics Colon-specific drug delivery Mechanisms of action Targeted therapy of UC