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| 1 | New Trends in Olefin Production显示文摘Most olefins (e.g., ethylene and propylene) will continue to be produced through steam cracking (SC) ofhydrocarbons in the coming decade. In an uncertain commodity market, the chemical industry is investingvery little in alternative technologies and feedstocks because of their current lack of economic viability,despite decreasing crude oil reserves and the recognition of global warming. In this perspective, some of themost promising alternatives are compared with the conventional SC process, and the major bottlenecks ofeach of the competing processes are highlighted. These technologies emerge especially from the abundanceof cheap propane, ethane, and methane from shale gas and stranded gas. From an economic point of view,methane is an interesting starting material, if chemicals can be produced from it. The huge availability ofcrude oil and the expected substantial decline in the demand for fuels imply that the future for proventechnologies such as Fischer-Tropsch synthesis (FFS) or methanol to gasoline is not bright. The abundance ofcheap ethane and the large availability of crude oil, on the other hand, have caused the SC industry to shiftto these two extremes, making room for the on-purpose production of light olefins, such as by the catalyticdehydrogenation of orooane. | Ismael Amghizar Laurien A. Vandewalle Kevin M. Van Geem Guy B. Matin | 2017 | Engineering2017，3，2： | 33 |
| 2 | Thermal cracking of aviation kerosene for scramjet applications显示文摘Thermal cracking of China No.3 aviation kerosene was studied experimentally and analytically under supercritical conditions relevant to regenerative cooling system for Mach-6 scramjet applications. A two-stage heated tube system with cracked products collection/analysis was used and it can achieve a fuel temperature range of 700―1100 K,a pressure range of 3.5―4.5 MPa and a residence time of ap-proximately 0.5―1.3 s. Compositions of the cracked gaseous products and mass flow rate of the kerosene flow at varied temperatures and pressures were obtained experimentally. A one-step lumped model was developed with the cracked mixtures grouped into three categories:unreacted kerosene,gaseous products and residuals including liquid products and carbon deposits. Based on the model,fuel conversion on the mass basis,the reaction rate and the residence time were estimated as functions of temperature. Meanwhile,a sonic nozzle was used for the control of the mass flow rate of the cracked kerosene,and correlation of the mass flow rate gives a good agreement with the measurements. | ZHONG FengQuan FAN XueJun YU Gong LI JianGuo | 2009 | Science China(Technological Sciences)2009，52，9： | 18 |
| 3 | Disassembly of the fruit cell wall by the ripening-associated polygalacturonase and expansin influences tomato cracking显示文摘Fruit cracking is an important problem in horticultural crop production.Polygalacturonase(SlPG)and expansin(SlEXP1)proteins cooperatively disassemble the polysaccharide network of tomato fruit cell walls during ripening and thereby,enable softening.A Golden 2-like(GLK2)transcription factor,SlGLK2 regulates unripe fruit chloroplast development and results in elevated soluble solids and carotenoids in ripe fruit.To determine whether SlPG,SlEXP1,or SlGLK2 influence the rate of tomato fruit cracking,the incidence of fruit epidermal cracking was compared between wild-type,Ailsa Craig(WT)and fruit with suppressed SlPG and SlEXP1 expression(pg/exp)or expressing a truncated nonfunctional Slglk2(glk2).Treating plants with exogenous ABA increases xylemic flow into fruit.Our results showed that ABA treatment of tomato plants greatly increased cracking of fruit from WT and glk2 mutant,but not from pg/exp genotypes.The pg/exp fruit were firmer,had higher total soluble solids,denser cell walls and thicker cuticles than fruit of the other genotypes.Fruit from the ABA treated pg/exp fruit had cell walls with less water-soluble and more ionically and covalently-bound pectins than fruit from the other lines,demonstrating that ripening-related disassembly of the fruit cell wall,but not elimination of SlGLK2,influences cracking.Cracking incidence was significantly correlated with cell wall and wax thickness,and the content of cell wall protopectin and cellulose,but not with Ca^(2+)content. | Fangling Jiang Alfonso Lopez Shinjae Jeon Sergio Tonetto de Freitas Qinghui Yu Zhen Wu John M.Labavitch Shengke Tian Ann L.T.Powell Elizabeth Mitcham | 2019 | Horticulture Research2019，6，1： | 13 |
| 4 | Effect of hierarchical ZSM-5zeolite crystal size on diffusion and catalytic performance of n-heptane cracking显示文摘Hierarchical ZSM-5zeolite aggregates with different sizes of nanocrystals were synthesized using different amounts of the mesoporogen 3-aminopropyl- triethoxysilane.The effect of the crystal size on the catalytic cracking of n-heptane was investigated and the Thiele modulus and effectiveness factor were used to determine the reaction rate-limiting step.The crystal size affected the textual properties of the catalysts but not the acidic properties of the catalysts.The reaction rate was first order with respect to the n-heptane concentration.Cracking over hierarchical zeolites with nanocrystal sizes larger than about 50nm took place under transition-limiting conditions,whereas the reaction over hierarchical zeolites with nanocrystal sizes of 15 or 30nm proceeded under reaction control conditions.Hierarchical ZSM-5 zeolite aggregates with smaller nanocrystals had better selectivity for light olefins which can be ascribed to the shorter diffusion path lengths and lower diffusion resistance in these catalysts. Furthermore,these catalysts had lower coking levels which can be attributed to the substantial number of mesopores which prevent the formation of coke precursors. | Shuman Xu Xiaoxiao Zhang Dangguo Cheng Fengqiu Chen Xiaohong Ren | 2018 | Frontiers of Chemical Science and Engineering2018，12，4： | 10 |
| 5 | Hydrogen-enhanced dislocation emission, motion and nucleation of hydrogen-induced cracking for steel显示文摘The change in dislocation configuration ahead of a loaded crack tip before and after charging with hydrogen was in situ investigated in TEM using a special constant deflection loading device The results showed that hydrogen could facilitate dislocation emission, multiplication and motion The change in displacement field ahead of a loaded notch tip for a bulk specimen before and after charging with hydrogen was in situ measured by the laser moire interferometer technique. The results showed that hydrogen could enlarge the plastic zone and increase the plastic strain The in situ observation in TEM showed that when hydrogen-enhanced dislocation emission and motion reached a critical condition, a nanocrack of hydrogen-induced cracking ( HIC) would nucleate in the dislocation-free zone (DFZ) or at the main crack tip. The reasons for hydrogen-enhanced dislocation emission, multiplication and motion, and the mechanisms of nucleation of HIC have been | 吕宏 李密丹 张天成 褚武扬 | 1997 | Science China(Technological Sciences)1997，40，5： | 9 |
| 6 | DMTO:A Sustainable Methanol-to-Olefins Technology显示文摘1.Introduction Ethylene and propylene are the cornerstones of the chemical industry,with more than 75%of chemical products as their downstream derivatives.They are conventionally produced via naphtha steam cracking and fluid catalytic cracking(FCC),in which oil is mainly used as feedstock.China,however,relies heavily on imports for crude oil.The Dalian Institute of Chemical Physics(DICP),together with China Petroleum&Chemical Corporation(Sinopec)Luoyang Petrochemical Engineering Company and SYN Energy Technology Co.,Ltd.,have developed a methanol-to-olefins technology—namely DMTO—which opens up an alternative path to synthesize light olefins from methanol,a platform chemical that can be readily derived from coal[1].As coal is relatively abundant in China,the success of DMTO is of practical significance in balancing the supply and demand of light olefins,reducing China’s dependence on imports for crude oil,and promoting national energy security.This report outlines the catalyst,fluidized-bed reactor,and process of DMTO technology,with an emphasis on the key technologies involved in commercial units and sustainable development for future applications. | Mao Ye Peng Tian Zhongmin Liu | 2021 | Engineering2021，7，1： | 8 |
| 7 | Cracking Behavior in Additively Manufactured Pure Tungsten显示文摘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. | Dian-Zheng Wang Kai-Lun Li Chen-Fan Yu Jing Ma Wei Liu Zhi-Jian Shen | 2019 | Acta Metallurgica Sinica(English Letters)2019，32，1： | 8 |
| 8 | Performance of a novel bent-up bars system not interacting with concrete显示文摘Increasing the bending and shear capacities of reinforced concrete members is an interesting issue in structural engineering.In recent years,many studies have been carried out to improve capacities of reinforced concrete members such as using post and pre-tensioning,Fiber Reinforced Polymer and other techniques.This paper proposes a novel and significant technique to increase the flexural capacity of simply supported reinforced concrete beams.The proposed method uses a new reinforcement bar system having bent-up bars,covered with rubber tubes.This technique will avoid interaction of bent-up bars with concrete.They are located in the zone where compressive and tensile forces act against one anothe匚The compressive force in the upper point of the bent-up bars is exerted to the end point of these bars located under neutral axis.Moreover,the tensile stress is decreased in reinforcements located under the neutral axis.This will cause the Reinforced Concrete(RC)beam to endure extra loading before reaching yield stress.These factors may well be considered as reasons to increase bending capacity in the new system.The laboratory work together with finite element method analysis were carried out in this investigation.Furthermore,bending capacity,ductility,strength,and cracking zone were assessed for the new proposed system and compared with the conventional model.Both the FEM simulation and the experimental test results revealed that the proposed system has significant impact in increasing the load bearing capacity and the stiffness of the RC beams.In the present study,an equation is formulated to calculate bending capacity of a new reinforcement bar system beam. | Aydin SHISHEGARAN Mohammad Reza GHASEMI Hesam VARAEE | 2019 | Frontiers of Structural and Civil Engineering2019，13，6： | 8 |
| 9 | Deformation and fracture mechanisms of an annealing-tailored 'bimodal' grain-structured Mg alloy显示文摘Through investigating and comparing the mechanical behavior of an as-rolled Mg-3%Al-1%Zn(wt%)alloy before and after annealing treatments,it was revealed that the formation of annealing-tailored bimodal grain structure ensured the 330℃/4 h samples having a good combination of tensile strength and plasticity.Failure analysis demonstrated that for the as-rolled and 330℃/1 h samples with fine grain structure,their plastic deformation was mainly attributed to basal slips,whereas the deformation mechanism in the bimodal grain-structured samples was dominated by basal slips in fine grains and twinning in coarse grains.For the 330℃/8 h samples with coarse grain structure,high densities of twins were activated.Meanwhile,basal slips occurred in the twinned and un-twinned areas of coarse grains and could pass through twin boundaries.For differently treated samples,cracking preferentially occurred along slip bands,resulting in their transgranular fractures. | Baojie Wang Daokui Xu Liyuan Sheng Enhou Han Jie Sun | 2019 | Journal of Materials Science & Technology2019，35，11： | 8 |
| 10 | Cracking conditions of crude oil under different geological environments显示文摘There are mainly 3 kinds of existing states of oil generating from source rocks,that is,dispersive liquid hydrocarbon inside of source rock,dispersive liquid hydrocarbon outside of source rock and concentrated liquid hydrocarbon outside of source rock.Because of the differences in thermal history and medium conditions around,and the interaction of organic and inorganic matter,the liquid hydrocarbon with 3 kinds of existing state has different cracking conditions.The gas generation dynamics experiments of crude oil matching different mediums indicate that the distribution of activation energy of methane changes a lot according to medium difference.The carbonate has a main influence on oil cracking conditions and can largely reduce its activation energy,which reflects the lower cracking temperature of crude oil.The mudstone takes a second place and the sandstone is the smallest.The catalytic cracking function to the oil of the carbonate,of the mudstone and of the sandstone changes weaken in turn.The corresponding Ro values of main gas generation period in different mediums are as follows:1.5%―3.8%with pure crude oil,1.2%―3.2%with dispersive crude oil in carbonate,1.3%~3.4% with dispersive crude oil in mudstone and 1.4%―3.6%with dispersive crude oil in sandstone.The influence of pressure to crude oil cracking is relatively complicated.In the low heating speed condition, pressure restrains the oil cracking and gas generation,but in the high heating speed condition,pressure has an indistinctive influence to the oil cracking and gas generation.Pressure also makes a different effort in different evolvement stage.Taking the middle and lower Cambrian source rocks in the Tarim Basin as an example,primary oil generating quantity is 2232.24×10 8 t,residual oil and oil cracking gas quantity is 806.21×10 8 t and 106.95×10 12 m 3 respectively. | ZHAO WenZhi,WANG ZhaoYun,ZHANG ShuiChang&WANG HongJun Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China | 2008 | Science China Earth Sciences2008，51，S1： | 8 |
| 11 | 7050铝合金软接触连铸扁锭裂纹抑制原因分析显示文摘7050铝合金软接触电磁连铸过程中的电磁场能促使熔体产生受迫流动,改善铸坯质量,抑制微裂纹。电磁场一方面通过均匀温度场降低内应力或应变,使金属高温脆性区主要处于受压状态,减少了热裂纹形成的外部诱因;另一方面,通过细化组织,减小不可补缩区间,减少晶界低熔点化合物数量,降低了合金铸锭的热裂倾向性,从而达到了抑制铸造裂纹的目的。 | 曹志强 李廷举 张红亮 刘吉东 王家淳 | 2010 | 稀有金属材料与工程2010，39，12： | 7 |
| 12 | Corrosion-enhanced dislocation emission and motion resulting in initiation of stress corrosion cracking显示文摘A special constant deflection device for TEM has been designed, and then change of dislocation configuration ahead of a crack tip during stress corrosion cracking (SCC) of brass in water and of Ti-24Al-11Nb alloy in methanol and initiation of SCC can he observed in TEM In situ tensile test in TEM for brass was carried out for comparison The results show that anodic dissolution during SCC can facilitate dislocation emission, multiplication and motion, and a dislocation free zone (DFZ) is formed The stress at a particular site in the DFZ, which is an elastic zone and is thinned gradually through corrosion-enhanced dislocation emission and motion, is possibly up to the cohesive strength, resulting in initiating of a nanocrack of SCC in the DFZ or sometimes at the crack tip. Because of the action of the corrosion solution the nanocrack of SCC propagates into a cleavage or intergranular microcrack rather than blunts into a void like in situ tension in | 褚武扬 谷飚 高克玮 黄一中 肖纪美 | 1997 | Science China(Technological Sciences)1997，40，3： | 7 |
| 13 | 裂化生活废旧塑料与SBS改性沥青及其混合料性能对比显示文摘对比研究了裂化生活废旧塑料(CRP)改性沥青与SBS改性沥青的软化点、针入度、延度及黏度指标,及相应沥青混合料的马歇尔试验指标、高温与低温稳定性、水稳定性及疲劳特性等;研究了两种改性剂掺加工艺——干法、湿法——CRP改性沥青混合料性能及施工工艺,并与湿法SBS改性沥青混合料性能进行了对比。结果表明:5%CRP改性沥青与4%SBS改性沥青性能相近,两种改性沥青的软化点都得到了提高;两种改性沥青混合料的动稳定度均大于4 000次/mm,可以用CRP改性沥青拌制与SBS改性沥青性能相近的AC级配沥青混合料;在CRP掺量5%、SBS掺量4%的条件下,干法CRP改性沥青混合料的动稳定度、冻融劈裂强度比和疲劳寿命与SBS改性沥青混合料的相近,但干法施工工艺更为简单。 | 杨锡武 方宇亮 刘克 | 2017 | 重庆交通大学学报(自然科学版)2017，36，3： | 7 |
| 14 | Research and Development of Novel Heavy Oil Catalytic Cracking Catalyst RCC-1显示文摘A novel heavy oil catalytic cracking catalyst RCC-1 was developed by using the ultra-stable zeolite, which was hydrothermally treated and modified through cleaning its pores to serve as the active component. The chemical composition and physicochemical properties of RCC-1 catalyst were studied by XRF, BET, pore volume analysis, attrition index analysis, and particle size distribution determination methods, and its catalytic cracking performance was also evaluated by a microreactor for light oil cracking and the ACE device. The test results showed that the new type of heavy oil catalytic cracking catalyst RCC-1 had good physicochemical properties and heavy oil cracking ability, strong anti-metallic contamination capability, good product distribution, good coke selectivity and gasoline selectivity, and excellent reduction of gasoline olefin content characteristics. | Zhang Jiexiao Zhou Yan Xu Yun Tian Huiping | 2014 | China Petroleum Processing & Petrochemical Technology2014，16，4： | 6 |
| 15 | 裂解C9加氢催化剂性能研究显示文摘采用两段加氢工艺对裂解C9进行了加氢处理,一段采用Ni系催化剂将易结焦的二烯烃、链烯基芳烃等热敏物质除去,并使部分单烯烃加氢饱和;二段采用CoMoNi系催化剂进行加氢脱硫同时将单烯烃加氢饱和。重点考查了反应温度、压力、氢油比、空速对一段加氢效果的影响,并初步探讨了二段反应温度对加氢性能的影响,研究结果表明两段加氢后的产品溴值小于2.0 g Br/100 g,总硫小于1.0μg/g,胶质含量小于5mg/100 mL,可用于汽油调和组分或芳烃溶剂油。 | 吴阳春 王泽 夏大寒 王国兴 张先茂 | 2014 | 当代化工2014，43，7： | 6 |
| 16 | Hazard potential of zones of weakness in gravity dams under impact loading conditions显示文摘Dam constructions worldwide are designed and constructed in view of the strictest safety aspects for all static and dynamic load cases.As experience shows,however,formation of cracks in the“homogeneos concrete”as well as unsatisfactory compound behavior of lift joints are not to be excluded.These zones of weakness especially on the upstream side of the dam-exposed to high water pressure(static and dynamic)-represent an increased risk of safety.The main investigation,apart from the computation of the dynamic effects on the dam as a global structure,focuses on the stability analysis of a pressure-water filled crack configuration subjected to“dynamic loading”in the form of seismic action on the dam-reservoir-system and alternatively by“impact spot-loading”within sectors of the reservoir.A fracture mechanics based analysis shows an excessive potential of damage for the afflicted structure. | Herbert LINSBAUER | 2011 | Frontiers of Structural and Civil Engineering2011，5，1： | 6 |
| 17 | Experimental investigation on the cracking behavior of 3D printed kinked fissure显示文摘Uniaxial compression tests were carried out for 3 D printed samples having various types of kinked fissures by using the rock mechanics servo-controlled testing system. Photo-elastic technique is adopted to characterize and visualize the stress distribution and evolution of 3 D printed models subjected to vertical compression. The stress field in the loading process can clearly be captured via a high-speed camera. The results showed that fringes around the kinked fissure tips formed a central symmetrical interference fringe pattern, and failure firstly occurred at interference fringe of highest order. Two failure types i.e. tip-cracking and non-tip-cracking are categorized on the basis of crack propagation pattern of 3 D printed samples. Tensile crack propagation of wing cracks is the main form of failure of the antisymmetric kinked fissures, but the inclination of the branch fissures also played a key role on the location of initial fracture. The finite element method was applied to numerically simulate the process of crack propagation. The isochromatic fringe patterns are in good agreement with the experimental investigation. The current work gives an insight for implication of advanced technique to quantify and visualize the distribution of stress field, and provides further understanding of kinked fissure behavior at failure. | MA GuoWei DONG QianQian WANG Li | 2018 | Science China(Technological Sciences)2018，61，12： | 6 |
| 18 | Rock mechanics contributions to recent hydroelectric developments in China显示文摘Rock mechanics plays a critical role in the design and construction of hydroelectric projects including large caverns under high in situ stress,deep tunnels with overburden more than 2500 m,and excavated rock slopes of 700 m in height.For this,this paper conducts a review on the rock mechanics contributions to recent hydroelectric developments in China.It includes the development of new testing facilities,mechanical models,recognition methods for mechanical parameters of rock masses,design flowchart and modeling approaches,cracking-restraint method,governing flowchart of rock engineering risk factors enabling the development of risk-reduced design and risk-reduced construction,and initial and dynamic design methods.As an example,the optimal design of underground powerhouses at the Baihetan hydroelectric plant,China,is given.This includes determination of in situ stresses,prediction of deformation and failure depth of surrounding rock masses,development of the optimal excavation scheme and support design.In situ monitoring results of the displacements and excavation damaged zones(EDZs)have verified the rationality of the design methodology. | Xia-Ting Feng Yang-Yi Zhou Quan Jiang | 2019 | Journal of Rock Mechanics and Geotechnical Engineering2019，11，3： | 6 |
| 19 | Self-Healing Concrete with Crystalline Admixture——A Review显示文摘The scope of the present paper is to understand the effects of crystalline admixture on the selfhealing capacity of the cementitious composites. Previous studies were examined and a conclusion was drawn to the effect that different additives to crystalline admixture tend to improve self-healing of concrete for larger cracks. It is recommended that initial treatment with chemical admixture can stimulate and heal further cracks and it has the better repeatability trend in mixing with the concretes and mechanical recovery is possible even under repetitive preloading. Effective self-healing with chemical admixtures even under open-air exposure, leads to study the importance of a service ability design parameter including the maximum allowable crack width by repeatability analysis as a function of the exposure with the concept of sealable crack width. | A Ravitheja Dr T Chandra Sekhara Reddy Dr C Sashidhar | 2019 | Journal of Wuhan University of Technology(Materials Science)2019，34，5： | 6 |
| 20 | Localized bursting of mesocarp cells triggers catastrophic fruit cracking显示文摘The so-called rain-cracking of sweet cherry fruit severely threatens commercial production.Simple observation tells us that cuticular microcracking(invisible)always precedes skin macrocracking(visible).The objective here was to investigate how a macrocrack develops.Incubating detached sweet cherry fruit in deionized water induces microcracking.Incubating fruit in D2O and concurrent magnetic resonance imaging demonstrates that water penetration occurs only(principally)through the microcracks,with nondetectable amounts penetrating the intact cuticle.Optical coherence tomography of detached,whole fruit incubated in deionized water,allowed generation of virtual cross-sections through the zone of a developing macrocrack.Outer mesocarp cell volume increased before macrocracks developed but increased at a markedly higher rate thereafter.Little change in mesocarp cell volume occurred in a control zone distant from the crack.As water incubation continued,the cell volume in the crack zone decreased,indicating leaking/bursting of individual mesocarp cells.As incubation continued still longer,the crack propagated between cells both to form a long,deep macrocrack.Outer mesocarp cell turgor did not differ significantly before and after incubation between fruit with or without macrocracks;nor between cells within the crack zone and those in a control zone distant from the macrocrack.The cumulative frequency distribution of the logtransformed turgor pressure of a population of outer mesocarp cells reveals all cell turgor data followed a normal distribution.The results demonstrate that microcracks develop into macrocracks following the volume increase of a few outer mesocarp cells and is soon accompanied by cell bursting. | Eckhard Grimm Jan Hahn Daniel Pflugfelder Moritz Jonathan Schmidt Dagmar van Dusschoten Moritz Knoche | 2019 | Horticulture Research2019，6，1： | 5 |
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