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New insight into fracturing characterization of shale under cyclic soft stimulation:A lab-scale investigation

Petroleum Science 2022年第6期19卷 2830-2843页

作者： Qiang Gao han cao Ting Bao Jiang-Zhan Chen Huan-Xiao Hu Ping-He Sun School of Geoscience and Info-Physics Central South UniversityChangsha410083HunanChina Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Ministry of Education) Central South UniversityChangsha410083HunanChina Hubei Intelligent Geological Equipment Engineering Technology Research Center Wuhan430074HubeiChina Pacific Northwest National Laboratory RichlandWA99352USA School of Resources and Safety Engineering Central South UniversityChangsha410083HunanChina

The cyclic soft stimulation(CSS)is a new method of reservoir reforming for which the mechanism of fracturing crack propagation is ambiguous with regard to the alternating fluid *** study aims to provide a comprehensive understanding of the fracturing mechanical characterizations of CSS under different magnitudes and amplitudes of the alternating fluid *** emission(AE)is recorded to investigate the damage evolution under CSS based on the b value analysis of *** results reveal the difference of pressure in a crack under different cyclic fluid pressure *** AE results show that the maximum radiated energy under CSS tends to be reduced with the increase in the amplitude and magnitude of the alternating fluid *** finishing crucial touch is that the crack extending criterion under CSS is proposed,which combines the injection parameters,the rock properties and in-situ *** to the crack extending criterion,the fluctuation fluid pressure causes the reduction of a critical crack extending pressure,and the CSS causes the crack to initiate and propagate under low fluid *** a higher-value magnitude of alternating fluid pressure,the cyclic times of CSS is less for the crack *** supplement to the crack extending criterion,a distinct relationship between the radiated energy and the cyclic fluid pressure also is established based on the energy dissipation *** new findings provide an insight into the determination of crack extending criterion under CSS for efficiently implementing shale fracturing.

关键词： Cyclic soft stimulation Fracturing mechanical characterization Damage evolution Crack extending criterion Radiated energy

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Laboratory study of fluid properties owing to cutting intrusions during horizontal directional drilling

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Underground Space 2020年第1期5卷 20-29页

作者： Pinghe Sun Dingqiang Mo Samuel T.Ariaratnam han cao Pengfei Zhang School of Geosciences and Information Physics Central South UniversityChangsha 410083China Key Laboratory of Metallogenic Prediction and Geoenvironmental Monitoring of Ministry of Education Central South UniversityChangsha 410083China School of Sustainable Engineering&The Built Environment Arizona State UniversityP.O.Box 873005TempeAZUSA State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengduChina

During horizontal directional drilling installations,a primary function of drilling fluids is to yield drill cuttings and lubricate the product *** paper presents the results of a research study of drilling fluid parameters,and the filter cake properties associated with drill cutting *** sand meshes and field cutting sizes were added to the drilling *** on the laboratory experiments of eighteen samples including testing drilling fluid rheology and filter cake properties,the influence of drill cuttings on low solid-phase drilling fluid systems were *** results reveal that drilling fluid plastic viscosity values increase with sand content and particle *** 100-mesh sand exhibits a larger plastic viscosity compared to the 200-mesh *** suggests that the coarser the sand,the greater is the plastic *** contrast,drilling fluids with 200-mesh sand exhibit greater shear forces than the 100-mesh *** the sand content is4%,the shear dilution ability of the drilling fluid begins to *** thinnest filter cake is formed after 6 h with a 100-mesh cutting size and 4%sand ***,when the cutting size changed to 150-mesh and 2%content,the largest filter cake toughness and strength after rolling for 12 h were ***,the combination of 200-mesh and 150-mesh with 2%–4%content rolling for 12–24 h indicate different *** the filter cake thickness,cutting content is the primary influencing factor followed by particle size and *** factor with the least influence is rolling *** found that rolling time and gradation were the most significant factors affecting the toughness of the filter cake,followed by cutting ***,particle size exhibits the least influence on filter cake *** results are important to better understand the solid-phase control of drilling fluids in the field.

关键词： Drilling fluid Filter cake Drilling cutting Solid-phase control Rheology Horizontal directional drilling

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Investigation of Hole Distribution in Y_(1-x)Pr_(x)Ba_(2)Cu_(3)O_(7)

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Chinese Physics Letters 1998年第7期15卷 525-527页

作者： YU Ya-bin cao Guang-han JIAO Zheng-kuan Department of Physics Zhejiang UniversityHangzhou 310027 Department of Physics Yantai UniversityYantai 264005

The electronic structure of Y_(1-x)Pr_(x)Ba_(2)Cu_(3)O_(7) is described by a tight-binding Hamiltonian in which the Pr-O hybridization and the 2p_(σ)-2p_(π) Coulomb repulsion are taken into *** dependence of planar hole-density,localized hole-density and chemical potential of holes on Pr concentration is calculated by a coherent potential *** result shows that the insensitivity of hole-density on the CuO_(3) chains with the Pr-doping is due to the 2p_(σ)-2p_(π) *** other experimental facts can also be well interpreted.

关键词： chains

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Polymeric catalyst with polymerization-enhanced Lewis acidity for CO_(2)-based copolymers

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Chinese Chemical Letters 2023年第12期34卷 246-250页

作者： Pei Chen Hao Zhou han cao Chunwei Zhuo Shunjie Liu Xianhong Wang School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China Key Laboratory of PolymerEcomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022Chi

Ring-opening copolymerization of CO_(2) and epoxides is a promising way to manufacture high value-added *** a variety of catalyst systems have been reported,the reaction is still limited by low activity and polymer ***,a strategy of polymerization-enhanced Lewis acidity is reported to construct a series of highly efficient polymeric aluminum porphyrin catalysts(PAPCs).The characterization of the coordination equilibrium constant(K_(eq))showed significantly enhanced Lewis acidity of PAPC(K_(eg)=18.2 L/mol)compared to the monomeric counterpart(K_(eq)=6.4 L/mol),accompanied with increased turnover frequency(TOF)from 136 h^(-1) to 5500 h^(-1).Through detailed regulation of Lewis acidity,the highly Lewis acidic PAPC-OTs displayed a record high TOF of 30,200 h^(-1) with polymer selectivity of up to 99%.

关键词： Carbon dioxide Ring-opening copolymerization Polymerization Lewis acidity Polymeric aluminum porphyrin catalyst

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An Investigation on the Production of Random Copolymer with Monothiocarbonate and Trithiocarbonate Units over Cyclic Thiocarbonate via Metal-free Catalysis

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Chinese Journal of Chemistry 2020年第3期38卷 269-274页

作者： Jia-Liang Yang Lan Fang Hu Xiao han cao Ying Wang Xing Hong Zhang MOE Key Llaborotory of Macromolecular Synthesis and Functionolizotion Department of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang 310027China

Synthesis of poly(thiocarbonate)s from the copolymerization of epoxides and carbon disulfide(CS2)remains a tough challenge,due to inevitable oxygen-sulfur atom scrambling *** this work,we utilied the oxygen-sulfur exchange reaction(0-S ER)to synthesize a random copolymer with monothiocarbonate and trithiocarbonate units from CS2 and phenyI glycidyI ether(PGE)via metal-free Lewis *** copolymers contained monothiocarbonate and trithiocarbonate units of which the molar fraction could be tuned by va rying either the types of Lewis pairs or the reaction *** track on the intermediate provided an insight in the process of O-S ER and thus gave a hint to control the product *** and consumption of phenyl thioglycidyl ether was the key process to regulate the chain ***,the oxygen atoms of PGE could be excluded out of the chain,resulting in the nearly complete production of poly(trithiocarbonate)***,the refractive index of this kind of copolymer could be regulated in a wide range of 1.73-1.79(at 590 nm).

关键词： structure. temperature. process.

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Structural evolution and superconductivity tuned by valence electron concentration in the Nb-Mo-Re-Ru-Rh high-entropy alloys

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Journal of Materials Science & Technology 2021年第26期85卷 11-17页

作者： Bin Liu Jifeng Wu Yanwei Cui Qjnqing Zhu Guorui Xiao Siqi Wu Guang-han cao Zhi Ren School of Science Westlake University18 Shilongshan RoadHangzhou310064China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou310064China Department of Physics Fudan UniversityShanghai200433China Department of Physics Zhejiang UniversityHangzhou310027China

The crystal structure and physical properties of Nb_(25)Mo_(5+x)Re_(35)Ru_(25-x)Rh_(10)(0≤x≤10)and Nb_(5)Mo_(35-y)Re_(15+y)Ru_(35)Rh_(10)(0≤y≤15)high-entropy alloys(HEAs)have been studied by X-ray diffraction,electrical resistivity,magnetic susceptibility,and specific heat *** results show that the former HEAs with valence electron concentration(VEC)values of 6.7-6.9 crystallize in a noncentrosymmetric cubicα-Mn structure,while the latter ones with VEC values of 7.1-7.25 adopt a centrosymmetric hexagonal close-packed(hcp)*** different structures,both series of HEAs are found to be bulk superconductors with a full energy gap,and the superconducting transition temperature Tc tends to decrease with the increase of ***,the Tc values of the hcp-type HEAs are higher than those of theα-Mn-type ones,likely due to a stronger electron phonon ***,we show that VEC and electronegativity difference are two key parameters to control the stability ofα-Mn and hcp-type *** results not only are helpful for the design of such HEAs,but also represent the first realization of structurally different HEA superconductors without changing the constituent elements.

关键词： High-entropy alloys Hcp toα-Mn structural evolution Superconducting properties Valence electron concentration Electronegativity difference

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Superconductivity and strong spin-orbit coupling in a new noncentrosymmetric compound ThIrP

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Science China(Physics,Mechanics & Astronomy) 2021年第10期64卷 95-102页

作者： GuoRui Xiao QinQing Zhu YanWei Cui WuZhang Yang BaiZhuo Li SiQi Wu Guang-han cao Zhi Ren Department of Physics Zhejiang UniversityHangzhou 310027China School of Science Westlake UniversityHangzhou 310064China Institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310064China Department of Physics Fudan UniversityShanghai 200433China

A new noncentrosymmetric phosphide ThIrP has been synthesized and characterized. X-ray difraction analysis shows that this compound crystallizes in a LaPtSi-type tetragonal lattice(space group I41md, Z = 4), whose lattice parameters are a = b =4.0676(1) ?, c = 14.3354(2) ?, and V = 237.191(8) ?3. Moreover, ThIrP is discovered to be an intermediately coupled,type-Ⅱ superconductor with possibly multiple gaps below Tc= 5.07 K. The upper critical magnetic field, Sommerfield coefficient, and Ginzburg-Laudau parameter are determined based on physical property measurements, which are Bc2= 0.83 T, γ =7.5 mJ mol-1 K-2, and κGL= 7.5, respectively. The electronic band structure calculations point out nearly equal contributions of Ir and Th atoms on the density of states around the Fermi surface. In addition, the spin-orbit coupling induced band splitting reaches as large as 270 meV along the Γ-Z line. Our results suggest that ThIrP provides a platform to study the interplay between inversion-symmetry breaking, strong spin-orbit coupling, and superconductivity.

关键词： ThIrP noncentrosymmetric superconductivity spin-orbit coupling

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Organic matter fractions within macroaggregates in response to long-term fertilization in calcareous soil after reclamation

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Journal of Integrative Agriculture 2021年第6期20卷 1636-1648页

作者： cao han-bing XIE Jun-yu HONG Jie WANG Xiang HU Wei HONG Jian-ping College of Resources and Environment Shanxi Agricultural UniversityTaigu 030801P.R.China Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources Taiyuan 030031P.R.China College of Environment Zhejiang University of TechnologyHangzhou 310014P.R.China College of Land Science and Technology China Agricultural UniversityBeijing 100193P.R.China New Zealand Institute for Plant&Food Research Limited Christchurch 8140New Zealand

Soil organic carbon(SOC)plays a key role in improving soil quality and optimizing crop *** little is known about the fate of macroaggregates(>0.25 mm)under long-term fertilization and their relative importance in SOC sequestration in reclaimed calcareous ***,the effects of mineral fertilizers and organic manure on the mechanisms of organic carbon(OC)stabilization in macroaggregates were investigated in this *** treatments were used:unfertilized control(CK),mineral fertilizer(NPK),compost chicken manure alone(M),and mineral fertilizers plus manure(MNPK).Samples from the 0–20 cm layer of soil receiving 11-year-long fertilization were separated into four fractions based on the macroaggregates present(unprotected coarse and fine particulate organic matter,cPOM and fPOM;physically protected intra-microaggregate POM,i POM;and biochemically protected mineral associated OM,MOM)by the physical fractionation *** with the control,the long-term application of NPK had little effect on SOC content,total nitrogen(TN)content,and OC and TN contents of macroaggregate *** contrast,incorporation of organic manure(MNPK)significantly increased SOC(45.7%)and TN(24.3%)*** of MNPK increased OC contents within macroaggregate-extracted fractions of cPOM(292.2%),fPOM(136.0%)and iPOM(124.0%),and TN contents within cPOM(607.1%),fPOM(242.5%)and iPOM(127.6%),but not the mineral associated organic carbon(MOM-C)and nitrogen(MOM-N)*** C fractions were more strongly and positively correlated with SOC increase than protected C fractions,especially for cPOM-C,indicating that SOC sequestration mainly occurred via cPOM-C in the studied calcareous *** conclusion,MNPK increased the quantity and stability of SOC by increasing the contents of cPOM-C and cPOM-N,suggesting that this management practice(MNPK)is an effective strategy to develop sustainable agriculture.

关键词： long-term fertilization carbon sequestration macroaggregate physical fractionation coarse particulate organic carbon calcareous soil

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Effects of planting patterns plastic film mulching on soil temperature,moisture, functional bacteria and yield of winter wheat in the Loess Plateau of China

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Journal of Integrative Agriculture 2023年第5期22卷 1560-1573页

作者： ZHAO Xiao-dong QIN Xiao-rui LI Ting-liang cao han-bing XIE Ying-he College of Biological Sciences and Technology Taiyuan Normal UniversityYuci 030619P.R.China College of Resources and Environment/State Key Laboratory of Integrative Sustainable Dryland Agriculture(in preparation) Shanxi Agricultural UniversityTaiyuan 030031P.R.China

The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of *** common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat *** previous study indicated that FP could improve wheat yield more effectively than RP,but the reason remains *** effect of mulching method on functional bacteria also needs to be further *** this study,winter wheat was employed to evaluate the impacts of mulching method on soil temperature,moisture content,microorganisms and grain *** results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too ***,the ability to regulate soil temperature in the RP method was unstable and varied with *** lowest negative accumulated soil temperature was found in the FP treatment,which was 20–89 and 43–99%lower than that of the RP and flat sowing with non-film mulching control (NP) treatments,*** soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment,which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of ***,due to the limited water resources in the study area,there was almost no difference between treatments in topsoil water storage during the later *** wheat yield in the FP treatment was significantly higher,by 12–16and 23–56%,respectively,than in the RP and NP *** positive correlations were observed among the negative accumulated soil temperature,spike number and wheat *** Chao1 and Shannon indices in the RP treatment were 17 and 3.9%higher than those in the NP treatment,***,according to network relationship analysis,the interspecific relationships of bacteria were weakened i

关键词： winter wheat soil temperature moisture functional bacteria grain yield

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Online Junction Temperature Measurement of Double-sided Cooling IGBT Power Module through On-state Voltage with High Current

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Chinese Journal of Electrical Engineering 2022年第4期8卷 104-112页

作者： Xiaoguang Chai Puqi Ning han cao Dan Zheng Huakang Li Yunhao Huang Yuhui Kang Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100190China Wuxi Power Supply Company of State Grid Wuxi 214026China

The aim of this study is to achieve online monitoring of the junction temperature of double-sided-cooling insulated gate bipolar transistor(IGBT)power modules by using the on-state voltage under a high current to maximize the utilization of IGBT power *** junction temperature measurement plays an important role in improving the reliability of the inverter with IGBT,increasing the power density of the motor controller of electric vehicles,and reducing the cost of electric vehicles.

关键词： Double-sided-cooling IGBT junction temperature monitoring on-state voltage with high current

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