The primary radiation damage in pure V and TiVTa concentrated solid-solution alloy(CSA)was studied using a molecular dynamics method.We have performed displacement cascade simulations to explore the generation and evo...The primary radiation damage in pure V and TiVTa concentrated solid-solution alloy(CSA)was studied using a molecular dynamics method.We have performed displacement cascade simulations to explore the generation and evolution behavior of irradiation defects.The results demonstrate that the defect accumulation and agglomeration in TiVTa CSA are significantly suppressed compared to pure V.The peak value of Frenkel pairs during cascade collisions in TiVTa CSA is much higher than that in pure V due to the lower formation energy of point defects.Meanwhile,the longer lifetime of the thermal spike relaxation and slow energy dissipation capability of TiVTa CSA can facilitate the recombination of point defects.The defect agglomeration rate in TiVTa CSA is much lower due to the lower binding energy of interstitial clusters and reduced interstitial diffusivity.Furthermore,the occurrence probability of dislocation loops in TiVTa CSA is lower than that in pure V.The reduction in primary radiation damage may enhance the radiation resistance of TiVTa CSA,and the improved radiation tolerance is primarily attributed to the relaxation stage and long-term defect evolution rather than the ballistic stage.These results can provide fundamental insights into irradiation-induced defects evolution in refractory CSAs.展开更多
In this paper, we propose a thermal model of a hybrid photovoltaic/thermal concentration system. Starting from the thermal balance of the model, the equation is solved and simulated with a MATLAB code, considering air...In this paper, we propose a thermal model of a hybrid photovoltaic/thermal concentration system. Starting from the thermal balance of the model, the equation is solved and simulated with a MATLAB code, considering air as the cooling fluid. This enabled us to evaluate some of the parameters influencing the electrical and thermal performance of this device. The results showed that the temperature, thermal efficiency and electrical efficiency delivered depend on the air mass flow rate. The electrical and thermal efficiencies for different values of air mass flow are encouraging, and demonstrate the benefits of cooling photovoltaic cells. The results show that thermal efficiency decreases air flow rate greater than 0.7 kg/s, whatever the value of the light concentration used. The thermal efficiency of the solar cell increases as the light concentration increases, whatever the air flow rate used. For a concentration equal to 30 sun, the thermal efficiency is 0.16 with an air flow rate equal to 0.005 kg/s;the thermal efficiency increases to 0.19 with an air flow rate equal to 0.1 kg/s at the same concentration. An interesting and useful finding was that the proposed numerical model allows the determination of the electrical as well as thermal efficiency of the hybrid CPV/T with air flow as cooling fluid.展开更多
A Zr-Gd alloy with neutron poisoning properties and resistance to boiling concentrated HNO3 corrosion was developed based on a corrosion-resistant Zr-702 alloy to meet the demand for neutron shielding in the closed-lo...A Zr-Gd alloy with neutron poisoning properties and resistance to boiling concentrated HNO3 corrosion was developed based on a corrosion-resistant Zr-702 alloy to meet the demand for neutron shielding in the closed-loop treatment of spent fuel and the nuclear chemical industry.In this study,1 wt.%,3 wt.%,5 wt.%,7 wt.%,and 9 wt.%Zr-Gd alloys were designed and fabricated with Zr-702 as the control element.The electrochemical behavior of the Zr-Gd alloys in boiling concentrated HNO3 was investigated,and the neutron shielding effect on plate thickness and Gd content was simulated.The experimental results demonstrate that the corrosion resistance of the alloy decreased slightly before~7-9 wt.%with increasing Gd content;this is the inflection point of its corrosion resistance.The alloy uniformly dissolved the Gd content that could not be dissolved in the Zr lattice,resulting in numerous micropores on the passivation coating,which deteriorated and accelerated the corrosion rate.The MCNP simulation demonstrated that when the Gd content was increased to 5 wt.%,a 2-mm-thick plate can shield 99.9%neutrons;an alloy with a Gd content≥7 wt.%required only a 1-mm-thick plate,thereby showing that the addition of Gd provides an excellent neutron poisoning effect.Thus,the corrosion resistance and neutron shielding performance of the Zr-Gd alloy can meet the harsh service requirements of the nuclear industry.展开更多
Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition re...Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds.The control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment groups.Results:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d 10.SPC also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.展开更多
Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein sup...Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.展开更多
The electrolyte integrated with lithium metal anodes is subjected to the issues of interfacial compatibility and stability,which strongly influence the performances of high-energy lithium metal batteries.Here,we repor...The electrolyte integrated with lithium metal anodes is subjected to the issues of interfacial compatibility and stability,which strongly influence the performances of high-energy lithium metal batteries.Here,we report a new electrolyte recipe viz.a moderately concentrated electrolyte comprising of 2.4 M lithium bis(fluorosulfonyl)imide(LiFSI)in a cosolvent mixture of fluorinated ethylene carbonate(FEC)and dimethyl carbonate(DMC)with relatively high ion conductivity.Owing to the preferential decomposition of LiFSI and FEC,an inorganic-rich interphase with abundant Li_(2)O and LiF nanocrystals is formed on lithium metal with improved robustness and ion transfer kinetics,enabling lithium plating/stripping with an extremely low overpotential of~8 mV and the average CE of 97%.When tested in Li||LiFePO_(4) cell,this electrolyte provides long-term cycling with a capacity retention of 98.3%after 1000 cycles at 1 C and an excellent rate performance of 20 C,as well as an areal capacity of 1.35 mA h cm^(-2)at the cathode areal loading of 9 mg cm^(-2).Moreover,the Li||LiFePO_(4) cell exhibits excellent wide-temperature performances(-40~60℃),including long-term cycling stability over 2600 cycles without visible capacity fading at 0℃,as well as extremely high average CEs of 99.6%and 99.8% over 400 cycles under-20℃ and 45℃.展开更多
Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed t...Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.展开更多
In the presentmanuscript,a Layer-Wise(LW)generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface ...In the presentmanuscript,a Layer-Wise(LW)generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface loads.The unknown field variable is modelled employing polynomials of various orders,each of them defined within each layer of the structure.As a particular case of the LW model,an Equivalent Single Layer(ESL)formulation is derived too.Different approaches are outlined for the assessment of external forces,as well as for non-conventional constraints.The doubly-curved shell is composed by superimposed generally anisotropic laminae,each of them characterized by an arbitrary orientation.The fundamental governing equations are derived starting from an orthogonal set of principal coordinates.Furthermore,generalized blending functions account for the distortion of the physical domain.The implementation of the fundamental governing equations is performed bymeans of the Generalized Differential Quadrature(GDQ)method,whereas the numerical integrations are computed employing theGeneralized IntegralQuadrature(GIQ)method.In the post-processing phase,an effective procedure is adopted for the reconstruction of stress and strain through-the-thickness distributions based on the exact fulfillment of three-dimensional equilibrium equations.A series of systematic investigations are performed in which the static response of structures with various curvatures and lamination schemes,calculated by the present methodology,have been successfully compared to those ones obtained fromrefined finite element three-dimensional simulations.Even though the present LW approach accounts for a two-dimensional assessment of the structural problem,it is capable of well predicting the three-dimensional response of structures with different characteristics,taking into account a reduced computational cost and pretending to be a valid alternative to widespread numerical implementations.展开更多
A new concentrated ternary salt ether-based electrolyte enables stable cycling of lithium metal battery(LMB)cells with high-mass-loading(13.8 mg cm^(−2),2.5 mAh cm^(−2))NMC622(LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2))cathodes ...A new concentrated ternary salt ether-based electrolyte enables stable cycling of lithium metal battery(LMB)cells with high-mass-loading(13.8 mg cm^(−2),2.5 mAh cm^(−2))NMC622(LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2))cathodes and 50μm Li anodes.Termed“CETHER-3,”this electrolyte is based on LiTFSI,LiDFOB,and LiBF4 with 5 vol%fluorinated ethylene carbonate in 1,2-dimethoxyethane.Commer-cial carbonate and state-of-the-art binary salt ether electrolytes were also tested as baselines.With CETHER-3,the electrochemical performance of the full-cell battery is among the most favorably reported in terms of high-voltage cycling stability.For example,LiNi_(x)Mn_(y)Co_(1-x-y)O_(2)(NMC)-Li metal cells retain 80%capacity at 430 cycles with a 4.4 V cut-off and 83%capacity at 100 cycles with a 4.5 V cut-off(charge at C/5,discharge at C/2).According to simulation by density functional theory and molecular dynamics,this favorable performance is an outcome of enhanced coordination between Li^(+)and the solvent/salt molecules.Combining advanced microscopy(high-resolution transmission electron microscopy,scanning electron microscopy)and surface science(X-ray photoelectron spectroscopy,time-of-fight secondary ion mass spectroscopy,Fourier-transform infrared spectroscopy,Raman spectroscopy),it is demonstrated that a thinner and more stable cathode electrolyte interphase(CEI)and solid electrolyte interphase(SEI)are formed.The CEI is rich in lithium sulfide(Li_(2)SO_(3)),while the SEI is rich in Li_(3)N and LiF.During cycling,the CEI/SEI suppresses both the deleterious transformation of the cathode R-3m layered near-surface structure into disordered rock salt and the growth of lithium metal dendrites.展开更多
Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellet...Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.展开更多
The decomposed process of bastnaesite, monazite and mixed rare earth concentrate in CaO-CaCl-CaCl2 was studied by means of TG-DTA method. The relationship among decomposition ratio, roasting temperature, and CaO-NaCl ...The decomposed process of bastnaesite, monazite and mixed rare earth concentrate in CaO-CaCl-CaCl2 was studied by means of TG-DTA method. The relationship among decomposition ratio, roasting temperature, and CaO-NaCl addition was studied by the quadratic regression orthogonal analysis, and then the regression equation was obtained. Through analysis, the optimum process conditions of mixed rare earth concentrate decomposed by CaO-CaCl-CaCl2 were obtained as follows: roasting temperature: 700℃, CaO addition: 15%, NaCl-CaCl2 addition: 10%, roasting time: 60 min, the decomposition ratio: 91.3%.展开更多
The reaction of the mixed rare earth concentrate including monazite ( REPO4 ) and bastnaesite ( REFCO3 )decomposed by CaO and NaCl additives at the temperature range from 100 to 1000 ℃ was studied by means of XRD and...The reaction of the mixed rare earth concentrate including monazite ( REPO4 ) and bastnaesite ( REFCO3 )decomposed by CaO and NaCl additives at the temperature range from 100 to 1000 ℃ was studied by means of XRD and TG-DTA.The results show that when CaO and NaCl are not added, only REFCO3 can be decomposed at the temperature of 377 ~ 450 ℃.The decomposition products include REOF, RE2O3 and CeO2.However, REFCO3 can not be decomposed.When CaO is added, the decomposition reactions occur at the temperature range from 660 to 750 ℃.CaO has three decomposition functions: ( 1 ) REPO4 can be decomposed by CaO and the decomposition products include RE2O3 and Ca3 (PO4)2; (2) CaO can decompose REOF, and the decomposition products are RE2O3 and CaF2; (3)CaO can decompose REPO4 with CaF2, and the decomposition products are RE2 O3, Ca5 F( PO4 )3.The decomposition ratio of the mixed rare earth concentrate increased obviously, when CaO and NaC1 were added.NaC1 can supply the liquid for the reaction, improve the mass transfer process and accelerate the reaction.At the same time, NaC1 participated in the reaction that REPO4 was decomposed by CaO.展开更多
A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as ...A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as 88.98%,while the leaching rate of impurity iron is only 1.79%.Moreover,the leached pellets can be used as raw materials for blast furnace ironmaking after secondary roasting.X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy with energy dispersive X-ray spectrometry(SEMEDS)analyses showed that V^(3+)was oxidized to V^(5+)after roasting at 1200℃,and V^(5+)was then leached by H_(2)SO_(4).X-ray diffraction(XRD)analyses and single factor experiment revealed a minimal amount of dissolved Fe_(2)O_(3) during H_(2)SO_(4) leaching.Therefore,a high separation degree of V and iron(Fe)from V-Ti magnetite concentrate was achieved through H_(2)SO_(4) leaching.Compared with the traditional roastingleaching process,this process can achieve a high selectivity of V and Fe,and has excellent prospects for industrial production.展开更多
Iron and titanium were recovered from beach titanomagnetite(TTM) concentrate by embedding direct reduction and magnetic separation. The reduction products and the effects of the reductant type and reduction temperatur...Iron and titanium were recovered from beach titanomagnetite(TTM) concentrate by embedding direct reduction and magnetic separation. The reduction products and the effects of the reductant type and reduction temperature on the reduction behavior were investigated. The results showed that the reduction of TTM concentrate was strongly related to the gasification reactivity of the reductant. Bitumite presented a better product index than wheat-straw biochar and coke, mainly because the gasification reactivity of bitumite was better than that of the other reductants. In addition, high temperatures were not beneficial to embedding direct reduction because of the emergence of a molten phase and iron-joined crystals, which in turn reduced the diffusion rate of the reducing gas and impeded the reduction reaction in the central area of the roasted briquette. The use of bitumite as the reductant at a C/Fe molar ratio of 1.4 and a reduction temperature of 1200°C for 120 min resulted in direct-reduction iron powder assaying 90.28 wt% TFe and 0.91 wt% TiO_2 with an iron recovery of 91.83% and titanium concentrate assaying 46.01 wt% TiO_2 with a TiO_2 recovery of 91.19%. Titanium existed mainly in the form of anosovite and ilmenite in the titanium concentrate.展开更多
Microwave assisted leaching of complex copper sulphide concentrate with ferric chloride was investigated, and its mechanism was analyzed. The results show that the leaching rate by microwave irradiation heating is mu...Microwave assisted leaching of complex copper sulphide concentrate with ferric chloride was investigated, and its mechanism was analyzed. The results show that the leaching rate by microwave irradiation heating is much faster than that by conventional heating.展开更多
Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reducti...Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.展开更多
The aim of this study was to determine the structural, compositional, and mineralogical composition of carbonatitic copper sulfide concentrator plant streams. Three samples, each from a different stream(run of mine(RO...The aim of this study was to determine the structural, compositional, and mineralogical composition of carbonatitic copper sulfide concentrator plant streams. Three samples, each from a different stream(run of mine(ROM), concentrate, and tailings) of a copper concentrator were characterized using various techniques, including stereomicroscopy, X-ray fluorescence, X-ray diffraction, Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy(SEM) in conjunction with energy-dispersive X-ray spectroscopy(EDS), and optical microscopy. The results reveal that each stream possesses its own unique compositional features. Carbonate minerals associated with calcite and dolomite, followed by quartz, remain the major minerals in both the ROM and tails streams. In the ROM stream, chalcopyrite appears to occur as veins within the carbonatite-hosting ore body. Mineral phase mutation was discovered in the tails stream because magnetite formerly identified in the ROM as the primary iron oxide had evolved into hematite. This metamorphosis was likely promoted by the concentration process. The concentration process was effective, upgrading the chalcopyrite content from 2 wt% in the ROM stream to 58 wt% in the concentrate stream; it was accompanied by bornite(4 wt%), anilite(3 wt%), and digenite(2.5 wt%). In addition, the concentrate stream exhibited properties distinctive from those of the other streams. The FTIR analysis showed the existence of a sulfide group related to the chalcopyrite mineral. Free chalcopyrite grains were observed in the concentrate by SEM analysis, and their mineral presence was supported by the EDS analysis results. All characterization techniques corresponded well with each other regarding the structure, chemistry, and composition of the samples.展开更多
The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results sh...The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results show that the Ore-A exhibits good granulation properties, strong liquid flow capability, high bonding phase strength and crystal strength, but poor assimilability. With increasing Ore-A ratio, the tumbler index and the reduction index (RI) of the sinter first increase and then decrease, whereas the softening interval (Delta T) and the softening start temperature (T (10%)) of the sinter exhibit the opposite behavior; the reduction degradation index (RDI+3.15) of the sinter increases linearly, but the sinter yield exhibits no obvious effects. With increasing Ore-A ratio, the distribution and crystallization of the minerals are improved, the main bonding phase first changes from silico-ferrite of calcium and aluminum (SFCA) to kirschsteinite, silicate, and SFCA and then transforms to 2CaO center dot SiO2 and SFCA. Given the utilization of Ore-A and the improvement of the sinter properties, the Ore-A ratio in the high-limonite sintering process is suggested to be controlled at approximately 6wt%.展开更多
Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparat...Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.展开更多
Platelet concentrates(PC) [platelet-rich plasma(PRP) and platelet-rich fibrin(PRF)] are frequently used for surgical procedures in medical and dental fields,particularly in oral and maxillofacial surgery,plastic surge...Platelet concentrates(PC) [platelet-rich plasma(PRP) and platelet-rich fibrin(PRF)] are frequently used for surgical procedures in medical and dental fields,particularly in oral and maxillofacial surgery,plastic surgery and sports medicine.The objective of all these technologies is to extract all the elements from a blood sample that could be used to improve healing and promote tissue regeneration.Although leukocyte rich and leukocyte poor PRP's have their own place in literature,the importance of non-platelet components in a platelet concentrate remains a mystery.PC have come a long way since its first appearance in 1954 to the T-PRF,A-PRF and i-PRF introduced recently.These PC find varied applications successfully in periodontics and implant dentistry as well.However,the technique of preparation,standing time,transfer process,temperature of centrifuge,vibration,etc.,are the various factors for the mixed results reported in the literature.Until the introduction of a proper classification of terminologies,the PC were known by different names in different countries and by different commercial companies which also created a lot of confusion.This review intends to clarify all these confusion by briefing the exact evolution of PC,their preparation techniques,recent advances and their various clinical and technical aspects and applications.展开更多
基金Project supported by the Dean’s Fund of China Institute of Atomic Energy(Grant No.219256)the CNNC Science Fund for Talented Young Scholars.
文摘The primary radiation damage in pure V and TiVTa concentrated solid-solution alloy(CSA)was studied using a molecular dynamics method.We have performed displacement cascade simulations to explore the generation and evolution behavior of irradiation defects.The results demonstrate that the defect accumulation and agglomeration in TiVTa CSA are significantly suppressed compared to pure V.The peak value of Frenkel pairs during cascade collisions in TiVTa CSA is much higher than that in pure V due to the lower formation energy of point defects.Meanwhile,the longer lifetime of the thermal spike relaxation and slow energy dissipation capability of TiVTa CSA can facilitate the recombination of point defects.The defect agglomeration rate in TiVTa CSA is much lower due to the lower binding energy of interstitial clusters and reduced interstitial diffusivity.Furthermore,the occurrence probability of dislocation loops in TiVTa CSA is lower than that in pure V.The reduction in primary radiation damage may enhance the radiation resistance of TiVTa CSA,and the improved radiation tolerance is primarily attributed to the relaxation stage and long-term defect evolution rather than the ballistic stage.These results can provide fundamental insights into irradiation-induced defects evolution in refractory CSAs.
文摘In this paper, we propose a thermal model of a hybrid photovoltaic/thermal concentration system. Starting from the thermal balance of the model, the equation is solved and simulated with a MATLAB code, considering air as the cooling fluid. This enabled us to evaluate some of the parameters influencing the electrical and thermal performance of this device. The results showed that the temperature, thermal efficiency and electrical efficiency delivered depend on the air mass flow rate. The electrical and thermal efficiencies for different values of air mass flow are encouraging, and demonstrate the benefits of cooling photovoltaic cells. The results show that thermal efficiency decreases air flow rate greater than 0.7 kg/s, whatever the value of the light concentration used. The thermal efficiency of the solar cell increases as the light concentration increases, whatever the air flow rate used. For a concentration equal to 30 sun, the thermal efficiency is 0.16 with an air flow rate equal to 0.005 kg/s;the thermal efficiency increases to 0.19 with an air flow rate equal to 0.1 kg/s at the same concentration. An interesting and useful finding was that the proposed numerical model allows the determination of the electrical as well as thermal efficiency of the hybrid CPV/T with air flow as cooling fluid.
基金supported by the National Natural Science Foundation of China (Nos.52201021 and 52101099)Key Research and Development Program of Shaanxi (2021GY-249,2021GY-233)+1 种基金Natural Science Basic Research Program of Shaanxi (No.2020JC-50)Shaanxi Provincial Natural Science Youth Foundation (2022JQ-410).
文摘A Zr-Gd alloy with neutron poisoning properties and resistance to boiling concentrated HNO3 corrosion was developed based on a corrosion-resistant Zr-702 alloy to meet the demand for neutron shielding in the closed-loop treatment of spent fuel and the nuclear chemical industry.In this study,1 wt.%,3 wt.%,5 wt.%,7 wt.%,and 9 wt.%Zr-Gd alloys were designed and fabricated with Zr-702 as the control element.The electrochemical behavior of the Zr-Gd alloys in boiling concentrated HNO3 was investigated,and the neutron shielding effect on plate thickness and Gd content was simulated.The experimental results demonstrate that the corrosion resistance of the alloy decreased slightly before~7-9 wt.%with increasing Gd content;this is the inflection point of its corrosion resistance.The alloy uniformly dissolved the Gd content that could not be dissolved in the Zr lattice,resulting in numerous micropores on the passivation coating,which deteriorated and accelerated the corrosion rate.The MCNP simulation demonstrated that when the Gd content was increased to 5 wt.%,a 2-mm-thick plate can shield 99.9%neutrons;an alloy with a Gd content≥7 wt.%required only a 1-mm-thick plate,thereby showing that the addition of Gd provides an excellent neutron poisoning effect.Thus,the corrosion resistance and neutron shielding performance of the Zr-Gd alloy can meet the harsh service requirements of the nuclear industry.
基金the earmarked fund for Jiangsu Agricultural Industry Technology System(JATS[2021]403)Su Xi Broiler Industry Cluster Project(2022)。
文摘Background:Research on nutrition in early-life commonly focuses on the maturation of the intestine because the intestinal system is crucial for ensuring continued growth.To explore the importance of early nutrition regulation in animals,soy protein concentrate(SPC)was added to the early diet of broilers to investigate its effects on amino acid digestibility,intestinal development,especially intestinal microorganisms,and broiler metabolites.A total of 192 oneday-old Arbor Acres(AA)male broilers were randomly assigned to two experimental treatments with 8 replicates of 12 birds.The control group was fed a basal diet(control),and the treatment group was fed a basal diet supplemented with 12%SPC(SPC12)during the first 10 d(starter phase).From d 11 to 21(grower phase)and d 22 to 42(finisher phase),a basal diet was fed to both treatment groups.Results:SPC reduced the pH value and acid-binding capacity of the starter diet(P<0.05,d 10);SPC in the early diet enhanced the gizzard weight(P<0.05,d 10 and d 42)and the ileum weight(P<0.05,d 10)and decreased the weight and length of the jejunum(P<0.05,d 10)and the relative length of the duodenum and jejunum(P<0.05,d 10).At the same time,SPC enhanced villus height(P<0.05,d 10)and muscle thickness in the jejunum and ileum(P<0.05,d 10)and increased the number of goblet cells in the duodenum(P<0.05,d 10).Meanwhile,SPC increased the Chao1 index and the ACE index(P<0.05,d 10)and altered the composition of caecal microflora at d 10.SPC also increased the relative abundance of Alistipes,Anaerotruncus,Erysipelatoclostridium,Intestinimonas and Flavonifractor bacteria(P<0.05,d 10).At the same time,the concentrations of caecal butyric acid and total short-chain fatty acids(SCFAs)were also increased in the SPC12 group(P<0.05,d 10).Conclusions:In summary,the results showed that supplementing the starter diet of broilers with SPC has a significant effect on the early development of the intestine and the microflora.
基金awarded and funded by USDA-NIFA Hatch Fund (#02636, Washington DC, USA)North Carolina Agricultural Foundation (#660101, Raleigh, NC, USA)CJ Cheil Jedang (Seoul, Korea)
文摘Background Soy protein supplements,with high crude protein and less antinutritional factors,are produced from soybean meal by different processes.This study evaluated the comparative effects of various soy protein supplements replacing animal protein supplements in feeds on the intestinal immune status,intestinal oxidative stress,mucosaassociated microbiota,and growth performance of nursery pigs.Methods Sixty nursery pigs(6.6±0.5 kg BW)were allotted to five treatments in a randomized complete block design with initial BW and sex as blocks.Pigs were fed for 39 d in 3 phases(P1,P2,and P3).Treatments were:Control(CON),basal diet with fish meal 4%,2%,and 1%,poultry meal 10%,8%,and 4%,and blood plasma 4%,2%,and 1%for P1,P2,and P3,respectively;basal diet with soy protein concentrate(SPC),enzyme-treated soybean meal(ESB),fermented soybean meal with Lactobacillus(FSBL),and fermented soybean meal with Bacillus(FSBB),replacing 1/3,2/3,and 3/3 of animal protein supplements for P1,P2,and P3,respectively.Data were analyzed using the MIXED procedure in SAS 9.4.Results The SPC did not affect the BW,ADG,and G:F,whereas it tended to reduce(P=0.094)the ADFI and tended to increase(P=0.091)crypt cell proliferation.The ESM did not affect BW,ADG,ADFI,and G:F,whereas tended to decrease(P=0.098)protein carbonyl in jejunal mucosa.The FSBL decreased(P<0.05)BW and ADG,increased(P<0.05)TNF-α,and Klebsiella and tended to increase MDA(P=0.065)and IgG(P=0.089)in jejunal mucosa.The FSBB tended to increase(P=0.073)TNF-α,increased(P<0.05)Clostridium and decreased(P<0.05)Achromobacter and alpha diversity of microbiota in jejunal mucosa.Conclusions Soy protein concentrate,enzyme-treated soybean meal,and fermented soybean meal with Bacillus could reduce the use of animal protein supplements up to 33%until 7 kg body weight,up to 67%from 7 to 11 kg body weight,and entirely from 11 kg body weight without affecting the intestinal health and the growth performance of nursery pigs.Fermented soybean meal with Lactobacillus,however,increased the immune reaction and oxidative stress in the intestine consequently reducing the growth performance.
基金the Innovation-Driven Project of Central South University(2019CX033)the National Natural Science Foundation of China(51904344 and 52172264)the Natural Science Foundation of Hunan Province of China(2021JJ10060 and 2022GK2033)。
文摘The electrolyte integrated with lithium metal anodes is subjected to the issues of interfacial compatibility and stability,which strongly influence the performances of high-energy lithium metal batteries.Here,we report a new electrolyte recipe viz.a moderately concentrated electrolyte comprising of 2.4 M lithium bis(fluorosulfonyl)imide(LiFSI)in a cosolvent mixture of fluorinated ethylene carbonate(FEC)and dimethyl carbonate(DMC)with relatively high ion conductivity.Owing to the preferential decomposition of LiFSI and FEC,an inorganic-rich interphase with abundant Li_(2)O and LiF nanocrystals is formed on lithium metal with improved robustness and ion transfer kinetics,enabling lithium plating/stripping with an extremely low overpotential of~8 mV and the average CE of 97%.When tested in Li||LiFePO_(4) cell,this electrolyte provides long-term cycling with a capacity retention of 98.3%after 1000 cycles at 1 C and an excellent rate performance of 20 C,as well as an areal capacity of 1.35 mA h cm^(-2)at the cathode areal loading of 9 mg cm^(-2).Moreover,the Li||LiFePO_(4) cell exhibits excellent wide-temperature performances(-40~60℃),including long-term cycling stability over 2600 cycles without visible capacity fading at 0℃,as well as extremely high average CEs of 99.6%and 99.8% over 400 cycles under-20℃ and 45℃.
基金supported by the National Natural Science Foundation of China (22125802 and 22108012)Natural Science Foundation of Beijing Municipality (2222017)Fundamental Research Funds for the Central Universities (BUCTRC-202109)。
文摘Latex wastewater is a kind of refractory organic wastewater containing high concentrations of organics and ammonia nitrogen.In this work,the combined process of forward osmosis(FO)and reverse osmosis(RO)was designed to treat the latex wastewater in the whole process,achieving the water recovery rate of 99%and basically no waste discharge after the catalytic oxidation process.The turbidity of the latex wastewater was decreased to below 1 NTU by microfiltration pretreatment,and then using MgCl_2 worked as the draw solution for FO process to treat the latex wastewater.Different operation conditions including adding acid or scale inhibitor as the pretreatment methods were conducted to improve the treatment performance of the combined process.After the treatment of the whole process,the concentration of COD was less than 20 mg·L^(-1),the concentration of NH_3-N was less than 10 mg·L^(-1),and the concentration of TP was less than 0.5 mg·L^(-1)for the treated latex wastewater.The water quality met standards of industrial water reuse after the complete analysis of the treated latex wastewater,meanwhile,useful substances of L-Quebrachitol(L-Q)were successfully extracted from the concentrated solution.Therefore,the combined process of FO and RO could realize the efficient treatment and reuse of latex wastewater,which provided with some important guidance on the industrial application.
文摘In the presentmanuscript,a Layer-Wise(LW)generalizedmodel is proposed for the linear static analysis of doublycurved shells constrained with general boundary conditions under the influence of concentrated and surface loads.The unknown field variable is modelled employing polynomials of various orders,each of them defined within each layer of the structure.As a particular case of the LW model,an Equivalent Single Layer(ESL)formulation is derived too.Different approaches are outlined for the assessment of external forces,as well as for non-conventional constraints.The doubly-curved shell is composed by superimposed generally anisotropic laminae,each of them characterized by an arbitrary orientation.The fundamental governing equations are derived starting from an orthogonal set of principal coordinates.Furthermore,generalized blending functions account for the distortion of the physical domain.The implementation of the fundamental governing equations is performed bymeans of the Generalized Differential Quadrature(GDQ)method,whereas the numerical integrations are computed employing theGeneralized IntegralQuadrature(GIQ)method.In the post-processing phase,an effective procedure is adopted for the reconstruction of stress and strain through-the-thickness distributions based on the exact fulfillment of three-dimensional equilibrium equations.A series of systematic investigations are performed in which the static response of structures with various curvatures and lamination schemes,calculated by the present methodology,have been successfully compared to those ones obtained fromrefined finite element three-dimensional simulations.Even though the present LW approach accounts for a two-dimensional assessment of the structural problem,it is capable of well predicting the three-dimensional response of structures with different characteristics,taking into account a reduced computational cost and pretending to be a valid alternative to widespread numerical implementations.
基金National Natural Science Foundation of China,Grant/Award Numbers:21905265,52072322,U1930402,61974042National Science Foundation,Civil,Mechanical and Manufacturing Innovation,Grant/Award Number:1911905+3 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:WK2060140026Department of Science and Technology of Sichuan Province,Grant/Award Numbers:2019‐GH02‐00052‐HZ,2019YFG0220Scientific and Technological Innovation Foundation of Shunde Graduate School,Grant/Award Number:BK19BE024National Key Research and Development Program of China,Grant/Award Number:2017YFA0303403。
文摘A new concentrated ternary salt ether-based electrolyte enables stable cycling of lithium metal battery(LMB)cells with high-mass-loading(13.8 mg cm^(−2),2.5 mAh cm^(−2))NMC622(LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2))cathodes and 50μm Li anodes.Termed“CETHER-3,”this electrolyte is based on LiTFSI,LiDFOB,and LiBF4 with 5 vol%fluorinated ethylene carbonate in 1,2-dimethoxyethane.Commer-cial carbonate and state-of-the-art binary salt ether electrolytes were also tested as baselines.With CETHER-3,the electrochemical performance of the full-cell battery is among the most favorably reported in terms of high-voltage cycling stability.For example,LiNi_(x)Mn_(y)Co_(1-x-y)O_(2)(NMC)-Li metal cells retain 80%capacity at 430 cycles with a 4.4 V cut-off and 83%capacity at 100 cycles with a 4.5 V cut-off(charge at C/5,discharge at C/2).According to simulation by density functional theory and molecular dynamics,this favorable performance is an outcome of enhanced coordination between Li^(+)and the solvent/salt molecules.Combining advanced microscopy(high-resolution transmission electron microscopy,scanning electron microscopy)and surface science(X-ray photoelectron spectroscopy,time-of-fight secondary ion mass spectroscopy,Fourier-transform infrared spectroscopy,Raman spectroscopy),it is demonstrated that a thinner and more stable cathode electrolyte interphase(CEI)and solid electrolyte interphase(SEI)are formed.The CEI is rich in lithium sulfide(Li_(2)SO_(3)),while the SEI is rich in Li_(3)N and LiF.During cycling,the CEI/SEI suppresses both the deleterious transformation of the cathode R-3m layered near-surface structure into disordered rock salt and the growth of lithium metal dendrites.
基金The Key Project of the 9th Five year Plan of Ministry of Science andTechnology!(No .960 40 2 0 2A)the Foundation for Unive
文摘Successfully developed an innovative process of direct reduction of cold bound pellets from iron ore concentrate with a coal based rotary kiln, in comparison with the traditional direct reduction of fired oxide pellets in coal based rotary kilns , possesses such advantages as: shorter flowsheet, lower capital investment, greater economic profit, good quality of direct reduced iron. The key technologies , such as the composite binder and corresponding feasible techniques were employed in practice. A mill utilizing this process and with an annual capacity of 50 thousand ton DRI has been put into operation.
基金Project supported by the National Natural Science Foundation of China (50574031)Scientific Research Special Foundation of Doctor Subject of Chinese University (20030145015)
文摘The decomposed process of bastnaesite, monazite and mixed rare earth concentrate in CaO-CaCl-CaCl2 was studied by means of TG-DTA method. The relationship among decomposition ratio, roasting temperature, and CaO-NaCl addition was studied by the quadratic regression orthogonal analysis, and then the regression equation was obtained. Through analysis, the optimum process conditions of mixed rare earth concentrate decomposed by CaO-CaCl-CaCl2 were obtained as follows: roasting temperature: 700℃, CaO addition: 15%, NaCl-CaCl2 addition: 10%, roasting time: 60 min, the decomposition ratio: 91.3%.
文摘The reaction of the mixed rare earth concentrate including monazite ( REPO4 ) and bastnaesite ( REFCO3 )decomposed by CaO and NaCl additives at the temperature range from 100 to 1000 ℃ was studied by means of XRD and TG-DTA.The results show that when CaO and NaCl are not added, only REFCO3 can be decomposed at the temperature of 377 ~ 450 ℃.The decomposition products include REOF, RE2O3 and CeO2.However, REFCO3 can not be decomposed.When CaO is added, the decomposition reactions occur at the temperature range from 660 to 750 ℃.CaO has three decomposition functions: ( 1 ) REPO4 can be decomposed by CaO and the decomposition products include RE2O3 and Ca3 (PO4)2; (2) CaO can decompose REOF, and the decomposition products are RE2O3 and CaF2; (3)CaO can decompose REPO4 with CaF2, and the decomposition products are RE2 O3, Ca5 F( PO4 )3.The decomposition ratio of the mixed rare earth concentrate increased obviously, when CaO and NaC1 were added.NaC1 can supply the liquid for the reaction, improve the mass transfer process and accelerate the reaction.At the same time, NaC1 participated in the reaction that REPO4 was decomposed by CaO.
基金funded by the National Science Foundation of China(No.51704028)the Key R&D Program of Yunnan Province(No.2018IB027)。
文摘A novel method of pellet calcification roasting-H_(2)SO_(4) leaching was proposed to efficiently separate and extract vanadium(V)from vanadium-titanium(V-Ti)magnetite concentrates.The leaching rate of V is as high as 88.98%,while the leaching rate of impurity iron is only 1.79%.Moreover,the leached pellets can be used as raw materials for blast furnace ironmaking after secondary roasting.X-ray photoelectron spectroscopy(XPS)and scanning electron microscopy with energy dispersive X-ray spectrometry(SEMEDS)analyses showed that V^(3+)was oxidized to V^(5+)after roasting at 1200℃,and V^(5+)was then leached by H_(2)SO_(4).X-ray diffraction(XRD)analyses and single factor experiment revealed a minimal amount of dissolved Fe_(2)O_(3) during H_(2)SO_(4) leaching.Therefore,a high separation degree of V and iron(Fe)from V-Ti magnetite concentrate was achieved through H_(2)SO_(4) leaching.Compared with the traditional roastingleaching process,this process can achieve a high selectivity of V and Fe,and has excellent prospects for industrial production.
基金financially supported by the National Natural Science Foundation of China (Nos. 51474018 and 51674018)
文摘Iron and titanium were recovered from beach titanomagnetite(TTM) concentrate by embedding direct reduction and magnetic separation. The reduction products and the effects of the reductant type and reduction temperature on the reduction behavior were investigated. The results showed that the reduction of TTM concentrate was strongly related to the gasification reactivity of the reductant. Bitumite presented a better product index than wheat-straw biochar and coke, mainly because the gasification reactivity of bitumite was better than that of the other reductants. In addition, high temperatures were not beneficial to embedding direct reduction because of the emergence of a molten phase and iron-joined crystals, which in turn reduced the diffusion rate of the reducing gas and impeded the reduction reaction in the central area of the roasted briquette. The use of bitumite as the reductant at a C/Fe molar ratio of 1.4 and a reduction temperature of 1200°C for 120 min resulted in direct-reduction iron powder assaying 90.28 wt% TFe and 0.91 wt% TiO_2 with an iron recovery of 91.83% and titanium concentrate assaying 46.01 wt% TiO_2 with a TiO_2 recovery of 91.19%. Titanium existed mainly in the form of anosovite and ilmenite in the titanium concentrate.
文摘Microwave assisted leaching of complex copper sulphide concentrate with ferric chloride was investigated, and its mechanism was analyzed. The results show that the leaching rate by microwave irradiation heating is much faster than that by conventional heating.
基金financially supported by the National Natural Science Foundation of China(No.51674018)
文摘Effects of calcium compounds on the carbothermic reduction of vanadium titanomagnetite concentrate(VTC) were investigated. It was found that calcium compounds had great effects on the metallization rate of the reduction product, the order of the metallization rate of reduction product being CaCO3 > no additive > CaSO4 > CaCl2, which indicated that the addition of CaCO3 was more conducive to promoting the reduction of iron than other calcium compounds. Gas analysis showed that there were mainly two processes in the carbothermic reduction of VTC, a solid–solid and a solid–gas reaction. The concentrations of CO and CO2 were highest when CaCO3 was added, while that in a roasting system decreased the most when CaCl2 was added. X-ray diffraction(XRD) analysis showed that calcium compounds could change the reduction process of ilmenite in VTC. The phase compositions of the reduction products were changed from metallic iron(Fe) and anosovite(FeTi2O5) to metallic iron(Fe) and perovekite(CaTiO3) when calcium compounds were added. Additionally, CaSO4 and CaCl2 could significantly promote the growth of metallic iron particles, though the existence of Fe-bearing Mg2TiO4 in reduction products was not conducive to the reduction of iron. The formation of FeS would further hinder the reduction of iron after adding CaSO4.
基金the chemical engineering department at the North-West University for the support
文摘The aim of this study was to determine the structural, compositional, and mineralogical composition of carbonatitic copper sulfide concentrator plant streams. Three samples, each from a different stream(run of mine(ROM), concentrate, and tailings) of a copper concentrator were characterized using various techniques, including stereomicroscopy, X-ray fluorescence, X-ray diffraction, Fourier transform infrared(FTIR) spectroscopy, scanning electron microscopy(SEM) in conjunction with energy-dispersive X-ray spectroscopy(EDS), and optical microscopy. The results reveal that each stream possesses its own unique compositional features. Carbonate minerals associated with calcite and dolomite, followed by quartz, remain the major minerals in both the ROM and tails streams. In the ROM stream, chalcopyrite appears to occur as veins within the carbonatite-hosting ore body. Mineral phase mutation was discovered in the tails stream because magnetite formerly identified in the ROM as the primary iron oxide had evolved into hematite. This metamorphosis was likely promoted by the concentration process. The concentration process was effective, upgrading the chalcopyrite content from 2 wt% in the ROM stream to 58 wt% in the concentrate stream; it was accompanied by bornite(4 wt%), anilite(3 wt%), and digenite(2.5 wt%). In addition, the concentrate stream exhibited properties distinctive from those of the other streams. The FTIR analysis showed the existence of a sulfide group related to the chalcopyrite mineral. Free chalcopyrite grains were observed in the concentrate by SEM analysis, and their mineral presence was supported by the EDS analysis results. All characterization techniques corresponded well with each other regarding the structure, chemistry, and composition of the samples.
基金financially supported by the National Basic Research Program of China (No. 2012CB720401)the National Natural Science Foundation of China (U1260202)
文摘The basic characteristics of Australian iron ore concentrate (Ore-A) and its effects on sinter properties during a high-limonite sintering process were studied using micro-sinter and sinter pot methods. The results show that the Ore-A exhibits good granulation properties, strong liquid flow capability, high bonding phase strength and crystal strength, but poor assimilability. With increasing Ore-A ratio, the tumbler index and the reduction index (RI) of the sinter first increase and then decrease, whereas the softening interval (Delta T) and the softening start temperature (T (10%)) of the sinter exhibit the opposite behavior; the reduction degradation index (RDI+3.15) of the sinter increases linearly, but the sinter yield exhibits no obvious effects. With increasing Ore-A ratio, the distribution and crystallization of the minerals are improved, the main bonding phase first changes from silico-ferrite of calcium and aluminum (SFCA) to kirschsteinite, silicate, and SFCA and then transforms to 2CaO center dot SiO2 and SFCA. Given the utilization of Ore-A and the improvement of the sinter properties, the Ore-A ratio in the high-limonite sintering process is suggested to be controlled at approximately 6wt%.
文摘Osteochondral lesions of the talus are common injuries in the athletic patient. They present a challenging clinical problem as cartilage has a poor potential for healing. Current surgical treatments consist of reparative(microfracture) or replacement(autologous osteochondral graft) strategies and demonstrate good clinical outcomes at the short and medium term follow-up. Radiological findings and second-look arthroscopy however, indicate possible poor cartilage repair with evidence of fibrous infill and fissuring of the regenerative tissue following microfracture. Longer-term follow-up echoes these findings as it demonstrates a decline in clinical outcome. The nature of the cartilage repair that occurs for an osteochondral graft to become integrated with the native surround tissue is also of concern. Studies have shown evidence of poor cartilage integration,with chondrocyte death at the periphery of the graft, possibly causing cyst formation due to synovial fluid ingress. Biological adjuncts, in the form of platelet-rich plasma(PRP) and bone marrow aspirate concentrate(BMAC), have been investigated with regard to their potential in improving cartilage repair in both in vitro and in vitro settings. The in vitro literature indicates that these biological adjuncts may increase chondrocyte proliferation as well as synthetic capability, while limiting the catabolic effects of an inflammatory joint environment. These findings have been extrapolated to in vitro animal models, with results showing that both PRP and BMAC improve cartilage repair. The basic science literature therefore establishes the proof of concept that biological adjuncts may improve cartilage repair when used in conjunction with reparative and replacement treatment strategies for osteochondral lesions of the talus.
文摘Platelet concentrates(PC) [platelet-rich plasma(PRP) and platelet-rich fibrin(PRF)] are frequently used for surgical procedures in medical and dental fields,particularly in oral and maxillofacial surgery,plastic surgery and sports medicine.The objective of all these technologies is to extract all the elements from a blood sample that could be used to improve healing and promote tissue regeneration.Although leukocyte rich and leukocyte poor PRP's have their own place in literature,the importance of non-platelet components in a platelet concentrate remains a mystery.PC have come a long way since its first appearance in 1954 to the T-PRF,A-PRF and i-PRF introduced recently.These PC find varied applications successfully in periodontics and implant dentistry as well.However,the technique of preparation,standing time,transfer process,temperature of centrifuge,vibration,etc.,are the various factors for the mixed results reported in the literature.Until the introduction of a proper classification of terminologies,the PC were known by different names in different countries and by different commercial companies which also created a lot of confusion.This review intends to clarify all these confusion by briefing the exact evolution of PC,their preparation techniques,recent advances and their various clinical and technical aspects and applications.