Physicochemical Problems of Mineral Processing最新文献

{"title":"Synergistic effect between starch and sulfuric acid on the separation of galena from chalcopyrite","authors":"Qinbo Cao, Dianwen Liu","doi":"10.37190/ppmp/209128","DOIUrl":"https://doi.org/10.37190/ppmp/209128","url":null,"abstract":"Galena (PbS) is still hard to separate from chalcopyrite (CuFeS<sub>2</sub>) in China, necessitating more effective depressants. This study investigated a combined depressant system using sulfuric acid (H<sub>2</sub>SO<sub>4</sub>) and starch to selectively depress PbS in a PbS−CuFeS<sub>2</sub> mixture. Single-mineral flotation experiments identified the optimal parameters to depress PbS at pH 3, 6 min reaction time, an H2SO4 to starch ratio of 6:1, and 700 mg/dm<sup>3</sup> of H<sub>2</sub>SO<sub>4</sub>. Under these conditions, PbS recovery has decreased to 9.2%, while CuFeS<sub>2</sub> recovery reached 81.1%, Furthermore, the PbS recovery with this combined depressant was significantly lower than the recovery with 700 mg/dm3 of H<sub>2</sub>SO<sub>4</sub> (83.2%) or 116.7 mg/dm<sup>3</sup> of starch (32.1%). FTIR results also showed that starch molecules could physically adsorb onto the PbS surface. Furthermore, XPS and SEM-EDS analyses revealed that the interaction between H<sub>2</sub>SO<sub>4</sub> and the PbS surface produced oxidative components, i.e., Pb-O and SO<sub>4</sub><sup>2−</sup>. These oxidative species may interact with the OH groups in starch molecules, enhancing the adsorption of starch molecules and thus efficiently producing a hydrophilic PbS surface. This study proposes an effective approach for the depression of PbS using the H<sub>2</sub>SO<sub>4</sub> and starch combination. These combined reagents exhibit outstanding industrial potential, owing to their low prices.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-209128-127895?filename=Synergistic effect.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147895206","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flotation separation of fine scheelite and calcite by microbubbles using gum arabic as depressant","authors":"Xianping Luo, Hao Xu, Wei Guo, Jinrui Zhou, Zongkang Li","doi":"10.37190/ppmp/204867","DOIUrl":"https://doi.org/10.37190/ppmp/204867","url":null,"abstract":"This study examined the role of gum arabic (GA) as a depressant in the flotation separation of fine-grained scheelite and calcite using flotation and adsorption tests, Zeta potential and contact angle measurements, and X-ray photoelectron spectroscopy (XPS). Microbubbles were introduced to improve the flotation separation of scheelite and calcite, addressing the poor flotation performance of fine-grained minerals. In the pH 9 slurry, GA significantly depress calcite while having minimal effect on scheelite. A concentrate with a WO<sub>3</sub> grade of 60.47% and a recovery of 74.29% was achieved using GA and sodium oleate as the depressant and collector for a 1:1 mixed mineral. Adsorption tests indicated that scheelite adsorbed less GA on its surface compared to calcite. Contact angle measurements demonstrated that GA altered calcite's wettability, rendering it hydrophilic. XPS analysis indicated that GA formed a chemical interaction with the surface Ca<sup>2+</sup> ions of calcite, whereas it exhibited weak physical adsorption on scheelite. Zeta potential measurements revealed selective chemical adsorption of GA anions on fine-grained calcite surfaces. In conclusion, the inhibition mechanism of GA on calcite is related to the chemical chelation with surface Ca<sup>2+</sup>, enabling the efficient flotation separation of fine-grained scheelite and calcite, and the introduction of microbubbles can enhance the recovery of scheelite.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-05-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-204867-125201?filename=Flotation separation of.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147896608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of flocculation behavior on the flotation of synthetic apatite-dolomite mixtures based on FBRM and PVM","authors":"He Gong, Aoao Chen, Lina Zhao, Qin Zhang, Wubin Li, Jun Xie, Jieliang Wang","doi":"10.37190/ppmp/202595","DOIUrl":"https://doi.org/10.37190/ppmp/202595","url":null,"abstract":"This study investigates the influence of various factors on shear flocculation in the apatite-dolomite mixed ore flotation system. The Box-Behnken response surface methodology is employed to evaluate the interactions of these factors on flocculation behavior. Additionally, the Focused Beam Reflectance Measurement (FBRM) and Particle Vision Measurement (PVM) techniques are applied to investigate the mechanisms by which these factors affect shear flocculation. The results show that sodium oleate (NaOL) concentration, pH, and shear rate significantly influence the size of the flocculated particles. Notably, the interaction effect between NaOL concentration and pH is particularly pronounced. FBRM and PVM analysis reveals that pH and NaOL concentration play dominant roles in controlling particle flocculation, while H3PO4 has a relatively minor impact on agglomerate morphology and size. At low shear rates, the flocs are larger and more uniformly distributed, resulting in a more stable process. In contrast, although high shear rates enhance initial flocculation efficiency, they reduce floc size. Furthermore, the modified Smoluchowski model is applied to evaluate the impact of different factors on flocculation kinetics. The findings suggest that the effects of these factors vary across different stages of flocculation. The combined influence of NaOL concentration, pH, and shear rate is crucial in determining the stability of the flocs, with these three factors being key determinants of floc morphology and stability.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-202595-123133?filename=Effect-of-flocculation-be.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147331771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Strengthening effect of a microwave field on sulfurization flotation of hemimorphite","authors":"Kai Jia, Yanjie Zhai, Congcong Han, Yinghua Jin, Tiantian Lu, Liang Si, Guosheng Li, Xiangyu Song, Guixia Fan, Minghui Ding","doi":"10.37190/ppmp/200459","DOIUrl":"https://doi.org/10.37190/ppmp/200459","url":null,"abstract":"Hemimorphite is a typical silicate zinc oxide mineral characterized by strong hydrophilicity and poor floatability. It is commonly recovered by the “sulfurization pretreatment-xanthate collector flotation” method. However, the Zn<sup>2+</sup> in hemimorphite is blocked by SiO<sub>4</sub><sup>2-</sup>, making Zn-O bonds difficult to break and preventing the reaction between Zn<sup>2+</sup> and S<sup>2-</sup> in solution. Therefore, enhancing sulfurization is essential for the flotation of hemimorphite. In this study, a microwave field was used for the first time to increase the surface sulfurization of hemimorphite, and the interactions between the minerals and collectors were increased by forming a sulfurization layer on the mineral surface to improve hemimorphite flotation. Compared with the conventional sulfurization pretreatment, microwave field sulfurization pretreatment exhibited better floatability under the same conditions, and the recovery reached 29.82%, which was much higher than that without microwave treatment. The mechanism of hemimorphite sulfurization in the microwave field was investigated with infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. These results indicated that the microwave field enhanced the surface sulfurization of hemimorphite, and increased the proportions of newly generated sulfides, thus boosting sulfurization flotation of hemimorphite.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-200459-120758?filename=Strengthening-effect-of-a.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147330903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Depressant-free flotation separation of chalcopyrite and galena by surface oxidation pretreatment: Effect of applying potassium peroxymonosulfate as a novel and efficient oxidant","authors":"Hepeng Zhou, Jiangfeng Guo, Guang‐Jie Zhu, Hao Xu, Xuekun Tang, Xianping Luo","doi":"10.37190/ppmp/195497","DOIUrl":"https://doi.org/10.37190/ppmp/195497","url":null,"abstract":"The flotation separation of chalcopyrite and galena presents significant challenges due to their similar surface properties, resulting in comparable floatability. In the process of flotation separation, conventional depressants encounter issues related to high toxicity or limited effectiveness. In this paper, it was found that the floatability of galena decreased significantly after pretreatment with potassium peroxymonosulfate (PMS) oxidation. The influence on chalcopyrite, however, is relatively insignificant. In flotation tests of mixed binary minerals, without PMS oxidation, the two minerals are basically floating; When the pH is 8 and the dosage of PMS is 0.375 g/L, it is possible to obtain a flotation concentrate with a Pb grade of 26.78% and recovery of 36.10%, as well as a Cu grade of 21.53% and recovery of 83.66%, when the raw ore contains Pb 44.88% and Cu 15.57%. The oxidation pretreatment method enables the separation of galena and chalcopyrite without the need for a depressant. The XPS and AFM measurements revealed a significantly higher oxidation degree of galena compared to chalcopyrite after treatment with PMS, indicating a notable difference in their floatability. Consequently, the separation of chalcopyrite and galena is greatly facilitated by this distinction. In conclusion, PMS can be considered as a novel oxidant that provides an effective approach for selectively floating chalcopyrite and galena.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-195497-115953?filename=Depressant-free-flotation.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147889750","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of metal ions on the adsorption of octyl hydroxamic acid in the flotation of bastnaesite and the adsorption mechanism","authors":"Rongxiang Liu, Zhanfeng Yang, Jie Li, Zhao Cao, Qiang Li","doi":"10.37190/ppmp/192809","DOIUrl":"https://doi.org/10.37190/ppmp/192809","url":null,"abstract":"The influence mechanism of metal ions on the adsorption of octyl hydroxamic acid (OHA) by bastnaesite in a flotation system was studied by flotation experiments, adsorption capacity tests, X-ray photoelectron spectroscopy (XPS) characterization, and density functional theory (DFT) study. From the experimental results, it can be seen that the flotation and the adsorption capacity tests showed that the single metal ions Ca2+, Ba<sup>2+</sup>, and Fe<sup>3+</sup> promoted the flotation recovery of bastnaesite, and the order of their ability was Ba<sup>2+</sup>>Fe<sup>3+</sup>>Ca<sup>2+</sup>. The addition of mixed metal ions inhibited the adsorption of OHA on the surface of bastnaesite, resulting in a decrease in the flotation recovery of bastnaesite. The XPS analysis showed that the N concentration on the surface of bastnaesite after single metal ion action was significantly higher than that without metal ion action, while the N concentration on the surface of bastnaesite after mixed metal ion action was significantly lower than that without metal ion action. When Ca<sup>2+</sup>, Ba<sup>2+</sup>, and Fe<sup>3+</sup> ions were added, new peaks appeared at 401.24 eV, 397.68 eV, and 397.19 eV in the N1s fitting peaks, respectively, which may be caused by the formation of N-M (OH) chemical bonds between M(OH)<sup>+</sup> (M: Ca<sup>2+</sup>, Ba<sup>2+</sup>, Fe<sup>3+</sup>) and nitrogen atoms in OHA. This indicated that metal ions Ca<sup>2+</sup>, Ba<sup>2+</sup>, and Fe<sup>3+</sup> form metal chelated with nitrogen atoms in OHA. The DFT study on the (100) surface of bastnaesite also showed that the doping of metal ions showed a stronger spontaneity and enhanced adsorption capacity due to the decrease of adsorption energy between OHA and bastnaesite surface. There were two adsorption sites of bastnaesite, one is that the Ce atom adsorbs two oxygen atoms of OHA to form a five-membered chelate, and the other adsorption site was that O-M(OH) on bastnaesite interacts with OHA; Therefore, the configuration of the oxygen atom adsorption site is O-M-O-N bond, during which M(OH)<sup>n+(n:1,2)</sup> loses OH<sup>-</sup>, and the N-O-H chemical bond on OHA loses H<sup>+</sup> to form an H<sub>2</sub>O molecule, a typical dehydration reaction, so the adsorption is more stable. Therefore, the surface of bastnaesite has two adsorption forms with OHA, one is R-NH-O-M-CeFCO<sub>3</sub> and R-NH-O-CeFCO<sub>3</sub>.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-192809-113789?filename=The-influence-of-metal-io.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147879420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of wet-process phosphoric acid for high-quality phosphogypsum","authors":"Xuyang Fan, Chenyu Zhou, Tingting Xiao, Haoran Wang, Han‐Jun Wu, Zhongjun Li, Zhiquan Pan, Hong Zhou","doi":"10.37190/ppmp/192938","DOIUrl":"https://doi.org/10.37190/ppmp/192938","url":null,"abstract":"The chronical accumulation of phosphogypsum (PG) has caused serious environmental pollution problems in wet-process phosphoric acid (WPPA) industry. An innovation technical route for turning PG into a resource has been realized by introducing floc flotation and acid cleaning in WPPA. The floc flotation using cationic polyacrylamide as a flocculant and micro lotion which composed of dioctyl phthalate, nonaphenol polyethyleneoxy (10) ether, kerosene and n-octanol as a collector has been performed. The effect of floc flotation on the quality of products and its mechanism were investigated by XRF，FT-IR, SEM and 2-dimensional fractal dimension analysis. The optimal parameters have been determined by single factor experiment as followings: floc flotation temperature 65℃, cationic polyacrylamide 180 g/Mg, collector 1.08 kg/Mg, and flushing sulfuric acid concentration 20%. The obtained purified PG had a high grade of 95.61%, whiteness reached 70.8% with the yield of 82.15% and gypsum recovery of 95.33%. Moreover, the soluble phosphorus and soluble fluorine are less than 0.1%. In the flotation, polyacrylamide and collector combined fine organic matter and siliceous material with hydrophobic bubble to float up, separating from PG. The new WPPA with higher product quality and lower production cost can be widely used in the WPPA factory to improve benefits of enterprise, providing a green approach to produce phosphoric acid and high-quality PG.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.journalssystem.com/ppmp/pdf-192938-113796?filename=Optimization-of-wet-proce.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147922235","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of microbubble dose in combined microflotation of fine particles","authors":"Nickolay Rulyov","doi":"10.37190/ppmp/190630","DOIUrl":"https://doi.org/10.37190/ppmp/190630","url":null,"abstract":"Flotation of small particles is one of the global challenges facing the mineral raw materials processing industry. Large amounts of non-ferrous and rare metals are lost in the flotation tailings in the form of mineral particles below 15 µm in size as a result of the low effectiveness of their capture by coarse bubbles generated in conventional flotation machines. The method of combined microflotation, developed in recent years, uses conventional coarse bubbles (CB) and microbubbles (MB) produced in the stand-alone generator of air-in-water microdispersion, which serves as the flotation carriers. Depending on the MB dose, the effect of their application may be positive or negative. The theoretical analysis of various mechanisms of particle transfer onto the surface of coarse bubbles and further into the froth layer allowed to obtain the formula for the optimal MB dose f=dd/2dprp, where dd is MB size; dp and rp respectively are the size and the density of particles. Experiments performed on the copper ore flotation tailings at the Atalaya Mining (Spain) and Chaarat Kapan (Armenia) concentrators showed that, besides the optimal MB dose in the range of 1-3 ml/g, there is another optimal MB dose in the range of 10-20 ml/g, where the copper recovery increases by several percent compared to the reference test (f = 0). The deep minimum in copper recovery is observed in the area between the optimal MB doses, which is by several percent lower than the value in the reference test.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"26 37","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141685430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The inhibition mechanism of esterified starch on flotation separation of fluorite and calcite","authors":"Bangqi Wei, Jie Li, Zhao Cao, Saisai Ma, Yuhan Zhang","doi":"10.37190/ppmp/190698","DOIUrl":"https://doi.org/10.37190/ppmp/190698","url":null,"abstract":"Herein, the flotation behavior of fluorite and calcite was examined before and after starch esterification through mineral flotation experiments. Moreover, the adsorption action mechanisms on minerals before and after starch esterification were investigated using methods such as solution surface tension measurement, infrared spectroscopy, and extended Derjaguin–Landau–Verwey–Overbeek theory. The results showed that after starch esterification (esterified starch), there was a greater difference in the mineral recovery rate compared to before starch esterification (ordinary starch), with a better inhibition effect on calcite. The interaction between mineral surfaces and ordinary starch was weaker than the interaction between minerals and esterified starch. In particular, after starch esterification, the surface tension increased, two minerals contact angle decreased, the surface potential became more negative, and the difference in the mineral recovery rate was greater than before starch esterification. After the interaction between minerals and esterified starch, calcite particles displayed good dispersibility, while the cohesion between calcite particles and sodium oleate particles decreased; notably, the effect on fluorite was opposite. Calcite and esterified starch exhibited chemical adsorption, impeding the adsorption of sodium oleate onto calcite and resulting in calcite inhibition. The interaction between fluorite surface and esterified starch involved electrostatic adsorption, with sodium oleate chemically adsorbed onto the fluorite surface. Chemical adsorption proved stronger than electrostatic adsorption, enabling sodium oleate to capture fluorite.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"128 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141687054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement of ilmenite magnetic properties by oxidation roasting and magnetic separation","authors":"Jiantao Gu, Zhitao Yuan, Yusheng Du, Wei Ji Lu, Chuan Yang, Hongyang Lv","doi":"10.37190/ppmp/190706","DOIUrl":"https://doi.org/10.37190/ppmp/190706","url":null,"abstract":"Oxidation roasting was proposed to treat the problem of the weak magnetic properties of ilmenite. The effects of roasting temperature, roasting time and cooling method on the results of ilmenite magnetic separation were studied. At the same time, the mechanism of the oxidation roasting process was analyzed by XRD, VSM, SEM-EDS. Determine ilmenite suitable oxidation roasting conditions for roasting temperature 750 °C, roasting time of 20 min, and cooling method of air cooling; at this time, the yield of 96.79% can be achieved in the magnetic field intensity of 238.74 kA/m. The XRD results showed that phase changes in the roasting process occur in the order of ilmenite to hematite and rutile to pseudobrookite. The results of VSM showed that the maximum specific magnetization coefficient of ilmenite increased from 3.25×10-5 m3/kg to 5.58×10-5 m3/kg after roasting, and the magnetic property was enhanced. The results of SEM-EDS showed that the phase transition of ilmenite during the roasting process occurs in a spatial order from the edge of the particles to the interior.","PeriodicalId":508651,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"30 10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141688197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}