Flotation performance of a novel Gemini collector for kaolinite at low temperature

How to sustainably produce bauxite by effective reverse froth flotation of kaolinite at low temperature is an urgent problem to be solved in the field of mineral processing.In this work,a novel amino-based Gemini surfactant butadiyl-1,4-bis(dimethyl dodecylammonium bromide)(BBDB) was prepared and first utilized as a novel collector for kaolinite flotation.Its flotation performance for kaolinite was compared with that of the common monomolecular surfactant 1-dodecylamine(DDA) by micro-flotation tests.The tests results indicated that 95% kaolinite recovery was obtained using 2.0×10^(-4) mol/L BBDB at 25℃ which was half of the dosage when DDA obtained the maximum kaolinite recovery of81%.At extremely low temperature(0℃),3.0×10^(-4) mol/L BBDB could still collect 91% kaolinite,while DDA showed a frustrating ability.The contact angle tests indicated that BBDB could still significantly improve the hydrophobicity of the kaolinite surface(contact angle 71.7°) than DDA(contact angle only25.8°) at 0℃.The Krafft point comparison tests indicated that BBDB had a much lower Krafft point(below0℃) than DDA.Fourier transform infrared spectroscopy(FTIR)-spectrum analysis and zeta potential measurements showed that BBDB was physically adsorbed on the surface of kaolinite through electrostatic interaction.

Flotation separation of wolframite from calcite using a new trisiloxane surfactant as collector

Since wolframite is usually associated with calcite,the separation and enrichment of wolframite by froth flotation remains a great challenge.Herein,a novel trisiloxane surfactant N-(2-aminoethyl)-3-ami nopropyltrisiloxane(AATS)was successful synthesized,which was used for the separation of wolframite from calcite for the first time.The flotation separation performance of AATS was studied by flotation test,and its adsorption mechanism was explored based on contact angle,infrared spectrum analysis(FTIR),zeta potential and density functional theory(DFT)calculation.The results of microflotation test and binary mixed ore flotation test pointed that AATS had excellent selectivity and more prominent collection capacity for the flotation of wolframite when compared with industrial reagent sodium oleate(NaOL).The measurement results of contact angle proved that AATS improved the hydrophobicity of the wolframite surface.The highly selective adsorption mechanism of AATS surfactant on mineral surfaces were further researched and analyzed by FTIR and zeta potential.The results revealed that AATS surfactant had significant adsorption effect on wolframite,yet almost no adsorption on calcite.DFT calculation indicated that AATS produced electrostatic adsorption with wolframite surface through—N+H3 group.

RANSACs for 3D Rigid Registration:A Comparative Evaluation

Estimating an accurate six-degree-of-freedom(6-Do F)pose from correspondences with outliers remains a critical issue to 3D rigid registration.Random sample consensus(RANSAC)and its variants are popular solutions to this problem.Although there have been a number of RANSAC-fashion estimators,two issues remain unsolved.First,it is unclear which estimator is more appropriate to a particular application.Second,the impacts of different sampling strategies,hypothesis generation methods,hypothesis evaluation metrics,and stop criteria on the overall estimators remain ambiguous.This work fills these gaps by first considering six existing RANSAC-fashion methods and then proposing eight variants for a comprehensive evaluation.The objective is to thoroughly compare estimators in the RANSAC family,and evaluate the effects of each key stage on the eventual 6-Do F pose estimation performance.Experiments have been carried out on four standard datasets with different application scenarios,data modalities,and nuisances.They provide us with input correspondence sets with a variety of inlier ratios,spatial distributions,and scales.Based on the experimental results,we summarize remarkable outcomes and valuable findings,so as to give practical instructions to real-world applications,and highlight current bottlenecks and potential solutions in this research realm.

Technology Roadmap of IGCC Industry in China

With the increasing energy demand and environmental pressures caused by consumption of fossil fuels, the world casts their eyes on new energy, hoping to transform the existing energy structure through technological innovation to new energy field, to promote the optimization and upgrading of the world’s energy structure. The new energy in key areas of Chinese high-tech industries includes mainly nuclear power, wind power, solar power, IGCC (Integrated Gasification Combined Cycle), new energy vehicles and smart grids. The present paper will carry on an in-depth study on IGCC industry technology roadmap in China. Technology roadmap is a kind of technology management tool, expressing the structure and time dimension of technical elements’ evolution with icons. It spans a wide range of applications from a single company to industry, and national and international coalition, from detailed product technology to component technology, as well as the integration of several relevant industry technologies. The roadmap is a kind of multi-layered time-dependent icon. IGCC industry has excellent environmental characteristics and benefits, which are in accordance with the principle of coordinated development between energy and environment. Based on the analysis of current situation, market demand, industry objectives and technical barriers of IGCC technology, we highlight IGCC industrial development model with Chinese characteristics, and concisely propose the major research needs and technology projects of key technology areas in IGCC industry. We highlight IGCC industrial development model with Chinese characteristics, and concisely propose the major research needs and technology projects of key technology areas in IGCC industry. Furthermore, some relevant suggestions on IGCC technology management and industry development are put forward to promote the remarkable progress in the development of IGCC industry in China and build an efficient, economical and clean sustainable energy supply system in line with the requirements of low-carbon economy.

Preparation of cinnamic hydroxamic acid collector and study on flotation characteristics and mechanism of scheelite

In this paper,using methyl cinnamate as raw material,the new cinnamic hydroxamic acid collector(CIHA)was synthesized by the hydroxylamine method.The collector performance of hydroxamic acid was investigated for scheelite and gangue calcite,and the flotation separation test of scheelite and calcite was carried out with CIHA as the collector.The interaction mechanism between hydroxamic acid and scheelite minerals has also been investigated through zeta potential,Fourier transform infrared spectroscopy(FTIR)experiments,X-ray photoelectron spectroscopy(XPS)experiments,and density functional theory(DFT)calculation.The single mineral flotation test and artificially mixed ore showed that CIHA had an excellent collection effect and selectivity.Zeta potential,FTIR,and XPS showed that CIHA was adsorbed on the scheelite surface by strong chemical adsorption.The active group of CIHA was analyzed through quantum chemical calculation.It was speculated that C=O and N-O bonds could synthesize a five-membered chelated hydroxamic acid group with Ca element chelate on scheelite surface,changing hydrophobicity and making it more likely to emerge from the pulp.

Analysis of the Weight Loss of High Temperature Cement Slurry

The weight loss of cement slurry is the main cause of early annular air channeling and accurate experimental evaluation of the law of loss change is the key to achieve compression stability and prevent this undesired phenomenon.Typically,tests on the pressure loss of cement slurry are carried out for temperature smaller than 120°C,and this condition cannot simulate effectively the situation occurring in high temperature wells.For this reason,in this study a series of experimental tests have been conducted considering a larger range of temperatures,different retarders and fluid loss additives.The results show that with an increase in the temperature,the weight loss curve of cement slurry changes from a“two-stage”to a“three-stage”behavior,and the risk of channeling increases accordingly.On increasing the amount of retarder and fluid loss additive,the transition time of cement slurry displays a non-monotonic behavior(it decreases first and then increases).It is found that the optimized retarder and fluid loss additive dosage are 0.2%and 2.5%,respectively.

Experimental Evaluation of the Mechanical Properties of Cement Sheath under High-Temperature Conditions

The sealing integrity of cement sheath in offshore wells is seriously threatened under high-temperature conditions,resulting in gas channeling and other problems.Given the lack of experimental results,in this study relevant samples of a cement slurry sealing section of a typical offshore high-temperature well have been prepared and analyzed.In particular,the mechanical properties have been assessed with a triaxial pressure servo instrument and a high-temperature curing kettle.The density and the Poisson’s ratio of the samples have also been tested.The stress-strain curve has been drawn to obtain the elastic modulus and the compressive strength.The rock brittleness index has been calculated according to the measured elastic modulus and the Poisson’s ratio,together with the brittleness and the compressibility of the cement samples.The test results show that the mechanical properties and bonding strength of the cement samples are optimal at 130°C,medium at 150°C,and poor at 180°C.

Dynamic thermo-mechanical coupled simulation of statistically inhomogeneous materials by statistical second-order two-scale method

In this paper,a statistical second-order twoscale（SSOTS） method is developed to simulate the dynamic thcrmo-mechanical performances of the statistically inhomogeneous materials.For this kind of composite material,the random distribution characteristics of particles,including the shape,size,orientation,spatial location,and volume fractions,are all considered.Firstly,the repre.sentation for the microscopic configuration of the statistically inhomogeneous materials is described.Secondly,the SSOTS formulation for the dynamic thermo-mechanical coupled problem is proposed in a constructive way,including the cell problems,effective thermal and mechanical parameters,homogenized problems,and the SSOTS formulas of the temperatures,displacements,heat flux densities and stresses.And then the algorithm procedure corresponding to the SSOTS method is brought forward.The numerical results obtained by using the SSOTS algorithm are compared with those by classical methods.In addition,the thermo-mechanical coupling effect is studied by comparing the results of coupled case with those of uncoupled case.It demonstrates that the coupling effect on the temperatures,heat flux densities,displacements,and stresses is very distinct.The results show that the SSOTS method is valid to predict the dynamic thermo-mechanical coupled performances of statistically inhomogeneous materials.

Microstructural Modeling and Multiscale Mechanical Properties Analysis of Cancellous Bone

This paper is devoted to the microstructure geometric modeling and mechanical properties computation of cancellous bone.The microstructure of the cancellous bone determines its mechanical properties and a precise geometric modeling of this structure is important to predict the material properties.Based on the microscopic observation,a new microstructural unit cell model is established by introducing the Schwarz surface in this paper.And this model is very close to the real microstructure and satisfies the main biological characteristics of cancellous bone.By using the unit cell model,the multiscale analysis method is newly applied to predict the mechanical properties of cancellous bone.The effective stiffness parameters are calculated by the up-scaling multi-scale analysis.And the distribution of microscopic stress in cancellous bone is determined through the down-scaling procedure.In addition,the effect of porosity on the stiffness parameters is also investigated.The predictive mechanical properties are in good agreement with the available experimental results,which verifies the applicability of the proposed unit cell model and the validness of the multiscale analysis method to predict the mechanical properties of cancellous bone.

Optimization of Solid-state Fermentation Conditions of Sophora japonica cv.jinhuai by Response Surface Methodology

[Objectives]To optimize the solid-state fermentation process of Flos Sophorae Immaturus by Penicillium with Sophora japonica cv.jinhuai as raw material.[Methods]The fermentation conditions were optimized by single factor experiment and response surface methodology with quercetin content as the dependent variable.[Results]According to the established model,the optimal fermentation process of Flos Sophorae Immaturus was obtained as follows:temperature 29.97℃,time 6.88 d,rotation speed 180.86 rpm,inoculation amount 3.93 mL,and the expected content of quercetin was 34.8053 mg/g.Based on this,the fermentation parameters were adjusted,and the actual content was 33.67 mg/g,which was close to the predicted value.[Conclusions]The optimization of fermentation process of Flos Sophorae Immaturus by response surface methodology provides a reference for the development and utilization of this medicinal material.

Effects of Polysaccharide from Polygala fallax on Apoptosis of B16 Melanoma

[Objectives]The paper was to study the effects of polysaccharide from Polygala fallax on apoptosis of B16 melanoma and its mechanism.[Methods]P.fallax polysaccharide was prepared by water extraction and alcohol precipitation method combined with Sevag method.The effects of different concentrations of P.fallax polysaccharide on B16 cell proliferation were detected by MTT assay.Apoptosis was detected by Hoechst 33258 staining assay and flow cytometry.The expressions of Bcl-2,Bax,Cleaved Caspase-3 mRNA were detected by Real-time PCR assay.The expressions of Bcl-2,Bax,Caspase-3,Caspase-8,Caspase-9,Cleaved Caspase-3,Cleaved Caspase-9,ERK,p-ERK,JNK,p-JNK proteins were detected by Western Blot assay.[Results]P.fallax polysaccharide inhibited the cell proliferation of B16 melanoma in a concentration-dependent manner(24 h IC 50=0.2133 mg/L;48 h IC 50=0.08489μg/mL).P.fallax polysaccharide up-regulated the expressions of Bax,Cleaved Caspase-3 mRNA and protein,down-regulated the expressions of Bcl-2 mRNA and protein,activated Caspase-3,Caspase-8 and Caspase-9,and decreased the levels of p-ERK/ERK and p-JNK/JNK.[Conclusions]P.fallax polysaccharide can inhibit the cell proliferation of B16 melanoma and induce their apoptosis,probably attributed to the regulation of MAPK,Bcl-2 and Caspase family signaling pathways.

The transcriptional control of LcIDL1–LcHSL2 complex by LcARF5 integrates auxin and ethylene signaling for litchi fruitlet abscission

At the physiological level,the interplay between auxin and ethylene has long been recognized as crucial for the regulation of organ abscission in plants.However,the underlying molecular mechanisms remain unknown.Here,we identified transcription factors involved in indoleacetic acid(IAA)and ethylene(ET)signaling that directly regulate the expression of INFLORESCENCE DEFICIENT IN ABSCISSION(IDA)and its receptor HAESA(HAE),which are key components initiating abscission.Specifically,litchi IDAlike 1(LcIDL1)interacts with the receptor HAESA-like2(LcHSL2).Through in vitro and in vivo experiments,we determined that the auxin response factor LcARF5 directly binds and activates both LcIDL1 and LcHSL2.Furthermore,we found that the ETHYLENE INSENSITIVE 3-like transcription factor LcEIL3 directly binds and activates LcIDL1.The expression of IDA and HSL2 homologs was enhanced in Lc ARF5and Lc EIL3 transgenic Arabidopsis plants,but reduced in ein3 eil1 mutants.Consistently,the expressions of LcIDL1 and LcHSL2 were significantly decreased in Lc ARF5-and LcEIL3-silenced fruitlet abscission zones(FAZ),which correlated with a lower rate of fruitlet abscission.Depletion of auxin led to an increase in 1-aminocyclopropane-1-carboxylic acid(the precursor of ethylene)levels in the litchi FAZ,followed by abscission activation.Throughout this process,LcRF5 and LcEIL3 were induced in the FAZ.Collectively,our findings suggest that the molecular interactions between litchi AUXIN RESPONSE FACTOR 5(LcARF5)-LcIDL1/LcHSL2 and LcEIL3–LcIDL1 signaling modules play a role in regulating fruitlet abscission in litchi and provide a long-sought mechanistic explanation for how the interplay between auxin and ethylene is translated into the molecular events that initiate abscission.

A comprehensive review of animal models for cancer cachexia:Implications for translational research

Cancer cachexia is a multifactorial syndrome characterized by progressive weight loss and a disease process that nutritional support cannot reverse.Although progress has been made in preclinical research,there is still a long way to go in translating research findings into clinical practice.One of the main reasons for this is that existing preclinical models do not fully replicate the conditions seen in clinical patients.Therefore,it is important to understand the characteristics of existing preclinical models of cancer cachexia and pay close attention to the latest developments in preclinical models.The main models of cancer cachexia used in current research are allogeneic and xenograft models,genetically engineered mouse models,chemo-therapy drug-induced models,Chinese medicine spleen deficiency models,zebrafish and Drosophila models,and cellular models.This review aims to revisit and summarize the commonly used animal models of cancer cachexia by evaluating existing preclinical models,to provide tools and support for translational medicine research.

输油转子泵啮合间隙与转子叶数对泵性能影响规律研究

为了提高输油转子泵腔内部流动稳定性,同时提高泵的容积效率,建立了5种啮合间隙、3种转子叶数的输油转子泵模型进行对比分析。基于动网格技术和SSTκ-ω湍流模型对输油转子泵腔内部进行数值模拟,并通过试验验证了研究方法的可行性,分别研究了啮合间隙、转子叶数对输油转子泵性能影响规律,并对输油转子泵的啮合间隙、转子叶数进行了优化设计。结果表明,啮合间隙从0.1 mm增至0.3 mm,2叶输油转子泵腔内高速流动区域扩大,转子腔内漩涡强度增大,泵腔内流体流动的平稳性和容积效率降低;转子叶数由2增加为4,转子腔内压力变化的多样性增加,3叶转子泵腔内流体流动最平稳。优化设计的输油转子泵腔内流动平稳性得到提高,同时容积效率提高了2.1%,能更好地满足油田输油的需要。

基于16S rRNA基因测序分析微生物群落多样性

微生物群落多样性的研究对于挖掘微生物资源,探索微生物群落功能,阐明微生物群落与生境间的关系具有重要意义。随着宏基因组概念的提出以及测序技术的快速发展,16S rRNA基因测序在微生物群落多样性的研究中已被广泛应用。文中系统地介绍了16S rRNA基因测序分析流程中的四个重要环节,包括测序平台与扩增区的选择、测序数据预处理以及多样性分析方法,就其面临的问题与挑战进行了探讨并对未来的研究方向进行了展望,以期为微生物群落多样性相关研究提供参考。

Devonian-Carboniferous Pillow OIB-Type Basalts in the Youjiang Basin,SW China:Implications for the Eastern Extension of the Paleo-Tethys Branch Ocean

Late Paleozoic pillow basalts are well preserved in the Youjiang Basin of SW China.In this study,we conducted geochemical and Sr-Nd isotopic study on the Late Devonian and Late Carboniferous basalts in Napo area,Youjiang Basin.The analyzed samples comprise moderate SiO2,TiO2,Mg#,and REE contents,with slightly positive or negative Eu anomalies,similar to the chemical nature of OIB(Oceanic island basalt).All basalts show low(^(143)Nd/^(144)Nd)iand(^(87)Sr/^(86)Sr)ivalues,close to EMI-type(I-type Enriched Mantle)magma source.Late Carboniferous basalts display higher(^(87)Sr/^(86)Sr)i,Nb/Th,and lowerε_(Nd)(t),Zr/Nb values than those of the Late Devonian basalts,implying progressively decreased enrichment components in the magma source processes.Such evolution trend reflects a continuous lithospheric thinning event,supporting a progressive rifting setting of the Youjiang Basin along the southwestern margin of the Yangtze Block in Late Paleozoic.Combined with regional geological background,the Youjiang Basin is viewed as a continental rift basin related to the opening of the Paleo-Tethys Ocean in Late Devonian and became a passive continental margin basin in Carboniferous.The Paleo-Tethys branch ocean probably extended further to the southern Youjiang Basin,likely corresponding to the Song Ma suture zone.

Reliability analysis of Lan Chengyu corroded pipeline with associated defects

Traditional reliability evaluation method for corroded pipeline exists the problem of not considering the associated defects.We therefore propose a new calculation method considering the associated defects.In this paper,the traditional and new methods are respectively used to calculate and contrastively analyze the failure probability of corroded pipeline;we then perform the research of residual life prediction for the corroded pipeline,followed by the sensitivity calculation of all random evaluation parameters.And then the Monte Carlo method(MCS)is applied to verify the rationality of the new method.The research results show that:the method considering associated defect is more objective,and truly react corroded pipeline's dynamic reliability changes;obtain new method to predict residual life of corroded pipeline;corrosion depth,radial corrosion rate have a significant impact on reliability of corroded pipeline considering associated defects.The calculation results of the method are more accurate,more time-saving.

Overview of 6π 1,5-Electrocyclization over the Past 40 Years

As an important part of pericyclic reaction,6π 1,5-electrocyclization plays an important role in organic synthesis and chemical theory.Many types of five-membered rings could be constructed via 1,5-electrocyclization with high atom economy.Some elegant works have been reported in this field in the past few decades.However,it still needs a lot of effort in further advancements of 1,5-electrocyclization.