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Using a fluxonium qubit with in situ tunability of its Josephson energy, we characterize its energy relaxation at different flux biases as well as different Josephson energy values. The relaxation rate at qubit energy values, ranging more than one order of magnitude around the thermal energy $k_B T$, can be quantitatively explained by a combination of dielectric loss and $1/f$ flux noise with a crossover point. The amplitude of the $1/f$ flux noise is consistent with that extracted from the qubit dephasing measurements at the flux sensitive points. In the dielectric loss dominant regime, the loss is consistent with that arises from the electric dipole interaction with two-level-system (TLS) defects. In particular, as increasing Josephson energy thus decreasing qubit frequency at the flux insensitive spot, we find that the qubit exhibits increasingly weaker coupling to TLS defects thus desirable for high-fidelity quantum operations.

High-pressure diamond anvil cells have been widely used to create novel states of matter. Nevertheless, the lack of universal in-situ magnetic measurement techniques at megabar pressures makes it difficult to understand the underlying physics of materials' behavior at extreme conditions, such as high-temperature superconductivity of hydrides and the formation or destruction of the local magnetic moments in magnetic systems, etc. Here we break through the limitations of pressure on quantum sensors and develop the in-situ magnetic detection technique at megabar pressures with high sensitivity (~1{\mu}T/Hz^(1\2)) and sub-microscale spatial resolution. By directly imaging the magnetic field and the evolution of magnetic domains, we observe the macroscopic magnetic transition of Fe3O4 in the megabar pressure range from strong ferromagnetism ({\alpha}-Fe3O4) to weak ferromagnetism ({\beta}-Fe3O4) and finally to non-magnetism ({\gamma}-Fe3O4). The scenarios for magnetic changes in Fe3O4 characterized here shed light on the direct magnetic microstructure observation in bulk materials at high pressure and contribute to understanding the mechanism of magnetic moment suppression related to spin crossover. The presented method can potentially investigate the spin-orbital coupling and magnetism-superconductivity competition in magnetic systems.

Additional file 2. : A complete list of clinic hospitals where data will be collected.

Additional file 1. : SPIRIT 2013 checklist.

Diarrhea-predominant irritable bowel syndrome (IBS-D) is one of the most common chronic functional gastrointestinal diseases with limited treatments. Gut microbiota play an important role in chronic gastrointestinal diseases. In traditional Chinese medicine (TCM), Spleen–Yang deficiency (SYD) is one of the root causes of IBS-D. Fuzi-Lizhong pill (FLZP) is well known for its powerful capacity for treating SYD and has a good clinical effect on IBS-D. However, the mechanism of FLZP on the gut microbiota of IBS-D has not been fully clarified. Our present study aimed to reveal the mechanism of FLZP regulating gut microbiota of IBS-D. The body mass, CCK, MTL, and Bristol fecal character score were used to verify the establishment of the IBS-D model. IL-6, TNF, IL-1β, and IFN-γ were crucial targets screened by network pharmacology and preliminarily verified by ELISA. Eighteen gut microbiota were important for the treatment of IBS-D with FLZP. Bacteroidetes, Blautia, Turicibacter, and Ruminococcus_torques_group were the crucial gut microbiota that FLZP inhibits persistent systemic inflammation in the IBS-D model. Lactobacillus is the crucial gut microbiota that FLZP renovates intestinal immune barrier in the IBS-D model. In summary, FLZP can affect bacterial diversity and community structures in the host and regulate inflammation and immune system to treat IBS-D.

Vanillin and syringaldehyde are widely used as flavoring and fragrance agents in the food products. The potential of a macro-mesoporous adsorption resin was assessed for separation of these binary mixtures. This work focuses on modeling of the competitive adsorption behaviors and exploration of the adsorption mechanism. The characterization results showed the resin had a large BET surface area and specific pore structure with hydrophobic properties. By analysis of the physicochemical properties of the solutes and the resin, the separation mechanism was mainly contributed by hydrophobic effect. Subsequently, the competitive Langmuir isotherm model was used to fit the competitive adsorption isotherms. The pore diffusion coefficient was obtained by macropore diffusion model. Afterwards, a mathematical model was established to predict the breakthrough curves of the binary mixture at various operating conditions. The data and model presented are valuable for design and simulation of the continuous chromatographic separation process.

Microstructure and phase transformation of disodium guanosine 5′-monophosphate (5′-GMPNa 2 ) are extremely important for controlling the process and understanding the mechanism of crystallization. In this work, the thermodynamic properties of polymorphous 5′-GMPNa 2 especially the solubility were studied, the solubility results show that 5′-GMPNa 2 is more soluble in ethanol–water (E–W) than in isopropanol–water (I–W). The amorphous form of 5′-GMPNa 2 is more soluble than the crystalline form at the same mole fraction and temperature. Meanwhile, the crystalline forms and morphologies of the residual solids were characterized by PXRD and SEM. The results indicate that solid forms of 5′-GMPNa 2 transformed spontaneously from amorphous to crystalline when the ethanol proportion is ≥ 20%. In addition, increasing the pH facilitates the dissolution of 5′-GMPNa 2 and helps to maintain the crystalline form. The associated Gibbs free energy values were calculated to verify the trend of transformation from amorphous to crystalline 5′-GMPNa 2 . These results should help to guide the industrial crystallization process and to obtain the crystalline form of 5′-GMPNa 2 .

In order to simplify the process of extracting 5′-ribonucleotides from hydrolysate in industry in an environmentally friendly manner, electrodialysis was introduced as an alternative route. The feasibility of electrodialysis for the separation of 5′-ribonucleotides from hydrolysate was investigated using a series of membranes under different conditions. The results of the lab-scale experiments indicate that ChemJoy membranes are most suitable for the separation of 5′-ribonucleotides. At a current density of 13.2 A m−2 or constant voltage of 30 V in batch operation, the yield of 5′-ribonucleotides reaches 97.2% and 95.4%, respectively. Furthermore, the decolorization ratio of 91.6% indicates that most pigments are blocked by the membranes and the current efficiency reaches 70% for guanosine 5′-monophosphate (GMP) production. Remarkably, the 5′-ribonucleotides are 1.3-times more concentrated. Finally, membrane fouling was investigated via SEM and ATR-FTIR, and the TingRun, ChemJoy and Astom cationic membranes showed the same membrane fouling resistance. However, among the anionic membranes, ChemJoy showed the best fouling resistance. The total energy cost of the pilot-scale operation was estimated to be 155.44 $ per t 5′-ribonucleotides. This process integrates preliminary purification, decolorization and concentration, providing a simple, cost-effective and green way to produce 5′-ribonucleotides.

An innovative benign process for recovery lactic acid from its fermentation broth is proposed using a novel hyper-cross-linked meso-micropore resin and water as eluent. This work focuses on modeling the competitive adsorption behaviors of glucose, lactic acid and acetic acid ternary mixture and explosion of the adsorption mechanism. The characterization results showed the resin had a large BET surface area and specific pore structure with hydrophobic properties. By analysis of the physicochemical properties of the solutes and the resin, the mechanism of the separation is proposed as hydrophobic effect and size-exclusion. Subsequently three chromatographic models were applied to predict the competitive breakthrough curves of the ternary mixture under different operating conditions. The pore diffusion was the major limiting factor for the adsorption process, which was consistent with the BET results. The novel HD-06 resin can be a good potential adsorbent for the future SMB continuous separation process.

Solvent-mediated transformation of disodium guanosine 5′-monophosphate (5′-GMPNa2) from amorphous to hydrated crystal phases was studied. The SMT process is dominated by the dissolution of the amorphous form and nucleation and growth of the crystal polymorph. The kinetic estimation based on population balance equation was carried out according to experimental data, including polymorphic fraction in the solid phase, solute concentration, and crystal size distribution. Furthermore, independent seeded batch experiments were carried out to estimate the kinetic parameters. The experimental data showed that the nucleation and growth of the crystal polymorph occurred shortly after the dissolution of the amorphous form. The estimated growth, nucleation, and dissolution rates indicated that the solution-mediated transformation was governed by the nucleation and growth of crystal polymorph. We believe that the results hold great importance toward understanding the transformation process of 5′-GMPNa2, which provides...

Fabrication of biocompatible micro- and nanoparticles is attractive because of their potential for application as enzyme immobilization tools. Mesoporous TiO 2 microparticles with high crystallinity, high hydroxyl density, and large pore size (20 nm) were prepared by solid-state calcination and a soft chemistry method. The large pores of the microparticles were efficient in adenosine deaminase (ADA) encapsulation. The hydroxyl-coated microparticles could optimize amino-silane modification and be efficiently utilized as ADA-immobilization carriers. However, the adsorbed enzymes were easily leached when cycled. Sequential application of the coupling agent 3-aminopropyltriethoxysilane and cross-linker glutaraldehyde (GLU) enabled effective ADA coupling. After eight batch cycles, the immobilized ADA retained 80% of its initial activity, much higher than that by direct enzyme adsorption (30%). GLU prevented enzyme desorption and loss of activity. We thus improved ADA loading efficiency, recycling, and stability. TiO 2 microparticles could be suitable ADA immobilization candidates for detection and industrial inosinic acid production.

Conventional activated carbon used in decolorization of citric acid fermentation broth has the disadvantage of high citric acid loss. In this study, a novel biomass-based carbon material, namely HBCM, was prepared via H3PO4 activation of hydrothermally treated corncob. The material was fully characterized by SEM, BET, TG, FTIR, XPS and pHpzc. The results showed that the material's SBET was as high as 1720 m2 g−1 and several weak-acid functional groups existed on its surface, which contributed to efficient decolorization with low citric acid loss. By adjusting the solution pH value to around 7, nearly no citric acid was lost. Furthermore, the adsorption behavior of pigments on HBCM was systematically investigated under optimized pH. The results indicated that the adsorption was spontaneous and endothermic. Intra-particle diffusion was the rate-limiting step. By comparing FTIR data before and after adsorption, it was found that oxygen-containing functional groups on the HBCM surface participated in pigment adsorption. Overall, the tailor-made HBCM performed excellently with a 99% decolorization ratio and nearly no citric acid loss under optimum operating conditions. It could be a potential adsorbent in the removal of pigments from citric acid fermentation broth.

L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of l -phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of l -phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically. A modified Donnan ion-exchange (DIX) model, which takes the activity into account, was established to predict the uptake of l -phenylalanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest l -phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.

The use of graphene oxide (GO) nanosheets for functional enzyme support has attracted intensive interest owing to their unique planar structure and intriguing physical and chemical properties. However, the detailed effects of the interface properties of GO and its functionalized derivatives on active biomolecules are not well understood. We immobilize nuclease P1, a common industrial nucleic acid production enzyme, on pristine and amino poly(ethylene glycol) (PEG-NH2) modified GO nanosheets with interface property heterogeneity using two approaches, physical adsorption and chemical crosslinking. It is demonstrated that nuclease P1 could be stable immobilized on the surface of pristine GO by physical adsorption and on the edge of modified GO nanosheets by chemical crosslinking. The resultant loading capacity of nuclease P1 on pristine GO is as high as 6.45mg/mg as a consequence of strong electrostatic and hydrophobic interactions between the enzyme and carrier. However, it is determined that the acid resistance, thermal stability, reusability and degradation efficiency of the immobilized enzyme on PEG-NH2-modified GO are obviously improved compared to those of the enzyme immobilized on pristine GO. The enhanced catalytic behavior demonstrates that GO and its derivatives have great potential in efficient biocatalytic systems.

Mesoporous TiO 2 microparticles featuring distinct, well-defined pore sizes (3.7–40 nm) were used for investigating the effect of geometrical topography and surface chemistry on the immobilization of adenosine deaminase (ADA). We determined that the pore size of the microparticles can be tuned by varying the post-heat-treatment process. The ADA-adsorption properties of microparticles displaying distinct geometrical topographies were compared, and the relations between pore sizes and the levels of protein loading and enzyme activity were investigated. Although the specific surface area of large-pore microparticles was smaller than that of microparticles harboring small pores, carriers derived from large-pore microparticles exhibited comparatively superior enzyme loading; an overall enzyme loading of 13.5 mg/g was achieved in the case of TiO 2 carriers featuring 20 nm intra-particle pores. In order to strengthen operational stability, surface modification with (3-aminopropyl) triethoxysilane (APTES) and crosslinking with glutaraldehyde were performed; the operational stability of ADA immobilized on TiO 2 –APTES microparticles featuring various pore sizes was considerably higher than that of ADA immobilized on blank TiO 2 . Thus, both the geometrical topography and surface chemistry of mesoporous TiO 2 microparticles and ADA were crucial for achieving high biocatalysis activity and operational stability.

Here we report two new crystal forms of adenosine 3′,5′-cyclic monophosphate sodium and the discovery of the direct solid–solid transformation process from its methanol trihydrate (solvate) to its pentahydrate form (hydrate) that is only mediated by humidity. These findings provide a potential approach for the removal of residual solvents in the manufacturing of pharmaceuticals and food additives.

The influence of the solvent on the nucleation of disodium guanosine 5′-monophosphate (GMPNa2) in eight methanol (ethanol)–water mixtures and at three supersaturation levels at 293.15 K was investigated. The interfacial free energy, the critical size for nucleation, and the number of molecules were calculated using equations re-derived from the classical nucleation theory. GMPNa2 nucleation involves not only a primary nucleation process but also the conversion from a homogeneous to a heterogeneous process. The transformation experiment indicated that the nucleation of GMPNa2 follows the two-step model. A surface entropy factor (fb) was proposed to relate the solvent composition and interfacial free energy in order to explain the solvent effects on the nucleation process. Although the fb values can be used to judge the crystal growth mode, nucleation and growth cannot be separated, since pure primary nucleation does not occur for this compound. The fb values clearly increased with increasing solvent content and decreasing supersaturation. For the homogeneous process in a methanol–water system, regular crystals can be formed only when fb > 5, regardless of the supersaturation, as was observed for solvent contents of 40 mol% and 30 mol% (S = 1.83 and 1.70, respectively). These results can help select a suitable solvent system and its composition during anti-solvent crystallization.

An intermittent simulated moving bed (3F-ISMB) operation scheme, the extension of the 3W-ISMB to the non-linear adsorption region, has been introduced for separation of glucose, lactic acid and acetic acid ternary-mixture. This work focuses on exploring the feasibility of the proposed process theoretically and experimentally. Firstly, the real 3F-ISMB model coupled with the transport dispersive model (TDM) and the Modified-Langmuir isotherm was established to build up the separation parameter plane. Subsequently, three operating conditions were selected from the plane to run the 3F-ISMB unit. The experimental results were used to verify the model. Afterwards, the influences of the various flow rates on the separation performances were investigated systematically by means of the validated 3F-ISMB model. The intermittent-retained component lactic acid was finally obtained with the purity of 98.5%, recovery of 95.5% and the average concentration of 38 g/L. The proposed 3F-ISMB process can efficiently separate the mixture with low selectivity into three fractions.

In this work nanofiltration technology has been employed for removal of inhibitors and recovery of monosaccharides from dilute acid lignocellulose hydrolysates. The influences of feed solution pH, permeate flux, and Na2SO4 concentration on the rejection of monosaccharides and inhibitors were investigated. The results showed that the pH for the separation of carboxylic acids and furans from monosaccharides should be as low as possible. With increase of Na2SO4 concentration carboxylic acid and furan rejection decreased. Subsequently, the Donnan steric pore and dielectric exclusion model coupled with mass balance was used to predict the rejection of solutes at different permeate fluxes. In order to select a suitable permeate flux and operating time, multi-objective optimization was carried out to obtain the maximum total inhibitor removal efficiency, the maximum monosaccharide recovery rate, and the minimum water consumption. The optimal operating conditions were then verified using the real hydrolysate as feed solutions. More specifically, for the treatment of 6 L of a hydrolysate solution, 13 L of water and a treatment time of 35 min were required. This process allowed the removal of 90% inhibitors, while 93.55% glucose, 90.75% xylose, and 90.53% arabinose were recovered. Finally, a batch column equipped with a strong acid cation exchange resin was employed to recover the monosaccharides from the hydrolysate. Using water as an eluent, 95.37% of the sulfuric acid and 94.87% of the monosaccharides were recovered. In all, we demonstrated that the combination of nanofiltration with electrolyte exclusion chromatography is a promising integrated process for the recovery of monosaccharides and inorganic acids from dilute acid corncob hydrolysates.

N-acetyl-D-neuraminic acid (Neu5Ac) is a high value-added product widely applied in the food industry. A suitable equilibrium model is required for purification of Neu5Ac based on ion-exchange chromatography. Hence, the equilibrium uptake of Neu5Ac on a strong anion exchanger, AD-1 was investigated experimentally and theoretically. The uptake of Neu5Ac by the hydroxyl form of the resin occurred primarily by a stoichiometric exchange of Neu5Ac(-) and OH(-). The experimental data showed that the selectivity coefficient for the exchange of Neu5Ac(-) with OH(-) was a non-constant quantity. Subsequently, the Saunders' model, which took into account the dissociation reactions of Neu5Ac and the condition of electroneutrality, was used to correlate the Neu5Ac sorption isotherms at various solution pHs and Neu5Ac concentrations. The model provided an excellent fit to the binary exchange data for Cl(-)/OH(-) and Neu5Ac(-)/OH(-), and an approximate prediction of equilibrium in the ternary system Cl(-)/Neu5Ac(-)/OH(-). This basic information combined with the general mass transfer model could lay the foundation for the prediction of dynamic behavior of fixed bed separation process afterwards.

The recovery and purification of biobutanol based on the adsorption method were performed in dynamic conditions. Computational and theoretical modeling is an important tool in the characterization, development, and validation of fixed-bed columns. Relevant breakthrough curves provide valuable information for designing fixed-bed adsorption processes for field applications. In the present study, a general rate model (GRM), implementing convection/diffusion approach theory and a competitive isotherm model, was used to predict the competitive sorption dynamics of acetone–butanol–ethanol (ABE) on a KA-I resin in a fixed-bed column under different operating conditions, i.e., inlet feed flow rate, initial adsorbate concentration, and bed height. The model simulation was quantified by the absolute average deviation (AAD). The calculated AAD values, ranging from 0.05 to 0.1, indicated that the GRM gives a general prediction for experimental data. The axial dispersion, external mass transfer, and pore diffusion coefficients were calculated by a series of empirical correlations. Biot number was used to identify the rate controlling step for the adsorption process of ABE on the resin. And the pore diffusion coefficient was found to be major governing factor for adsorption of ABE. The data and modeling presented are valuable for designing the continuous chromatographic separation process and simulation of ABE.

The conventional ion exchange process used for recovery of uridine 5'-monophosphate (UMP) from the enzymatic hydrolysate of RNA is environmentally harmful and cost intensive. In this work, an innovative benign process, which comprises adsorption technology and use of a hyper-cross-linked resin as a stationary phase is proposed. The adsorption properties of this kind of resin in terms of adsorption equilibrium as well as kinetics were evaluated. The influences of the operating conditions, i.e., initial UMP concentration, feed flow rate, and bed height on the breakthrough curves of UMP in the fixed bed system were investigated. Subsequently, a chromatographic column model was established and validated for the prediction of the experimentally attained breakthrough curves of UMP and the main impurity component (phosphate ion) with a real enzymatic hydrolysate of RNA as a feed mixture. At the end of this paper, the crystallization of UMP was carried out. The purity of the final product (uridine 5'-monophosphate disodium, UMPNa2) of over 99.5 % was obtained.

Desorption is essential to design an integrated recovery process for 1-butanol, a potential biofuel. The modeling of desorption processes is a significant tool to optimize the separation process of 1-butanol. In this work, we systematically studied the desorption of 1-butanol from a porous polymeric resin KA-I by solvent desorption technique. The desorption equilibrium, desorption kinetics and dynamic desorption behaviors were studied experimentally and simulated theoretically. About 1.5 bed volumes of absolute ethanol could desorb 1-butanol completely with 73.6 g L−1 1-butanol in the effluent in the fixed bed system. A pore diffusion model was used to fit the desorption kinetics of 1-butanol satisfactorily. The concentration evolution of eluent and 1-butanol in the resin pore was simulated. During desorption, the concentration of 1-butanol in the resin pore increases gradually at first, and then decreases gradually due to the slower pore diffusion. Moreover, a general rate model was used to predict the dynamic desorption profiles of 1-butanol under different operating conditions successfully. Finally, repeated adsorption and desorption dynamic cycles were predicted by the general rate model quite well.

Metastable zone widths (MSZWs) and induction times (tind’s) were measured by turbidity techniques during the antisolvent crystallization of disodium guanosine 5′-monophosphate (5′-GMPNa2). Measured MSZWs can be affected by numerous process parameters, including temperature, the agitation rate, and the antisolvent addition rate. An exponential equation was used to correlate the supersolubility and solubility data for different conditions, and to afford predictions of the MSZW values. Values of tind at different temperatures and mole fractions of water were assessed to determine the primary nucleation and growth mechanisms of 5′-GMPNa2 crystals in the water–ethanol system. The measured tind’s were then correlated using mononuclear and polynuclear mechanistic models. The fitting results identified the primary nucleation mechanism for 5′-GMPNa2 as polynuclear, which relates tind and the supersaturation for various growth mechanisms. The growth mechanism of 5′-GMPNa2 was found to be diffusion-controlled at all...

A series of porous-carbon adsorbents termed as HDPC (hydrochar-derived pyrolysis char) were prepared from corncob and used for the 1-butanol recovery from aqueous solution. The influences of pyrolysis temperature on properties of the adsorbents were systematically investigated. The results showed that hydrophobicity, surface area, and pore volume of HDPC samples increased with an increase in pyrolysis temperature. Furthermore, the adsorption mechanism of 1-butanol on the adsorbents was explored based on correlation of the samples properties with adsorption parameters extracted from the 1-butanol adsorption isotherms (K F and Q e12 ). Overall, the 1-butanol adsorption capacity increased with a decrease in polarity and an increase in aromaticity, surface area and pore volume of HDPC samples. However, at different pyrolysis temperature, the factors causing the increase of 1-butanol adsorption on the adsorbents are variable. The kinetic experiments revealed that the pores played a vital role in the 1-butonal adsorption process. The intraparticle diffusion model was used to predict the adsorption kinetic process. The simulation results showed that intraparticle diffusion was the main rate-controlling step in the 1-butanol adsorption process.

Separation of butanol based on sorption methodology from acetone-butanol-ethanol (ABE) fermentation broth has advantages in terms of biocompatibility and stability, as well as economy, and therefore gains much attention. In this work a chromatographic column model based on the solid film linear driving force approach and the competitive Langmuir isotherm equations was used to predict the competitive sorption behaviors of ABE single, binary, and ternary mixture. It was observed that the outlet concentration of weaker retained components exceeded the inlet concentration, which is an evidence of competitive adsorption. Butanol, the strongest retained component, could replace ethanol almost completely and also most of acetone. In the end of this work, the proposed model was validated by comparison of the experimental and predicted ABE ternary breakthrough curves using the real ABE fermentation broth as a feed solution.

The solubility of biological chemicals in solvents provide important fundamental data and is generally considered as an essential factor in the design of crystallization processes. The equilibrium solubility data of inosine-5′-monophosphate disodium (5′-IMPNa2) in water, methanol, ethanol, acetone, as well as in the solvent mixtures (methanol + water, ethanol + water, acetone + water), were measured by an isothermal method at temperatures ranging from (293.15 to 313.15) K. The measured data in pure and mixed solvents were then modelled using the modified Apelblat equation, van’t Hoff equation, λh equation, ideal model and the Wilson model. The modified Apelblat equation showed the best modelling results, and it was therefore used to predict the mixing Gibbs free energies, enthalpies, and entropies of 5′-IMPNa2in pure and binary solvents. The positive values of the calculated partial molar Gibbs free energies indicated the variations in the solubility trends of 5′-IMPNa2. Water and ethanol (in the binary mixture with water) were found to be the most effective solvent and anti-solvent, respectively.

Acetoin is a high value-added product widely used in the food industry. Recovery of acetoin from the aqueous solution based on a polymeric adsorbent is an efficient method. Hence, a novel hyper-cross-linked resin was prepared and the adsorption behaviors of acetoin on the resin were investigated systematically. The results showed that the maximum adsorption capacity of acetoin onto the resin decreased with increasing temperature, ranged from 192 to 102 mg/g. Batch kinetic experiments revealed that the adsorption process was rapid and the equilibrium was reached in 30 min. The intraparticle diffusion and macropore diffusion models were used to predict the adsorption process. The simulation results showed that the macropore diffusion was the adsorption-rate controlling step. The obtained diffusivity (0.77 × 10 −8 m 2 /min at the temperature of 293.15 K) had the same magnitude as the acetoin molecular diffusivity, indicating that the mass transfer into the resin pores was occurred by molecular diffusion.

Summary Immobilized fermentation has several advantages over traditional suspended fermentation, including simple and continuous operation, improved fermentation performance and reduced cost. Carrier is the most adjustable element among three elements of immobilized fermentation, including carrier, bacteria and environment. In this study, we characterized carrier roughness and surface properties of four types of natural fibres, including linen, cotton, bamboo fibre and silk, to assess their effects on cell immobilization, fermentation performance and stability. Linen with higher specific surface area and roughness could adsorb more bacteria during immobilized fermentation, thereby improving fermentation performance; thus, linen was selected as a suitable carrier and was applied for acetone–butanol–ethanol (ABE) fermentation. To further improve fermentation performance, we also found that microbes of Clostridium acetobutylicum were negatively charged surfaces during fermentation. Therefore, we then modified linen with polyetherimide (PEI) and steric acid (SA) to increase surface positive charge and improve surface property. During ABE fermentation, the adhesion between modified linen and bacteria was increased, adsorption was increased about twofold compared with that of unmodified linen, and butanol productivity was increased 8.16% and 6.80% with PEI‐ and SA‐modified linen as carriers respectively.

A novel polar macroporous adsorption resin (AX-1) has been applied for separation of d -lactic acid (DLA) from aqueous solutions in a fixed-bed chromatographic column. The adsorption equilibrium and kinetics were investigated experimentally. A column model was subsequently established and validated by comparison of the simulation results to the experimental data obtained at different operating conditions in terms of feed flow rates and initial concentrations as well as bed heights. At the end of this work, the recycling studies were carried out. It was found that the saturated resin could be washed out DLA completely and repeated use by 353 K hot water. The results show that the AX-1 resin has a high adsorption capacity to DLA while no retention to sulfate ion. Based on this kind of resin, a green-production refining process could be established since only water is added in the entire separation process.

The molecular structure of cytidine 5′-diphosphocholine sodium (CDPC) grown from a mixture of ethanol and water was determined by X-ray diffraction (XRD). CDPC was found to have an orthorhombic structure with confirmed lattice parameters of a = 6.978 A, b = 12.406 A and c = 29.326 A. This nucleotide coenzyme was highly folded and net-like. Each crystallographic unit consisted of one sodium atom, one pyrophosphate group, one cytosine group, one coordinated water molecule, one pentose molecule, and three lattice water molecules. The interspaces of neighboring CDPC molecules were filled with water molecules and methyl groups. Although the coordinated water was connected to sodium atoms, the lattice water molecules formed chair-shaped water hexamers. The hydrogen bonds which played an important role in maintaining the structure included O H···O, N H···O and C H···O and ranged in length from 2.682 (17) to 3.349 (17) A. Fourier transform infrared spectroscopy (FTIR) showed a broad absorption in the 400–2000 cm−1 region characteristic of short hydrogen bonds. So for industrial crystallization, methods which could eliminate the influence of hydrogen bonds should be taken, and it would be beneficial for the process of crystallization.

Motor speed control system is used more and more widely in all fields along with the development of power switch device. Speed measurement is an essential part in closed-loop control. And it has an important influence on the speed control performance. The current speed measurement method can not meet the requirements of the application object for speed control system in the whole range high precision measurement with high reliability. This paper presents one speed measurement method based on MEMS gyroscope. The MEMS gyroscope is fixed on rotor. Its output reflects motor rotating state. The slip ring is used to solve signal transmission between dynamic state MEMS gyroscope and static state controller. It is applied to AC motor speed control system designed by our research group. The experimental results show the validity of that the proposed method.

The adsorption of quaternary mixtures of ethanol/glycerol/glucose/acetic acid onto a microporous hyper-cross-linked resin HD-01 was studied in fixed beds. A mass transport model based on film solid linear driving force and the competitive Langmuir isotherm equation for the equilibrium relationship was used to develop theoretical fixed bed breakthrough curves. It was observed that the outlet concentration of glucose and glycerol exceeded the inlet concentration ( c / c 0 > 1), which is an evidence of competitive adsorption. This phenomenon can be explained by the displacement of glucose and glycerol by ethanol molecules, owing to more intensive interactions with the resin surface. The model proposed was validated using experimental data and can be capable of foresee reasonably the breakthrough curve of specific component under different operating conditions. The results show that HD-01 is a promising adsorbent for recovery of ethanol from the fermentation broth due to its large capacity, high selectivity, and rapid adsorption rate.

This paper, first analyzes the method of wireless network intrusion detection, presents a wireless network intrusion detection algorithm based on association rule mining. The application of fuzzy association rules in the wireless network intrusion detection is mainly discussed, and the steps to implement the algorithm are expressed. A comparative analysis with the classical algorithm Apriori is made by experiment. The results show that wireless network intrusion detecting using fuzzy association rules mining algorithm is a feasible method.

The paper analyzes the sturcture of heating network monitoring system and introduces the design and realization of the heating network monitoring system based on industry ethernet and configuration software, the building of industry ethernet and the realization follow and function of the upper monitoring interface software is expounded emphatically. By adopting double redundancy ring ethernet,configuration monitoring and OPC communication technology the system realizes intelligent and informative management of heating network power supply system and improve its stability and reliability.