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The full utilization of adsorption sites is crucial for adsorption technology. Metal-organic frameworks (MOFs), which are hot spot materials in environmental remediation, are not satisfied in many cases for their high specific surface area and relatively low adsorption capacity. In this work, a series of zirconium-iron bimetallic MOFs (ZrxFe(1-x)-MOF-808) was prepared. The optimal material (Zr0.8Fe0.2-MOF-808) possesses a superb adsorption capacity of 524 and 310 mg g–1 for antimonate and antimonite, respectively. The carboxyl and hydroxyl groups were identified as the main adsorption sites by FTIR and XPS. The role of Fe in the adsorption process of Zr0.8Fe0.2-MOF-808 were further explored by DFT simulations, four binding manners were discovered and consistent with the adsorption capacity data. Subsequently, the application potential tests proved that the Zr0.8Fe0.2-MOF-808 shows good anti-interference ability, wide pH adaptability, and recyclability. Overall, this high-performance bimetallic MOF has been analyzed from the macrocosm to microcosmic, which provides a certain support for the development of MOFs modification.

In this paper, the effect of traction speed on the four-lumen plastic micro-catheter (FLPMC) was numerically studied. Moreover, the numerical simulations of FLPMC based on two kinds of extrusions, i.e., traditional extrusion and gas-assisted extrusion were performed and compared. Numerical results show that with the increase of traction speed, the sizes of FLPMC for both extrusions all decrease. The sizes of FLPMC based on gas-assisted extrusion are sightly larger than those of the traditional extrusion. To ascertain the reasons, the flow velocities, pressure, shear stress and first normal stress difference distributions of melt based on both extrusions under two different traction speeds were obtained and compared. Results show that with the increase of traction speed under the fixed volume inlet flow rate, the radial flow velocities of melt at the outlet of die decrease but the axial flow velocities increase, which results in the decrease of the die swell at the outlet of die and the size shrinkage of exit face for the FLPMC based on both extrusions. However, for the gas-assisted extrusion, the axial velocities are larger, and the pressure, shear stress and first normal stress difference are far less than those of traditional extrusion, which results in the larger unit volume flow rate, then the sizes of cross-section face are larger than those of the traditional extrusion.

Metal-organic frameworks are compounds with a reticulated skeletal structure formed by chemically bonding inorganic and organic units that are widely used in many fields, such as photocatalysis, gas separation and energy storage, because of their unique structures. In this paper, we prepared a metal-organic framework [(μ2-2-methylimidazolyl)12-Zn(ii)6-H18O10]n(ZM) with well-developed pores and high specific surface area of MOFs by the solution method. And MOF-derived porous carbon was prepared by the direct charring method in an argon atmosphere using a mixture of ZM, ZM and potassium citrate as carbon precursors. Characterization analysis revealed that the maximum specific surface area of ZMPC-800-1:15 was 2014.97 m2⋅g−1, and the pore size structure was mainly mesoporous. At a current density of 1.0 A⋅g−1 the specific capacitance of ZMC-800 and ZMPC-800-1:15 was 121.3 F⋅g−1 and 226.6 F⋅g−1, respectively, with a substantial increase of 86.8%. The specific capacitance of ZMPC-800-1:15 decays to 168.8 F⋅g−1, with a decay rate of 25.5%, when the current density increases to 10.0 A⋅g−1. After 5000 constant current charge/ discharge cycles, the capacitance retention rate was still 96.41%. These results prove that the application of MOF-derived carbon materials in future supercapacitors is very promising.

An automated platform for diffraction experiments at room temperature for the study of macromolecular structures and dynamics with important biological significance is reported here. This platform preserves the virgin quality of crystal samples and requires low sample consumption., Direct observation of functional motions in protein structures is highly desirable for understanding how these nanomachineries of life operate at the molecular level. Because cryogenic temperatures are non-physiological and may prohibit or even alter protein structural dynamics, it is necessary to develop robust X-ray diffraction methods that enable routine data collection at room temperature. We recently reported a crystal-on-crystal device to facilitate in situ diffraction of protein crystals at room temperature devoid of any sample manipulation. Here an automated serial crystallography platform based on this crystal-on-crystal technology is presented. A hardware and software prototype has been implemented, and protocols have been established that allow users to image, recognize and rank hundreds to thousands of protein crystals grown on a chip in optical scanning mode prior to serial introduction of these crystals to an X-ray beam in a programmable and high-throughput manner. This platform has been tested extensively using fragile protein crystals. We demonstrate that with affordable sample consumption, this in situ serial crystallography technology could give rise to room-temperature protein structures of higher resolution and superior map quality for those protein crystals that encounter difficulties during freezing. This serial data collection platform is compatible with both monochromatic oscillation and Laue methods for X-ray diffraction and presents a widely applicable approach for static and dynamic crystallographic studies at room temperature.

During the manufacture of plastic micro-pipe, a certain volume of gas should be properly injected into the inner cavity to overcome the collapse and adhesion problems. In this work, the extrusion forming of plastic micro-tube under the role of inner cavity’s gas were numerically studied. At the same time, the effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-pipe was also numerically investigated by using the finite element method. A kind of 2D two-phase fluid geometric model and finite element mesh were established and some reasonable boundary conditions and material parameters were imposed. Under a fixed volume flow rate of melt, different flow rates of inner cavity gas were imposed on the inlet of inner cavity’s gas. The extrusion deformation profile and deformation ratio of plastic micro-pipe under different flow rates of gas were all obtained. To ascertain the mechanisms of effect of inner cavity’s gas flow rate on the extrusion deformation of plastic micro-tube, the flow velocities, pressure, shear rate, normal stress, and the first normal stress difference of melt all obtained and analyzed. Numerical results show that with the increase of inner cavity’s gas flow rate, the radial velocity, axial velocity, pressure, shear rate, normal stress, and the first normal stress difference of melt all increase, which makes the extrusion deformation become more and more serious. In practice, reasonable controlling of the inner cavity’s gas flow rate is very important. In the other hand, it can adjust the size of extruded plastic micro-pipe.

To ascertain the influence of gases temperature on the viscosity and flow velocity of melt in the gas-assisted extrusion forming of plastic micro-tube, the three phase fluid geometric model was established and the finite element numerical simulation method was used in this paper. In the simulations, four different assisted-gases temperatures were imposed on the inlet boundaries of inner and outer assisted gas layers. Under a certain inlet volume flow rate of melt and assisted gases, as well as the thermal boundaries conditions, the numerical results about the effect of gases temperature on the viscosity and flow velocity of melt for the gas-assisted extrusion forming of the plastic micro-tube were obtained. Results show that with the increase of gases temperature, the viscosity distribution of melt in the radial direction of die channel decreases. However, at the axial direction of die channel, when the gases temperature is less than that of the melt, the viscosity of melt increases first and then decreases finally increases outside of die. When the gases temperature is larger than that of melt, the viscosity of melt decreases first and then increases finally increases outside of die. In addition, the flow velocity of melt increases with the gases temperature.

The non-invasive detection of blood glucose based on photoacoustic spectroscopy is a very popular method used to monitor the diabetes mellitus in recent years. The basic mechanism of photoacoustic spectroscopy is the effect of photo-induced ultrasonic. The detection accuracy of blood glucose can be improved due to the captured ultrasonic rather than the photons. The properties of ultrasonic transducer is one of the important influence factors on the detection accuracy of glucose. To study the effect of detection frequency for ultrasonic transducer on the glucose detection based on photoacoustic spectroscopy, a set of photoacoustic detection system was established. The optical parameters oscillator (OPO) pulsed laser pumped with 532nm was used as the excitation light source. Three kinds of ultrasonic transducers with different central echo frequencies (1MHz, 2.5MHz, and 30MHz) were respectively used to capture the photoacoustic signal of test blood phantoms with different concentrations of glucose. The time-resolved photoacoustic signal and peak-to-peak values of test blood phantoms were obtained. The results show that with the increase of glucose concentration, the photoacoustic amplitudes and peak-to-peak values of phantoms increase. Moreover, the time of photoacoustic signal shifts left with the increase of concentration. The prediction models based on linear fitting method were established for three kinds of ultrasonic transducers. Prediction results show that for the ultrasonic transducer with central frequency of 1MHz, the correction coefficient is 0.8681, the root-mean-square error (RMSE) of glucose concentration is about 13.3%. For the ultrasonic transducer with central frequency of 2.5MHz, the correction coefficient is 0.83127, the RMSE of glucose concentration is about 1.8149%. For the ultrasonic transducer with central frequency of 30MHz, the correction coefficient is 0.99598, the RMSE of glucose concentration is about 0.3808%. Therefore, the detection effect of the ultrasonic transducer with central frequency of 30MHz is best compared with the two others.

Many microorganisms can harvest energy from sun light to establish electrochemical potential across cell membrane by pumping protons outward. Light driven proton pumping against a transmembrane gradient entails exquisite electronic and conformational reconfigurations at fs to ms time scales. However, transient molecular events along the photocycle of bacteriorhodopsin are difficult to comprehend from noisy and inconsistent electron density maps obtained from multiple experiments. A major challenge arises from the coexisting intermediate populations as a heterogenous conformational mixture continuously evolves over 13 decades in time. This study reports a meta-analysis of the recent time-resolved datasets collected by several consortia. By resolving structural heterogeneity, this in-depth analysis substantially improves the quality of the electron density maps, and provides a clear visualization of the isolated intermediates from I to M. The earliest photoproducts revealed by the deconvoluted maps suggest that a proton transfer uphill against 15 pH units is accomplished by the same physics governing the tablecloth trick. While the Schiff base is displaced at the beginning of the photoisomerization within ~30 fs, the proton stays due to its inertia. This affinity-independent early deprotonation builds up a steep proton concentration gradient that subsequently drives the directional proton conductance toward the extracellular medium. This mechanism fundamentally deviates from the widely adopted notion on multiple steps of chemical equilibrium driven by light-induced changes of proton affinity. The method of a numerical resolution of concurrent events from mixed observations is also generally applicable.Significance StatementMicroorganisms can exploit solar energy to offset their cellular acidity from the environment by pumping protons outward under light illumination. The ability to transport ions across the cell membrane in response to light makes this family of small transmembrane proteins a highly desirable toolkit in development of new biotechnologies. It is important to understand how these ion pumps operate at the molecular level. This study finds that the outward proton conductance through bacteriorhodopsin, the most studied model system in the class, is driven by a steep concentration gradient of protons established in the light induced process rather than by an affinity gradient previously sought for decades.Summary of RevisionThis is the companion manuscript of another paper already published in PNAS Nexus (Ren, Photoinduced isomerization sampling of retinal in bacteriorhodopsin, PNAS Nexus, 1(3), 2022, 10.1093/pnasnexus/pgac103). The original version of this manuscript was submitted to PNAS Nexus on February 18, 2022. The manuscript was reviewed by three reviewers and the Decision Notification was received on April 5, 2022. I appealed the decision to reject the manuscript on May 28, 2022, and the appeal was accepted. A revised version of the manuscript was submitted on July 25, 2022, with an extensive response to the peer review. The editor sent the revised version and the response to peer review back to the three reviewers. Reviewer 3 declined to review the revised manuscript. The editor extended the invitation to several other scientists to review the revised manuscript. All of them declined to review. The second Decision Notification based on the opinions of Reviewers 1 and 2 was received on September 14, 2022. The revised manuscript, the supplementary materials, and all review documents are listed below in the Table of contents. Second revision is underway.

With the development in additive manufacturing, the use of surface treatments for gas turbine design applications has greatly expanded. An experimental investigation of the pressure loss and heat transfer characteristics within impingement jet arrays with arrays of target surface micro cooling units is presented. The discharge coefficient and Nusselt number are measured and determined for an evaluation of the pressure loss of the flow system and heat transfer level, respectively. Considered are effects of impingement jet Reynolds number ranging from 1000 to 15,000 and micro cooling units (square pin fin) height (h) with associated values of 0.01, 0.02, 0.05, 0.2, and 0.4 D, where D is the impingement hole diameter. Presented are variations of Nusselt number, and Nusselt number ratio, discharge coefficient, discharge coefficient ratio, discharge coefficient correlation. Depending upon the micro cooling unit height, discharge coefficient ratios slightly decrease with height, and the ratio values generally remain unit value (1.0). When Rej = 1000 and 2500 for several cooling units height values, discharge coefficient ratios show the pressure loss decreases about 2–18% and 3–6%, respectively, when compared to the data of a baseline smooth target surface plate. The observed phenomenon is due to the effects of flow blockage of micro cooing units, local flow separation, and near-wall viscous sublayer reattachment. Results also show that heat transfer levels increase 20–300% for some of the tested toughened target surface plates when compared to smooth target surface plates. The heat transfer level enhancement is because of an increase in thermal transport and near-wall mixing, as well as the increased wetted area. In addition, micro cooling units elements break the viscous sublayer and cause greater turbulence intensity when compared to the smooth target surface. Overall, results demonstrate that the target surface micro cooling units do not result in a visible increment in pressure loss and reduce pressure loss of the flow system for some of the tested patterns. Moreover, results show the significant ability of micro cooling units to enhance the surface heat transfer capability of impingement cooling relative to smooth target surfaces.

Upon performing electrochemical measurements, XPS and TEM characterizations, the influence of sulfide on the passive behavior of Super 13Cr martensitic stainless steel was deciphered. Mechanism interpretation is performed by optimizing the Point Defect Model based upon the impedance data. It is revealed that the passive film display n-type semiconductivity, and the donor density dropped with increasing concentration of sulfide ion. Sulfide ion can induce a current peak at −250 mVSCE (Epeak). The addition of Na2S generates a continuous outer layer which is comprised of Cr(OH)3, FeS2 and FeS at potential lower than Epeak, and Cr(OH)3 at potential higher than Epeak. This result leads to the thinner barrier layer and lower charge transfer resistance, implying a weaker protection of the substrate by the passive film.

In this study, to eliminate the extrudate swell, melt fracture and extrudate distortion problems of polypropylene (PP) micro-tube, the experiments of gas-assisted extrusion forming was firstly carried out. Meanwhile, a set of modified gas-assisted extrusion system was set-up, and a kind of novel gas-assisted die was also designed and manufactured. Under the role of gas-assisted extrusion system, PP micro-tubes were successfully prepared. Moreover, the macroscopic and microscopic qualities of PP micro-tubes for gas-assisted extrusion were obtained and compared with those of the traditional extrusion. Experimental results show that gas-assisted extrusion not only overcomes extrudate swell, but also greatly improves the smoothness and transparency of PP micro-tube. In addition, to ascertain the mechanisms of gas-assisted extrusion of PP micro-tube, numerical simulations were also performed. The swell ratios, flow velocities, pressure and stresses distributions of melt for gas-assisted extrusion and traditional extrusion were analyzed and compared. Moreover, the effects of inner cavity’s gases pressures and traction force on the gas-assisted extrusion of PP micro-tube were numerically investigated and discussed with the traditional extrusion. Numerical results show that the swell ratio of PP micro-tube increases with the inlet volume flow rate for traditional extrusion, but it is nearly equal to 0 for the gas-assisted extrusion. Moreover, due to the assistance of gas-layers, not only the axial flow velocity of melt is uniformed and radial flow velocity is removed, but also the pressure, shear stress and first normal stress difference of melt are all greatly reduced, especially at the outlet of die. These weakened pressure and stresses diminish the elastic energy storage and tensile stress of melt, and finally result in the elimination of extrudate swell, melt fracture and extrudate distortion. With the increase of inner cavity’s pressure, the inner and outer radiuses of the gas-assisted extrusion of PP micro-tube all increase, but the wall thickness decreases because the swell ratios of inner radius are all larger than that of the outer radius. In addition, under the same traction force, the sizes of gas-assisted extrusion of PP micro-tube are smaller than that of the traditional extrusion, although the sizes for the both extrusions of PP micro-tube all exponentially decrease with the increase of traction force. Moreover, the extrudate radial swell and melt fracture problems for the traditional extrusion are always existed at the outlet of die although the radial swell of melt decreases with the increase of traction force. However, the extrudate swell and melt fracture problems are greatly removed by the gas-assisted extrusion.

Bilayer polymer coatings that consisted of a highly cross-linked polyethylene glycol diacrylate (PEGDA) bottom layer and nanostructured poly(perfluorodecyl acrylate-co-ethylene glycol diacrylate) (P(PFDA-co-EGDA)) top layer were synthesized via a single-step vapor deposition method. The vapor-synthesized PEGDA single-layer film exhibits excellent barrier performance with oxygen permeability of 0.0066 Barrer, which is more than 16-fold smaller than that of commercial PET packaging film. The P(PFDA-co-EGDA) layer, grown on top of PEGDA, shows conical array structure. Such nanostructure combined with the low surface energy of PFDA moiety enables superhydrophobicity of the coating with water contact angle of 159°. The achieved superhydrophobicity is stable over more than 168 h upon immersion in NaCl solution. The bilayer coating structure imparts a synergistic effect to minimize both the diffusion of water and ions and permeation of oxygen, resulting in a significant drop of corrosion rate to 2.19 × 10−7 mm year−1, a more than 104-fold decrease compared to bare copper.

In order to accurately and non-destructively identify the true or fake of blood, the photoacoustic spectroscopy technique was used in this paper. Meanwhile, a kind of custom-built photoacoustic spectroscopy detection system was established. In this system, a 532nm pumped OPO pulsed laser was used as the excitation source, and a focused ultrasonic detector with central echo frequency of 2.5MHz was used to capture the photoacoustic signals of the blood samples. In experiments, five kinds of different blood samples, i.e, three kinds of animal blood, and two kinds of fake blood (props blood and red ink) was used as the experimental blood samples. The sample groups were 125, the train samples were 100 groups, the test samples were 25 groups. The photoacoustic signals and peak-to-peak values of all blood samples were obtained. To distinct accurately the blood, two different algorithms, i.e,, PCA-KNN, and BP-GA were used. The photoacoustic peak-to-peak values were used as the input data. For PCA-KNN, the distinction correct rate of five kinds of blood is 96%, which is larger than that of the KNN (88%). For the BP-GA, the distinction correct rate of five kinds of blood is 100%. Therefore, the photoacoustic spectroscopy combined with artificial intelligence algorithms have the significant values in the distinction can classification of blood

In the work, a set of photoacoustic detection system of glucose based on different influence factors was established. In the system, a kind of Nd: YAG pumped 532nm OPO pulsed laser was used as the excitation source, and a focusing ultrasonic transducer with central frequency of 9.5MHz was used to capture the photoacoustic signals of glucose. In the experiments, the time-resolved photoacoustic signals and peak-to-peak values of glucoses with different concentrations and other three factors (temperature, excitation energy, and flow velocity) were obtained by using the orthogonal experiment method. To precisely predict the photoacoustic peak-to-peak values and glucose concentrations, the back propagation neural network (BPNN) was used to build a nonlinear models between the multiple factors and the photoacoustic peak-to-peak values and glucose concentrations. In BPNN, 108 train samples and 36 test samples were used. To further improve the prediction accuracy, BPNN combined with intelligent optimization algorithms, i.e., genetic algorithm (GA) and particle swarm optimization (PSO) algorithms were used. At the same time, the parameters adjusting for all algorithms were performed. Results show that the prediction root-mean-square error (RMSE) values of peak-to-peak values and glucose concentration were all improved, the RMSE of peak-to-peak values improve 19.9%, and the RMSE of glucose concentrations improve 34.62%. Therefore, it is found that the BPNN combined with intelligent optimization algorithms has an efficient effect on the prediction of photoacoustic detection for glucose concentration.

The present study investigates flow and heat transfer characteristics in a rotor-stator pre-swirl system. Considered are rotational Reynolds numbers ReФ ranging from 3.4 × 105 to 6.8 × 105, with jet Reynolds numbers Rew of approximately 8.8 × 104 to 3.81 × 105, and associated turbulent flow parameter λT = Cw/ReФ0.8 varying from 0 to 0.4. Experimentally-measured and numerically-predicted results illustrate the combined and separate influences of jet impingement and rotor entrainment, as they affect and govern flow and heat transfer characteristics within the cavity. These results show that the relative strength of the two effects varies with ReФ and Rew, with similar performance for flow conditions with similar magnitudes of the turbulent flow parameter λT. When 0 0.27, the effects of rotor entrainment are less pronounced.

The effects of four difference viscoelastic constitutive parameters, i.e., viscosity, relaxation time, ε and ξ on the extrudate swell of plastic micro-tubes were studied by using the numerical method. Numerical results show that the extrudate swell of plastic micro-tube increases with the increase of the relaxation time, but decreases with the increase of ε and ξ. In addition, the extrudate swell ratio of plastic micro-tube is not changed with the increase of the viscosity of melt. To ascertain the effect of four different viscoelastic constitutive parameters on the extrudate swell of plastic micro-tube, the physical field distributions, i.e., flow velocity, shear rate, shear stress, and first normal stress difference distributions of melt were obtained, respectively. Results show that the extrudate swell phenomenon of plastic micro-tube is closely dependent on the elastic energy storage of melt induced by the above mentioned physical field distributions, especially at the outlet of die.

In this paper, the photoacoustic detection of aqueous solutions mixed glucose and salt was experimentally studied based on the established photoacoustic detection system in the lateral mode. In the experimental system, the OPO pulsed laser was used as the excitation light source and the non-focused ultrasonic transducer was used to capture the photoacoustic signals. In the experiments, the test mixed aqueous solutions with different concentrations of glucose and salt were prepared by using the pure water. The time-resolved photoacoustic signals and photoacoustic peak-to-peak values of mixed aqueous solutions with different concentrations of glucose and salt were acquired with the average times of 128. Results show that the photoacoustic peak-to-peak values of mixed aqueous solutions increase with the increase of glucose concentration and salt concentration. At the same time, the ultrasonic velocity in the mixed aqueous solutions increases with the increase of glucose and salt concentrations. To better predict the glucose concentration in the mixed aqueous solutions, a kind of modified glucose concentration prediction models combined the photoacoustic peak-to-peak values with the ultrasonic velocity were established under the different concentrations of salt. The root-mean-square error (RMSE) of models were obtained and compared with the individual models of photoacoustic peak-to-peak value or the ultrasonic velocity. The prediction results show that the prediction RMSE values of modified model are less than that of the individual models, the RMSE value of predicted glucose concentration under 100mg/dl concentration of salt is about 8.75mg/dl.

A hybrid diamond/silicon air-clad ridge waveguide platform is demonstrated. The air-clad structure coupled with the wide transmission window of diamond can allow for the use of this architecture over a large wavelength range, especially for the longer infrared wavelengths. In order to provide vertical confinement, the silicon substrate was isotropically etched using S F6 plasma to create undercut diamond films. An in-depth analysis of the etch characteristics of this process was performed to highlight its potential to replace wet isotropic etching or XeF 2 isotropic vapour phase etching techniques. The performance of the waveguide at 1550 nm was measured, and yielded an average loss of 4.67 +/- 0.47 dB/mm.

Determination of blood glucose characteristic absorption wavelengths is one of most important steps in the photoacoustic measurement of diabetes mellitus. In this paper, a kind of custom-built photoacoustic measurement system of glucose solutions based on OPO pulsed laser and ultrasonic detector with central frequency of 10MHz was established. The photoacoustic peak-to-peak values of glucose solutions with six different concentrations were obtained under the scanning wavelengths from 1300 nm to 2300nm. To obtain the characteristic wavelengths of glucose, the differential spectrals between the photoacoustic peak-to-peak spectrals with different concentrations and that of the pure water were firstly gotten. Then, the synergy interval partial least square (siPLS) algorithm was used to optimally choose the characteristic wavelengths of glucose. The mean method was used to pre-process the photoacoustic peak-to-peak data. The photoacoustic peak-to-peak spectrals of glucose were divided into different sub-intervals, and different components and different segments were chosen. In addition, different synergies of sub-intervals were test to get the maximum correction coefficients for the calibration samples. After computing and compare with each other, 30 sub-intervals, 7 components, 4 segments, and 3 synergies sub-intervals were chosen because the root mean square error of cross validation (RMSECV) and the prediction bias are least. Finally, combined with the differential spectral, the optimal characteristic absorption wavelengths of glucose were determined.

The present study provides new heat transfer data for both the surfaces of the full coverage effusion cooling plate within a double wall cooling test facility. To produce the cooling stream, a cold-side cross-flow supply for the effusion hole array is employed. Also utilized is a unique mainstream mesh heater, which provides transient thermal boundary conditions, after mainstream flow conditions are established. For the effusion cooled surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). For the coolant side, presented are spatially-resolved distributions of surface Nusselt numbers (measured using liquid crystal thermography). Of interest are the effects of streamwise development, blowing ratio, and Reynolds number. Streamwise hole spacing and spanwise hole spacing (normalized by effusion hole diameter) on the effusion plate are 15 and 4, respectively. Effusion hole diameter is 6.35 mm, effusion hole angle is 25°, and effusion plate thickness is 3 hole diameters. Considered are overall effusion blowing ratios from 2.9 to 7.5, with subsonic, incompressible flow, and constant freestream velocity with streamwise development, for two different mainstream Reynolds numbers. For the hot side (mainstream) of the effusion film cooling test plate, results for two mainflow Reynolds numbers of about 145000 and 96000 show that the adiabatic cooling effectiveness is generally higher for the lower Reynolds number for a particular streamwise location and blowing ratio. The heat transfer coefficient is generally higher for the low Reynolds number flow. This is due to altered supply passage flow behavior, which causes a reduction in coolant lift-off of the film from the surface as coolant momentum, relative to mainstream momentum, decreases. For the coolant side of the effusion test plate, Nusselt numbers generally increase with blowing ratio, when compared at a particular streamwise location and mainflow Reynolds number.

Recent developments in serial crystallography at X-ray free electron lasers (XFELs) and synchrotrons have been driven by two scientific goals in structural biology – first, static structure determination from nano or microcrystals of membrane proteins and large complexes that are difficult for conventional cryocrystallography, and second, direct observations of transient structural species in biochemical reactions at near atomic resolution. Since room-temperature diffraction experiments naturally demand a large quantity of purified protein, sample economy is critically important for all steps of serial crystallography from crystallization, crystal delivery to data collection. Here we report the development and applications of “crystal-on-crystal” devices to facilitate large-scale in situ serial diffraction experiments on protein crystals of all sizes – large, small, or microscopic. We show that the monocrystalline quartz as a substrate material prevents vapor loss during crystallization and significantly reduces background X-ray scattering. These devices can be readily adopted at XFEL and synchrotron beamlines, which enable efficient delivery of hundreds to millions of crystals to the X-ray beam, with an overall protein consumption per dataset comparable to that of cryocrystallography.

In this work, N-tetradecyl-isopropanolamine (NTIA) is synthesized and used as a new collector on the flotation separation process of scheelite from calcite to further improve the efficiency of the selective flotation. The effects of NTIA on minerals are investigated through microflotation experiments. Flotation experimental results show that NTIA provides good flotation and separation effects on the scheelite in a wide range of pulp pH (6.0–10.0). At pH 7.0, the flotation recovery of scheelite reaches 96.89%, while calcite to only 10%. Moreover, it also reveals an efficient separation effect for artificial mixed minerals of scheelite and calcite under certain conditions. The adsorption behavior of NTIA on scheelite is further studied using wettability test, infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and zeta potential analysis. The results demonstrate that the surface of scheelite is preferentially modified, increasing its hydrophobicity after treatment with NTIA. Meanwhile, under the action of hydrogen bonding and strong electrostatic field in the hydrophilic N–H group of NTIA, the NTIA molecules are absorbed on the scheelite surface.

Previously, optimal eccentric parameters were considered to be greatly overall size- dependent, but the inherent factor haven’t been determined. In this study, we suggest that areas above and below inner tube may be the core factor, based on this, “eccentric space ratio” is proposed to explore the thermal behavior of phase change material in different radius ratio models. The results indicate the melting period can be shortened by more than 40% between 4:1 and 14:1, as is generally valid for different radius ratios. Additionally, the solidification can be shortened consistently by more than 45% between 1:4 and 1:14 in large radius ratios models which breaks the previous consensus, but still extended for small radius ratios models. Remarkably, optimal eccentric range in solidification is symmetrical with that in melting. With these numerical and mechanistic analyses, we find that areas above and below inner tube can significantly influence natural convection and temperature distribution, while, as a simple approximation, “eccentric space ratio” is well employed to analyze the area effect irrespective of diameters. Further, this analysis strategy provides a robust optimal eccentric parameter range for phase change heat exchangers and can be widely applied in rapid latent heat storage.

The present investigation considers the effects of special roughness patterns on impingement target surfaces to improve the effectiveness and surface heat transfer augmentation levels of impingement jet array cooling. This investigation utilizes various sizes, distributions, shapes, and patterns of surface roughness elements for impingement cooling augmentation. The surface roughness shape considered here is rectangle, in combination with larger rectangular pins. Combinations of small rectangle roughness and large pins are considered together, along with arrays of small rectangular roughness alone. Tests are performed at impingement jet Reynolds numbers of 900, 1500, 5000, and 11,000. Local and overall impingement cooling performance depends upon the pattern, distribution, arrangement, and height of the roughness elements, as well as upon the jet Reynolds number. Depending upon the magnitude of jet Reynolds number, different behavior and trends are observed for the small rectangle roughness and large pins together, compared with arrays of small rectangular roughness alone. Overall, results demonstrate the remarkable ability of target surface roughness to produce increased surface heat transfer augmentation levels of impingement jet array cooling, relative to target surfaces which are smooth.

The cathode material LiFePO4/C composites were synthesized by solid-phase method using cheap and extensive FePO4 as iron ingredients and glucose as carbon source. The synthesis conditions were studied by changing the calcined temperatures and the ratio of lithium. The results show that the LiFePO4/C composite synthesized at 600 °C for 10 h exhibits the most homogeneous particle size distribution and excellent electrochemical properties. And it exhibits a specific discharge capacity of 127 mA h/g at 1 C.

PBO fiber is a kind of super fibers which has both high tension strength and high modulus. After the heat-treatment procedure, the PBO fiber would present more perfect mechanical properties. The process route of heat-treatment on as-spun fibers (PBO-AS fibers) was optimized, and the obtained high modulus fibers (PBO-HM fibers) were tested and characterized by SEM, XRD, XPS, FT-IR and Universal material machine. The higher the temperature is, the shorter the heat treatment time required for the same heat treatment. And the most preferred procedure in the air atmosphere of heat-treatment was 550°C with the resident time of 32 s and the pre-stress of 2.35 cN/dtex. After the heat-treatment, the modulus of PBO-HM grew up to 229.4 GPa (1487.78 cN/dtex). The tensile strength would not be greatly decreased, if the fiber could be kept in the nitrogen atmosphere. Besides, the XRD data and the XPS data proved that after the heat-treatment, the crystal size and the crystallinity would have a huge growth and the content of phosphorus element on the surface of PBO-HM fibers would fall sharply.

Pressure-sensitive phenoxy-imine titanium catalyst (FI-catalyst) was successfully synthesized by covalently immobilizing it on the surface of functionalized polystyrene (PS) nanoparticles, which acted as a support and a giant ligand simultaneously. The supported catalyst shows high catalytic activities in ethylene polymerization. Utilizing this catalyst, a serious of unimodal polyethylenes with tailored molecular weights ranging from 2 000 000 to 300 000 were produced under various reaction pressures and temperatures. Particularly, when the polymerization pressure was shifted during the reaction, the ethylene polymer with bimodal molecular weight distribution was successfully synthesized in only a single reactor. Differential scanning calorimetry analysis of the resultant polyethylene revealed a large difference between crystallinities at the first and second heating cycles, indicating that the synthesized polyethylene is of low entanglement.

The present investigation considers the effects of special roughness patterns on impingement target surfaces to improve the effectiveness and surface heat transfer augmentation levels of impingement jet array cooling. This investigation uses various sizes, distributions, shapes, and patterns of surface roughness elements for impingement cooling augmentation. The surface roughness shapes considered here are the rectangle and triangle, in combination with larger rectangle roughness. The configurations considered include 1) arrays of small rectangle roughness, 2) arrays of small triangle roughness, 3) combinations of small rectangle roughness and large roughness together, and 4) combinations of small triangle roughness and large roughness together. Tests are performed at impingement jet Reynolds numbers of 900, 1500, 5000, and 11,000. Local and overall impingement cooling performance depends upon the shape of the roughness elements, as well as upon the jet Reynolds number. Depending upon the magnitude of the...

The present investigation considers special small-scale roughness patterns on impingement target surfaces to increase surface heat transfer augmentation levels of impingement jet array cooling. Utilized are three different heights of cylinder small roughness elements, which are mounted on three different test surfaces. The cylinder-shaped roughness is small-scale because diameter is 7.5 percent and maximum height is 25 percent of impingement hole diameter. Associated results are compared with spatially-averaged Nusselt number ratio distributions measured on target surfaces with triangle small roughness, or rectangle small roughness. Data are obtained for impingement jet Reynolds numbers of 900, 1500, 5000, and 11,000. Nusselt number variations for the small cylinder roughness show different trends with streamwise development and changing roughness height, compared to target plates with small rectangle roughness and small triangle roughness. In general, this is because roughness elements which contain surface shapes with sharp edges generate increased magnitudes of vorticity with length scales of the order of the roughness element diameter. Such generation is not always present in an abundant fashion with the small cylinder roughness because of the smooth contours around each roughness element periphery. Such effects are illustrated by several data sets, including Nusselt numbers associated with the small cylinder roughness with a height of 0.250D at a turbulent Reynolds number of 11,000.

Using the material testing machine of electro-hydraulic servo fatigue tests had been carried out on ordinary concrete and steel fiber reinforced concrete. The fatigue life, strength, stress and strain had been measured under tension and compression loading. The variation of fatigue was analyzed based on the test results. Having regression analysis, obtained the fatigue strength. Mean-while, the fatigue strain-life curves of ordinary concrete and steel fiber reinforced concrete had been made after data processing. The results had been showed that the fatigue property of steel fiber reinforced concrete was significantly higher than that of ordinary concrete. And the fatigue strength increased about 32.6% compared with ordinary concrete. The tensile and compressive fatigue strain were slightly smaller than that of ordinary concrete.

Direct visualization of electronic and molecular events during chemical and biochemical reactions will offer unprecedented mechanistic insights. Ultrashort pulses produced by X-ray free electron lasers (XFELs) offer an unprecedented opportunity for direct observations of transient events as short-lived as tens of femtoseconds. This paper presents an in-depth analysis of the serial crystallographic datasets collected by Barends & Schlichting et al. (Science 350, 445, 2015) that probe the ligand photodissociation in carbonmonoxy myoglobin (MbCO), a long-serving hallmark for observing ultrafast dynamics in a biological system. This analysis reveals electron density changes that are caused directly by the formation of high-spin 3datomic orbitals of the heme iron upon the CO departure and the dynamic behaviors of these newly formed orbitals in a time series within the first few picoseconds. The heme iron is found vibrating at a high frequency and developing a positional modulation that causes the iron to pop out of and recoil back into the heme plane in succession. These findings here provide long-awaited visual validations for previous works using ultrafast spectroscopy and molecular dynamics simulations. This analysis also extracts electron density variations largely in the solvent during the first period of a low frequency oscillation previously detected by coherence spectroscopy. This work demonstrates the power and importance of the analytical methods in detecting and isolating transient, often very weak signals of electronic changes arising from chemical reactions in proteins.SummaryDirect imaging of ultrafast and subtle structural events during a biochemical reaction, such as a single electronic transition from one atomic or molecular orbital to another, is highly desirable but has been beyond the reach of protein crystallography. It entails the capability of observing changes in electronic distributions at both an ultrafast time scale and an ultrahigh spatial resolution (Itatani et al., Nature 432, 867, 2004). The recent developments in femtosecond serial crystallography at X-ray free electron lasers (XFELs) have brought the achievable temporal resolution within a striking distance. This paper presents the electron density map decomposed from the XFEL data that shows the remanence of several 3datomic orbitals of the heme iron at an available spatial resolution although the map component is not an accurate image of the atomic orbitals. A key strategy that has enabled the findings here is a numerical deconvolution to resolve concurrent variations in a series of time-resolved electron density maps so that the electron densities influenced by an electron transfer event can be isolated as a partial change from the overwhelming presence of the bulk electrons that are not directly involved in bonding. Even at the limited spatial resolution, the subtle changes in electron distribution due to a spin crossover can be decoupled from far greater changes due to atomic displacements. Direct observations of electronic orbitals could offer unprecedented mechanistic insights into a myriad of chemical and biochemical reactions such as electron transfer in redox reactions, and formation, rupture, and isomerization of chemical bonds.Ligand photodissociation in carbonmonoxy myoglobin (MbCO) has been a benchmark for studying ultrafast protein dynamics in a biological system. A number of studies in time-resolved crystallography have progressively improved the time resolution (from Šrajer et al., Science 274, 1726, 1996 to Barends et al., Science 350, 445, 2015). This paper presents an in-depth analysis of the serial crystallographic datasets of MbCO that Barends & Schlichting et al. (2015) contributed to the Protein Data Bank. First, a component of electron density distributions clearly shows the characteristic shape of the high-spin 3dorbitals reappeared at the heme iron upon the photodissociation of the CO ligand despite the limited accuracy of the orbital image due to the available spatial resolution. Second, the dynamic behaviors of these newly regained 3dorbitals within picoseconds after the photolysis provide long-awaited structural validation for previous spectroscopic observations and computational simulations. Specifically, the newly formed densities are oscillating with the heme iron at a high frequency of a thousand wavenumbers and developing a positional modulation during the first few picoseconds (Champion, Science 310, 980, 2005). The iron pops out of the heme plane at a few picoseconds and recoils back and pops out again afterwards. The dominant oscillation at a low frequency of several tens wavenumbers previously detected by coherence spectroscopy can be clearly resolved from the time series of electron density maps. The associated changes in electron density during the first cycle of the oscillation are largely located in the solvent rather than on the protein or heme, which suggests that the low frequency oscillations in a number of heme proteins, including MbCO, likely originate from a photolysis triggered pressure wave propagating in the solvated protein. Finally, these findings of chemical signals are isolated from coexisting thermal artifacts also by the numerical deconvolution. It is modeled in this study that the ultrashort XFEL pulses cause a transient spike of the local temperature at the heme site of hundreds of K.

The non-invasive detection of blood glucose with the photoacoustic technique has attracted many attentions in the world. To study the effects of multiple factors on the photoacoustic detection of glucose, a Nd: YAG 532nm pumped optical parameters oscillator (OPO) pulsed laser induced photoacoustic detection system were established in this paper. The lateral model was used to capture the photoacoustic signals of glucose by using the ultrasonic transducer. In the system, several components about the effects of the influence factors were considered and designed. In the experiments of glucose aqueous solutions, the photoacoustic experiments about four different influence factors, i.e., concentrations, temperatures, laser energies and flow velocities were performed. Not only the relationships between each factor and the photoacoustic detection of glucose were built, but also the coupled relationship model between the multiple factors on the concentration of glucose was also established by using the partial least square algorithm. Results show that the photoacoustic peak-to-peak value of glucose linearly increases with the glucose’s concentration, laser’s energy and temperature, but decreases with the increasing of flow velocity. Moreover, the glucose concentration prediction accuracy is improved with the increasing of laser’s energy. At the same time, it was found that the influences of glucose concentration and laser energy on the photoacoustic detection of glucose are larger than that of the temperature and flow velocity. Finally, the concentration prediction model of coupled several factors has good prediction effect.

Glucose detection by means of the photoacoustic spectroscopy was performed in this paper. A set of photoacoustic detection system of glucose based on pulsed laser induced ultrasonic detection was established. Based on the photoacoustic system, a series of photoacoustic detection experiments for glucoses with different concentrations were performed. The time-resolved photoacoustic signals and photoacoustic peak-to-peak values of glucose under the excitation wavelengths of pulsed laser from 1300nm-2300nm were obtained. In order to get the optimal absorption wavelengths of glucose, the difference spectrum of photoacoustic peak-to-peak values between the glucoses and the pure water were used. At the same time, the interval partial least square algorithm was used to get the optimal absorption wavelength regions. The integrated wavelength region was divided into 10-15 sub-regions. For each sub-region, the model of partial least square was established, and the cross-validation method was also used. Results show that the wavelength regions of 1350-1440nm and 1490-1550nm are the optimal characteristic wavelength region. The prediction models were established in the optimal wavelength regions, four components of the partial least square algorithm were used. In the chosen optimal wavelengths, the correction coefficient between the glucose predicted concentration and original concentration can reach 0.9879 and 0.9969, respectively, the root mean square error of cross validations (RMSECV) are about 12.5mg/dl and 6.2mg/dl, respectively, the concentration bias is about 0.0581mg/dl, and 2.09mg/dl, respectively.

Experimentally measured results are presented for different experimental conditions for a test plate with double wall cooling, composed of full-coverage effusion-cooling on the hot side of the plate, and cross-flow cooling on the cold side of the plate. The results presented are different from those from past investigations, because of the addition of a significant mainstream pressure gradient. Main stream flow is provided along a passage with a contraction ratio of 4, given by the ratio upstream flow area, to downstream flow area. With this arrangement, local blowing ratio decreases significantly with streamwise development along the test section, for every value of initial blowing ratio considered, where this initial value is determined at the most upstream row of effusion holes. Experimental data are given for a sparse effusion hole array. The experimental results are provided for mainstream Reynolds numbers of 92,400–96,600, and from 128,400 to 135,000, and initial blowing ratios of 3.3–3.6, 4.4, 5.2, 6.1–6.3, and 7.3–7.4. Results illustrate the effects of blowing ratio for the hot side and the cold side of the effusion plate. Of particular interest are values of line-averaged film cooling effectiveness and line-averaged heat transfer coefficient, which are generally different for contraction ratio of 4, compared to a contraction ratio of 1, because of different amounts and concentrations of effusion coolant near the test surface. In regard to cold-side measurements on the crossflow side of the effusion plate, line-averaged Nusselt numbers for contraction ratio 4 are often less than values for contraction ratio 1, when compared at the same main flow Reynolds number, initial blowing ratio, and streamwise location.

Currently, biometrics are widely used in recognition technology; however, biometric recognition systems are vulnerable to malicious spoofing attacks. Thus, the security of such systems requires enhancements. This paper reports a novel vascular recognition system based on simple photoacoustic imaging to resist spoofing attacks. The amplitude and the delay of the maximum-value arrival time of the photoacoustic signal were used for detecting the vascular optical absorption and depth prior to vascular imaging. The proposed photoacoustic detection system detected fake vascular biometrics and demonstrated improved recognition rates with resistance toward spoofing attacks. In addition, the recognition rate increased from 95% to 97.5% as only real vasculatures were imaged. Moreover, the results verified the feasibility of using photoacoustic images for vascular recognition. The proposed photoacoustic system is noninteracting, low cost, robust, and highly anticounterfeiting.

With the material testing machine of electro-hydraulic servo, fatigue test have been carried out on coarse aggregate concrete with pre-crack .The fatigue life and fatigue strength of the concrete have been measured under tension and compression loading. The effect of pre-crack on concrete fatigue behavior has been analyzed based on the test results. Having regression treatment, obtained the concrete S-N curve and S-lgN curve of fatigue life. Mean-while, applying ANSYS finite element software, analysis and comparison of the fatigue behavior have been performed. The results show that pre-crack has a great influence on the fatigue behavior of concrete, and the fatigue life is reduced for 75%~80%.

According to the properties of hollow square-typed polymer extrudate, the three dimensional numerical simulation of hollow square-typed polymer extrudate based on gas-assisted extrusion technology was performed by using finite element method. Meanwhile, four different gas-assisted modes imposed on the outer and inner wall of hollow square-type extrudate were considered. The extrudate swell ratios and field distributions, such as pressure drop, velocities and normal stresses of four different gas-assisted modes were obtained and compared with each other. Research results show that the extrudate swell ratios and field distributions of different gas-assisted modes are completely different. For the mode of gas-assisted on the single wall, the extrudate swell or shrink phenomena are large due to the non-symmetric properties of field distributions. For the no gas-assisted mode, although the physical field values are large, the extrudate swell ratio is not large due to the interaction role of both walls. For the mode of gas-assisted on both walls, the physical field values, such as pressure drop, normal velocities and stresses are all diminished, and the extrudate swell phenomenon was completely eliminated.

We report morphology, thermal analysis and beam diffraction of polyethylene chlorine-substituted precisely on every 21st backbone carbon, after solution crystallization induced by low-dimensional carbonaceous nanofillers (carbon nanotube and graphene). Kebab-like and rod-like nanofiller-induced crystals were separately observed on the surfaces of carbon nanotube and graphene. Fast-scan differential scanning calorimetry revealed that while the melting point of crystals grown on carbon nanotube remains close to that in the bulk phase, the melting point of crystals grown on graphene is 75 °C higher. X-ray diffraction and selected area electron diffraction suggested that graphene induces the formation of orthorhombic form, which is of higher density than the triclinic form in the bulk.

Janus particles, especially amphiphilic ones, are known to be highly active when involved in interfacial self-assembly processes. However, experimental reports on employing Janus particles as an interfacial stabilizer to establish functional structures are rather limited. In this paper, amphiphilic Janus silica particles were prepared by selective chemical treatment on the particle “colloidosomes”. Different ways (decoration of Au nanoparticles, interfacial adsorption test) were used to confirm the acquirement of the Janus character of the particles. Upon successful synthesis of amphiphilic Janus particles, they were employed in the breath figures method for the first time. It turned out that by using the Janus particles, a regularly arranged pore array could be easily obtained. Characterization of the morphology of the patterned structure shows that Janus particles were densely located on the interior wall of the entire holes, forming finer particle arrays compared to the case of isotropic particles. The result indicates that Janus particles show optimized behavior when they are involved in the interfacial self-assembly processes. With further work, by choosing Janus particles with functional features, selective functionalization of porous films could be achieved with high efficiency and great ease using this method.

Three-dimensional and morphology-tunable superstructures were produced by engineering the interactions among functional groups in organic thin films, adsorbed precursors and the formed metal nanoparticles. The type and amount of functional groups take a leading role over controlling the superstructure shape. This approach is general and promising for fabricating various metal superstructures.

Crystallization of well-defined precision polyethylene with fluorine substituent on every 21st backbone carbon (PE21F) induced by low-dimensional carbonaceous nanofillers (carbon nanotube (CNT) and reduced graphene oxide (RGO)) via solution crystallization and supercritical CO 2 assisted solution crystallization were investigated. Transmission electron microscopy was used to investigate the morphology of carbonaceous nanofiller-induced PE21F crystals. The kebab-like and rod-like crystals formed on the CNT and RGO, respectively. Selected area electron diffraction (SAED) pattern revealed that the c-axis of polymer chain is parallel to the surface of the RGO. Differential scanning calorimetry (DSC) revealed the melting temperatures (T m ) of PE21F lamellae nanocomposites increased with crystallization temperature increasing. The X-ray diffraction (XRD) results showed that the incorporation of nanofillers did not influence the crystal structure of PE21F. The chemical composition of the PE21F nanocomposites measured by X-ray photoelectron spectra (XPS) confirmed substituent F as a defect of chain was accommodated into the crystal lattice.