Apr 2025, Volume 24 Issue 6
    

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  • Tianya Tan, Jing Shan, Wei Wu, Yongxin Guo, Jianda Shao, Zhengxiu Fan

    Frequency-doubled antireflection coatings simultaneously effective at 1064 nm and 532 nm were deposited on the lithium triborate (LiB3O5 or LBO) crystals using the electron beam evaporation method. Comparing with the sample without buffer layer, it is found that the adhesion of the sample with buffer layer of SiO2 between coating and LBO substrate is improved significantly from 137.4 mN to greater than 200 mN. And the laser-induced damage threshold is increased by 20% from 15.1 J/cm2 to 18.6 J/cm2. The strengthening mechanism of adhesion of the buffer layer of SiO2 is discussed by considering full plastic indentation and shear theory.

  • Ye Li, Hui Yang, Fangming Cao, Xiaodong Zhao, Jing Wang

    The synthesized C-phycocyanins (C-PCs) doped silica biomaterials were characterized by the SEM and BET surface area analysis measurement. The morphology of C-PCs doped silica biomaterials indicates that the surface of the silica cluster is formed by a great number of silica particles with an average size of between 30 and 40 nm. Silica itself is a porous structure with the average pore diameter of 2.95 nm. Pores with their diameter less than 5 nm account for 84.07%. In addition, the C-PCs can be utilized as a fluorescent protein probe to monitor influence of the protein encapsulation and to study matrix and protein interaction and stability of protein in silica matrix. Application of protein encapsulation silica materials requires biomolecules to keep bioactivity and stability on potentially unfavorable industrial conditions. The C-PCs in solution or in silicate matrix irradiated by ultraviolet ray can result in photobleaching, whereas the protein in the silica is less affected. The measured photodamage rate constant of C-PCs in buffer solution is 25 times faster than that of C-PCs in silica matrix. However, the lifetime of C-PCs in silica matrix or phosphate buffer is unaffected. These studies suggest that entrapment of C-PCs into silica matrixes not only can maintain their biological activity but also noticeably improve their photostability.

  • Yanli Song, Lin Hua, Ben Wang

    The behavior that different magnetic treatment directions induce various amounts of welding residual stress reductions in low alloy steel was studied. Reductions of 26%–28% in the longitudinal stress σ x were obtained when low frequency alternating magnetic treatment was applied perpendicularly to the welding bead, whereas reductions of 20%–21% in σ x were measured by using the same treatment parameters except that the field direction was applied parallel to the bead. It is proposed that different extent of stress reductions caused by the above two treatment directions is attributed primarily to the alteration of the energy absorbed by domains from the external magnetic field, which part of energy can arouse plastic deformation in microstructures by the motion of domain walls.

  • Shijian Yan, Mingang Zhang, Yuesheng Chai, Wenhuai Tian

    A method of conventional chemical reaction to prepare delithiated cathode materials of Li-ion battery was introduced. The cathode material of Li-ion battery was mixed with oxidizing agent Na2S2O8 in water solution, and the solution was stirred continuously to make the chemical reaction proceed sufficiently, then the reaction product was filtered and finally the insoluble delithiated cathode material was obtained. A series of tests were conducted to verify the composition, crystal structure and electrochemical property of the delithiated cathode materials were all desirable. This method overcomes the shortcomings of battery charging preparation and chemical extraction preparation employing other oxidizing agents.

  • Fang Shao, Zhanqiang Liu, Yi Wan

    The essence of oxidation wear machanism of cenmented carbide tool was studied based on thermodynamics. Standard Gibbs free energy of possible reactions in cutting process at different temperature was calculated using substance Gibbs free energy function methods, and the sequence of reaction possibility order was researched as well as characteristics of every reaction. Theoretical calculation shows that WO3, Co3O4, TiO2 and CoWO4 are the main resultants, which are proved with the experiment results.

  • Qiaoxin Zhang, Hao Liu, Xiaohui Wang, Xiaoliang Shi, Xinglong Duan

    Silver powder was fabricated by spray pyrolysis, using 2%–20% AgNO3 solution, 336–500 mL/h flux of AgNO3 solution, 0.28–0.32 MPa flux of carrier gas and in the 620–820 °C temperature range. The effects of furnace set temperature, concentration of AgNO3 aqueous solution, flux of AgNO3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder, were investigated. The experimental results showed that with the high concentration of AgNO3 aqueous solution, the average grain size of silver decreased with the increasing of furnace set temperature. But the gain size distribution was not homogenous, the discontinuous grain growth occurred. With the low concentration of AgNO3 aqueous solution, the higher furnace set temperature made the nano sliver grains sintered together to grow. Nano silver powder about 100 nm was fabricated by spray pyrolysis, using 2wt% AgNO3 solutions, 336 mL/h flux of AgNO3 aqueous solution, 0.32 MPa flux of carrier gas at 720 °C furnace set temperature.

  • Xue Li, Ping Ren, Junxi Zhang, Lingsong Zhang, Guoping Liu

    Mn-Zn ferrites (Mn1−xZn xFe2O4) with different compositions were prepared by the coprecipitation method, and the influences of such synthesis conditions as pH value, composition and volume ratio (R) of the mixed solution and NH4HCO3 solution on their microstructures and magnetic properties were discussed. The samples were characterized by X-ray diffraction (XRD) and magnetization measurement instrument. Lattice parameters and average crystalline size of the synthesized materials were calculated from the corresponding XRD patterns with the related software Jade.5. For samples of different pH values, only one phase was found when pH values were 7.0, 8.0 and 9.0. The sample with pH value of 7.0 exhibited the highest saturation magnetic induction, the lowest coercive force, and crystallized best. For samples of different R values with pH value of 7.0, only one phase was observed in all samples, and the sample with R value of 2.3 exhibited the highest saturation magnetic induction and the lowest coercive force. The composition has mainly afected the magnetic properties, and the saturation magnetic induction increases with the increase of the content of Zn (x), but decreases when x is beyond 0.6. The trend of coercive force is on the contrary. However, no magnetism is exhibited when the x value is up to 0.8.

  • Hua Chen, Jinyong Zhang, Zhengyi Fu

    Fe-Ni-Al mixtures as hot-pressing sintering additive to Titanium diboride (TiB2) were studied. It is found that liquid alloy formed under high temperature hardly has effects on the densification behaviors of TiB2-independent. Fe-Ni-Al additive just works as filler between TiB2 particles and does not change the TiB2-independent sintering behaviors. Pressing mode has a great effect on the liquid flowing between TiB2 particles. Multiple-steps pressing mode will give more time and space for the liquid flowing and improve the relative density of TiB2-Fe-Ni-Al cermet.

  • Hongxing Wang, Chenglin Chu, Xiaobo Sheng, Pinghua Lin, Yinsheng Dong

    Silicide coating was prepared on electro-deposited nickel layer by the slurry pack cementation process on copper matrix at 1173 K for 12 h using SiO2 as Si source, pure Al powder as reducer, a dual activator of NaF+NH4Cl and albumen (egg white) as cohesive agent. Microstructure, properties and siliconizing mechanism of silicide coating were discussed. The experimental results show that the silicide coating with 220 µm thickness is mainly composed of a Ni2Si phase and a small amount of Ni31Si12 phase. Its mean microhardness (HV 790) is ten times than that of copper substrate (HV 70). The coefficient of friction decreases from 0.8 of pure copper to about 0.3 of the siliconzed sample. SiF2, SiCl2 and SiCl3 are responsible for the transportation and deposition of Si during the slurry pack cementation process.

  • Bingbing Fan, Tiecui Hou, Ruiyu Liu, Li Guan, Hailong Wang, Rui Zhang

    SiC/Cu composites were prepared by hot pressing. The high temperature tribological properties of the composites were investigated. XRD, SEM techniques were carried out to characterize the samples. It is found that the friction coefficient of SiC/Cu composites increases with the increasing SiC content. The SiC reinforcement particles are worn down other than removed by pulling out during the wear test. Oxidation of Cu debris leads to the smooth contacting surface. Ring crack is formed under the cyclic wear test. The crack propagates through the damaged matrix and along the brittle interface between SiC particles and Cu matrix.

  • Xiaoxue Ni, Xiaogang Li, Sanping Zhang, Dajian Qiu

    The aging behavior of polyurethane adhesive in medium was investigated and compared by means of scanning electronic microscopy(SEM), infrared spectroscopy(IR), interface analysis and shearing strength test. The experimental results show that the shear strength of polyurethane adhesive in salt water is decreased more quickly than that in water. Na+ and Cl ions could make the polyurethane adhesive age faster and the interface metal corrosion. The high temperature accelerates the diffusion of water molecule, Na+ and Cl ions and the degradation of the giant molecule.

  • Zhaohui Xie, Fangbao Ye

    In-situ magnesia-rich spinel fiber was formed resulting from the addition of ferrocene into MgO-C refractory matrixes. The formation of in-situ spinel fiber was detected to start at 1300 °C. The amount, diameter and length of the fibers increased with rising temperature. Ferrocene may have catalytic effects on the growth of the fibers in two aspects. First, the reaction between MgO and C and the decomposition of Al4C3 may be catalyzed at high temperature. Suitable concentration gaseous phase is then created for vapor-vapor reaction which could result in the in-situ formation of fibers. Second, Fe nanoparticle produced from ferrocene can act as catalytic droplets and catalyze the growth of the fibers. The fibers are formed via the vapor-liquid-solid and vapor-solid mechanisms. In terms of chemical thermodynamics, the partial pressure of CO and Mg(g) are found to play an important role in the in-situ fibers formation. Different concentration of vapors affects the size, amount and composition of the fibers at different temperatures. The mechanical properties of MgO-C brick was found to be improved by ferrocene addition.

  • Jianqing Li, Songliu Yuan, Zaoming Tian

    Systematical investigations of zero-field resistivity, magnetoresistance and magnetization were performed for a typical manganese compound La2/3Ca1/3MnO3. It is argued that the common origin for insulator-metal and paramagenetic ferromagnetic-transitions as well as colossal magnetoresistance is due to the formation of ferromagnetic clusters in the paramagnetic background. The transition to metallic state is resulted from percolation of ferromagnetic metallic clusters, while the colossal magnetoresistance is due to the application of magnetic field, which accelerates the growth of ferromagnetic metallic clusters and causes the shift of the onset temperature for the metallic percolation to higher temperature. Based on the random resistor network model, the zero-field resistivity versus temperature dependence is simulated by using experimental parameters, and experimental data well agree with those in whole temperature range, giving a strong support to our approach.

  • Ying Zhang, Dijiang Wen, Jian Zhou, Jiuhui Gan

    Co1−xZn xFe2O4 ferrites were prepared by solid state reaction. The microstructure and performance were studied by X-ray diffraction, X-ray absorption fine-structure analysis and IRE-2 infrared radiant test. It is found that infrared radiance show a nonlinear change with x, exhibiting the infrared radiance of this material improved and the average radiance in the 8–14 µm waveband reached 0.91. The Co3+ and Zn2+ ions are found to occupy both tetrahedral and octahedral sites, and correspondingly, the fraction of Fe3+ ions in B-site decreases nonlinearly in ferrites. The lattice parameters are found to concern with Zn2+, and the activation energy deduces from crystal strain and crystal vibrate increases with content Zn2+. The redistribution of the Co3+ and Zn2+ ions between tetrahedral and octahedral sites is related to the providing a selective tetrahedral and octahedral sites infrared radiance of Co1−xZn xFe2O4 ceramics with increasing x.

  • Meijun Yang, Lianmeng Zhang, Qiang Shen

    Preparation and thermoelectric properties of nanostructured n-type Mg2Si bulk materials were reported. Nanosized Mg2Si powder was obtained by mechanical milling of the microsized Mg2Si powder prepared by solid-state reaction. The bulk materials with 30 nm and 5 µm were prepared by spark plasma sintering of the nanosized and microsized Mg2Si powder, respectively. Both the samples show n-type conduction and the Seebeck coefficient of the sintered samples increase determinately with the grain size decrease from 5 µm to 30 nm. On the other hand, the electrical and thermal conductivity decrease with the decrease of grain size. Accordingly, decreasing their grain size increases their thermoelectric-figure-of-merit. A maximum thermoelectric figure of merit of 0.36 has been obtained for the nanostuctured Mg2Si sample at 823 K, which is 38% higher than that of microsized Mg2Si bulk materials and higher than results of other literatures. It could be expected that the properties of the nanocomposites could be further improved by doping optimization.

  • Lei Wang, Cairu Gao, Xianghua Liu, Yanfeng Wang

    The effects of TMCP parameters, consisting of finish cooling temperature and start rolling temperature in non-recrystallization region, on the final microstructure and mechanical properties of Q460 qNH steel were studied by tensile, Charpy impact tests and optical microscopy. The TMCP parameters for Q460 qNH steel were optimized by laboratory experiments. The results show that the yield strength and tensile strength increase with the finish cooling temperature, and the microstructure of Q460 qNH steel consists of ferrite and granular bainite.

  • Yongtao Zhang, Sixin Zhao, Jiamiao Liang, Hanqian Zhang, Jinfu Li

    The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to solve this problem. The precipitated multicomponents’ mass fraction of M3C, MC, M7C3 and M23C6 were evaluated precisely and relatively quickly. It is found evolution of carbides apparently occurs during tempering at high temperatures, and a two-step transformation mechanism is proposed for M7C3 during early tempering treatment. The method is an effective way on the investigation of precipitation kinetics, which may play a promising role in propertities’ enhancement and design of the heat-resistant steels.

  • Ping Ren, Junxi Zhang, Huiyong Deng

    Spinel zinc ferrites ZnFe2O4, prepared by co-precipitation method using the zinc nitrate Zn(NO3)2·6H2O and ferric nitrate Fe(NO3)3·2H2O as the raw materials, were characterized by the thermo gravimetric analysis (TG) and differential scanning calorimeter (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The influence of synthesis conditions, such as Zn/Fe molar ratio, pH value, the sintering temperature and time, on the microstructures was detailedly investigated. The relationships between the microstructures and the synthesis conditions were discussed. The results show that the pure spinel zinc ferrites ZnFe2O4 are formed when the Zn/Fe molar ratio is 1.05:2 at pH=8.5 or Zn/Fe molar ratio is 1:2 at Ph=9-10, and the precursors are sintered at 1100 °C for 4 h. Especially no other phases are observed when the Zn/Fe molar ratio is 1:2 at pH=10 and the precursor is sintered above 700 for 4 °C h. The higher sintering temperature and longer sintering time contribute to grain growth.

  • Guizhen Fu, Wenqi Gong, Gangwei Liu

    Calcium montmorillonite from Liao-ning was organically intercalated by using cety1 trimethy1 ammonium bromide after it was treated with sodium carbonate. The optimal dosage of intercalating agent was tested. The organically intercalated montmorillonite composites were characterized by the methods of XRD, FTIR and DTA/TG. The results show that the intercalating effect of the organically intercalated montmorillonite composite is the best when the amount of intercalating agent reached 120% cation exchange capacity (CEC)

  • Qin Zou, Mingzhi Wang, Bin Lv, Yanguo Li, Hui Yu, Lianghua Zou, Yucheng Zhao

    Onion-like carbon (OLC) was fabricated by annealing nanodiamond at 1000 °C for 2 hours in low vacuum (1 Pa). The OLC was characterized by X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). The experimental results show that the OLC exhibits similarity to the original nanodiamond particles in shape. The size of the OLC is found to be approximately 5 nm. The transformation mechanism of the OLC from nanodiamond was discussed also.

  • Wuman Zhang, Wei Sun, Yunsheng Zhang, Huisu Chen

    Hardened cement paste was subjected to the flexural loading and wet-dry cycles in sea water. The degradation of microstructures was obtained using scanning electron microscope (SEM), and the energy dispersive spectrum (EDS) analysis was carried to analyze the local composition. Mercury intrusion porosimetry (Poremaster GT-60) was used to analyze the degradation of pore structures. The experimental results show that the synergistic action of the flexural loading, wet-dry cycles and sea water leads to significant deterioration of hardened cement paste. The degradation of microstructures in the tensile region is more serious than that in the compressive region. The flexural loading and wet-dry cycles accelerate the chemical attack of sea water.

  • Shumei Liu, Yi Fu, Zhijie Jiang, Jianqing Zhao, Chen Zhang

    The hydrolytic co-condensation of hydrophobic phenyltriethoxysilane (PTES) and hydrophilic γ-aminopropyltriethoxysilane (APS) was investigated in toluene and water by using hydrochloric acid (HCl) catalyst. A soluble and meltable poly(aminopropyl/phenylsilsesquioxane) (PAPSQ) was formed by controlling HCl amounts, APS/PTES molar ratios, water/silane molar ratios (Rw/si), organic co-solvents and re-equilibration steps as well. The compositions of PAPSQ bearing aminopropyl and phenyl groups with the capping of trimethylsilyl group were confirmed by element analysis, fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (NMR) and thermogravimetric analysis (TGA). Differential scanning calorimetry (DSC) was employed to characterize the melting behavior of the product. PAPSQ can be easily employed as functional molecular building blocks for the synthesis of diverse and novel inorganic-organic materials.

  • Yinquan Yuan, Liyun Ding

    The coupled-mode equations for fiber Bragg grating (FBG) and long period fiber grating (LPFG) undergoing linear and quadratic temperature change were given. The effects of temperature gradient and quadratic temperature change on the reflectivity spectrum of fiber Braggs grating and the transmission spectrum of long period fiber grating were investigated using the numerical simulation, and the dependence relationships of the central wavelength shift, the full-width-at-half-maximum, and the peak intensity upon temperature gradient were also obtained. These relationships may be used to design a novel fiber optical sensor which can simultaneously measure the temperature and temperature gradient.

  • Bin Wu, Qixin Zheng, Xiaodong Guo, Yongchao Wu, Yu Wang, Fuzai Cui

    A biomimetic scaffold based on mineralized recombinant collagen, nano-hydroxyapatite/recombinant human-like collagen/poly(lactic acid) (nHA/RHLC/PLA), was prepared with recombinant human bone morphogenic protein-2 (rhBMP-2) for improving the osteoinductive property of the scaffold. The nHA/RHLC/PLA scaffolds loaded with 10 µg rhBMP-2 and the unloaded scaffolds were implanted subcutaneously in the rat model. The osteogenetic capacity of these composites was evaluated by CT scan, ALP activity test and histological observation at 4 and 8 weeks after implantation. The experimental results indicated that the osteogenic capability of the scaffolds loaded with rhBMP-2 was superior to the unloaded scaffold. It was concluded that rhBMP-2 can enhance the osteoinductive property of the nHA/RHLC/PLA scaffold and the nHA/RHLC/PLA scaffold loaded with rhBMP-2 have the good potential of being used in bone tissue engineering.

  • Haixing Xu, Yuhua Yan, Shipu Li

    Chitosan—L-lactic acid composite scaffold for the regeneration of peripheral nerve is obtained by grafting L-lactic acid onto the amino groups in chitosan with combined vacuum freezer drier. The composite scaffold was characterized by ATR-FTIR and SEM. The scaffold has a better graft efficiency and has a dense inner layer and a loose outer layer with porous structure, and the pore size is about 100 µm. The NGF release properties of the scaffold were investigated. The experimental results showed that, at the 1st day, 15.2 ng of NGF on average was released from the scaffold. From day 2 to day 10, the release rate obviously slowed down and 1.64 ng of NGF was released on average every day. After 10 days, the release rate was slower and 10.3 ng of NGF was released on average every day. After 60 days, NGF could also maintained a certain concentration. These properties show that the scaffold is a better carrier for NGF which can be more advantageous to the regeneration of the damaged peripheral nerve. As a result, this composite scaffold would be an ideal candidate for the regeneration of damaged peripheral nerve.

  • Yafang Zhang, Hao Liu, Lei Qi

    The stress distribution on the failure progress of fiber pushed-out test was studied. A numerical program, developed by meso-damage mechanics, was adopted to simulate the whole failure process of interface debonding and fiber pushing out. From the simulation, it can be concluded that, the interfacial stress on load side and support side is larger than other portions. Simultaneously, the shear stress in both sides becomes larger when thickness of sample reduces. Furthermore, when the diameter of fiber increases, the shear stress on load side is getting larger but in support side it is diminishing. On the other hand, changes of the support hole’s diameter only affect the interfacial shear stress on the support side.

  • Xiaoxia Zhang, Ning Chen, Jianxin Shi, Menglian Gong, Jianhua Zhang, Di Wang

    A simple but effective doping method, immersion method, was presented. Rare earth complexes [Na3Tb(DPA)3·9H2O and Na3Eu(DPA)3·9H2O] were introduced into porous silicon (PS), where H2DPA is 2,6-dicarboxy pyridine acid. Rare earths were proved to dope into PS effectively by photoluminescence (PL) and X-ray energy dispersive spectroscopy (EDS). And the prepared hybrid samples of PS/RE were found to emit intense room-temperature red and green luminescence while the luminescence of porous silicon are almost thoroughly quenched.

  • Yanli Su, Zhengyi Fu, Peiyan Ma, Weimin Wang, Jinyong Zhang

    In order to improve the bioavailability, Radix salvia miltiorrhiza raw powder mixed with distilled water (5.5wt%) was ultrafinely ground to nanosize particles using HSCS pulverizer, and the dissolving-out quantity of tanshinone IIA in the filtrate that obtained from nanoparticles suspension and raw powder marinated in water for different time was determined by HPLC. The experimental results show that raw powder can be ultrafinely ground to 133.5 nm at 1500 r/min for 50 min and the molecular structure of active ingredients doesnot change, and the dissolving-out quantity of tanshinone IIA obtained from the filtrate is increased greatly from 12.77 µg/g to 54.55 µg/g.

  • Weigang Wu, Qixin Zheng, Xiaodong Guo, Weidong Huang

    Three dimensional (3D) printing technology was utilized to fabricate a new type of drug implant with complicated architectures, employing levofloxacin (LVFX) and rifampicine (RFP) as model drugs. The prepared drug implant prototype consists of a double-layer structure, of which the upper region is a reservoir system containing RFP and the lower region is a matrix one containing LVFX. The release test in vivo revealed that LVFX was released in the early stage; no RFP was detected until 8th day; both of them continuously released more than 6 weeks. Therefore, 3D printing technology provides a precise and feasible method to fabricate a controlled-releasing drug implant with complicated architectures and this drug implant may present a new strategy for the prophylaxis and treatment of bone diseases such as combined bone infections and bone tuberculosis in the near future.

  • Lingchao Lu, Zeye Lu, Shiquan Liu, Shoude Wang, Xin Cheng

    The durability of the cement was mainly studied. Under 1.0 MPa of hydraulic pressure for 8 hours, water could penetrate completely through the sample made by portland cement, but could not penetrate through that by alite-barium sulphoaluminate cement. Under the condition of freezing and thawing cycle, the loss ratio of compressive strength of the cement was only about 17.3% at curing 28 d ages, but the loss of portland cement was as high as 29.5%. Alite-calcium barium sulphoaluminate cement also has an excellent resistance to sulfate attack. The coefficients of resistance to sulfate attack of the cement exceeded 1.0. Meanwhile, the composition and microstructure of the hardened paste of alite-calcium barium sulphoaluminate cement were analyzed by XRD and SEM.

  • Fujun Li, Youjian Peng, Bin Peng

    To evaluate the shear bond strength(SBS) and bond failure interface after the debonding of orthodontic brackets with a resin-modified glass ionomer cement(RMGIC) under six bonding conditions, 140 premolar teeth were randomly divided into seven groups. The brackets of all groups, except for control group, were bonded using a RMGIC. The teeth were debonded using a universal testing machine. The shear bond strength, adhesive remnant index (ARI) and enamel fracture were examined for each debonding. A significant difference existed in SBS under wet and dry conditions in two groups of Fuji Ortho LC. Different degree of enamel fracture was seen in groups of Fuji Ortho LC(dry/37% phosphoric acid treated) after debonding. Bond failed predominantly at the enamel-adhesive interface, except for phosphoric acid treated groups. The RMGIC achieve a clinically effective adhesion in orthodontics under different bonding conditions.

  • Zhenxing Zhang, Qixin Zheng, Yongchao Wu, Yudong Liu

    In order to study the biocompatibility of self-assembled FGL peptide nanofibers scaffold with neural stem cells (NSCs), FGL pepitide-amphiphile (FGL-PA) was synthesized by solid-phase peptide synthesis technique. The diluted hydrochloric acid was added into FGL-PA solution to reduce the PH value and accordingly induce self-assembly. The morphological features of the assembled material were studied by transmission electron microscope. NSCs were cultured and added with self-assembled FGL-PA. CCK-8 kit was used to test its effect on the proliferation of NSCs. The differentiation of NSCs was also tested after FGL-PA assembled material added. The experimental results showed that FGL-PA could be self-assembled to form a hydrogel. TEM analysis showed the self-assembled hydrogel was nanofibers with diameter of 10–20 nm and length of hundreds nanometers. FGL-PA with concentrations of 50,100, or 200 mg/L could promote the proliferation of NSCs, and absorbance of them was increased (P<0.05). The rate of neurons differentiated from NSCs was improved greatly by FGL-PA assembled material compared with control (P<0.05). The findings suggested that FGL-PA could self-assemble to nanofiber hydrogel, which had good biocompatibility with NSCs.

  • Zhongjian Wang, Jifa Zhang, Yichen Hu, Fengzhen Hou

    ZrO2, TiO2 and P2O5 were doped in CaO-B2O3-SiO2 glass-ceramics as nucleating additives. Effects of different nucleating additives on the phase separation and crystalline behaviors were investigated by using gradient temperature furnace, DTA and XRD. Then, sintering process of the glass-ceramics was investigated by testing sintering shrinkage, dielectric constant and loss. The experimental results shows that the glass-ceramics doped with nucleating additives represents higher crystallization, with ZrO2 as an exceptional effective dopant to promote the precipitation of wollastonite crystal. Finally, ZrO2 containing glass-ceramics was chosen to study the influence of sintering temperature and soaking time with the help of X-ray diffraction analysis and density measurement. The glass-ceramics can be well consolidated at 850 °C for 10 min, with low dielectric constant (5.87) and loss (3.21 × 10−4), which is desirable for LTCC application.

  • Yongli Zhao, Jiupeng Zhang

    On basis of the Burgers model, a new model consisting of modified dashpot and Van Der Poel model was derived from rheological and viscoelastic theory. Subsequently, triaxial repeated load permanent deformation tests of AC16 asphalt mixtures were conducted to validate this new developed model. Parameters of new developed model were obtained by a nonlinear regression analysis of test data, and then permanent strains and flow number of each mixture were calculated. The experimental results prove that the new developed model can well describe three phases permanent deformation of asphalt mixture under repeated load and it can be used for pavement mechanical analysis and rutting prediction.

  • Jinxin Guo, Qiuhua Pan, Cui Huang, Yanbing Zhao, Xiaobai Ouyang, Yonghong Huo, Sansan Duan

    Nanocapsules with triethylene glycol dimethacrylate (TEGDMA) as core material and polyurethane as wall material used for self-healing bonding resin were prepared by interfacial polycondensation in miniemulsion. The influence of surfactant and costabilizer concentration on nanocapsules size and stability of nanocapsules was investigated. The size and its polydispersity of the nanocapsules were measured by light-scattering particle size analyzer. When the concentration of SDS were increased from 2.5wt% to 10wt%, the size decreases from 340.5 nm to 258.3 nm, PDI decreased from 0.210 to 0.111. As the concentration of HD increased, the size and PDI were both decreased, When reaching 10wt%, the size was 258.0 nm, PDI was 0.130. SDS and HD play important effect in synthesis of Nanocapsules containing TEGDMA. By changing the surfactant and costabilizer concentration it was possible to synthesize a wide variety of nanocapsules sizes. The performance and technical parameters of nanocapsules had been researched preliminarily, which built the solid foundation for the application to the self-repairing bonding resin.