EFFECTIVE DETECTION DEPTH OF NEEDLE-LIKE OPTICAL PROBE

The effective detection depth of the needle-like optical probe is studied. The light transport model in highly scattering tissue is the diffusion equation and the boundary is Neuman. The sensitivity matrix is related to the position of the light source and the detector. It can be used to evaluate the effective detection depth. The sensitivity matrix is defined as the multiplication of the source and detector hght distribution. Six different groups about ix parameters including the source diameter and detector fibers, the core-to-core distance between the source and detector fibers, the opotode depth, the absorption, and reduced scattering coefficient, are used as experimental models. The relationship between the six parameters and the effective detection depth is analyzed. Resuits can be used to study the spatial resolution and the depth of multi-fibers.

Noncolinear Second-Harmonic Generation Pairs and Their Scatterings in Nd3+:SBN Crystals with Needle-Like Ferroelectric Domains

Second-harmonic generation in Nd3＋ ：SBN crystal with needle-like ferroelectric with aperiodic domain structures is investigated. Two pairs of second harmonic （SH） waves appearing in lines are observed in unpoled Nd3＋ ：SBN crystals with aperiodic needle-like domains. A pair of SH waves emit from the exit face, whose intensities are angle-dependent. The angular dependence is corresponding to the spatial frequency spectrum of the aperiodic domain structure. Another pair of SH waves emit from both the side surfaces, which are mainly the scattered SH waves by needle-like domain walls and obey the theory of Rayleigh scattering.

Mo-doped one-dimensional needle-like Ni_(3)S_(2) as bifunctional electrocatalyst for efficient alkaline hydrogen evolution and overall-water-splitting

Hydrogen energy plays an important role in clean energy system and is considered the core energy source for future technological development owing to its lightweight nature,high calorific value,and clean combustion products.The electrocatalytic conversion of water into hydrogen is considered a highly promising method.An electrocatalyst is indispensable in the electrocatalytic process,and finding an efficient electrocatalyst is essential.However,the current commercial electrocatalysts(such as Pt/C and Ru)are expensive;therefore,there is a need to find an inexpensive and efficient electrocatalyst with high stability,corrosion resistance,and high electrocatalytic efficiency.In this study,we developed a cost-effective bifunctional electrocatalyst by incorporating molybdenum into nickel sulfide(Ni_(3)S_(2))and subsequently tailoring its structure to achieve a one-dimensional(1D)needle-like configuration.The hydrogen production efficiency of nickel sulfide was improved by changing the ratio of Mo doping.By analyzing the electrochemical performance of different Mo-doped catalysts,we found that the Ni_(3)S_(2)-Mo-0.1 electrocatalyst exhibited the best electrocatalytic effect in 1 M KOH;at a current density of 10 mA cm^(-2),it exhibited overpotentials of 120 and 279 mV for hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),respectively;at a higher current density of 100 mA cm^(-2),the HER and OER overpotentials were 396 and 495 mV,respectively.Furthermore,this electrocatalyst can be used in a two-electrode water-splitting system.Finally,we thoroughly investigated the mechanism of the overall water splitting of this electrocatalyst,providing valuable insights for future hydrogen production via overall-water-splitting.

Porous needle-like Fe-Ni-P doped with Ru as efficient electrocatalyst for hydrogen generation powered by sustainable energies

Electrocatalytic water electrolysis,involving hydrogen evolution reaction(HER)and oxygen evolution reaction(OER),two halfreactions,is an eco-friendly approach toward hydrogen production.In this work,needle-like Ru-Fe-Ni-P on NiFe foam is prepared through corrosive engineering and following a low-temperature phosphorization procedure for overall water-splitting.The as-designed Ru-Fe-Ni-P exhibits a porous needle-like structure,surface,and binder-free merits,and then can expose rich active sites,favor the transportation of mass/electron,and accelerate the reaction kinetics during catalytic process.Then,the synthesized Ru-Fe-Ni-P owns remarkable catalytic performance for HER,with 18 and 67 mV to reach 10 mA·cm^(−2)in alkaline and neutral media.Moreover,a low cell voltage of 1.51 V is required to produce a current of 10 mA·cm^(−2)in a two electrode electrolyzer with excellent stability.Interestingly,sustainable energies can power the electrolyzer effectively with abundant hydrogen generation.

Synthesis, characterization and luminescent properties of needle-like lanthanide-doped orthorhombic Y5O4F7

Thermal annealing of YOH1.1F1.9 and YOH1.1F1.9：Ln3＋ （Ln3＋=Eu3＋, Tb3＋ and Gd3＋） precursors in air gave access to synthe- size yttrium oxyfluoride phosphors with well-preserved needle-like morphologies. The phase purities of samples strongly depended on the thermal annealing temperature. At 600 ℃, pure Y5O4F7 with orthorhombic structure were obtained, as evidenced by powder X-ray diffraction measurement and chemical analysis. The interesting microstructure evolution of the annealed sample from well-organized nanoparticles on curly slices to microrod-bundle structure had been aroused by raising annealing temperature. The multicolor fluorescent emissions of Y5O4F7：Ln3＋ phosphors were observed, e.g. ultraviolet emission for Gd3＋, green emission for Tb3＋ and red emission for Eu3＋, which resulted from characteristic transitions of different lanthanide ions.

Needle-like cobalt phosphide arrays grown on carbon fiber cloth as a binder-free electrode with enhanced lithium storage performance

Cobalt phosphide(CoP) is a promising anode candidate for lithium-ion batteries(LIBs) due to its high specific capacity and low working potential.However,the poor cycling stability and rate performance,caused by low electrical conductivity and huge volume variation,impede the further practical application of CoP anode materials.Herein,we report an integrated binder-free electrode featuring needle-like CoP arrays grown on carbon fiber cloth(CC) for efficient lithium storage.The as-prepared CoP/CC electrode integrates the advantages of 1 D needle-like CoP arrays for efficient electrolyte wettability and fast cha rge transpo rtation,and 3 D CC substrate for superior mechanical stability,flexibility and high conductivity.As a result,the CoP/CC electrode delivers an initial specific capacity of 1283 mAh/g and initial Coulombic effeciencies of 85.4%,which are much higher than that of conventional CoP electrode.Notably,the Co P/CC electrode shows outstanding cycling performance up to 400 cycles at 0.5 A/cm^(2) and excellent rate performance with a discharge capacity of 549 mAh/g even at 5 A/cm^(2).This work demonstrates the great potential of integrated CoP/CC hybrid as efficient bind-free and freestanding electrode for LIBs and future flexible electronic devices.

Preparation of Thermal Insulation Ceramics Using Felsic Tailings as Main Raw Material and Soda-ash Dregs as Flux

Low-cost thermal insulation porous ceramics with uniform pore diameter and low bulk density were prepared with soda-ash dregs and felsic tailings.We investigated the effect of temperature,foaming agent,fluxing agent,Al_(2)O_(3)and CaO content on the pore structure and crystal phase of porous ceramics.The effect of Ca^(2+)in soda-ash dregs on the preparation of quartz-feldspar based porous ceramics was studied.The results showed that the contribution of Ca^(2+)to the preparation of porous ceramics in this system was mainly to accelerate the Si-O bond fracture and reduce the sintering temperature at the initial stage of sintering,which destroyed the needle-like feldspar in the high temperature melt and reduced the melt viscosity,thus reduced the foaming resistance and promoted the porous products with uniform pore size distribution.The Ca^(2+)content on the high side can participate in the formation of crystals in sintering.The generated needle-like diopside and augite,which have small length-diameter ratio,will negligibly change in the viscosity of melt at high temperatures,and their inhibition effect on pores is not as good as that of feldspar with large length-diameter ratio,resulting in the merger and collapse of pores.But the increase of diopside and augite can improve the compressive strength of porous products to some extent.Porous ceramic products containing needle-like feldspar phase can be prepared by using two kinds of solid waste,which can improve the compressive strength of the products and reduce the raw material cost and energy consumption while comprehensively utilizing the double solid waste.The optimal product has a bulk density of 0.45 g/cm^(3),a compressive strength of 3.17 MPa,and a thermal conductivity of 0.11 W/(m·K).

Preparation and Properties of Friction Materials by Using Two Kinds of Fibrous Industrial Minerals

The basic technology and properties of the brake blocks made of modified needle-like wollastonite and fibrous sepiolite were intensively researched.The impact strengthes and fixed velocity friction of the brake blocks prepared by different recipes were tested. The testing results show that it is feasible for needle-like wollastonite and fibrous sepiolite to take the place of asbestos as the reinforced materials of friction materials.The braking effect of the brake blocks is the best when the ratio of the needle-like wollastonite to the fibrous sepiolite was 1∶6.