Pressure-relief and permeability-increase technology of high liquid–solid coupling blast and its application

As for the coal seam with high stress,high gas and low permeability,a single technology cannot prevent the complex dynamic disasters.Because of this,the study proposes a new method of pressure-relief and permeability-increase technology of the high liquid–solid coupling blast.Through coal seam injection and charging structure change,the paper fully works out the dual functions of the water and explosion.Using the theoretical calculation,numerical simulation and physical experiments,we obtained that the initial blasting stress,displacement and overpressure of the liquid–solid coupling blast are much better than that of ordinary blasting.The technology has been used in the relative coal mine,and the application results show that the technique has effectively prevented the coal and gas outburst,which has a wide range of application.

High Coupling Efficiency of the Fiber-Coupled Module Based on Photonic-Band-Crystal Laser Diodes

The coupling efficiency of the beam combination and the fiber-coupled module is limited due to the large vertical divergent angle of conventional semiconductor laser diodes. We present a high coupling efficiency module using photonic-band-crystal （PBC） laser diodes with narrow vertical divergent angles. Three PBC single-emitter laser diodes are combined into a fiber with core diameter of 105μm and numerical aperture of 0.22. A high coupling efficiency of 94.4% is achieved and the brightness is calculated to be 1.T MW/（cm2.sr） with the injection current of 8A.

Determination of trace elements in high purity nickel by high resolution inductively coupled plasma mass spectrometry

The contents ofMg, Al, Si, Ti, Cr, Mn, Fe, Co, Cu, Ga, As, Se, Cd, Sb, Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. The sample was dissolved in HNO3 and HCI by microwave digestion. Most of the spectral interferences could be avoided by measuring in the high resolution mode. The matrix effects because of the presence of excess HC1 and nickel were evaluated. Correction for matrix effects was made using Sc, Rh and T1 as internal standards. The optimum conditions for the determination were tested and discussed. The detection limits range from 0.012 to 1.76 ~tg/g depending on the type of elements. The applicability of the proposed method is also validated by the analysis of high purity nickel reference material （NIST SRM 671）. The relative standard deviation （RSD） is less than 3.3%. Results for determination of trace elements in high purity nickel were presented.

Quantification of trace amounts of impurities in high purity cobalt by high resolution inductively coupled plasma mass spectrometry

A An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of 24 elements （Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb） in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.

Analysis of Low-polar Ginsenosides in Steamed Panax Ginseng at High-temperature by HPLC-ESI-MS/MS

A high performance liquid chromatography coupled with electrospray ionization-tandem mass spectrome try（HPLC-ESI-MS/MS） method was developed for the analysis and identification of ginsenosides in the extracts of raw Panax ginseng（RPG） and steamed Panax ginseng at high temperatures（SPGHT）. A total of 25 ginsenosides were extracted include of which 10 low-polar ginsenosides, such as ginsenosides F4, Rk3, Rh4, 20S-Rg3, 20R-Rg3 and so on, were identified according to their HPLC retention time and MS/MS data. The results indicated that the low polar ginsenosides were seldom found in RPG. For the exploration of the transformation pattern of the ginsenosides in steam processing, the standards of ginsenosides Re, Rg1, Rb1, Rc, Rb2, Rb3 and Rd were selected and hydrolyzed at a temperature of 120 oC. The results show that these polar ginsenosides can be converted to low-polar ginsenosides such as Rg2, Rg6, F4, Rk3 and Rg5 by hydrolyzing the sugar chains.

Progress in octahedral spherical hohlraum study

In this paper,we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study.From our theoretical study,the octahedral spherical hohlraums with 6 Laser Entrance Holes(LEHs)of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7.In addition,the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology.We studied the laser arrangement and constraints of the octahedral spherical hohlraums,and gave a design on the laser arrangement for ignition octahedral hohlraums.As a result,the injection angle of laser beams of 50°-60°was proposed as the optimum candidate range for the octahedral spherical hohlraums.We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields,in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport.We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums,the rugby hohlraums and the cylindrical hohlraums,and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive.Up till to now,we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG)laser facilities,including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums,spherical hohlraum energetics on the SGIII prototype laser facility,and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.

Quantification of Trace Amounts of Impurities in High Purity Cobalt by High Resolution Inductively Coupled Plasma Mass Spectrometry

An analytical method using high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS） for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%-111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.

Direct Determination of Trace Impurities in High Purity Zinc Oxide by High Resolution Inductively Coupled Plasma Mass Spectrometry

The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry （ HR-ICP-MS ） was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.

Determination of Trace Elements in High Purity Gold by High Resolution Inductively Coupled Plasma Mass Spectrometry

Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry （HR-ICP-MS）. Sample were decomposed by aqua regia. To overcome some potentially problematic spectra/ interference, measurements were acquired in both medium and high resolution modes. The matrix effects due to the presence of excessive HCl and Au were evaluated. The optimum conditions for the determination was tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits range from 0.01ug/g to 0.28ug/g depending on the elements. The method is accurate, quick and convenient. It has been applied to the determination of trace elements in high purity gold with satisfactory results.

Un-powered gliding aircraft's ballistic missile optimal design

In this dissertation, un-powered gliding aircraft＇s optimal extended rangeproblem is discussed. The aircraft movement model was built. According to the degree of coupling, the model can be classified into a simple model or a complicated model. Using an optimal control method, two different movement models gave out the aircraft＇s attitude angle optimal flight path. Complicated model＇s optimal solution can be found by the genetic algorithm. This method can transfer the analytic solution of complicated model to a numerical value solution. Comparing the simulation results of different methods, it showed that the genetic algorithm combined with the complicated model＇s numerical value solution had the best performance in control strategy. This method solved the problem in which the highly coupling complicated model＇s analytic solution was hard to obtain. It verified that the genetic algorithm has validity in the field of extended range solution searching.

Analytical Case Study on a Dedicated Pigment in Recycling Processes of Polyethylene

The ability to track & trace materials is a key feature in the entire chain, and it ensures circularity principles. Examples from plastic recycling show the enormous added value that analytical technology can have for the circular economy. During polymer production and recycling processes, pigments can be added for different purposes;e.g. as colouring agent of the polymeric product but also as tracer for tracking process development and control in the final recycle products versus possible by-products. An analytical method for tracking the pigment Solvent Blue 15 in input materials, in intermediates as well as in recyclates was developed by tracing and quantifying an indicator metal which is copper (Cu). Therefore, suitable digestion procedures and a quantification method by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) were developed and used for measuring the polymeric digests. The method was tested on relevant samples from chemical recycling processes. The background concentrations in base/raw material are in the range of 0.05 - 0.1 mg·kg-1 Cu. The processing concentrations are in the range of 4.2 to 28 mg·kg-1 Cu, while the pigment starting material (polyethylene, PE) has a concentration of around 50 mg·kg-1 Cu.

Researching the 915 nm high-power and high-brightness semiconductor laser single chip coupling module

Based on the high-speed development of the fiber laser in recent years, the development of researching 915 nm semiconductor laser as main pumping sources of the fiber laser is at a high speed. Because the beam quality of the laser diode is very poor, the 915 nm laser diode is generally based on optical fiber coupling module to output the laser. Using the beam-shaping and fiber-coupling technology to improve the quality of output beam light, we present a kind of high-power and high-brightness semiconductor laser module, which can output 13.22 W through the optical fiber. Based on 915 nm GaAs semiconductor laser diode which has output power of 13.91 W, we describe a thoroughly detailed procedure for reshaping the beam output from the semiconductor laser diode and coupling the beam into the optical fiber of which the core diameter is 105 μm and the numerical aperture is 0.18. We get 13.22 W from the output fiber of the module at 14.5 A, the coupling efficiency of the whole module is 95.03% and the brightness is 1.5 MW/cm2-str. The output power of the single chip semiconductor laser module achieves the advanced level in the domestic use.

Interruption Characteristics of High-speed Switches in 500 kV Fault Current Limiter with High Coupled Split Reactance

A 500 kV high-voltage AC fault current limiter(FCL)based on a high coupled split reactor(HCSR)is pro-posed by the National key R&D project team.Low impedance under normal conditions and high impedance under short-circuit conditions are accomplished by the cooperation of HCSR and high-speed switches.High-speed switches play an important role in current limiting processes,thus interruption characteristics of the high-speed switch in the 500 kV FCL are studied in this paper.The simulation model of the FCL and the external equivalent power grid are established.The short-circuit current and recovery voltage characteristics of the high-speed switch in FCL are simulated.The results show that maximum DC component of the short-circuit current of the high-speed switch reaches 91%,the maximum peak value is 118 kA,and the longest arcing time is 14.8 ms.There is a discontinuity in the curve of the short-circuit current peak and arcing time as a function of the short-circuit occurrence time;the peak recovery voltage of a single break of the high-speed switch has a maximum value of 87.5 kV under a three-phase ungrounded short-circuit condition,and the rate of rise of recovery voltage is o.22 kV/s.The recovery voltage peak shows a period change with the short-circuit occurrence time,and the period is 10 ms.The effects of the shunt capacitor value and short-circuit ground resistance on the recovery voltage of high-speed switching are also studied.The research can be used for reference by R&D personnel and testersof500kVFCLs.Index Terms-Fault current limiter(FCL),high coupled split reactor(HCSR),high-speed switch,interruption characteristics,short circuit current.

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures （CCSs） in two-dimensional （2D） photonic crystals （PCs） are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain （FDTD） method, and the results show that within a very short coupling distance of about 3λ, where ）, is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.

A NUMERICAL STUDY ON THE INFLUENCE OF WIND FIELDS AT UPPER LEVELS IN THE MEIYU PERIOD ON THE DEVELOPMENT OF LOW LEVEL JET AND MESOSCALE SYSTEMS

Using a mesoscale model,a numerical study on a heavy rainfall case occurring in the Changjiang-Huaihe River Basin is made in this paper.The influence of the intensity of northeasterly wind in front of the Qinghai-Xizang high at upper level on the low level wind field and development of mesoscale systems as well as heavy rainfall is investigated.The model well reproduced the heavy rainfall process and the weather systems associated.And it indicates that the strong northeasterly flow around the high at upper troposphere will bring about not only the strengthening of low level southeasterly wind,but also the appearance of shear-line and mesoscale vortex at low level.The coupling of northerly wind at upper level and southerly wind at lower level constructs a vertical indirect circulation which is most favourable for the development of convective motions.Its ascending branch in the shear-line area is very strong and shows a pronounced mesoscale characteristic.