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In laser-drive ICF, hybrid drive (HD) combined direct drive (DD) and indirect drive (ID) offers a smoothed HD pressure $P_{HD}$, far higher than the ablation pressure in ID and DD, to suppress hydrodynamic instabilities. In this letter, simulations of a new robust HD ignition target show that maximal HD pressure as high as $P_{HD} \sim$ 650 Mbar driven by a novel "bulldozer" effect is achieved, resulting in nonstagnation hotspot ignition at the convergence ratio $C_r \sim $23, and finally, fusion energy gain $\sim$ 10 in total laser energy = 1.42 MJ. Two-dimensional simulations have confirmed that hydrodynamic instabilities are suppressed. A well-fitted scale of maximal HD pressure $P_{HD}$ (Mbar)= $BE_{DD}^{1/4} T_r$ is found from simulations of different targets and laser energies as long as $T_r> 160$ eV, where B is the constant depending on ablator materials, $E_{DD}$ in kJ is DD laser energy and $T_r$ in 100 eV is radiation temperature depending on ID laser energy $E_{ID}$. $P_{HD}\geq$ 450 Mbar is requested for hotspot ignition. This scale from "bulldozer" effect is also available as $E_{DD}$ is reduced to kJ. Experiments have verified $P_{HD}$ about 3.5 times radiation ablation pressure for CH ablator using $E_{ID}=43$ kJ ($T_r \simeq$200 eV) and $E_{DD}$=3.6 kJ, also shown that both backscattering fraction and hot-electron energy fraction for DD laser intensity $\sim 1.8 \times 10^{15} {\rm w\cdot cm^{-2}}$ are about a third of the traditional DD laser-plasma interaction, 10 pages, 4 Postscript figures

The coupling evolutions of stimulated Raman scattering (SRS) and Raman rescattering (re-SRS) are studied under the parameter conditions of relevance to the gas-filled hohlraum experiments at the National Ignition Facility by a nonenveloped fluid code for the first time. It is found that re-SRS works as a frequency filter of backscattered light of SRS in the gas region. The low frequency modes originated from density points higher than about 0.1nc would stimulate re-SRS and be heavily depleted by re-SRS at the region of their effective quarter critical density region. Due to the high collisional damping of the rescattered light, the energy of rescattered light is deposited quickly into the plasmas along with its propagation, which limits the re-SRS in a small region. Large amplitude of the daughter Langmuir wave of re-SRS would stimulate cascade Langmuir decay instabilities and induce obvious low frequency density modulations, which can further result in the inflation of high frequency modes generated at density points lower than the growth region of re-SRS.

A low shrinkage and viscosity-reducing type polycarboxylate superplasticizer was synthesized with maleic anhydride (MAH), diethylene glycol monobutyl ether (DGBE) and methoxypoly (ethylene glycol) methacrylate (MPEGnMA). The surface tension, early shrinkage of concrete, cement paste and application performance in concrete (slump spread, T50, V-funnel) were measured. The results show that the polycarboxylate superplasticizer we prepared has good low shrinkage and excellent viscosity-reducing capability for concrete.

A high strength liquid alkali-free setting accelerator in sprayed concrete was prepared by ultrasonic heating technology, to inorganic and organic compounds as the main raw material. The cement setting time, mortar and concrete mechanics performance and durability are studied, and its coagulation mechanism is studied by pore structure analysis. The test results show that the SA content was 5%, it initial setting time is less than 4 min, final setting time is less than 8 min, 1 d compressive strength ratio is more than 193.3%, and 28d compressive strength ratio can be increased by 118.5%.

Macromolecules with pendant chlorine groups on their main chains were synthesized via free-radical copolymerization of 2-hydroxyethyl acrylate(HEA), TPEG and vinylbenzyl chloride(VBC) in the presence of intiator and chain transfer agent according to molecular structure design principle. The subsequent Arbuzov reaction between trimethoxyphosphine(TMP) and chlorine groups of macromolecules(PHVT) gave rise to new type of polycarboxylate superplaticizer with clay-inerting and high slump retention capability. The molecular structure of superplasticizer was determined by Fourier Transform Infrared Spectroscopy (FT-IR) and Gel Permeation Chromatography (GPC), respectively. The adaptability of clays, Zata potential, adsorption behavior and application performance in concrete were measured. The results shows that the polycarboxylate superplaticizer we prepared has good clay compatibility, excellent clay-inerting and high slump retention capability.

A novel superplasticizer was synthesized by polycondensation of Alkyl phenol phosphate and toluene diisocyanate grafting with methoxy polyoxyethylene ether (MPEG). The chemical structure and molecular weight of polycondensates molecules were determined by 1H nuclear magnetic resonance (NMR) and gel permeation chromatography respectively. The experimental results indicated that the polycondensates of Alkyl phenol phosphate and toluene diisocyanate grafting with MPEG not only exhibited good water-reducing properties but also demonstrated effective anti-clay abilities alone. Furthermore, the polycondensates showed good fluidity maintaining abilities within 1–3 h and good workability of concrete. The results of T500 Time experiments show that lower plastic viscosity of the polycondensates leads to fresh concrete much "looser" than conventional PCEs in self-compacting concrete.

A new alkali-free liquid accelerator for shotcrete was prepared through normal temperature drop process by using the nano activated alumina and the modified alcohol amine as the main raw materials. The effect of alkali-free liquid accelerator on the cement setting time and the mechanical properties of mortar, the effect of the penetration strength on the shotcrete rebound were investigated. And the accelerating mechanism of the as-prepared alkali-free liquid accelerator was also analyzed via XRD and SEM characterization methods. The experimental results indicated that the hydration of C3A was accelerated by the polyamine complexation of accelerator, resulting in forming a large number of acicular ettringite and reducing the amount of Ca(OH)2 crystal, which would not affect the later hydration of cement. When the content of alkali-free liquid accelerator was 6%, the initial setting time and final setting time were less than 3min and 8min respectively, and 1d and 28d compressive strength ratios reached 207.6% and 114.2% respectively; beside that, the shotcrete rebound was very low because of the high penetration strength within 30min.

Beam deflection of a monospeckle laser beam propagating in a plasma with parameters relevant to Inertial Confinement Fusion is investigated using three dimensional Euler laser plasma interaction code LAP3D. Effects of the beam intensity and the speed of the transverse flow on the beam deflection are analyzed. Simulation results suggest that the beam deflection is caused by laser self-focusing and plasma transverse flow. It is found that the beam deflection is evident only when the speed of plasma transverse flow is closer to that of ion acoustic wave and the angle of the beam deflection is in proportion to the laser intensity. When the speed of plasma transverse flow becomes lower than that of ion acoustic wave, the beam deflection is suppressed. When the speed of plasma transverse flow becomes larger than that of ion acoustic wave, refraction effect becomes dominant.