Longitudinal-transverse separations of deep-inelastic structure functions at low Q2 for hydrogen and deuterium

We report on a study of the longitudinal to transverse cross section ratio, R=sigmaL/sigmaT, at low values of x and Q2, as determined from inclusive inelastic electron-hydrogen and electron-deuterium scattering data from Jefferson Laboratory Hall C spanning the four-momentum transfer range 0.06相似文献   

The taming of CN7(-): the azidotetrazolate 2-oxide anion

The highly sensitive 5-azidotetrazolate anion was oxidized to its corresponding N-oxide by aqueous oxidation in a buffered oxone solution to the azidotetrazolate 2-oxide anion. After acidic extraction and neutralization with ammonia, the ammonium salt was isolated. Several energetic salts of this novel anion were prepared from the ammonium salt, and in all cases were found to be of lower sensitivity than the corresponding 5-azidotetrazolate salt while still being highly sensitive towards mechanical stimuli. Explosive performances (detonation velocity, detonation pressure) of applicable salts were also found to be higher than the non-N-oxide variants. Preparation of the free acid 2-hydroxy-5-azidotetrazole was achieved by protonation of the anion and identified by NMR spectroscopy, whereas the majority of the azidotetrazolate 2-oxide salts have unequivocal crystallographic proof.     

Effect of Pr-Ca substitution on the transport and magnetic behavior of LaMnO3 perovskite

The effect of simultaneous substitution of a fluctuating cation and a divalent cation in LaMnO₃ perovskite modifies the properties of the material to exhibit large valence colossal magnetoresistance (CMR) effect. A good example of these properties is (La_1−2x Pr _x Ca _x )MnO₃ (LPCMO) type CMR material. In this communication it is reported that, with the increase in x (for x=0.1, 0.15, 0.2), the T _c varies between 100 and 120 K with improvisation in metal-insulator transition. Interestingly, resistance increases with x from few hundred ohms to few kilo ohms with corresponding decrease in the unit cell volume. The results of the studies using X-ray diffraction (XRD), electrical resistivity, magnetoresistance and ac susceptibility measurements on LPCMO samples for understanding the structural, transport and magnetic properties are discussed in detail.     

Tetrazole Azasydnone (C2N7O2H) And Its Salts: High-Performing Zwitterionic Energetic Materials Containing A Unique Explosophore

This work reports the first compound containing both a tetrazole and an azasydnone ring, a unique energetic material. Several energetic salts of the tetrazole azasydnone were synthesized and characterized, leading to the creation of new secondary and primary explosives. Molecular structures are confirmed by ¹H and ¹³C NMR, IR spectroscopy, and X-ray crystallographic analysis. The high heats of formation, fast detonation velocities, and straight-forward synthesis of energetic azasydnones should capture the attention of future energetics research.     

关于K个复相关矩阵相等的检验

§ 1.Ｉｎｔｒｏｄｕｃｔｉｏｎ　ＷｅａｒｅｇｉｖｅｎｋｉｎｄｅｐｅｎｄｅｎｔＷｉｓｈａｒｔｄｅｎｓｉｔｉｅｓｏｆｔｈｅ (ｐ +ｑ)× (ｐ +ｑ)ｒａｎｄｏｍｓｙｍｍｅｔｒｉｃｐｏｓｉｔｉｖｅｄｅｆｉｎｉｔｅｍａｔｒｉｃｅｓＧ1,… ,Ｇｋｔｏｂｅｇ(Ｇｉ) =Ｋｅｘｐ -12 ｔｒＲ- 1ｉ Ｇｉ Ｇｉ12 (ｎｉ- ｑ-ｐ- 1) ,(1 )ｗｈｅｒｅｉ=1 ,… ,ｋ,ａｎｄＲｉｄｅｎｏｔｅｓｔｈｅｐｏｐｕｌａｔｉｏｎｃｏｒｒｅｌａｔｉｏｎｍａｔｒｉｘｏｆｔｈｅｉ ｔｈｐｏｐｕｌａｔｉｏｎａｎｄＫａｓａｇｅｎｅｒｉｃｌｅｔｔｅｒｄｅｎｏｔｅ…     

Behavior of nuclear matter under extreme conditions in fission

The spontaneous fission of ²⁵²Cf has been studied via γ-γ-γ coincidence and γ-γ light charged particle coincidence with Gammasphere. The binary fission yields of correlated Mo?Ba pairs with 0–10 neutron emission have been remeasured. The existence of “hot” fission mode with 8–10 neutron emission seen previously in the Mo?Ba split is confirmed but with lower intensities. By gating on the light charged particles detected in ΔE-E detectors and a γ ray in one partner, the relative yields of correlated pairs in alpha ternary SF with zero to 6n emission are observed for the first time with the distribution peaked at 2.5n. New correlated pairs are identified in ¹⁰Be ternary SF. We observed essentially only cold, On ¹⁰Be and little, if any, hot, xn ¹⁰Be. New γ-γ-γ data with 2.3 times the total events show weak non-Doppler broadened high energy peaks in coincidence with transitions in correlated pairs in ¹⁰Be SF shifted by the same 6,1 to 26 keV from the 2-0 energy in ¹⁰Be as seen earlier.     

Synthesis of 5‐Aminotetrazole‐1 N‐oxide and Its Azo Derivative: A Key Step in the Development of New Energetic Materials

1‐Hydroxy‐5‐aminotetrazole ( 1 ), which is a long‐desired starting material for the synthesis of hundreds of new energetic materials, was synthesized for the first time by the reaction of aqueous hydroxylamine with cyanogen azide. The use of this unique precursor was demonstrated by the preparation of several energetic compounds with equal or higher performance than that of commonly used explosives, such as hexogen (RDX). The prepared compounds, including energetic salts of 1‐hydroxy‐5‐aminotetrazole (hydroxylammonium ( 2 , two polymorphs) and ammonium ( 3 )), azo‐coupled derivatives (potassium ( 5 ), hydroxylammonium ( 6 ), ammonium ( 7 ), and hydrazinium 5,5′‐azo‐bis(1‐N‐oxidotetrazolate ( 8 , two polymorphs)), as well as neutral compounds 5,5′‐azo‐bis(1‐oxidotetrazole) ( 4 ) and 5,5′‐bis(1‐oxidotetrazole)hydrazine ( 9 ), were intensively characterized by low‐temperature X‐ray diffraction, IR, Raman, and multinuclear NMR spectroscopy, elemental analysis, and DSC. The calculated energetic performance, by using the EXPLO5 code, based on the calculated (CBS‐4M) heats of formation and X‐ray densities confirm the high energetic performance of tetrazole‐N‐oxides as energetic materials. Last but not least, their sensitivity towards impact, friction, and electrostatic discharge were explored. 5,5′‐Azo‐bis(1‐N‐oxidotetrazole) deflagrates close to the DDT (deflagration‐to‐detonation transition) faster than all compounds that have been investigated in our research group to date.     

A Study of Cyanotetrazole Oxides and Derivatives thereof

In this work we report on the syntheses of energetic salts of cyanotetrazolate‐1‐ and ‐2‐oxides; this offers a unique ability to compare the effects of tetrazole 1‐ versus 2‐oxidation. 5‐Cyanotetrazolate‐2‐oxide can be synthesized by oxidation of the 5‐cyanotetrazolate anion with Oxone, while the corresponding 1‐oxide was synthesized by the rearrangement of azidoaminofurazan. Both chemical (multinuclear NMR, IR, and Raman spectroscopies, mass spectrometry, etc.) as well as explosive (impact, friction, and static sensitivities) properties are reported for these energetic salts. Calculated explosive performances using the EXPLO5 computer code are also reported. We furthermore detail the chemistry of these two anions, and their ability to form tetrazole‐carboxamides, dihydrotetrazines, and tetrazines. The ability to hydrolyze cyanotetrazole oxides to their amides was demonstrated by two copper complexes. Several crystal structures of these species are presented in addition to full chemical characterization. Finally, the unique 1,4,‐bis(2‐N‐oxidotetrazolate)‐1,2,4,5‐tetrazine anion was characterized as an energetic material as its ammonium salt.     

"Liquid-phase calcination" of colloidal mesoporous silica nanoparticles in high-boiling solvents

We report on a novel high temperature liquid phase "calcination" method with trioctylphosphine oxide (TOPO), tri-n-octylamine (TOA), and squalene for removing the template and strengthening the silica network in colloidal mesoporous silica (CMS) nanoparticles. For such materials, the common calcination procedure in air would result in strong agglomeration, thus preventing their use in colloidal suspensions. The highest efficiency of the new approach is obtained by thermal calcination in TOPO at only 275 °C, as shown by an increasing degree of silica condensation, and the retention of the high colloidal stability of the CMS nanoparticles. Moreover, we also show the ability of the TOPO treatment to remove the template, thus saving a preparation step. The resulting CMS nanoparticles retain the ordered mesostructure, high porosity, and large surface area of the original mesoporous nanoparticles, while showing a much greater degree of silica condensation and high stability. The concept of "liquid calcination" represents a powerful general approach for the preparation of stable colloidal porous nanoparticles.