N′-(4-Hydr­oxy-3-methoxy­benzyl­idene)acetohydrazide monohydrate

In the title compound, C10H12N2O3·H2O, the Schiff base mol­ecule is approximately planar [within 0.189 (1) Å]. The inter­planar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, mol­ecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydr­oxy H atom deviates from the 4-hydr­oxy-3-methoxy­phenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R 1 2(4) motif. A weak C—H⋯π inter­action is also present

N′-(3,4-Dihydroxy­benzyl­idene)acetohydrazide

In the title compound, C9H10N2O3, the Schiff base mol­ecule is approximately planar, the dihedral angle between the benzene ring and the acetohydrazide group (r.m.s. deviation = 0.034 Å) being 8.81 (7)°. An intra­molecular O—H⋯O hydrogen bond is observed. In the crystal, mol­ecules are linked into a three-dimensional network by O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonds

(E)-Methyl N′-(2-furylmethyl­ene)­hydrazinecarboxyl­ate

The title compound, C7H8N2O3, crystallizes with two independent but essentially identical mol­ecules in the asymmetric unit. Each mol­ecule adopts a trans configuration with respect to the C=N bond. The hydrazinecarboxyl­ate group is twisted from the furan ring by 7.78 (13)° in one mol­ecule and by 7.01 (17)° in the other. In the crystal structure, mol­ecules are linked into chains running along [010] by bifurcated N—H⋯(N,O) and N—H⋯O hydrogen bonds. In addition, weak C—H⋯O inter­actions and an O⋯C short contact [2.896 (3) Å] are observed

Free-running 4H-SiC single-photon detector with ultralow afterpulse probability at 266 nm

Ultraviolet single-photon detector (UVSPD) provides a key tool for the applications requiring ultraweak light detection in the wavelength band. Here, we report a 4H-SiC single-photon avalanche diode (SPAD) based free-running UVSPD with ultralow afterpulse probability. We design and fabricate the 4H-SiC SPAD with a beveled mesa structure, which exhibits the characteristic of ultralow dark current. We further develop a readout circuit of passive quenching and active reset with tunable hold-off time setting to considerably suppress the afterpulsing effect. The nonuniformity of photon detection efficiency (PDE) across the SPAD active area with a diameter of $\sim$ 180 $\mu$m is investigated for performance optimization. The compact UVSPD is then characterized, exhibiting a typical performance of 10.3% PDE, 133 kcps dark count rate and 0.3% afterpulse probability at 266 nm. Such performance indicates that the compact UVSPD could be used for practical ultraviolet photon-counting applicationsComment: 5 pages, 5 figures, accepted for publication in Review of Scientific Instrument

Detailed Componential Characterization of Extractable Species with Organic Solvents from Wheat Straw

Componential analysis of extractives is important for better understanding the structure and utilization of biomass. In this investigation, wheat straw (WS) was extracted with petroleum ether (PE) and carbon disulfide (CS2) sequentially, to afford extractable fractions EFPE and EFCS2, respectively. Detailed componential analyses of EFPE and EFCS2 were carried out with Fourier transform infrared (FTIR) spectroscopy, gas chromatography/mass spectrometry (GC/MS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy dispersive spectrometry (EDS), and electron probe microanalysis (EPMA). Total extractives were quantified 4.96% by weight compared to the initial WS sample. FTIR and GC/MS analyses results showed that PE was effective for the extraction of ketones and waxes derived compounds; meanwhile CS2 preferred ketones and other species with higher degrees of unsaturation. Steroids were enriched into EFPE and EFCS2 with considerable high relative contents, namely, 64.52% and 79.58%, respectively. XPS analysis showed that most of the C atoms in extractives were contained in the structures of C-C, C-COOR, and C-O. TEM-EDS and EPMA analyses were used to detect trace amount elements, such as Al, Si, P, S, Cl, and Ca atoms. Detailed characterization of extractable species from WS can provide more information on elucidation of extractives in biomass

(E)-Methyl N′-(3,4-dimethoxy­benzyl­idene)hydrazinecarboxyl­ate

The title compound, C11H14N2O4, crystallizes with two independent but essentially identical mol­ecules in the asymmetric unit. Each mol­ecule adopts a trans configuration with respect to the C=N bond. Mol­ecules are linked into a one-dimensional network by inter- and intra­molecular N—H⋯O and C—H⋯O hydrogen bonds

Electrical properties of yttrium calcium oxyborate crystal annealed at high temperature and low oxygen partial pressure

The yttrium calcium oxyborate crystal (YCa 4 O(BO 3 ) 3 , YCOB) has been actively studied for high-temperature piezoelectric sensing applications. In this work, the stability of electric properties of YCOB crystal annealed in critical conditions (high-temperatures of 900-1100 °C with a low oxygen partial pressure of 4 x 10 −6 atm for 24 h) was investigated and the recovery mechanism for the electrical resisitivity, dielectric permittivity and dielectric loss were studied, taking advantage of the X-ray photoelectron spectra and the first principle calculations. The electrical resistivity of the annealed YCOB crystal was slightly decreased when compared to the pristine counterpart, being (2-5) x 10 7 Ω cm at 850 °C. The dielectric permittivity and dielectric loss were found to increase after annealing, showing recoverable behaviours after thermal treatment above 650 °C in air. The calculated vacancy formation energy indicate that the oxygen vacancy is the dominant defects in YCOB. The formation of oxygen vacancy weakens the chemical bonding strength between B (Ca or Y) and O atoms, introduces extra donor levels in the band gap, which excites the electrons to conduction band more easily thus enhances the electrical conductivity and dielectric loss. The recovered electrical properties are believed to be associated with the reduced vacancy defects at elevated temperatures in air

Diethylene glycol poisoning and liver function following accidental diethylene glycol injection

The aim of the present study was to investigate the hepatotoxic effects of accidental intravenous diethylene glycol (DEG) poisoning in patients with liver disease. Clinical manifestations were recorded and liver function tests were carried out for 64 patients with liver disease who had been accidentally treated intravenously with DEG. Comparisons were made between the poisoned and non-poisoned groups. Of the 64 cases with preexisting liver disease, 15 cases (23.4 %) developed toxic presentations after exposure to DEG. All cases were men. Twelve of the 15 poisoned patients (80 %)died within seven days. The intravenous administration of DEG resulted in only mild liver function impairment. Gender (p = 0.039) and the severity of jaundice prior to DEG administration were risk factors related to the occurrence of toxin-induced renal failure (p < 0.006). The results suggest that DEG may worsen liver damage in patients with preexisting liver disease. However, our study demonstrated only mild, transient alterations in patients’ baseline liver functions. Severe liver damage secondary to DEG was only occasionally seen in patients with concomitant renal failure

(E)-Ethyl N′-(3,4-dimethoxy­benzyl­idene)hydrazinecarboxyl­ate monohydrate

In the title compound, C12H16N2O4·H2O, the mol­ecular skeleton of the hydrazinecarboxyl­ate is nearly planar [within 0.053 (3) Å]. In the crystal, chains propagating along the c axis arise, composed of alternating hydrazinecarboxyl­ate mol­ecules and crystalline water, which inter­act via N—H⋯O and O—H⋯O hydrogen bonds