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91.
We propose the test statistic to check whether the nonparametric func-tions in two partially linear models are equality or not in this paper. We estimate the nonparametric function both in null hypothesis and the alternative by the local linear method, where we ignore the parametric components, and then estimate the parameters by the two stage method. The test statistic is derived, and it is shown to be asymptotically normal under the null hypothesis. 相似文献
92.
Se Hee Kim 《Tetrahedron letters》2009,50(25):3038-2060
An expedient protocol for the synthesis of β-aralkyl cycloalkanones was developed via the conjugate addition of allyl arylacetate to cycloalkenones and the following Pd-catalyzed decarboxylative protonation strategy. 相似文献
93.
Born differential cross sections and the lowest-order radiative correction to them are obtained in the kinematics of large-angle
final photon emissions in high-energy electron-positron annihilation processes. Taking into account the possible emission
of real soft and hard photons in collinear kinematics, we show the validity of the Drell-Yan form of the differential cross
section with the nonsinglet structure functions of the initial leptons. The leading and next-to-leading contribution to the
cross sections is obtained. The relevant numerical estimations are presented.
The text was submitted by the authors in English. 相似文献
94.
Woo‐Hyung Lee Hoyoul Kong Se‐Young Oh Hong‐Ku Shim In‐Nam Kang 《Journal of polymer science. Part A, Polymer chemistry》2009,47(1):111-120
A series of modified thiophene groups containing PPV‐based semiconducting materials, poly[(2,5‐bis(octyloxy)‐1,4‐phenylenevinylene)‐alt‐(2,2′bithienylenevinylene)] ( PPBT ), poly[(2,5‐bis(octyloxy)‐1,4‐phenylenevinylene)‐alt‐(5,5‐thiostilylenevinylene)] ( PPTVT ), have been synthesized through a Horner coupling reaction. From the FTIR and 1H NMR spectroscopy, the configuration of the vinylene groups in the polymers was all trans (E) geometry. The weight‐average molecular weights (Mw) of PPBT and PPTVT were found to be 11,700 and 11,800, with polydispersity indices of 2.51 and 2.53, respectively. PPBT and PPTVT thin films exhibit UV–visible absorption maxima at 538 and 558 nm, respectively, and the strong absorption shoulder peaks at 578 and 602 nm, respectively. Solution processed field‐effect transistors (FET) fabricated using all the polymers showed p‐type OTFT characteristics. The field‐effect mobility of the PPTVT was obtained up to 2.3 × 10?3 cm2 V?1 s?1, an on/off ratio of 1.0 × 105 with ambient air stability. Studies of the atomic force microscopy (AFM) and X‐ray diffraction (XRD) analysis of the polymer thin films revealed that all the polymers were amorphous structure. The greater planarity and rigidity of PPTVT compared to PPBT results in elongation of conjugation length and better π–π stacking of polymer chains in amorphous region, which leads to improved FET performance. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 111–120, 2009 相似文献
95.
Apparent molal heat capacities as a function of the degree of neutralization have been determined for dilute aqueous solutions of poly(acrylic acid) (PAA), poly(methacrylic acid) (PMA), copoly(maleic acid-ethylene) (MAEt), and copoly(maleic acid-styrene) (MASt) using direct flow microcalorimetry. Apparent molal volumes were measured as well. Both molal heat capacity and molal volume decrease with increasing ionization of the polymer. The effect of the hydrophobic interactions of the methyl group or phenyl group was obtained from the difference in the molal quantities of PMA and PAA, or MASt and MAEt. No evidence of hydrophobic effects, as determined from the heat capacity, was found for the conformational transition of PMA, but the hydration of the phenyl groups in MASt was found to be changed significantly at a degree of neutralization of 0.4. 相似文献
96.
In Jung Chang Myung Gil Choi Yong Ae Jeong Sang Hun Lee Suk-Kyu Chang 《Tetrahedron letters》2017,58(5):474-477
A new Cu2+-selective colorimetric sensor was developed by combining the chromophore 3-hydroxynaphthalimide with diaminomaleonitrile. The sensor showed Cu2+-selective colorimetric signaling behavior in dimethylsulfoxide, indicated by a solution color change from yellow to pink, which was readily discernible without any external devices. Practical application of the sensor to the detection of Cu2+ in an aqueous solution containing other environmentally relevant metal ions by selective two-phase liquid-liquid extraction with ethyl acetate was possible. Particularly, extractive signaling of Cu2+ in simulated semiconductor wastewater with a readily-usable smartphone as a colorimetric data capture and analysis tool was successfully conducted. 相似文献
97.
Poly-substituted naphthalenes were synthesized via a Pd-catalyzed cyclization of modified Baylis–Hillman adducts having an o-bromophenyl acetonitrile moiety at the secondary position, in reasonable yields. The reaction involved a sequential 6-endo Heck reaction and an aerobic oxidation process. 相似文献
98.
A sensitive fluoroimmunoassay (FIA) was developed for the determination of human chorionic gonadotropin (β-HCG). It is based on fluorescent polymer nanoparticles (PFNPs) coated with anti-β-HCG monoclonal antibodies in a sandwich type of fluoroimmunoassay. The PFNPs were synthesized by precipitation polymerization using methacrylic acid (MAA) as the monomer, trimethylolpropane trimethacrylate as the cross-linker, azobisisobutyronitrile as the radical initiator, and fluorescein as the fluorophore. Anti-β-HCG monoclonal antibody was labeled with the PFNPs and then used in a FIA of β-HCG in human serum samples using low-fluorescent transparent 96-well microtiter plates. The calibration graph for β-HCG is linear over the range from 1.25 to 300 mIU mL-1 with a detection limit of 0.3 mIU mL-1 (3σ). The relative standard deviation for seven parallel measurements of 10 mIU mL-1 of β-HCG is 3.8%. The method has the specificity of an immunoassay and the sensitivity of fluorescent nanoparticle label technology. 相似文献
99.
100.
Zhouping Wang Nuo Duan Xu Hun Shijia Wu 《Analytical and bioanalytical chemistry》2010,398(5):2125-2132
A highly selective electrochemiluminescent biosensor for the detection of target nephrotoxic toxin, ochratoxin A (OTA), was
developed using a DNA aptamer as the recognition element and N-(4-aminobutyl)-N-ethylisoluminol (ABEI) as the signal-producing compound. The electrochemiluminescent aptamer biosensor was fabricated by
immobilizing aptamer complementary DNA 1 sequence onto the surface of a gold-nanoparticle (AuNP)-modified gold electrode.
ABEI-labeled aptamer DNA 2 sequence hybridized to DNA 1 and was utilized as an electrochemiluminescent probe. A decreased
electrochemiluminescence (ECL) signal was generated upon aptamer recognition of the target OTA, which induced the dissociation
of DNA 2 (ABEI-labeled aptamer electrochemiluminescent probe) from DNA 1 and moved it far away from the electrode surface.
Under the optimal conditions, the decreased ECL intensity was proportional to an OTA concentration ranging from 0.02 to 3.0 ng mL-1, with a detection limit of 0.007 ng mL-1. The relative standard deviation was 3.8% at 0.2 ng mL-1 (n = 7). The proposed method has been applied to measure OTA in naturally contaminated wheat samples and validated by an official
method. This work demonstrates the combination of a highly binding aptamer with a highly sensitive ECL technique to design
an electrochemiluminescent biosensor, which is a very promising approach for the determination of small-molecule toxins. 相似文献