Zhikai Li - Academia.edu (original) (raw)

Papers by Zhikai Li

A 2.6GHz Class-AB GaN Power Amplifier with Maximum Output Power of 56W Achieving 70% Power Added Efficiency

2018 1st Workshop on Wide Bandgap Power Devices and Applications in Asia (WiPDA Asia)

SSRN Electronic Journal, 2000

We address how value relevance of accounting information evolved as the new economy developed. Pr... more We address how value relevance of accounting information evolved as the new economy developed. Prior research concludes accounting information-primarily earnings-has lost relevance. We consider more accounting amounts and find no decline in combined value relevance from 1962 to 2014. We assess evolution in each amount's value relevance and find increases, most notably for amounts related to intangible assets, growth opportunities, and alternative performance measures, which are important in the new economy. The number of relevant amounts also increases. We also consider separately new economy, non-new economy profit, and non-new economy loss firms. Although the relevance trends are most pronounced for new economy firms, they are economy-wide. We base inferences on a non-parametric approach that automatically incorporates nonlinearities and interactions, thereby unconstraining the valuation relation. Taken together, our findings reveal a more nuanced, but not declining, relation between share price and accounting information that reflects the new economy.

System and method for providing a guided tour of a web site

A Simulation Study on Intracluster Correlation

Imecs, 2006

Implementation of Latest International Guidelines on Financial Intermediation Services

Macrocell comprised of two look-up tables and two flip-flops

Fluid Handling Cassette System for Body Fluid Analyzer

The two decompositions in the title of a semisimple Lie group are well-established [see S. Helgas... more The two decompositions in the title of a semisimple Lie group are well-established [see S. Helgason, Differential geometry, Lie groups, and symmetric spaces. Providence, RI: American Mathematical Society (AMS) (2001; Zbl 0993.53002)]. In this paper, we prove these decompositions of G=SO 0 (n,1) by elementary methods using the geometry of G/K where K≃SO(n).

Ultra-high sensitivity photodetector arrays with integrated amplification and passivation nano-layers

Optical Components and Materials VII, 2010

Miniaturized field-deployable spectrometers used for the rapid analysis of chemical and biologica... more Miniaturized field-deployable spectrometers used for the rapid analysis of chemical and biological substances require high-sensitivity photo detectors. For example, in a Raman spectroscopy system, the receiver must be capable of high-gain, low-noise detection performance due to the intrinsically weak signals produced by the Raman effects of most substances. We are developing a novel, high-gain hetero-junction phototransistor (HPT) detector which employs two nano-structures simultaneously to achieve 100 times higher sensitivity than InGaAs avalanche photodiodes, the most sensitive commercially available photo-detector in the near infrared (NIR) wavelength range, under their normal operation conditions. Integrated into a detector array, this technology has application for Laser-Induced Breakdown Spectroscopy (LIBS), pollution monitoring, pharmaceutical manufacturing by reaction monitoring, chemical & biological transportation safety, and bio-chemical analysis in planetary exploration.

Exploration of mechanisms by which production of C3 by dendritic cells (DCs) modulates their function of antigen presentation

Molecular Immunology, 2007

The Research of Group Hierarchy Access Control in E-Government System

Advanced Materials Research, 2013

In order to meet the requirements of E-Government System with complex user relationships and dive... more In order to meet the requirements of E-Government System with complex user relationships and diversified business process , this paper proposed an advanced RBAC model named Group Hierarchy Role-Based Access Control (GH-RBAC). In this model, tradition user role assignment have been reformed to multilayer user group role group assignment which improve the scalability and adaptability of access control. Finally, we design and implement the extend model which emphasis the way to carry out access control module with the low coupling.

A preliminary study on the occurrence and behavior of sulfonamides, ofloxacin and chloramphenicol antimicrobials in wastewaters of two sewage treatment plants in Guangzhou, China

Science of The Total Environment, 2006

Wastewater samples collected from two sewage treatment plants (STPs) in Guangzhou, China were aci... more Wastewater samples collected from two sewage treatment plants (STPs) in Guangzhou, China were acidified, solid-phase extracted (SPE) with Oasis HLB cartridges, followed by instrumental measurement by high performance liquid chromatography (HPLC) coupled with a diode array UV detector (DAD) and a fluorescence detector (FLD) for the occurrence and fate of antimicrobial compounds sulfadiazine (SDZ), sulfamethoxazole (SMX), ofloxacin (OFX) and chloramphenicol (CAP). Antimicrobials have been detected at 5.10-5.15, 5.45-7.91, 3.52-5.56 and 1.73-2.43 microg L(-1) for SDZ, SMX, OFX and CAP in the raw sewages of the two STPs, respectively. The concentrations of antimicrobials do not show substantial changes after preliminary mechanical sedimentation. No quantifiable sulfonamides and chloramphenicol have been identified, and &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;85% of ofloxacin has been removed in the effluents after activated sludge treatment in the two STPs, indicating that activated sludge treatment is effective and necessary to remove antimicrobial substances in municipal sewage.

Identification of PAH-DNA Depurinating Adducts by Means of Fluorescence Line Narrowing Spectroscopy

Polycyclic Aromatic Compounds, 1996

PAH carcinogens like benzo[a]pyrene, 7,12 dimethyl benz[a]anthracene, and most recently the extre... more PAH carcinogens like benzo[a]pyrene, 7,12 dimethyl benz[a]anthracene, and most recently the extremely potent dibenzo[a,l]pyrene have been found to react at the N3 or N7 positions of adenine or at the N7 or C8 positions of guanine. These reactions, which may proceed via a radical cation mechanism or via the diolepoxide pathway, lead to loss of the base (depurination) and leave

Evaluation of the HP 6890/5973 bench-top gas chromatograph/mass selective detector for use in mobile laboratories

Journal of Hazardous Materials, 2003

Introduced in 1996, the Agilent (Hewlett Packard) HP 6890/5973 GC/MSD system is the latest of the... more Introduced in 1996, the Agilent (Hewlett Packard) HP 6890/5973 GC/MSD system is the latest of the bench-top GC/mass spectrometry (MS) family. Started with the HP 5970 MSD, introduced in the mid-1980s, has provided small/medium size laboratories with the power of a true MS that provides selectively and library-searchable capability. This paper presents study results on instrumental sensitivity achieved with the new MSD, with examples illustrating trace-level analysis of semi-volatile compounds such as PCB and Dioxins. Investigations were carried out to study the effect of some operational parameters such as ionisation energy, dynode voltages and dwell time. In the standard electron impact selected ion monitoring (SIM) mode, the new MSD can provide sub-picogram level sensitivity for chlorinated hydrocarbons. In scan mode, under optimal condition, the system can generate library-searchable spectra from sub-nanogram quantity of analytes. This sensitivity level rivals traditional GC with selective detectors such as electron capture detector but at the same time possesses the advantage of computerised library search against a database of over 100 thousand spectra. The relatively compact size makes the system practical in a mobile laboratory, providing qualitative as well as quantitative data in spill emergencies analyses.

Microbial Growth Estimation in Liquid Media Exposed to Temperature Fluctuations

Journal of Food Science, 1993

ABSTRACT Comparisons of linear, square root and Arrhenius specific growth rate-temperature models... more ABSTRACT Comparisons of linear, square root and Arrhenius specific growth rate-temperature models showed no clear overall preference. At low aw and refrigeration temperature, the linear model was satisfactory for Brochothrix thermosphacta and ...

Phenol and methylphenol isomers determination in soils by in-situ microwave-assisted extraction and derivatisation

Journal of Chromatography A, 1997

... A Phenol and methylphenol isomers determination in soils by insitu microwaveassisted extracti... more ... A Phenol and methylphenol isomers determination in soils by insitu microwaveassisted extraction and derivatisation aa MP Llompart , RA Lorenzoa, R. Cela &#x27; , JR Jocelyn Par6b, Jacqueline MR Brlangerb ... V. Lopez-Avila, R. Young, J. Benedicto, P. Ho, R. Kim and WF Beckert. ...

Food Chemistry, 2011

Various dietary fibres (DF) from rice flours of Taichung Sen 10 (TCS10) and Tainung 67 (TNu67) ri... more Various dietary fibres (DF) from rice flours of Taichung Sen 10 (TCS10) and Tainung 67 (TNu67) rice cultivars were isolated while their roles in governing the pasting and the rheological properties of the rice starch were examined. The addition of DF (at 5 wt.% on dry starch basis), most notably from TCS10 cultivar generally caused significant increases in swelling power and pasting viscosities of 10 wt.% rice starch dispersions. Furthermore, the addition of DF was found to improve the rheological parameters of the 10 wt.% rice starch gel. Nuclear magnetic resonance (NMR) relaxation measurements revealed that the water mobility of starch gel was decreased with the addition of DF. The statistically significant factors were concluded to be arabinoxylan-related compositions for the increments of pasting and rheological characteristics, meanwhile the swelling power and setback viscosity mainly depend on b-glucan compositions and arabinose-to-xylose molar ratio (R AX).

Optimization of acid hydrolysis conditions for total isoflavones analysis in soybean hypocotyls by using RSM

Food Chemistry, 2001

The optimum hydrolysis conditions of soybean hypocotyls with HCl for a quantitative HPLC determin... more The optimum hydrolysis conditions of soybean hypocotyls with HCl for a quantitative HPLC determination of total isoflavones (TI) were studied by using response surface methodology (RSM). HCl concentration (HC), hydrolysis time (HT) and reaction temperature (RT) were assumed to be the most important factors affecting hydrolysis for the determination of TI. Optimum hydrolysis conditions for maximizing the determination of TI were: HC=3.42N, HT=205.5 min and RT=44.6°C. The model had a satisfactory coefficient of R2 (=0.967) and was verified experimentally. Furthermore, the recovery of individual isoflavones was 97–100% under the optimum hydrolysis conditions. The results suggested that the conditions were mild and useful for maximizing a quantitative HPLC determination of TI in soybean hypocotyls.

Food Chemistry, 2009

The yield, major phytochemicals (oryzanols, tocopherols (T), and tocotrienols (T3)) and antioxida... more The yield, major phytochemicals (oryzanols, tocopherols (T), and tocotrienols (T3)) and antioxidant properties of Japonica rice bran extracts were investigated, for illustrating the major effects from solvent property. Generally, the extract yield varied with the solvent used in the order of methanol (MeOH) > ethyl acetate (EtOAc) > hexane. In contrast to hexane extracts, both MeOH and EtOAc extracts exhibited a higher total content in phenolic compounds ($2.5 g gallic acid equivalent/kg bran), oryzanols (1.6-1.8 g/kg bran), or tocols (126-130 mg/kg bran), and a higher T3% in tocols (24-26%). The MeOH extract (at 1 mg/ml) showed the greatest capability in inhibiting linoleic acid peroxidation (57%), scavenging DPPH radicals (93%), reducing power (78%), and Fe 2+ chelating activity ($1300 lg EDTA equivalent/g) than the other two extracts, partly attributed to its high antioxidant contents. It is newly found that the yield, total content in phenolic compounds, oryzanols, and tocols, and T3% in tocols of the extracts increased with increasing Synder's polarity value in a quite good linear manner (R 2 = 0.923-1.000), associated with an increased solvent viscosity. This clearly suggests the potential of using Synder's polarity value as an index in isolation of desired rice bran phytochemical extracts.

Unsupervised learning for neural trees

Neural Networks, 1991. …, 1991

A self-organizing neural tree is studied. The neural tree is suited to hierarchical classificatio... more A self-organizing neural tree is studied. The neural tree is suited to hierarchical classifications. Unsupervised learning algorithms have been developed for the neural tree. A simulation study indicated that the vectors represented by the nodes of the tree tend to ...