129 research outputs found
Book Review: Urban Structure Matters
No full textJTLU, vol. 2, no. 1, (2009) pp. 81-83.The author reviews the book Urban Structure Matters by Petter Naess (Routledge, 2006).Chen, Xueming. (2009). Book Review: Urban Structure Matters. Retrieved from the University Digital Conservancy, 10.5198/jtlu.v2i1.107
Paleoproterozoic crustal growth in the North China Craton: evidence from the Luliang Complex
No full textAbstract not availableM. Santosh, Qiong-Yan Yang, Xueming Teng, Li Tan
Coexistence of strong and weak pulses in a fiber laser with largely anomalous dispersion
No full textThe coexistence of weakly sech-shaped solitons and strongly dissipative solitons is experimentally observed in an ultra-large net-anomalous-dispersion mode-locked fiber laser for the first time to author's best knowledge. Both sech-shaped and dissipative solitons appear to be the asymmetrically combined pulse state with one pulse component much smaller than the other. The energy of dissipative solitons is over three orders of magnitude larger than that of sech-shaped solitons. Two different types of pulse-shaping mechanisms coexist in the laser: one is the dissipative processes and the other is the balance between anomalous dispersion and nonlinear Kerr effect. Numerical simulations and analysis confirm the experimental observations. (c) 2011 Optical Society of Americ
Defect engineering coupled with pulsed laser annealing for p+/n junction formation and pMOSFETs device enhancement
No full textThe aggressive miniaturization of the MOS technology as anticipated by the Moore’s law, demands for the constant exploration of novel methods to obtain highly activated and abrupt shallow junctions. As the devices shrink down to nanoscale dimensions, it is becoming increasingly challenging to keep up with the scaling trend. Major issues arising from defect generation during the fabrication processes resulted in
anomalous phenomena such as Boron transient enhanced diffusion and dopant-defect clustering. Typically, these two effects caused adverse impact to the dopant diffusion and
deactivation, hindering the formation of good semiconductor junction characteristics. Tremendous efforts have been devoted to discover new solutions for resolving these daunting problems. One of the most promising techniques proposed is the usage of the advanced defect engineering. The main objective of this research work is to leverage on the various defect engineering methodologies to improve junction characteristics and to subsequently enhance the device performance. The defect engineering approaches were studied in depth to understand fundamentally the dopant diffusion and activation phenomenon in implanted substrates. Defects that generally contribute to junction degradation are
interstitial-type defects introduced by ion implantation. By monitoring the defect-dopant relationship and their associated interaction mechanisms, one can appropriately engineer
and optimize the junction properties. The thesis investigates and reports on two novel defect engineering techniques. One method utilizes the melt laser pre-irradiation to reduce the detrimental end-of-range defects. The mechanism is based on facilitating the recombination of the vacancy defects generated at the maximum laser melt depth with theinterstitials from the implantation induced end-of-range band. With a significant
reduction in the end-of-range defects via vacancy-interstitial annihilation, superior junction profile with low junction leakage current is realizable. Another technique involves the implementation of the high energy implantation for substrate modification. The concept is basically to create a spatial separation between the interstitial and vacancy point defects. High vacancy concentration present near the surface region promotes dopant activation. Repulsion of the interstitial defects to a relatively deep substrate depth minimizes the probability of interaction with the dopants, thereby suppressing dopant deactivation and diffusion. In addition, the creation of an intermediate amorphous layer serves as a diffusion barrier for both the downward dopant diffusion and up-migrating interstitial defects. Laser annealing has been demonstrated to be an attractive option for the formation of ultra-shallow junction due to several of its favorable features and advantages. It has a near-zero thermal budget capable of producing highly activated shallow junctions with high degree of abruptness. Integration of this advanced mode of annealing allows for a diffusionless junction with remarkable dopant activation exceeding the solid solubility limit of the substrate. The combination of both processes provide for a potentially viable option to satisfy the progressive scaling requirements in junction formation. By coupling the merits of both defect engineering and laser annealing, superior junction characteristics and significant improvement in the device electrical performance were demonstrated. Laser induced vacancies was verified to be highly effective in reducing and annihilating the implantation generated interstitial defects via the recombination mechanism of the two defect species. A 2-time enhancement in the forward current and a 50 % reduction of the reverse leakage current was reported for the laser pre-irradiated diode devices. Similar enhancement in the electrical characteristics was observed with the integration of the laser vacancy defect engineering process into transistor device. High energy defect engineering implant with a high dose implemented with low fluence laser annealing suppresses the leakage current and simultaneously achieves shallow junction formation. The key concept is to engineer the implantation induced amorphous silicon under-layer to become an insulator. Silicon germanium substrate with moderate doping of carbon was determined to attain the lowest sheet resistance. This provides for a compatible and promising technology for the advanced CMOS technology.Doctor of Philosophy (EEE
A dual-wavelength sampled fiber Bragg grating and its application in L-band dual-wavelength erbium-doped fiber lasers
No full textA novel dual-wavelength (DW) sampled fiber Bragg grating (SFBG) is proposed and demonstrated for the first time to the author's best knowledge. This kind of SFBG can realize a DW operation with uniform reflection peaks rather than multiple nonuniform peaks shown in conventional SFBGs. Based on the designed SFBG, we have proposed a novel L-band DW erbium-doped fiber laser, which has such a unique merit that the spacing of the two wavelengths keeps unchanged during tuning laser
Design of superstructure fiber Bragg gratings with a Fourier analysis technique and its applications to multiple ultranarrow transmission gratings
No full textSuperstructure fiber Bragg gratings (FBGs) have been comprehensively analyzed with Fourier theory and experimentally demonstrated. By using Fourier transforms, it has been proven that (1) the traditional uniform FBG produces only a single response in the spectrum, (2) multiple phase-sampled gratings can be regarded as independent interleaved FBGs with different phases, and (3) the multiple phase sampling technique has the capacity to densify the spectral channels. Based on Fourier theory, for the first time to the author's knowledge, a kind of superstructure FBGs with multiple ultranarrow transmission windows, obtained by introducing a pi phase shift into the center of grating, is proposed and has been confirmed experimentally. (C) 2008 Society of Photo-Optical Instrumentation Engineers. [DOI: 10.1117/1.3006090
Reconfiguration of the proteasome during chaperone-mediated assembly
No full textThe proteasomal ATPase ring, comprising Rpt1-Rpt6, associates with the heptameric α ring of the proteasome core particle (CP) in the mature proteasome, with the Rpt C-terminal tails inserting into pockets of the α ring[superscript 1-4]. Rpt ring assembly is mediated by four chaperones, each binding a distinct Rpt subunit[superscript 5-10]. We report that the base subassembly of the proteasome, which includes the Rpt ring, forms a high affinity complex with the CP. This complex is subject to active dissociation by the chaperones Hsm3, Nas6, and Rpn14. Chaperone-mediated dissociation was abrogated by a nonhydrolyzable ATP analog, indicating that chaperone action is coupled to nucleotide hydrolysis by the Rpt ring. Unexpectedly, synthetic Rpt tail peptides bound α pockets with poor specificity, except for Rpt6, which uniquely bound the α2/α3 pocket. Although the Rpt6 tail is not visualized within an α pocket in mature proteasomes[superscript 2-4], it inserts into the α2/α3 pocket in the base-CP complex and is important for complex formation. Thus, the Rpt-CP interface is reconfigured when the lid complex joins the nascent proteasome to form the mature holoenzyme
Travel Recommendation via Author Topic Model Based Collaborative Filtering
No full textMinistry of Education, Singapore under its Academic Research Funding Tier
Management of economic security in the field of financial and credit relations
No full textScientific advisor: Morozova N., PhD in economics, associate professor, department management, business and professional communicationsThe object of research is a process of ensuring economic security in the field of financial and credit relations. The subject of research covers the scientific and methodological principles and practical aspects of ensuring the economic security of the banking system as an important component of the financial and credit sphere of the economy. The purpose of the master's thesis is a theoretical justification and development of practical proposals for strengthening the economic security of the banking system and participants in financial and credit relations in conditions of economic instability. Tasks of a qualifying master's thesis include: to reveal the essence and role of economic security in the financial and credit sphere; to study the peculiarities of the system of financial and economic security of the banking sector and approaches to assessing its effectiveness; summarize the strategic aspects of ensuring the economic security of subjects of financial and credit relations; to analyze the level of economic security of the banking system of Ukraine; provide the organizational and economic characteristics of Credit Agricole Bank JSC; to assess the level of economic security of Credit Agricole Bank JSC; to generalize promising directions for strengthening the economic security of the banking system of Ukraine; justify directions for improving the subsystems of ensuring the economic security of the banking sector of the Ukrainian economy; to determine the peculiarities of credit risk management of banking institutions in the conditions of martial law. Based on the results of the research, theoretical and practical provisions have been formulated, which the author has developed into concrete proposals for ensuring economic security in the field of financial and credit relations
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