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A multilayer coal bed methane system with a complex superimposed relationship developed vertically in the Gujiao block. Taking the cumulative thickness of mudstone between neighbouring coal seams and open faults as object of research, the key strata for the division of different CBM systems was defined. The connection of an open fault for the fluid pressure system and the spatial distribution of the CBM system were analysed. The results showed that the porosity of compact mudstone is extremely low. When the mudstone thickness of the roof and floor increases, the gas content increases. Taking the Lijiashe and Wangzhimao faults as the boundary lines, the fluid pressure gradient between the Shanxi and Taiyuan formations is less than 0.08 MPa /100 m in the northern fracture zone, such as the Zhenchengdi, the Xiqu, the Tunlan, and the northern Dongqu well fields. The vertical gas units of different strata may belong to the same CBM system. The structure is simple in the southern Lijiashe fault. The vertical gas units in the southern Lijiashe fault belong to different CBM systems. Combined with the minimum thickness of the mudstone layer (2 m) and coal seam (0.5 m) standards, the spatial distribution of CBM systems was analysed.

Based on first-principles calculations, we have studied the crystal, electronic structure and optical properties in both wurtzite and zinc blend structure of AlN doped with rare-earth element Er. T...

We present a 10-GHz granularity reconfigurable WDM superchannel filter in a photonic integrated circuit. The filter uses a ring-resonator-assisted tapped-delay-line topology. An example configuration with two ring resonators and four tapped delay lines provides a spectral filter with a flat-top passband, a roll-off factor of 8%, a tunable central wavelength, and a selectable free spectral range, i.e., 2× or 4× the 3-dB passband bandwidth. The device was fabricated in a silicon nitride (Si3N4/SiO2) waveguide with a chip area of 0.36 cm2 and has a fiber-to-fiber insertion loss of 5 dB. We experimentally demonstrate the filter for selecting a subchannel from a WDM superchannel comprising 10-GHz subchannels with 10% and zero guard bands. Owing to the infinite impulse responses of ring resonators, this filter requires a significantly smaller area and fewer tuning elements compared with designs based on only tapped-delay-line finite-impulse-response filters. This paper contributes to the creation of chip-scale all-optical WDM superchannel transceivers and reconfigurable optical add/drop multiplexers (ROADMs).

The roof, floor and gangue samples of coal seams were collected from a borehole in the Gujiao mining area. The vertical distribution of major elements, trace elements and rare earth elements (REEs) was tested through X-ray fluorescence spectrometry and inductively coupled plasma-mass spectrometry (ICP-MS). The formation environment and material source of the strata were analysed. The results showed that the major elements of the coal seam roof, floor and gangue are Si and Al, followed by Fe, K, and Ti. In the Shanxi Formation, Sn, B, Ta, Bi, Th, U, Li, Be, Nb, In, Cs and Hf are enriched. In the Taiyuan Formation, B, Bi, U, Li, Sr, Mo and Sb are enriched. Sn, B, Th, U, and Be of the Shanxi Formation and B, U, Mo, and Sb of Taiyuan Formation are enriched hazardous elements. The ratios of Sr/Ba, U/Th, Ni/Co and V/Cr could indicate the paleosalinity and redox conditions. The Shanxi Formation was mainly formed in an oxic environment. The roof and floor of the No. 7 coal and the roof of the No. 8 coal are limestone, indicating anoxic and suboxic to dysoxic environments. The lithology of the Shanxi Formation and Taiyuan Formation material source is complex, including sedimentary rocks, granite and alkaline basalt. Most samples are distributed at the intersection of the granite and alkaline basalt, indicating dual sourcing from the granite and alkaline basalt.

With the combination of molecular simulation and relevant experiments, the efficient Bronsted-Lewis acidic ionic liquid (IL) was designed and synthesized for biodiesel production from soapberry oil. In molecular simulation, 4-methylthiazole (MT) is proved to be the best matrix for IL preparation via electrostatic potential analysis and proton affinity analysis, and it also is verified by experiments. In orthogonal experiment, the relationship in catalytic activity between Bronsted-Lewis acidic IL and corresponding materials (Bronsted acidic IL and metal chloride) was revealed. Meanwhile, [Ps-MTH][CF3SO3] and FeCl3 are verified as the best materials for preparation of Bronsted-Lewis acidic IL, and [Ps-MTH][CF3SO3]-FeCl3(x = 0.65) is determined as the most efficient catalyst in the end. The Lewis acidity, Bronsted acidity and interaction of [Ps-MTH][CF3SO3] and FeCl3 in [Ps-MTH][CF3SO3]-FeCl3(x = 0.65) were characterized by FT-IR. And the catalytic mechanism of transesterification catalyzed by prepared IL was clarified. In order to maximize the biodiesel yield, optimization of process variables was conducted using Box-Behnken response surface methodology. The 97.04% of high biodiesel yield is obtained under the optimum conditions: reaction temperature was 127 °C, molar ratio (methanol to soapberry oil) was 27.96:1, catalyst amount was 3.06 mmol and reaction time was 8 h. Furthermore, [Ps-MTH][CF3SO3]-FeCl3(x = 0.65) presents good catalytic activity in different transesterification for biodiesel production. And its catalytic activity decreases from 97.04% to 93.59% after being used for 5 times, which reflects good reusability. The main properties of soapberry biodiesel were also measured and compared to the ASTM D6751 standard.

Chip-scale integrated optical signal processors promise to support a multitude of signal processing functions with bandwidths beyond the limit of microelectronics. Previous research has made great contributions in terms of demonstrating processing functions and device building blocks. Currently, there is a significant interest in providing functional reconfigurability, to match a key advantage of programmable microelectronic processors. To advance this concept, in this work, we experimentally demonstrate a photonic integrated circuit as an optical signal processor with an unprecedented combination of two key features: reconfigurability and terahertz bandwidth. These features enable a variety of processing functions on picosecond optical pulses using a single device. In the experiment, we successfully verified clock rate multiplication, arbitrary waveform generation, discretely and continuously tunable delays, multi-path combining and bit-pattern recognition for 1.2-ps-duration optical pulses at 1550 nm. These results and selected head-to-head comparisons with commercially available devices show our device to be a flexible integrated platform for ultrahigh-bandwidth optical signal processing and point toward a wide range of applications for telecommunications and beyond.

Coalbed methane (CBM) resources are abundant in Gujiao blocks, Xishan coalfield, China. However, there is little previous geological research regarding coalbed methane. Using a quantitative and qualitative index, the hydrocarbon source rocks and preservation conditions of No. 2, 8 and 9 coalbed methane systems in Gujiao blocks were evaluated through a multi-level fuzzy method. On this basis, the comprehensive favourable area of three CBM systems and multi-layer commingled production were predicted. The results showed that the comprehensive score trend of hydrocarbon source rocks in Gujiao blocks gradually increases from southeast to northwest. The comprehensive score trend of preservation conditions increases gradually from north to south. The No. 2 coalbed methane system of the Shanxi formation is given priority over level II, which is distributed in the central and southern study area. The No. 8 coalbed methane system of the Taiyuan formation is given priority over level III, followed by level IV. The No. 9 coalbed methane system of the Taiyuan formation is given priority over level II and level III, which is distributed in the central and southern study area. Most of the area is suitable for individual CBM exploitation of No. 8 coal. The favourable area for the No. 2+8 coal layer is located in parts of the central, south-western and south-eastern study area. The favourable area for No. 8+9 coal layer is located in the Dongqu well field and the southern Tunlan well field. The favourable area for No. 2+8+9 coal layer is located in the eastern Yang Zhuang well field.

Recent studies have shown that the poor flowability of waxy crude oil can be obviously improved by the application of an external electric field. Available studies about this novel technique to treat waxy oils focus on the efficacy of this technique while the sustainability of the efficacy is not well understood. In this work, the impacts of shearing and thermal cycling on the stability of the electric treatment efficacy were investigated. A representative waxy crude treated by electric field was subjected to shearing at different conditions and reheating to an elevated temperature and cooling, then the viscosity and the yield stress were inspected and wax particle microscopic images were observed to examine the impacts of shear and thermal histories on the sustainability of waxy crude oil flowability improvement by electric treatment. The experimental results show that the electric treatment efficacy of waxy crude oil gradually diminishes after the removal of electric field. However, shearing at a high shear rate and for a prolonged duration partially preserves the efficacy of the electric treatment and intensively shearing the electric treated oil provides some additional flowability improvement. The flowability improvement by electric treatment is weakened by reheating the treated oil to an elevated temperature. When the treated oil is heated above the wax dissolution temperature, the efficacy of the electric treatment is eventually eliminated. The results presented in this work further the understanding of the flowability improvement of waxy crudes by electric treatment.

Previous studies have shown that the application of a high-voltage electric field to a liquid or gelled waxy crude oil can significantly improve its cold flowability, such as reducing viscosity and yield strength. However, the mechanism of the electrorheological behaviors of waxy oils remains largely unknown. In this study, the impedance spectroscopy was firstly used to investigate the mechanism of the electrorheological behaviors of waxy oils. The impedance of the waxy oil increases and the conductivity decreases after an oil is exposed to electric fields. Based on this finding and with the aid of further experiments using model oils of controlled compositions, i.e. to control the absence of wax, resins and asphaltenes in the oil, interfacial polarization of wax particles was demonstrated as the primary and essential mechanism of the electrorheological behaviors. The interfacial polarization of wax particles means that charged colloidal particles in the oil, i.e., resins and asphaltenes, would accumulate on the surface of wax particles upon the application of the external electric field, and the resulted electrostatic repulsion will diminish the van der Waals force between wax particles, thus reducing viscosity and the strength of wax particle structure.

Integrated optical signal processors have been identified as a powerful engine for optical processing of microwave signals. They enable wideband and stable signal processing operations on miniaturized chips with ultimate control precision. As a promising application, such processors enables photonic implementations of reconfigurable radio frequency (RF) filters with wide design flexibility, large bandwidth, and high-frequency selectivity. This is a key technology for photonic-assisted RF front ends that opens a path to overcoming the bandwidth limitation of current digital electronics. Here, the recent progress of integrated optical signal processors for implementing such RF filters is reviewed. We highlight the use of a low-loss, high-index-contrast stoichiometric silicon nitride waveguide which promises to serve as a practical material platform for realizing high-performance optical signal processors and points toward photonic RF filters with digital signal processing (DSP)-level flexibility, hundreds-GHz bandwidth, MHz-band frequency selectivity, and full system integration on a chip scale., Nanophotonics, 7 (2), ISSN:2192-8614

Adsorption and desorption of coal to methane are substantially related to coal facies, referring to the production potential of a coalbed methane (CBM) well. Based on analyses of the stratified channel samples from coal seams No. 2, No. 4 and No. 9 in the Xiqu Drainage Area, Gujiao CBM Block, North China, the relationship between coal facies and adsorption-desorption behaviors was first proposed and discussed. Using the coal facies diagrams suggested by previous investigators, four types of coal facies were distinguished in the coal seams, including the upper delta plain wet forest swamp (I), the lower delta plain fen (II), the lower delta plain marsh (III) and the back barrier low moor (IV). The upper delta plain wet forest swamp occurred dominantly, developing at the bottom and top of all the coal seams. Both the ash yield and groundwater index (GWI) tend to increase from coal facies I to IV, whereas the volatile compounds, fixed carbon, organic sulfur, total sulfur, micropore volume and specific surface area, tissue preservation index (TPI) and vegetation index (VI) decreased, which indicates changes in the vegetation types, water supplements and disturbance, acid-base properties and redox conditions in the paleomires. Paleomire evolution accompanied the rise and drop of the sea level, with a transgression or regression process that could be represented by the coal facies sequence. Coal seams No. 2, No. 4 and No. 9 were discriminated into two, three and two evolving stages, respectively, and these stages were characterized by complete cycles, except stage 4-I from the lower delta plain marsh. Mudstone partings in the coal seams deposited during the highest sea level. Collectively, paleomire environments, especially the variation of vegetation types and mire water condition, result in adsorption and desorption divergences among different coal facies. Arborescent plants decrease from coal facies I to IV as the hydrodynamic intensity increases, leading to corresponding changes in botanical tissue preservation, medium oxidizability, mineral content and, ultimately, adsorption and desorption behaviors. In view of the gas content and desorption capacity of the coal layers in the same coal seam, the layers from the upper delta plain wet forest swamp may have the best potential for CBM drainage, followed by those from the lower delta plain fen and marsh, while those from the back barrier low moor may have the worst potential.

We compare the noise figure (NF) of chip-based tunable microwave photonic bandpass filters using stimulated Brillouin scattering (SBS) gain and loss responses, respectively. The filter using SBS loss scheme exhibits 10-dB lower NF than that using SBS gain scheme.

Asphaltenes are the most polar components of crude oils. The influences of asphaltene polarity on the wax deposition were studied in this investigation using model waxy oils. Asphaltenes contained by a Venezuelan crude oil were fractionated into four subfractions of different polarity utilizing a liquid/liquid extraction technique and used to prepare asphaltene-containing waxy model oils. The mass, composition, dielectric characteristics and mechanical characteristics of the waxy deposits formed in the presence of asphaltene fractions of different polarity were characterized. It was found that the less polar asphaltenes in waxy oils lower the deposit mass but cause the wax content of the deposits to increase. In addition, the inner diffusion of longer n-alkanes and the outer diffusion of shorter n-alkanes are accelerated by the less polar asphaltenes. Furthermore, the waxy deposits formed with waxy oils containing less polar asphaltenes are enriched with less amount of asphaltene and present reduced internal effective diffusion coefficient as was characterized by NMR. Besides, the presence of less polar asphaltenes causes the radius of Nyquist diagram of waxy deposits to increase, indicating higher resistance. Eventually, rheological characteristics, such as gelation temperature and yield stress, suggest increased structural strength of waxy deposits formed in the presence of less polar asphaltenes.

It has been reported that the application of a high-voltage electric field parallel to the oil flow direction or to a quiescent waxy crude oil can reduce the viscosity of the oil. In this work, an electric field perpendicular to the flow direction is applied to a flowing waxy crude oil in a rheometer equipped with in-situ electric field manipulation, and it is observed that viscosity reduction similar to that obtained with electric field parallel to the flow direction can also be achieved. This, therefore, confirms that the treatment efficacy is insensitive to the direction of the electric field compared to the oil flow direction. Moreover, the non-Newtonian characteristics of the treated crude oil become less significant, and more viscosity reduction is achieved at higher electric field strength and lower oil temperature. After the removal of the electric field, the reduced viscosity gradually recovers and the viscosity reduction disappears after about two days. Though it is found that the electric treatment causes an increase in wax crystal size and aggregation of particles to some extent, we think that weakened interaction between wax particles due to electric field exposure should be the primary reason of the viscosity reduction according to the knowledge of suspension rheology and the mechanism of waxy crude oil rheology.

Here, we develop the self-adaptive mechanical metamaterials (SMM) using shape memory polymers (SMPs) to obtain the programmable thermo-mechanical response under thermal excitations. The generalized fractional viscoelastic model of SMPs is expanded to the mechanical metamaterials with arbitrary corrugation patterns, and the effective material properties (i.e., effective Young’s modulus) are obtained for the theoretical characterization of the SMM. Theoretical models are developed to investigate the self-adaptive thermo-mechanical response (i.e., postbuckling response) of the SMM under thermal excitations using the modified couple stress theory. Parametric studies are carried out to investigate the tunability of the effective bending stiffness and temperature sensitivity. The SMM provide a promising strategy to exploit the performance of the mechanical metamaterials for temperature-triggered response with programmable self-adaption, and the reported theoretical models, comparing with the previous study, offer an effective approach to predict and maneuver the self-adaptive mechanical response for advanced technological devices, such as thermo-mechanical sensing devices.

// Ying Wang 1, 3, * , Bingyu Chen 3, * , Zhen Wang 3 , Wei Zhang 4 , Ke Hao 3 , Yu Chen 4 , Kaiqiang Li 3 , Tongtong Wang 4 , Yiwei Xie 3 , Zhihui Huang 1, 2 , Xiangmin Tong 1, 4 1 Key Laboratory of Laboratory Medicine, Ministry of Education, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China 2 Institute of Neuroscience and Hypoxia Medicine, Wenzhou Medical University, Wenzhou, Zhejiang, 325035, China 3 Department of Blood Transfusion, Zhejiang Provincial People’s Hospital, Hangzhou, Zhejiang, 310014, China 4 Clinical Research Institute, Zhejiang Provincial People’s Hospital, Hangzhou, 310014, China * These authors have contributed equally to this work Correspondence to: Xiangmin Tong, email: tongxiangmin11@163.com Zhihui Huang, email: hzhzju021@163.com Keywords: Marsdenia tenacissimae extraction, T-cell acute lymphoblastic leukemia, proliferation, apoptosis, PTEN Received: June 29, 2016 Accepted: October 03, 2016 Published: October 14, 2016 ABSTRACT Marsdenia tenacissimae extraction (MTE) as a traditional Chinese herb has long been used to treat some diseases such as tumors in China. However, the potential effectiveness of MTE in leukemia has not yet been fully understood, and the related molecular mechanism is still unknown. In the present study, we aimed to evaluate the effects of MTE on the proliferation and apoptosis of Jurkat cells (T-ALL lines) and lymphocytes from T-ALL (T-cell acute lymphoblastic leukemia) patients. Firstly, CCK8 assays and flow cytometry assays revealed that MTE dose-dependently reduced the proliferation of Jurkat cells by arresting cell cycle at S phase. Secondly, Annexin V-FITC/PI-stained flow cytometry and TUNEL staining assays showed that MTE promoted the apoptosis of Jurkat cells. Mechanistically, MTE enhanced PTEN (phosphatases and tensin homolog) level and inactivated PI3K/AKT/mTOR signaling pathway in Jurkat cells, which mediated the inhibition of cell proliferation by MTE and MTE-induced apoptosis. Finally, MTE significantly inhibited the proliferation and promoted the apoptosis of lymphocytes from T-ALL patients, compared with lymphocytes from healthy peoples. Taken together, these results reveal an unrecognized function of MTE in inhibiting the proliferation and inducing the apoptosis of T-ALL cells, and identify a pathway of PTEN/PI3K/AKT/mTOR for the effects of MTE on leukemia therapy.

We present a Nyquist-filtering optical (de)multiplexer using a ring resonator-assisted interferometer circuit. It features a near-rectangular passband spectrum, scalable port count, and can be designed with sub-GHz spectral resolution. The circuit can be constructed using ordinary passive photonic-integrated circuit building blocks. In contrast to its counterparts using tapped-delay-line circuit topologies, this circuit has a chip area two-orders-of-magnitude smaller. The results of this study show the potential for realizing high-spectral-efficiency multicarrier transceivers and reconfigurable optical add-drop multiplexers in a fully integrated form.

Architected metastructures with beam-like shape configurations have demonstrated promising mechanical performance due to their corrugation-induced geometric nonlinearity. Extensibility of the metabeams caused by corrugation plays a role in the geometric nonlinearity, which, however, has been omitted in the literature. Motivated by investigating the influence of stretching (or shrinking) on the mechanical characteristics, this study analytically and numerically investigates the metabeams designed with different corrugation patterns. A new discretized model is developed to considers the extensibility of the metastructures by modifying the Hencky bar-chain method (HBM). A size-dependent (i.e., length scale factor l) analytical model is developed using the modified couple-stress theory and closed-form results are obtained. Good agreements are observed between the HBM and theoretical results. Parametric studies are conducted to investigate the influence of extensibility and length scale factor on the mechanical behavior the metabeams with the rhombille, cylindrical, hexagonal and basketweave corrugations. Optimal pattern ratio (i.e., pattern diameter-to-pattern gap ratio D pat W pat ) and geometric ratio (i.e., width-to-thickness ratio W t ) are obtained by minimizing the self-weight of the patterned plates. The reported HBM accurately predict the mechanical behavior of extensible metabeams, which can be used to design plate-shaped advanced structures for applications requiring rigidity and well deformation recovery.

Recently, there has been a growing interest in deploying smart materials as sensing components of structural health monitoring systems. In this arena, piezoelectric materials offer great promise for researchers to rapidly expand their many potential applications. The main goal of this study is to review the state-of-the-art piezoelectric-based sensing techniques that are currently used in the structural health monitoring area. These techniques range from piezoelectric electromechanical impedance and ultrasonic Lamb wave methods to a class of cutting-edge self-powered sensing systems. We present the principle of the piezoelectric effect and the underlying mechanisms used by the piezoelectric sensing methods to detect the structural response. Furthermore, the pros and cons of the current methodologies are discussed. In the end, we envision a role of the piezoelectric-based techniques in developing the next-generation self-monitoring and self-powering health monitoring systems.

A novel wavelength-selective 2 × 2 optical switch based on a Ge 2 Sb 2 Te 5 (GST)-assisted microring-resonator (MRR) is proposed. The present GST-assisted MRR consists of two access optical waveguides and an MRR coupled with a bent GST-loaded silicon photonic waveguide. The 2 × 2 optical switch is switched ON or OFF by modifying the GST state to be crystalline or amorphous. In particular, the microring waveguide and the bent GST-loaded waveguide are designed to satisfy the phase-matching condition when the GST is crystalline. As a result, the MRR becomes highly lossy and the resonance peak is depressed significantly. On the other hand, when it is off, there is little coupling due to the significant phase mismatching. Consequently, one has a low-loss transmission at the drop port for the resonance wavelength. In this paper, the simulation using the three-dimensional finite-difference method shows that the extinction ratio of the designed photonic switch is ∼ 20 dB at the resonance wavelength, while the excess losses at the through port and drop port are 0.9 dB and 2 dB. In particular, the resonance wavelength changes little between the ON and OFF states, which makes it suitable for multichannel wavelength-division-multiplexing systems.

Radio frequency (RF) switches are essential for implementing routing of RF signals. However, the increasing demand for RF signal frequency and bandwidth is posing a challenge of switching speed to the conventional solutions, i.e., the capability of operating at a sub-nanosecond speed or faster. In addition, signal frequency reconfigurability is also a desirable feature to facilitate new innovations of flexible system functions. Utilizing microwave photonics as an alternative path, we present here a photonic implementation of an RF switch providing not only the capability of switching at a sub-nanosecond speed but also options of frequency doubling of the input RF signals, allowing for flexible output waveforms. The core device is a traveling-wave silicon modulator with a device size of 0.2 mm × 1.8 mm and a modulation bandwidth of 10 GHz. Using microwave frequencies, i.e., 15 GHz and 20 GHz, as two simultaneous RF input signals, we experimentally demonstrated their amplitude and frequency switching as well as that of the doubled frequencies, i.e., 30 GHz and 40 GHz, at a switching frequency of 5 GHz. The results of this work point to a solution for creating high-speed RF switches with high compactness and flexibility.

Flow assurance issues related to wax precipitation, are one of the most challenging problems in the pipeline transportation of waxy crude oils. Flowability of waxy oils can be improved by suitable pour point depressants (PPDs). Besides chemical treatments, exposing waxy oils to high-voltage electric fields can also significantly improve their cold flowability. However, the combined effect of electric fields and PPD on the flowability of waxy oils is not yet clear. In this investigation, the effect of the combined electrical and EVA treatment on the flow properties of a waxy crude oil was studied. It is found that the combined treatment can lead to more significant reductions in the viscosity, the yield stress and the thixotropy of waxy oils compared to oils treated solely by electric field or EVA. However, the overall improvement in the flowability achieved by the joint treatment is lower than the sum of improvements achieved by the electric field and EVA. The combined treatment outperforms the individual treatments for hours under a low shear of 10 s−1. However, the performance cannot be preserved even for minutes under a high shear of 1200 s−1. Reheating has a negative impact on the electrical treatment, but an intricate impact on the EVA treatment and the combined treatment. The electrical- and chemical performance both undermine upon reheating, but chemical performance can be partially recovered when reheating temperature is above the wax disappearance temperature. Microscopic observation showed that the combined treatment leads to larger size and broader size distribution of wax particles.

An ultrahigh-Q silicon racetrack resonator is proposed and demonstrated with uniform multimode silicon photonic waveguides. It consists of two multimode straight waveguides connected by two multimode waveguide bends (MWBs). In particular, the MWBs are based on modified Euler curves, and a bent directional coupler is used to achieve the selective mode coupling for the fundamental mode and not exciting the higher-order mode in the racetrack. In this way, the fundamental mode is excited and propagates in the multimode racetrack resonator with ultralow loss and low intermode coupling. Meanwhile, it helps achieve a compact 180° bend to make a compact resonator with a maximized free spectral range (FSR). In this paper, for the chosen 1.6 μm wide silicon photonic waveguide, the effective radius R eff of the designed 180° bend is as small as 29 μm. The corresponding FSR is about 0.9 nm when choosing 260 μm long straight waveguides in the racetrack. The present high-Q resonator is realized with a simple standard single-etching process provided by a multiproject wafer foundry. The fabricated device, which has a measured intrinsic Q-factor as high as 2.3 × 10 6 , is the smallest silicon resonator with a > 10 6 Q-factor.

Carotenoids represent a diverse class of aliphatic C40 molecules with a variety of applications in the food and pharmaceutical industries. Sporidiobolus pararoseus NGR produces various carotenoids, including torulene, torularhodin and β-carotene. Salt stress significantly increases the torulene accumulation of S. pararoseus NGR. However, little is known, about the molecular mechanisms underlying the increased torulene biosynthesis. In this work, we investigated the effects of NaCl treatment on the contents of carotenoids (both qualitatively and quantitatively) and transcriptome. A total of 12.3 Gb of clean bases were generated in six cDNA libraries. These bases were de novo assembled into 9,533 unigenes with an average length of 1,654 nt and N50 of 2,371 nt. Transcriptome analysis revealed that of 3,849 differential expressed genes (DEGs) in response to salt stress, 2,019 were up-regulated, and 1,830 were down-regulated. Among these DEGs, we identified three carotenogenic genes crtE, crtYB, and crtI. In addition, fourteen candidate genes were predicted to participate in the conversion from torulene to torularhodin. Our findings should provide insights into the mechanisms of carotenoid biosynthesis and salt-tolerance of S. pararoseus NGR.

This thesis explores and develops optical high spectral efficiency optical systems and wideband microwave photonic (MWP) subsystems using photonic integrated circuits (PICs). The thesis not only expands the application of PICs in optical communications and MWPs, but also proposes the solutions to some issues in PICs, and improve the merits to the design performance. The work promotes the development of PICs, opening a possibility for creating fully integrated, and multi-purpose optical processing ‘engine’ using a single device.

The Gujiao blocks are abundant in coalbed methane (CBM) resources. The reservoir pressure and pressure gradient in this area vary different for different mine fields. With increasing burial depth, the reservoir pressure increases. The reservoir pressure gradient ranges from 0.41 to 0.95 MPa/100 m; therefore, the reservoir can be classified as an under-pressurized reservoir. The southern region of the study area is a groundwater retention area, whereas the northern region is a runoff area. The gas content gradually increases from north to south. Taking the Miaogou limestone (L 1 ) and Xiedao limestone (L 4 ) as the boundary, three separate gas-bearing units can be divided vertically. The sequence stratigraphy structure is closely related to the quality of the CBM systems. The transgressive system formation provides a good sealing barrier that can be vertically divided into three CBM systems. In controlling the coal reservoir and the tectonic and hydrology conditions, components of the CBM system can communicate with each other in fracture development areas, which are suited for multi-layer drainage. However, we must design a method of development according to the law of diminishing fluid pressure of different CBM systems.

Active photonic circuits use combinations of active semiconductor devices and passive elements to support many applications. We present four functions on a single active photonic integrated circuit (4.5 mm × 4 mm).

Optical delay lines implemented in photonic integrated circuits (PICs) are essential for creating robust and low-cost optical signal processors on miniaturized chips. In particular, tunable delay lines enable a key feature of programmability for the on-chip processing functions. However, the previously investigated tunable delay lines are plagued by a severe drawback of delay-dependent loss due to the propagation loss in the constituent waveguides. In principle, a serial-connected amplifier can be used to compensate such losses or perform additional amplitude manipulation. However, this solution is generally unpractical as it introduces additional burden on chip area and power consumption, particularly for large-scale integrated PICs. Here, we report an integrated tunable delay line that overcomes the delay-dependent loss, and simultaneously allows for independent manipulation of group delay and amplitude responses. It uses a ring resonator with a tunable coupler and a semiconductor optical amplifier in the feedback path. A proof-of-concept device with a free spectral range of 11.5 GHz and a delay bandwidth in the order of 200 MHz is discussed in the context of microwave photonics and is experimentally demonstrated to be able to provide a lossless delay up to 1.1 to a 5 ns Gaussian pulse. The proposed device can be designed for different frequency scales with potential for applications across many other areas such as telecommunications, LIDAR, and spectroscopy, serving as a novel building block for creating chip-scale programmable optical signal processors.

Viruses can escape from host recognition by degradation of RIG-I or interference with the RIG-I signalling to establish persistent infections. However, the mechanisms by which host cells stabilize RIG-I protein for avoiding its degradation are largely unknown. We report here that, upon virus infection, the E3 ubiquitin ligase FBXW7 translocates from the nucleus into the cytoplasm and stabilizes RIG-I. FBXW7 interacts with SHP2 and mediates the degradation and ubiquitination of SHP2, thus disrupting the SHP2/c-Cbl complex, which mediates RIG-I degradation. When infected with VSV or influenza A virus, FBXW7 conditional knockout mice (Lysm+FBXW7f/f) show impaired antiviral immunity. FBXW7-deficient macrophages have decreased RIG-I protein levels and type-I interferon signalling. Furthermore, PBMCs from RSV-infected children have reduced FBXW7 mRNA levels. Our results identify FBXW7 as an important interacting partner for RIG-I. These findings provide insights into the function of FBXW7 in antiviral immunity and its related clinical significance., The innate immune response to many RNA viruses depends on recognition of viral RNA by RIG-I. Here the authors show that, upon virus infection, FBXW7 interacts with RIG-I and inhibits ubiquitin-mediated degradation of RIG-I, resulting in increased interferon signalling in vitro and in vivo.

Few-mode-fiber (FMF) based mode division multiplexing (MDM) is a promising technique to further increase the transmission capacity of single mode fibers. We propose and numerically investigate a fiber-optical mode converter (MC) using long period gratings (LPGs) fabricated on the FMF by point-by-point CO 2 laser inscription technique. In order to precisely excite three modes (LP 01 , LP 11 , and LP 02 ), both untilted LPG and tilted LPG are comprehensively optimized through the length, index modulation depth, and tilt angle of the LPG in order to achieve a mode contrast ratio (MCR) of more than 20 dB with less wavelength dependence. It is found that the proposed MCs have obvious advantages of high MCR, low mode crosstalk, easy fabrication and maintenance, and compact size.

This paper proposed and experimentally demonstrated an all-fiber tunable and programmable bandpass filter using a linearly chirped fiber Bragg grating (CFBG). The center wavelength and spacing of the transmission peaks could be independently tuned via computer. The tunable range is about 18 nm. With this filter we demonstrated a tunable fiber ring laser which has an output power of about -7 dBm, full-width at half- maximum linewidth of ~0.017 nm which is limited by the resolution of the optical spectrum analyzer (OSA). Furthermore, a spacing tunable dual-wavelength fiber laser was achieved with the same setup. This all-fiber laser features advantages like simple structure, low cost, flexible and digital tuning capability.

We proposed and experimentally demonstrated an all-fiber structured programmable optical bandpass filter (waveshaper) based on a linearly chirped fiber Bragg grating and a digital-controlled thermal array. The key parameters of this filter such as the number of transmission channels, passing bandwidth per channel, central wavelength as well as the channel spacing can be reconfigured independently and flexibly by a program-controlled circuit. We have achieved in experiments the tunable passing bandwidth ranging from < 0.04 to 1.55 nm, adjustable central wavelength ranging from 1,547.16 to 1,558.64 nm, and a minimum wavelength spacing of 0.91 nm. The insertion loss of the whole device and the sideband rejection ratio are about 1.76 and 28 dB, respectively.

We propose and demonstrate by simulations a novel Nyquist-WDM (N-WDM) superchannel transmitter based on an arrayed waveguide grating router (AWGR). This approach can generate Nyquist pulses at multiple wavelengths using a single AWGR. Results for a 3-channel 960-Gbit/s QPSK superchannel system show that a 10% guard band reduces the inter-channel interference (ICI) sufficiently. The design introduces less than 0.16-dB penalty when the waveguide loss is 2 dB/cm and 0.73-dB penalty when the standard deviation of phase error is 10°. Such Nyquist pulse shapers can be realised on a chip scale using photonic integrated circuits technology, and could be compactly integrated with other functional components to create single-chip N-WDM superchannel transmitters.

Orthogonal time division multiplexing (OrthTDM) interleaves sinc-shaped pulses to form a high baud-rate signal, with a rectangular spectrum suitable for multiplexing into a Nyquist WDM (N-WDM)-like signal. The problem with generating sinc-shaped pulses is that they theoretically have infinite durations, and even if time bounded for practical implementation, they still require a filter with a long impulse response, hence a large physical size. Previously a method of creating chirped-orthogonal frequency division multiplexing (OFDM) pulses with a chirped arrayed waveguide (AWG) filter, then converting them into interleaved quasi-sinc pulses using dispersive fiber (DF), has been proposed. This produces a signal with a wider spectrum than the equivalent N-WDM signal. We show that a modification to the scheme enables the spectral extent to be reduced for the same data rate. We then analyse the key factors in designing an OrthTDM transmitter, and relate these to the performance of a N-WDM system. We show that the modified transmitter reduces the required guard band between the N-WDM channels. We also simulate a simpler scheme using an unchirped finite-impulse response filter of similar size, which directly creates truncated-sinc pulses without needing a DF. This gives better system performance than either chirped scheme.

We report a photonic integrated circuit implementation of an optical clock multiplier, or equivalently an optical frequency comb filter. The circuit comprises a novel topology of a ring-resonator-assisted asymmetrical Mach-Zehnder interferometer in a Sagnac loop, providing a reconfigurable comb filter with sub-GHz selectivity and low complexity. A proof-of-concept device is fabricated in a high-index-contrast stoichiometric silicon nitride (Si3N4/SiO2) waveguide, featuring low loss, small size, and large bandwidth. In the experiment, we show a very narrow passband for filters of this kind, i.e. a −3-dB bandwidth of 0.6 GHz and a −20-dB passband of 1.2 GHz at a frequency interval of 12.5 GHz. As an application example, this particular filter shape enables successful demonstrations of five-fold repetition rate multiplication of optical clock signals, i.e. from 2.5 Gpulses/s to 12.5 Gpulses/s and from 10 Gpulses/s to 50 Gpulses/s. This work addresses comb spectrum processing on an integrated platform, pointing towards a device-compact solution for optical clock multipliers (frequency comb filters) which have diverse applications ranging from photonic-based RF spectrum scanners and photonic radars to GHz-granularity WDM switches and LIDARs.

Phase-coded radio frequency (RF) pulses are widely adopted for radar systems as an effective signal format to enable high-range resolution. However, generating such signals conventionally requires high-speed electronics and complex RF circuitry that impose burdens on the system cost and power consumption. In particular, modern radar systems desire features such as high frequencies, e.g., in the millimeter-wave region, high compactness, and high system flexibility, which pose great challenges for the conventional all-electronics solutions. In contrast, integrated microwave photonics opens a way to solutions that are able to provide those features simultaneously, together with potential for full integration and low cost fabrication. Here, we present an integrated microwave photonic method of a binary-phase-coded millimeter-wave signal generation. The core device is a silicon microring modulator with a device size of 0.13 mm×0.32 mm and a modulation bandwidth of 23 GHz. Using RF seed frequencies of 17.5 GHz and 20 GHz, respectively, we experimentally demonstrated the generation of binary-phase-coded signals at 35 GHz and 40 GHz using our proposed approach, the performance of which was verified by a pulse compression ratio of 94 and 106, respectively. The result of this work points to the realization of a chip-scale flexible millimeter-wave signal generator.

Numerous studies have demonstrated that inflammation contributes to a variety of cancer formation, among them, colitis-associated cancer (CAC) represents a typical inflammation-related cancer. Interleukin 27 (IL-27) has been demonstrated to play an important role in inflammation-related disease. The effect of IL-27 in intestinal inflammation is controversial and its role in CAC is not elucidated yet. In our present study, we found that IL-27 has protective function in murine model of CAC through suppression of inflammatory cytokines in intestinal epithelial cells (IECs). IL-27Rα (WSX-1) deficiency promotes the CAC development in mice, which is driven by enhanced tumor cell proliferation, more intensive myeloid-derived suppressor cells (MDSC) accumulation in colon lamina propria and higher level of inflammatory cytokines and chemokines in IECs. The levels of IL-6, TNF-α, GM-CSF and CXCL1 triggered in vitro by toll-like receptor ligands are significantly upregulated in IECs from WSX-1 KO mice. Removal of commensal microorganism through antibiotic treatment in mice to eliminate TLR ligands deprives the protective function of IL-27 on CAC tumor growth. Thus, IL-27 suppresses CAC formation through an anti-inflammation mechanism targeting IECs and in turn resists the tumorigenesis. Hence, our study explained how IL-27 exerts its anti-inflammatory function on epithelial cells to fight against chronic-inflammation-associated cancer, which might provide new insights on the potential therapeutic strategies for cancer.

We proposed and experimentally demonstrated an all-fiber structured wavelength-tunable second-order optical temporal differentiator based on a linearly chirped fiber Bragg grating and a digital-controlled thermal array. The central frequency of the differentiation can be reconfigured from 192.141 to 192.616 THz by a programmable circuit. In the experiment, a second-order differentiator with 3 dB bandwidth of 0.086 THz is achieved with a root mean square error of 4.89%. Published version

Mode division multiplexing (MDM) transmission based on few-mode fibers (FMFs) appears to be an alternative solution for overcoming the capacity limit of single-mode fibers (SMFs). A FMF coupler-based mode division multiplexer/demultiplexer (MMUX/DeMMUX) is proposed and theoretically investigated after the fabricated FMF is characterized. MMUXs/DeMMUXs with a mode contrast ratio (MCR) of more than 20 dB can be obtained for two-mode multiplexing and three-mode multiplexing over a wavelength span of 60 and 10 nm, respectively. We numerically verify the proposed MMUX/DeMMUX which has the advantages of high MCR, easy fabrication and maintenance, and low wavelength dependence.

We propose a novel method to improve a system degraded by a low receiver electrical bandwidth. With optical pre-sampling, 4-dB sensitivity improvement at the 7% hard FEC limit is experimentally demonstrated.

We present an FPGA-based QPSK-encoded 9.375 Gb/s layered/enhanced ACO-OFDM transmitter giving a high spectral efficiency. The measured Q-factor is greater than 13 dB after 20­km standard single-mode fiber transmission.

We propose a method for generating Nyquist sine pulses, based on an arrayed waveguide grating router (AWGR) preceded by a multimode interference coupler. This outperforms previous methods using a chirped AWGR and a dispersive fiber.