Effects of Near-Critical Condensation and Cavitation on the Performance of S-CO₂ Compressor

The supercritical carbon dioxide (S-CO2) Brayton cycle efficiency increases as the compressor inlet condition approaches the critical point. However, the thermodynamic properties of CO2 vary dramatically near the critical point, and phase change is most likely to happen. Both cavitation and condensation bring about significant adverse effects on the performance of compressors. In this paper, the quantitative effects of nonequilibrium condensation and cavitation on the performance of an S-CO2 centrifugal compressor with different inlet-relative entropy values are investigated. The properties of CO2 were provided by the real-gas property table, and the nonequilibrium phase-change model was adopted. The numerical simulation method with the nonequilibrium phase-change model was validated in the Lettieri nozzle and Sandia compressor. Furthermore, simulations were carried out in a two-stage centrifugal compressor under conditions of various inlet-relative entropy values. The type of nonequilibrium phase change can be distinguished by inlet-relative entropy. Cavitation makes the choke mass flow rate decrease due to the drop in the speed of sound. Condensation mainly occurs on the leading edge of the main blade at a large mass flow rate, but cavitation occurs on the splitter. The condensation is more evenly distributed on the main blade, but the cavitation is mainly centered on the leading edge

Characteristics of water isotopes and their indication for water budget in a closed reservoir, Southeast China

Xili reservoir is one of the most important drinking water reservoirs in southeast China, ensuring the safety of water supply in Shenzhen city. Understanding the water balance in the reservoir system under climate change and human activities is essential for making optimal water use planning. To assess the water balance of the Xili reservoir system, the water isotope characteristics in rainfall, reservoir water, groundwater, soil, and plant were investigated. The variation of isotope composition in rainfall, reservoir water, and groundwater indicates the different recharging and mixing water sources. A mathematical mass-balance model was established to evaluate the water budget in the Xili reservoir. Roughly 35% of total incoming water was consumed by evaporation, which reminds managers to pay more attention to making scientific planning

Spectroscopic studies on the interaction of Phacolysin and bovine serum albumin

Scientific Research Fund of Hunan Provincial Education Department [12K101, 13A028]; Hunan Provincial Natural Science Foundation of China [14JJ7049]; Science and Technology Project of Hunan Province [2013SK3161]; Opening Project of State Key Laboratory of Physical Chemistry of Solid Surfaces (Xiamen University) [201309]; Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan ProvinceThe interaction between Phacolysin (PCL) and bovine serum albumin (BSA) under imitated physiological conditions was investigated by spectroscopic (fluorescence, UV-Vis absorption and Circular dichroism) techniques. The experiments were conducted at different temperatures (294 K, 302 K, 306 K and 310 K) and the results showed that the PCL caused the fluorescence quenching of BSA through a static quenching procedure. The binding constant (K-a), binding sites (n) were obtained. The corresponding thermodynamic parameters (Delta H, Delta S and Delta G) of the interaction system were calculated at different temperatures. The results revealed that the binding process was spontaneous and the acting force between PCL and BSA were mainly hydrogen bonding and van der Waals forces. According to Forster non-radiation energy transfer theory, the binding distance between PCL and BSA was calculated to be 2.41 nm. What is more, both synchronous fluorescence and Circular dichroism spectra confirmed the interaction, which indicated the conformational changes of BSA. (C) 2014 Elsevier B.V. All rights reserved

Bidirectional WDM Multi-Nodes Analog Radio-Over-Fiber Mobile Fronthaul Link Enhanced by Photonic Integrated Devices

A bidirectional wavelength division multiplexing (WDM) analog radio-over-fiber (A-RoF) mobile fronthaul (MFH) link is enhanced using photonic integrated devices. Two key photonic integrated devices are combined in the A-RoF link: an 8-channel InP directly modulated laser (DML) transmitter and a 32×100-GHz silicon array waveguide grating (AWG). The DML transmitter has 8 parallel monolithically integrated distributed feedback lasers, enabling cooperative and reconfigurable downlink analog transmission. Moreover, the 32×100-GHz AWG is featured by low insertion loss (<4.5-dB) and low crosstalk (<−20.4-dB), to achieve a high-density WDM system. In the distributed field experiments, we have successfully demonstrated a bidirectional A-RoF MFH over 10-km standard single mode fiber, providing an 8×5-Gbit/s 4-quadrature amplitude modulation (QAM) orthogonal frequency division modulation (OFDM) downlink transmission and a 3×12-Gbit/s 16-QAM uplink transmission

A Tanh Control Method for the Third Mirror’s Z Axis of Large Optical Telescope

The position accuracy of the third mirror’s Z axis will directly affect the measurement accuracy of the optical telescope, so it is necessary to improve the position accuracy. In order to improve the control performances of the third mirror’s Z-axis of a large optical telescope, this paper proposes a novel control algorithm based on hyperbolic tangent function (tanh). The proposed algorithm is used to replace the traditional integral separated proportional-integral (IS-PI) controller which is widely used in industry servo control system. Firstly, a mathematical model of the third mirror’s Z-axis is established. Secondly, a controller based on tanh is proposed, and the characteristics and stability of the algorithm are analyzed. Thirdly, the parameters tuning method of the proposed algorithm is given. The simulation results show that the proposed algorithm has higher tracking accuracy than IS-PI controller. Finally, experiments are carried out on a large optical telescope’s Z axis. In the experiments, IS-PI controller and tanh controller are compared, and the results show that the control performances are greatly improved

EFEMP1 as a Potential Biomarker for Diagnosis and Prognosis of Osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy. Our previous study revealed an association between the level of epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1) and the invasion, metastasis, and poor prognosis of OS. However, the exact correlation between the serum EFEMP1 level and OS diagnosis and progression was unclear. This study is aimed at determining the value of the serum EFEMP1 level in the diagnosis and prognosis of OS. Fifty-one consecutive OS patients were prospectively registered in this study. The serum EFEMP1 levels were measured using ELISA at diagnosis, after neoadjuvant chemotherapy, and before and after surgical treatment. Sixty-nine healthy subjects in the control group, nine patients with chondrosarcoma, and 12 patients with giant cell tumor of the bone were also enrolled in this study. Surgical orthotopic implantation was used to generate a mouse OS model, and the correlation between the circulating EFEMP1 levels and tumor progression was examined. Then, OS patients had significantly higher mean serum EFEMP1 levels (7.61 ng/ml) than the control subjects (1.47 ng/ml). The serum EFEMP1 levels were correlated with the Enneking staging system (r=0.32, P=0.021) and lung metastasis (r=0.50, P<0.001). There was also a correlation between the serum EFEMP1 level and EFEMP1 expression in the respective OS samples (r=0.49, P<0.001). Additionally, patients with either chondrosarcoma or giant cell tumor of the bone had significantly higher serum EFEMP1 levels than OS patients. Surgical and chemotherapeutic treatment led to an increase in the serum EFEMP1 levels. Then, the destruction of bone tissues might be one of the factors about the EFEMP1 levels. In the mouse OS model, the serum EFEMP1 level was correlated with tumor progression. Our results suggested that serum EFEMP1 levels might be used to distinguish OS patients from healthy controls and as an indicator for OS lung metastasis. Serum EFEMP1 levels could serve as a new and assisted biomarker for the auxiliary diagnosis and prognosis of OS

Pathological Detection of Micro and Fuzzy Gastric Cancer Cells Based on Deep Learning

In recent years, with the increasing incidence of cancer, regular physical examination is an important way to find cancer. Nuclear screening is an important method for the diagnosis of gastrointestinal diseases, but it is challenging in the face of small and fuzzy gastrointestinal images. Different from traditional medical objects, pathological slice images are mostly blurry and tiny, which is somewhat difficult to detect and segment. The traditional diagnostic method lacks rapid quantitative analysis and has a certain delay in medical diagnosis, and traditional image processing uses morphological features and pixel distribution to extract features; it is often difficult to achieve the desired effect on small blurry images. This paper proposes a small, microfuzzy pathology detection algorithm based on the attention mechanism; the YOLOv5 is improved under small and micro fuzzy scenarios of the detection of cancer cells in the full field of digital pathology and tests it in the gastric cancer slice dataset. The network structure is improved, and the ability to learn features on small and micro targets is enhanced according to the law of feature distribution. Spatial and channel changes in network attention and attention weight distribution. In the deep blur scenario, the attention mechanism is added to optimize its recognition ability, and the test result shows F1_score is 0.616, and the mAP is 0.611, which can provide the decision support for clinical judgment

Self-Activatable Photo-Extracellular Vesicle for Synergistic Trimodal Anticancer Therapy

Extracellular vesicles (EVs) hold great potential in both disease treatment and drug delivery. However, accurate drug release from EVs, as well as the spontaneous treatment effect cooperation of EVs and drugs at target tissues, is still challenging. Here, an engineered self-activatable photo-EV for synergistic trimodal anticancer therapy is reported. M1 macrophage-derived EVs (M1 EVs) are simultaneously loaded with bis[2,4,5-trichloro-6-(pentyloxycarbonyl) phenyl] oxalate (CPPO), chlorin e6 (Ce6), and prodrug aldoxorubicin (Dox-EMCH). After administration, the as-prepared system actively targets tumor cells because of the tumor-homing capability of M1 EVs, wherein M1 EVs repolarize M2 to M1 macrophages, which not only display immunotherapy effects but also produce H2O2. The reaction between H2O2 and CPPO generates chemical energy that activates Ce6, creating both chemiluminescence for imaging and singlet oxygen (O-1(2)) for photodynamic therapy (PDT). Meanwhile, O-1(2)-induced membrane rupture leads to the release of Dox-EMCH, which is then activated and penetrates the deep hypoxic areas of tumors. The synergism of immunotherapy, PDT, and chemotherapy results in potent anticancer efficacy, showing great promise to fight cancers