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High-speed Underwater Optical Wireless Communication (UWOC) can achieve Gbit/s signal transmission rate, which is of great significance for modern underwater applications. This paper first describes the development process of UWOC, and then compares different kinds of UWOC. Finally, we summarize the research status of high speed UWOC system, and discuss three parts of high speed UWOC: light source, receiver and signal processing. It is expected that this paper can bring help to the research and development of high-speed UWOC in the future.

Headspace solid phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was used to analyze the volatile aroma components of vanilla extract. The characteristic flavor compounds of vanilla extract were analyzed by a sensory-guided approach based on olfactory threshold and odor activity value (OAV) and reconstituted by aroma recombination test. The results showed that 83 aroma compounds were detected in vanilla extract, and 34 aroma components contributing to creamy, sweet, sour, acidic aroma, balsamic, burnt, bean-like and spicy aroma notes were found to be closely related to the characteristic flavor of vanilla extract. According to their OAV values, 14 aroma compounds including vanillin, 4-(ethoxymethyl) phenol, 2-methoxy-phenol, acetic acid, 4-vinyl guaiacol, and vanillin ethyl ether were identified as the key components contributing to the characteristic flavor of vanilla extract. The aroma recombination sample of these characteristic flavor compounds had vanilla-like creamy, sweet, smoked and sour aromas, and could be used to identify the characteristic aroma of vanilla with a sensory similarity of 92.33%, indicating that the 14 characteristic flavor compounds can be used as key indicators for quality control of natural perfumes with the characteristic flavor of vanilla and provide a material basis for the reconstitution of food additives with the characteristic flavor of vanilla.

In order to enhance the corrosion resistance of the 17-4PH low-pressure last stage blades，the steam inlet side of the 17-4PH blades needs to be treated with laser-enhanced solid solution.The last stage blades treated with laser solution often show obvious magnetic marks in the subsequent magnetic particle inspection.Optical microscope，scanning electron microscope，X-ray diffractometer，electron probe and other analytical means were used to prove that the reason for the appearance of magnetic marks at the boundary of the laser solid solution region was a large number of austenite structures that appeared at the boundary，which reduced the permeability at the boundary of the laser solid solution region.Besides，the residual stress of laser solid solution blade was determined as compressive stress by XRD，and the three-point bending fatigue test showed that the R＝0.1 fatigue limit of 17-4PH blade could be increased from 750 MPa to 860 MPa by laser-enhanced solid solution.

Underwater optical communication is a new and feasible underwater communication technology, which has developed rapidly in recent years. To build a high-performance and practical underwater optical communication system, it is necessary to consider and optimize the design from the device to the system, from the internal modulation to the external environment. This paper summarizes the current problems of underwater optical communication from the aspects of underwater optical communication system transmitter and receiver, modulation format and underwater channel. The paper also classifies and summarizes the three key technologies of improving underwater optical communication distance, communication rate and communication stability, and gives the possible solutions. It provides reference for the follow-up system design and experimental research.

In order to further improve the emulsion stability and the intrinsic performance of self-emulsified epoxy resin, a novel amphipathic resin was synthesized from dodecylsuccinic anhydride (DDSA), methoxypolyethylene glycols and bisphenol-A epoxy. Similar systems based on different anhydrides including methyl hexahydrophthalic anhydride (MHHPA) as well as phthalic anhydride (PA) were prepared simultaneously for comparison. The stabilities of various emulsions were evaluated according to particle diameter, centrifugal stability and surface tension tests. Meanwhile, the curing behaviors, thermal resistances and interface properties between resins and diverse reinforcement fibers were also investigated. The results showed that introducing of DDSA could effectively enhance the stability of emulsion with the surface tension reducing to 37.22 mN/m. The microdebonding strength between the self-emulsifying resin system and carbon fiber is poor, but its interfacial strength with ultra-high molecular weight polyethylene fibers is better than that of the MHHPA and PA systems, and it has excellent overall performance. [ABSTRACT FROM AUTHOR]

In the greenhouse environment,the concentration of nutrient solution was always ignored.At the same time,the core node coordinator of the ZigBee wireless monitoring system was easily compromised.A trusted solution monitoring system based on ZigBee wireless sensor network was designed and implemented.Firstly the hardware structure of sensor,router and coordinator was introduced.Then the processes of external voltage measurement and data cleaning were illustrated.For realizing the trusted boot of the coordinator,trusted u-boot to measure the integrity of some key files was designed.Experimental results show that the solution concentration data could be sent from each node to the monitoring computer and the remote terminal.At the same time,the trusted module of the coordinator can detect the captured coordinator node and warning.Therefore,the designed system has strong function and security.

Objective:To test the reliability and validity of the pain self-efficacy questionnaire in simplified Chinese version(SC-PSEQ)in patients with low back pain.Methods:A total of 86 participants with low back pain were recruited in four hospitals. They independently completed the simplified Chinese version of pain self-efficacy questionnaire, Numeric Pain Rating Scale, Oswestry Disability Index, Roland-Morris Disability Questionnaire, 36-Item Short Form Health Survey.Results:The average score of all the participants was(46.29±11.16),which was statistically different from the median score of SC-PSEQ(t=13.535,PICC=0.852,P

The grain body creep of waste dumps including deceleration creep and constant creep was described by the Burgers model.Using the layered summation method,the vertical filling waste dump was sliced and the bottom part settled under the variable weight load of the overlaid part.The computational formulas of settlement in the waste dump filling dynamic process,post-construction settlement and cumulative settlement were derived from theoretical analysis though the steady and unsteady Burgers creep models.The monitoring data of Qidashan Iron Mine were used as a case of proofing.The results show that the correlation coefficients of fitting with both the unsteady and steady Burgers models are high,and the final settlement value of the former is 5.07 m,while the settlement curve of the latter is divergent,thus the unsteady Burgers model performs better in simulating the real working condition of mine subsidence.The waste dump was divided into ten layers and the settle rate of each layer was calculated by the creep simulation model in Flac3D.The post-construction settlement of the top layers is smaller than that of the middle layers and bottom layers,the settlement of the top layers decreases when getting closed to the upper surface of the waste dump.The settlement of the middle layers is larger than that of the bottom layers,and the fifth layer performs a largest settlement.

The traditional Newton algorithm has heavy calculation burden and low efficiency, its iterations and time will significantly increase when load type is no longer a constant power. In view of these problems, an improved Newton algorithm for power flow was proposed. The algorithm considers load type to constitute ZIP model with constant power load, constant current load and constant impedance load, and uses matrix splitting and relaxation method of matrix inversion to make the algorithm not only has simple and fast computed process, but also can improve algorithm efficiency and weaken influence of load type on iterations and time. The effectiveness of the algorithm was verified by using 33 nodes system to test and compare the iterations and times. Influence of load types on system voltage was analyzed though power flow calculation results, it shows that increase of constant impedance load proportion can improve system node voltage.

In view of problem of difficult fault line selection for small current grounding system, the paper proposed a fault line selection method for small current grounding system based on multi-source information fusion. Taking fault line set, fault characteristics set of each line and amount domain regulated by fault characteristics of each line as three elements of matter element of extension fusion, taking size of fault angle as weight, the method effectively fuse energy line selection method with accurate line selection under small fault angle and wavelet packet line selection method with accurate line selection under big fault angle, so as to realize accurate line selection combining with reclosing technology. The simulation result validates effectiveness and reasonableness of the method.

The paper proposed a novel single-phase grounding fault line selection method of small current grounding system based on EMD and differential spectrum. The method uses EMD method to decompose transient zero-sequence current and extract high-frequency IMF1 component of each line, obtained differential spectrum and fluctuation value of IMF1 component of each line according to definitions of differential spectrum and fluctuation value, and found out the fault line which has the maximum fluctuation value of IMF1 component by comparing fluctuation values of IMF1 component of each line. The experiment results showed that the method has higher accuracy of line selection and is suitable for fault line selection of small current grounding system under different grounding resistances and different fault initial phase angles.

In order to solve problems of poor reliability and accuracy of existing fault location methods of underground cable, the paper introduced a fault location method of underground cable based on wavelet analysis and neural network, and compared performance of BP neural network and RBF neural network used in the method. The method uses 3B-spline semi-orthogonal wavelet to do wavelet transformation for transient-state zero-sequence current so as to get modulus maxima of transient-state zero-sequence current in specific frequency bands. The modulus maxima is taken as inputting signals of neural network, and realizes fault location according to mapping relationship between the modulus maxima and position of fault point. The simulation results showed that the method can realize fault location of underground cable, and the method with RBP neural network is better than BF neural network in location error and network training.

For problem of ineffectiveness of traditional line selection methods by use of single feature value caused by complex and random fault borderline, small steady component of fault and reverse phase of instantaneous zero-sequence power when single-phase grounding fault happens in power system connected to earth through an arc suppression coil, the paper proposed a new method of line selection based on transient zero-sequence energy. The method filters nonsymmetrical component and steady component of transient zero-sequence current through a digital filter and gets zero-sequence current of each line and pure transient fault component of zero-sequence voltage of bus in order to get transient zero-sequence energy. Then the method judges fault type and line according to the value and direction of transient zero-sequence energy. When single-phase grounding fault happens, the direction of transient zero-sequence energy of non-fault line is positive, the direction of transient zero-sequence energy of fault line is negative, and absolute value of transient zero-sequence energy of fault line is the sum of the ones of other lines. When the bus grounding fault happens, the value of transient zero-sequence energy of the bus is the sum of the ones of other lines. Meanwhile, in order to solve the problem of low sensitivity of line selection caused by influence of noise on transient zero-sequence energy of the bus, the paper proposed a scheme of usting auto-reclosing technique in the line selection method. The Matlab simulation result showed that the line selection method has high accuracy and reliability.

The paper analyzed influence of grid connection of distributed generation on traditional current protection of distribution network, used Matlab/Simulink simulation software to prove influence of different capacities and grid connected positions of distributed generation on each section of current protection of distribution network, and proposed an improved scheme which can meet with protection requirement of distribution network after grid connection of distributed generation. The implementing principle of the scheme is as follows: for downstream protection of distributed generation, taking power supply of power system and distributed generation as a whole, resetting set values of each section of current protection; for upstream protection of distributed generation, installing a direction relay based on fault current component on each protector, so as to ensure reliable action of protection when over-current relay and direction relay start simultaneously.

Functional tremor (FT) is the most common manifestation of functional movement disorder (FMD), but its clinical recognition is insufficient, and there is no clear diagnostic standard and effective treatment method at present. The diagnosis mainly depends on the medical history, clinical examination, physical signs, neuroelectrophysiological examinations. Early diagnosis and treatment are essential to improve the prognosis of the patients. The etiology and pathogenesis of FT have not been clarified. This article reviews the progress in diagnosis and treatment of FT in order to improve the clinicians' understanding of the disease and provide the possibility for treatment. [ABSTRACT FROM AUTHOR]

The flavor component in the Cordyceps sinensis extract were analyzed by GC-MS, the pyrolysis products of the Cordyceps sinensis characteristic components including cordycepin acid and cordyceps polysaccharide were qualitatively and quantitatively analyzed by pyrolysis coupled with gas chromatography and mass spectrometry(Py-GC-MS). Aroma style and influence on the sensory quality of cigarette after adding Cordyceps sinensis extract were evaluated according to the sensory evaluation methods for Chinese-stylistic features. The results showed that Cordyceps sinensis extract mainly included butanedione, ethyl lactate, γ-Butyrolactone, butyl butyryl lactate, coconut aldehyde and other aroma components with creamy sweet flavor. Cordycepic acid and cordyceps polysaccharide could release small molecular dehydrated monosaccharides, small molecular aldehydes, ketones and other flavor substances which influenced the flavor characteristics on cigarette during pyrolysis; the proportion of dehydrated glucose, mannitol and d-alose was high accordingly with high pyrolysis temperature. The effect of Cordyceps sinensis extract on cigarette aroma style was mainly manifested that it could significantly improve creamy aroma and sweet aroma and add flue-cured tobacco aroma, freshness and fruity aroma. In terms of taste style, it could enhance the sweetness of cigarette; In terms of comfort characteristics, it could reduce oral irritation/ tongue burning and oral residue, and increase smoking convergence, and reduce laryngeal dryness and nasal irritation; In terms of smoking characteristics, it could enhance the aroma, increase aroma richness, soften smoking, make the smoking more delicate and mellow, and cover up offensive taste. [ABSTRACT FROM AUTHOR]

A novel anti-aging silane coupling agent (Si-GD) was synthesized by the ring-opening reaction of p-phenylenediamine and 3-glycidoxypropyltriethoxysilane based on the mechanism of aging protection and coupling agent modification on silica. Natural rubber/silica composites were modified by Si-GD. The effects of different amounts of Si-GD on crosslinking density, micro-morphology, mechanical properties, aging resistance and wear resistance on natural rubber/composites were studied. The results show that the tear strength, tensile strength, modulus, resilience, Shore A hardness and hot air aging resistance of Si-GD modified composites are significantly increased. The natural rubber/silica composites modified with 4 phr of Si-GD has better wear resistance than that modified with 4 phr of Si-69. [ABSTRACT FROM AUTHOR]

In order to build an evaluation model for predicting the sensory irritation of cigarettes based on free amino acid contents in finished cigarettes, 12 different styles of cigarettes were selected as the research objects. The contents of free amino acids in cigarettes were determined by HPLC. The comprehensive evaluation model of cigarette irritation was established by principal component analysis, and the model was verified by cluster analysis and sensory irritation evaluation. The results show that the comprehensive evaluation model F=0.913F1+0.087F2 was established. Through cluster analysis, 12 kinds of cigarettes could be divided into 5 categories, which was basically consistent with the prediction results of the comprehensive evaluation model. The ranking of sensory evaluation scores of 12 kinds of cigarettes was generally consistent with that predicted by the comprehensive evaluation model. The model was used to calculate the comprehensive evaluation scores of free amino acids of different types of cigarettes. The scores of 12 kinds of cigarettes from low to high were wine fragrance

Traditional experiments and EDA technique-based CPLD experiments have their own characteristics in digital logic experiment teaching. Therefore, we try to combine such two kinds of experiments in teaching with the aim of taking full advantage of them. This paper introduces the practice in digital logic experiment teaching based on experimental platform, which is under the guidance of such ideas. We scheduled experimental contents to be performed on the platform developed by us, which considers the ratio of the two kinds of experiments, also arranges the comprehensive experiment with topics selected independently by students, and grades students taking comprehensive performances into consideration. The results prove that the combination of such two kinds of experiments is beneficial to train students in improving their software and hardware application ability, not only in mastering the digital logic course effectively, but also in strengthening the ability of practice. [ABSTRACT FROM AUTHOR]

With the VEC model and EGARCH model, an econometrical test was taken on the interactive effects of arbitrage between HS 300 index futures market and its spot market. The results showed that the selling of futures contracts in arbitrage trading led to a decline in futures' prices, but its spot prices were not driven by the buying of spot contracts due to the limited transactions, which meant the convergence of basis between HS 300 index futures market and its spot market was not caused by the negative feedback effects between them but by the futures price responding faster to information than the spot price. Thus, it can be concluded that the arbitrage between HS 300 index futures market and its spot market played a boosting role rather than a buffering role in the asymmetric volatility of the spot market. [ABSTRACT FROM AUTHOR]

Aimed at the complexity of conceptual model formal validation methods and subjectivity of conceptual model informal validation methods, this paper developed a conceptual models validation method based on rule reasoning. Then it introduced the principle, frame, implementary steps, validation contents and validation rules in detail. The essence of the method was that replacing domain experts with validation rules and reasoning machine to validate the semantic content of conceptual models automatically in the computer. The method could reduce the complexity of the formalized validation methods, decrease subjectivity and uncertainty of informal validation methods and improved the efficiency of the conceptual model validation. [ABSTRACT FROM AUTHOR]

In order to evaluate the vulnerability of highway slope hazard, the second-class highway from Wenshan to Tianbao in Yunnan province (Wentian highway) was taken as an example; three factors including economic density, road repair lime and road bypass capacity were used lo establish the index system of vulnerability assessment of highway slope hazard considering the function of highway; according lo the quantification and superposition calculation of indexes in ArcGIS platform, the vulnerability assessment of highway slope hazard was carried out; the vulnerabilities of different sections were classified and discussed according lo the evaluation result, and the methods to reduce the vulnerability of slope hazard were proposed. The results show that the vulnerabilities of different sections in Wentian highway are 0.07-1.00, and 30. 75% of Wentian highway is high or extremely high; the vulnerability for 3. 96% of Wentian highway is extremely high, and the ratio of length of bypass highway to length of corresponding Wentian highway is large, so that the length of bypass highway can be deceased in future highway construction in order to decease the vulnerability of highway slope hazard; although the economic density of the section near the starting point of Wentian highway is maximum, vulnerability of this section is moderate because of the shortest road repair time, dense road network an shorter length of bypass highway. [ABSTRACT FROM AUTHOR]

Background: Dissatisfaction with childbirth experience negatively affects self-esteem and maternal role development in new mothers. Purpose: This study examines the effectiveness of a birth ball exercise program during childbirth. Childbirth satisfaction and childbirth pain were measured. The mediating effect of childbirth pain on the relationship between the birth ball exercise program and childbirth satisfaction was also examined. Methods: This study was conducted in birth units at one regional hospital and one medical center. In a randomised controlled trial, 167 expectant mothers were recruited and allocated by block randomization into the two arms of the study, with 42 intervention and 32 control group partipants completing the trial. The birth ball exercise program consisted of a booklet and a DVD, with periodic follow-ups during prenatal checks. All members of the experimental group were asked to practice the exercises and positions at home for at least twenty minutes three times a week for a period of 6-8 weeks. Each woman in the experimental group was given a birth ball for use during labour and encouraged every hour to choose the most comfortable positions, movements, and exercises. Both experimental and control groups received standard nursing care from hospital staff nurses in all aspects of pregnancy and childbirth. The questionnaire used collected data using a demographic and obstetrics information datasheet, the Visual Analog Pain Scale (VAPS), and Chinese version of the Mackey Childbirth Satisfaction Rating Scale. Results: Our study revealed that birth ball exercises provided statistically significant improvements in childbirth satisfaction and pain. Pain had a 48.97% mediating effect on relationships between birth ball exercises and childbirth satisfaction. Conclusions/Implications for Practice: Clinical implementation of the birth ball exercise program could be an effective adjunctive tool to improve childbirth satisfaction and reduce pain among women in labour. Health professionals can educate women and their partners prenatally about how to use birth ball exercise to cope with childbirth in order to facilitate more positive feelings about the childbirth experience. [ABSTRACT FROM AUTHOR]

The empirical analysis was implemented with the linear regression model under classical assumptions and VAR model of the time series. The result of empirical analysis shows that the allocation of Chinese financial resource has been upgrading the "quantity" of its economic growth rather than improving the "quality", furthermore, with the constraints' change of China's economic growth, the problems of China's financial resources allocation, such as structural disequilibrium and "two-track" price, which originated in government monopoly, became more and more prominent. As a result, the marginal output of China' financial resources began to decline. Therefore, the effective system arrangements should be carried out to transfer financial rent from government sectors to private sectors, which can really incite financial innovation and technological progress. The ultimate policy objective is to implement market-oriented allocation of China's financial resources and enhance its total factor productivity. [ABSTRACT FROM AUTHOR]