With the successive optimization of the BeiDou navigation satellite system (BDS), the capacity of its regional short message communication (RSMC) has increased tenfold, and the maximum length of a single short message has reached 14,000 bits, providing a theoretical basis for voice transmission. In complex usage scenarios, BDS urgently requires instant voice communication to enhance the efficiency of command and rescue. Based on the mixed excitation linear prediction (MELP) algorithm and the performance of RSMC, this paper presents an improved ultra-low bit rate MELP algorithm. The improved MELP incorporates preprocessing for distinguishing unvoiced and voiced superframes; inter-frame prediction and residual vector quantization (IFP-RVQ); and inter-frame grouping and inter-stage clustering (IFG-ISC). The aim is to increase the coding rate, save coding bits, and improve the quality of coded speech. Multiple comparative tests show that the output speech of the improved MELP has a PESQ score of 2.15, a ViSQOL score of 3.32, and a DNSMOS score of 2.99, exhibiting high intelligibility and speech quality.

Upscaling flux tower measurements based on machine learning (ML) algorithms is an essential approach for large-scale net ecosystem CO2 exchange (NEE) estimation, but existing ML upscaling methods face some challenges, particularly in capturing NEE interannual variations (IAVs) that may relate to lagged effects. With the capacity of characterizing temporal memory effects, the Long Short-Term Memory (LSTM) networks are expected to help solve this problem. Here we explored the potential of LSTM for predicting NEE across various ecosystems using flux tower data over 82 sites in North America. The LSTM model with differentiated plant function types (PFTs) demonstrates the capability to explain 79.19% (R2 = 0.79) of the monthly variations in NEE within the testing set, with RMSE and MAE values of 0.89 and 0.57 g C m-2 d-1 respectively (r = 0.89, p < 0.001). Moreover, the LSTM model performed robustly in predicting cross-site variability, with 67.19% of the sites that can be predicted by both LSTM models with and without distinguished PFTs showing improved predictive ability. Most importantly, the IAV of predicted NEE highly correlated with that in flux observations (r = 0.81, p < 0.001), clearly outperforming that by the random forest model (r = -0.21, p = 0.011). Among all nine PFTs, solar-induced chlorophyll fluorescence, downward shortwave radiation, and leaf area index are the most important variables for explaining NEE variations, collectively accounting for approximately 54.01% in total. This study highlights the great potential of LSTM for improving carbon flux upscaling with multi-source remote sensing data.

Recently, many robust adaptive beamforming (RAB) algorithms have been proposed to improve beamforming performance when model mismatches occur. For a uniform linear array, a larger aperture array can obtain higher array gain for beamforming when the inter-sensor spacing is fixed. However, only the small aperture array can be used in the equipment limited by platform installation space, significantly weakening beamforming output performance. This paper proposes two beamforming methods for improving beamforming output in small aperture sensor arrays. The first method employs an integration algorithm that combines angular sector and gradient vector search to reconstruct the interference covariance matrix (ICM). Then, the interference-plus-noise covariance matrix (INCM) is reconstructed combined with the estimated noise power. The INCM and ICM are used to optimize the desired signal steering vector (SV) by solving a quadratically constrained quadratic programming (QCQP) problem. The second method proposes a beamforming algorithm based on a virtual extended array to increase the degree of freedom of the beamformer. First, the virtual conjugated array element is designed based on the structural characteristics of a uniform linear array, and received data at the virtual array element are obtained using a linear prediction method. Then, the extended INCM is reconstructed, and the desired signal SV is optimized using an algorithm similar to the actual array. The simulation results demonstrate the effectiveness of the proposed methods under different conditions.

Objective To explore and summarize the therapeutic effect of patients with gastric outlet obstruction（GOO） treated by endoscopic ultrasound-guided gastroenterostomy（EUS-GE）. Method The clinical data of 77 patients who underwent EUS-GE due to GOO from March 2017 to June 2021 were retrospectively analyzed. Attention was paid to preoperative assessment and preparation for gastric emptying, the clinical treatment effect, complication rate and improvement of patients’ quality of life after EUS-GE were statistically analyzed.Result All the 77 patients underwent EUS-GE successfully. The score of postoperative GOO increased from 0 or 1to 1 or 3; European Organization for Research and Treatment for Cancer quality of life questionnaire-core 30（EORTC QLQ-C30） increased from（6.94 ± 1.04） to（10.39 ± 1.11）（P ＜ 0.01）; After operation, 2 patients had stent obstruction, 2 patients had stent displacement, 2 patients had gastrointestinal bleeding, 3 patients had mild acute pancreatitis, and 35 patients had intestinal fistula with fever due to active perforation during operation. After symptomatic treatment, all patients recovered well and were discharged smoothly. Conclusion EUS-GE has the advantages of good curative effect, less trauma and high success rate. It can effectively improve the GOO and improve the patients’ quality of life. However, there are many postoperative complications. Effective preoperative evaluation and postoperative observation can reduce the incidence of postoperative complication.

目的:研究预见性护理在预防胆总管结石患者经内镜逆行性胰胆管造影术(ERCP)术后并发症中的效果.方法:择取2021年1月至12月在本院就诊的76例胆总管结石患者作为研究对象,通过计算机随机分组法将其分为对照组和观察组,每组38例.对照组患者实施常规围手术期护理,观察组患者则在对照组的基础上实施预见性护理,比较两组患者的干预效果.结果:术后12h、24h、48h,观察组患者的NRS评分均低于对照组(P<0.05).观察组患者的术后并发症发生率低于对照组(P<0.05).观察组患者的术后首次排气时间、首次进食时间、首次排便时间、下床活动时间均短于对照组(P<0.05).观察组患者的术后QLSOC评分、总满意度均高于对照组(P<0.05).结论:对行ERCP治疗的胆总管结石患者实施预见性护理,可有效预防术后并发症的发生,在减轻术后疼痛感的同时可加快患者的恢复速度,进而提高患者的生活质量和满意度,值得临床借鉴.

Ocean mesoscale eddies contribute significantly to water transport on a global scale, constituting the ubiquitous, irregular, discrete, nonlinear components. In this manuscript, we propose to explore whether and how the topographic effect of one meridional ridge, could exert considerable influences on the evolution and propagation of mesoscale eddies through their life cycle, directly from the perspectives of real observation statistics. We systematically investigate the known variability of mesoscale eddy trajectories, derived by multimission satellite altimetry from 1993 to 2018, of a life cycle more than 6 months, over the Izu-Ogasawara Ridge, and quantitatively examined the eddy-ridge interaction by observation statistics and wavelet coherence map, with respect to the intrinsic attributes, namely, the amplitude, the rotation speed, the radius. Due to the spatial-temporal diversity, a series of correlative steps have been particularly designed along time-frequency domain to trace back mesoscale eddy trajectories in a variety of origins, location, lifespan, polarity, either completely or partially passing over the ridge, and to facilitate the standardization in statistics across three phases of their life cycle, i.e., before, during and after the interaction with the ridge. It has been revealed in our experiment that three intrinsic attributes of mesoscale eddies within 25 years, all demonstrated noticeable correlation with the variation of topographic relief over the ridge. We observed that most of the cyclonic eddies obviously tended to begin to decay or even demise, while on the contrary, some of the anticyclonic eddies preferred to intensify slightly, or making no significant difference when encountering the upslope until climbing across the top, basically consistent with the expectation of potential vorticity (PV) conservation. The drifting velocity agreed with the tendency that the direction would be more probably modified toward equatorward or poleward by forcing to meridional component, with zonal component reduced at the beginning. The mesoscale eddies with the passage over the ridge exhibited the relatively high average horizontal scales, amplitude, rotation speed on the whole, compared to those with only partially passage. The developed scheme could integrate more evidences on how mesoscale eddies response to the topographic effects during their time-varying evolution and propagation process, and help provide opportunities to potentially identify and predict the underlying dynamic patterns and mechanisms that mesoscale eddies engage in ocean dynamics when proceeding toward meridional ridges on a global scale, with the promise of the end-to-end data-driven solution, such as deep learning architecture involved in the future.

Direction-of-arrival (DOA) mismatch can degrade the performance of adaptive beamforming algorithms.Thus, a projection method is proposed to correct this mismatch.In a beamforming algorithm, the DOA error is usually regarded as a steering vector error which is corrected using a steering vector optimization algorithm.This approach can provide an optimal steering vector but ignores the actual DOA estimate.The proposed algorithm provides correction after DOA estimation but before beamforming to improve both the DOA estimation accuracy and beamforming gain.First, the signal-to-noise ratio (SNR) of the signal is estimated and used to regularize the covariance matrix.Then, an estimated steering vector with DOA close to the true value is determined based on a minimum number of projections.Numerical results are presented to verify the effectiveness of the proposed method for DOA estimation correction.In most cases, this method improves the performance of the beamforming algorithms without changing them.

In this paper, a bullet shaped cilia turbulence sensor based on piezoresistive principle is proposed to solve the problems of low sensitivity, low resolution, high cost and difficult to realize multidirectional synchronous observation of the existing shear flow sensor. the core component of the sensor adopts cilia-cross beam structure. Because of the orthogonal relationship of the cross beam, the turbulence signal received by the cilia can be converted into X and Y signal output. The vector test results show that the sensor can realize the observation of two-dimensional turbulence signal. Secondly, the sensor chip is fabricated by MEMS piezoresistive process, which can realize the miniaturization of the product and ensure the consistency of structure and low cost. Finally, the sensor adopts “warhead” cilia, which has the same streamlined structure as the existing piezoelectric ceramic probe, and has smaller volume and higher resolution. At the same time, based on the comparative calibration method, it is verified that the sensitivity of the sensor is 94 times higher than that of the commercial PNS shear flow sensor, which can reach $4.86{}^{\ast}10-4\text{Vms}2/\text{kg}$. Therefore, the successful application of the bullet shaped cilia turbulence sensor has laid the foundation of sensing technology for the realization of ocean state transparency, process transparency and change transparency.

Autonomous underwater vehicle (AUV) has important significance for understanding, researching and developing the ocean. The research of path planning plays an important role in the safety of AUV and the improvement of work efficiency. Aiming at the complex underwater environment, irregular obstacles and planning difficulties, this paper proposes a dimension reduction path planning method suitable for three-dimensional space path planning. The space is expressed by the combination of horizontal stratification and longitudinal cutting, which simplifies the environmental model and improves the dimensionality disaster of path planning and long planning time. Furthermore, the inverse pruning and node reconstruction methods are used to further optimize the shortening path, which improves the practical value of the path. And the algorithm is fast, which reduces the energy consumption during the AUV travel. The simulation results show that the design path planning method is simple and effective, and it is suitable for complex underwater environment.

目的 探讨行经颈静脉肝内门体分流术(TIPS)治疗肝小静脉闭塞症(HVOD)患者术前术后针对性护理的方法和效果.方法 回顾性分析2015年1月至2017年12月60例行TIPS的HVOD患者的临床资料.围术期对患者实施了细致针对性的护理措施和监测:完善术前准备和密切护理观察;加强体位管理;指导适当的饮食控制;严密观察抗凝溶栓的疗效;加强导管的护理;监测体重、腹围和尿量的变化等.总结临床观察结果及护理经验.结果 TIPS术后60例患者住院期间均未发生肠系膜上静脉留置管滑脱、堵管等护理并发症,术后用药期间未出现明显皮下和黏膜出血,未发生脾静脉或肠系膜上静脉血栓的征象;术后门静脉血流速度和门静脉压力较术前均有明显改善(P＜0.01);肝脏储备功能(CPT)分级明显改善;均顺利出院.随访截止至2018年6月30日,除1例患者因肺空洞考虑霉菌感染致呼吸衰竭死亡;1例因不明原因出血未及时就诊死亡,1例因肝性脑病死亡,2例失访外,55例患者目前健在,生活质量均得到明显改善.结论 对行TIPS术的HVOD患者进行科学细致的护理,能有效保证治疗效果,降低并发症发生,改善患者预后,提高患者的生活质量.

国外的剪切流传感器已经趋于成熟,但仍存在测试信息量单薄、空间分辨率不高和价格昂贵的缺点.提出了一种新型高分辨率微电子机械系统(MEMS)湍流传感器,通过MEMS工艺的微结构实现湍流传感器的高分辨率探测,同时凭借Parylene真空气相沉积技术来实现传感器在海中的绝缘性和抗腐蚀性.经过5～45口C的高低温循环实验,验证了MEMS湍流传感器在复杂环境中的可靠性,并通过实验测量得到电压形式的湍流数据.

Conventional interference suppression techniques based on scalar antenna array may not be effective, when the satellite and interference signals have similar directions of arrival. In this paper, a power inversion (PI) algorithm with a novel constraint is proposed which is applied to electromagnetic vector sensor (EMVS) arrays and improve the performance of the standard PI algorithm. Interference with different polarization parameters than the satellite signal can be suppressed even when they have the same incident direction. A fast implement scheme is designed for the proposed algorithm and is effective for the Beidou satellite system public service signal.

目的 评价延伸护理对TIPS术后患者生活质量和肝性脑病发生率的应用效果.方法 采用随机数字分组研究.对照组105例,实验组105例.对照组给予常规出院指导,实验组在对照组基础上采用延续性护理.比较2组患者术后并发肝性脑病的发生率情况.结果 分别对护理干预后1、3、6和12个月后的数据统计显示,实验组肝性脑病总发生率及累积发生率均低于对照组.结论 TIPS术患者出院后,接受持续的、专业的疾病知识指导可降低术后HE发生率,提高了患者的生活质量;医患合作、患者及家属共同参与能达到有效的自我管理.

The accuracy of ocean microstructure shear signal plays a vital role in turbulence measurement and cognizing. According to the characteristics of signal and the designed measurement instrument, this paper proposes an improved processing algorithm based on fractional filtering to improve the accuracy of the measured turbulence signals. On the basis of the time-frequency characteristic of fractional filtering, the algorithm takes triaxial accelerations signals and measured shear signals to structure the optimal filtering. The key point is to obtain the optimal estimation of vibration noise signals calculated by weight coefficient and eliminated them from the measured shear signals especially in low frequency. The improved algorithm is used to process the sea trial data obtained from the Free Fall Vertical Profiler deployed in the Western Pacific in March 08, 2017. The results show that the corrected signal spectra agree well with the Nasmyth theoretical spectra and the dissipation rates of turbulent kinetic energy drop near an order of magnitude compared with the original measured data, which indicate that the improved processing algorithm can effectively eliminate the vibration noise signals, improve the accuracy of the data and solve the key problem of ocean turbulence adaptive observation.

目的 探讨由于十二指肠良性或恶性梗阻、狭窄导致普通鼻肠管置管困难患者经内镜置入鼻胆管替代鼻肠管行肠内营养的效果及护理.方法 回顾性分析2016年1月至2017年1月南京大学医学院附属鼓楼医院27例十二指肠良性或恶性梗阻、狭窄致普通鼻肠管置入困难改经内镜放置鼻胆管,通过鼻胆管输注肠内营养制剂的患者的临床护理资料,观察置管时间、一次置管成功率、意外拔管率和肠内营养期间的相关并发症等.结果 27例患者均一次性置管成功,置管最长时间为30 d,最短为10 d.所有患者留置鼻胆管行肠内营养期间均未出现出血、穿孔和误吸等并发症,无意外拔管、脱管及机械性压疮等护理不良事件.结论 对因十二指肠良性或恶性梗阻、狭窄导致普通鼻肠管置管困难的患者经内镜置入鼻胆管行短期肠内营养具有可行性,但鼻胆管的材质较普通鼻肠管硬,管腔偏细,护理难度较大,对护理提出更高的要求,个性化精细的护理是保证经鼻肠管肠内营养顺利进行、提高患者生存质量的关键.

Power inversion (PI) arrays have been employed to suppress interference in satellite navigation systems. When the incident direction of a satellite signal is near that of the interference, there will be a significant degradation in the signal to noise ratio (SNR). To reduce this degradation, a PI antenna array composed of a right-hand circular polarized (RHCP) antenna and a spatially-spread electromagnetic vector sensor (SS-EMVS) subarray is proposed, which can suppress interference and acquire satellite signals in both the polarized and spatial domains. Even when the satellite signal is incident from the same direction as the interference, the SNR degradation can be reduced by exploiting the difference in polarization states. It is shown that the filtering is improved in the polarization domain compared with an RHCP PI array, and the SNR loss is lower than with an SS-EMVS PI array while the computational complexity is not increased. Furthermore, the proposed PI array is effective for all Beidou satellite system public service signals.

目的 探讨改良十二指肠乳头腺瘤内镜切除术疗效、安全性和护理要点.方法 选取2013年至2017年32例行改良十二指肠乳头腺瘤内镜切除术患者为研究对象,总结其疗效、安全性及术前、术中和术后护理要点,观察护理满意度情况.结果 改良十二指肠乳头腺瘤内镜下切除术后完全切除率为93.8％,整块切除率为87.5％.32例患者中发生穿孔1例,迟发性出血2例,急性轻症胰腺炎2例,近期并发症发生率为15.6％.出血患者以钛夹及氩离子凝固术(APC)止血后未再出血,穿孔患者以钛夹封闭创面后经留置胃管负压吸引、禁食、预防感染、抑酸、营养支持等治疗后好转,2例胰腺炎患者给予禁食、抑酸、抑制胰腺分泌、营养支持治疗后好转.所有患者于2个月后复查内镜示创面愈合良好.护理满意度为93.8％.结论 改良十二指肠乳头腺瘤切除术疗效好、并发症少,恰当的术前宣教、精确的术中配合、严密的病情观察与处理能有效保障手术顺利完成.

Turbulent energy cascade and intermittency are very important properties in marine fluid flows and it has become an interesting field in physical oceanography research. To quantitatively characterize that how the turbulent dissipated energy are distributed among the various scales of motion and examine the different physical processes occurring on these different time scales, we propose a quantitative analysis method based on the adaptive empirical mode decomposition, wavelet transform technique and local intermittency measure approach. The energy cascade in the ocean turbulence is investigated using the measured shear data in the South China Sea. These collected long-term turbulence series are used to resolve the critical role of energy cascade and larger-scale ocean circulation dynamics.

Objective To analyze the usefulness of homogenate diet when applying for the bowel preparation in electronic colonoscopy. Methods one hundred and eighty patients were selected in Nanjing drum tower hospital from October 2015 to May 2016, including 90 cases in the treatment group and 90 cases in the control group. Using the Boston Bowel Preparation Scale, the intestinal tract cleanness and the adverse reaction between two groups were compared. Results The treatment group was better in the intestinal cleanliness compared with the control group, there was statistical difference (transversostomy:χ2=8.545, P=0.014;left colon:χ2=8.430, P=0.015). Adverse reactions in the treatment group was significantly lower than the control group (χ2=4.305, P=0.004). Conclusions Homogenate diet can guarantee nutrition supply before the preoperative, improve bowel preparation efficiency and reduce the incidence of adverse reactions.

A free-fall vertical profiler developed by Ocean University of China had been deployed in the South China Sea with the descend speed of 0.35-0.4 m/s. Both of the fast-response thermistor and shear probes are attached to the turbulence observation instrument, which are used to estimate the turbulence intensity. Throughout the observation period, the profiler succeed to collect time series of turbulence shear and temperature fluctuations and this allowed certain issues to be addressed. In this paper, the measured turbulence data are processed and analyzed in time domain and frequency domain. The shear probes are sensitive to the vibration of the platform. So, the measured turbulence data need to be corrected to improve its accuracy. To analysis the effectiveness of the collected data, power spectra of both the velocity shear and temperature gradient are compared with the theoretical spectra, respectively. Dissipation rate of turbulence kinetic energy ε can be directly estimated by integrating the wavenumber spectrum of the observed shear. Furthermore, by fitting the observed temperature gradient variance spectra to the Batchelor theoretical forms, an indirect measurement of ε T is obtained. Here, the temperature-derived dissipation rates ε T are compared to the shear-derived results ε. The dissipation rates from the above two independent methods agree to within a factor of 10 on average in a wide range of 10 -10 -10 -7 W/kg. Thus, turbulence estimation using free-fall vertical profiler confirmed to be valid, which extends possibility to obtain much more turbulence data in deep and wide oceans.