基于YOLO-OpenMax的水声通信信号开集识别方法

水声通信信号调制方式随着技术进步从典型的传统调制方式发展为水声通信机厂商私有开发的新型调制方式,这使得现有的水声通信信号闭集调制识别技术实用性受到制约,但现阶段鲜有研究基于深度学习的水声通信信号调制方式的开集识别方法。针对此现状,提出一种基于YOLO图像检测识别网络和OpenMax模型的开集识别方法。利用YOLOv5网络的输出特点,将传统OpenMax模型的处理方法进行改进,提出一种两步测试方法,实现了在多径信道下的水声通信信号的开集识别。仿真实验表明:在归一化系数为0.5,信噪比等于10 dB条件下的归一化开集识别准确率达到90%以上,实测数据同样验证了本文方法的有效性。

Self-healing Au/PVDF-HFP composite ionic gel for flexible underwater pressure sensor

Ionic gels can be potentially used in wearable devices owing to their high humidity resistance and non-volatility.However,the applicability of existing ionic gel pressure sensors is limited by their low sensitivity.Therefore,it is very import-ant to develop an ionic gel pressure sensor with high sensitivity and a wide pressure detection range without sacrificing mechan-ical stretchability and self-healing ability.Herein,we report an effective strategy for developing pressure sensors based on ion-ic gel composites consisting of high-molecular-weight polymers,ionic liquids,and Au nanoparticles.The resulting capacitive pressure sensors exhibit high pressure sensitivity,fast response,and excellent self-healing properties.The sensors composed of highly hydrophobic polymers and ionic liquids can be used to track underwater movements,demonstrating broad application prospects in human motion state monitoring and underwater mechanical operations.

Photodetector based on Ruddlesden-Popper perovskite microwires with broader band detection

Recently,the two-dimensional(2D)form of Ruddlesden-Popper perovskite(RPP)has been widely studied.However,the synthesis of one-dimensional(1D)RPP is rarely reported.Here,we fabricated a photodetector based on RPP microwires(RPP-MWs)and compared it with a 2D-RPP photodetector.The results show that the RPP-MWs photodetector possesses a wider photoresponse range and higher responsivities of 233 A/W in the visible band and 30 A/W in the near-infrared(NIR)band.The analyses show that the synthesized RPP-MWs have a multi-layer,heterogeneous core-shell structure.This structure gives RPP-MWs a unique band structure,as well as abundant trap states and defect levels,which enable them to acquire better photoresponse performance.This configuration of RPP-MWs provides a new idea for the design and application of novel heterostructures.

Massive presacral bleeding during rectal surgery: From anatomy to clinical practice

AIM: To investigate control of two different types of massive presacral bleeding according to the anatomy of the presacral venous system. METHODS: A retrospective review was performed in 1628 patients with middle or low rectal carcinoma who were treated surgically in the Department of Colorectal Surgery, Changhai Hospital, Shanghai, China from January 2008 to December 2012. In four of these patients, the presacral venous plexus (n = 2) or basivertebral veins (n = 2) were injured with massive presacral bleeding during mobilization of the rectum. The first two patients with low rectal carcinoma were operated upon by a junior associate professor and the source of bleeding was the presacral venous plexus. The other two patients with recurrent rectal carcinoma were both women and the source of bleeding was the basivertebral veins.RESULTS: Two different techniques were used to con-trol the bleeding. In the first two patients with massive bleeding from the presacral venous plexus, we used suture ligation around the venous plexus in the area with intact presacral fascia that communicated with the site of bleeding (surrounding suture ligation). In the second two patients with massive bleeding from the basivertebral veins, the pelvis was packed with gauze, which resulted in recurrent bleeding as soon as it was removed. Following this, we used electrocautery applied through one epiploic appendix pressed with a long Kelly clamp over the bleeding sacral neural foramen where was felt like a pit Electrocautery adjusted to the highest setting was then applied to the clamp to "weld" closed the bleeding point. Postoperatively, the blood loss was minimal and the drain tube was removed on days 4-7. CONCLUSION: Surrounding suture ligation and epiploic appendices welding are effective techniques for controlling massive presacral bleeding from presacral venous plexus and sacral neural foramen, respectively.

Preoperative carcinoembryonic antibody is predictive of distant metastasis in pathologically T1 colorectal cancer after radical surgery

AIM:To identify the predictors of distant metastasis in pathologically T1(pT1)colorectal cancer(CRC)after radical resection. METHODS:Variables including age,gender,preoperative carcinoembryonic antibody(CEA)level,tumor location,tumor size,lymph node status,and histological grade were recorded.Patients with and without metastasis were compared with regard to age,gender,CEA level and pathologic tumor characteristics using the independent t test orχ 2 test,as appropriate.Risk factors were determined by logistic regression analysis. RESULTS:Metastasis occurred in 6(3.8%)of the 159 patients during a median follow-up of 67.0(46.5%) mo.The rates of distant metastasis in patients with pT1 cancer of the colon and rectum were 6.7%and 2.9%, respectively(P<0.001).The rates of distant metastasis between male and female patients with T1 CRC were 6.25%and 1.27%,respectively(P<0.001).The most frequent site of distant metastasis was the liver. Age(P=0.522),gender(P=0.980),tumor location(P =0.330),tumor size(P=0.786),histological grade(P =0.509),and high serum CEA level(P=0.262)were not prognostic factors for lymph node metastasis.Univariate analysis revealed that age(P=0.231),gender(P =0.137),tumor location(P=0.386),and tumor size (P=0.514)were not risk factors for distant metastasis after radical resection for T1 colorectal cancer.Postoperative metastasis was only significantly correlated with high preoperative serum CEA level(P=0.001).Using multivariate logistic regression analysis,high preoperative serum CEA level(P=0.004;odds ratio 15.341; 95%CI 2.371-99.275)was an independent predictor for postoperative distant metastasis. CONCLUSION:The preoperative increased serum CEA level is a predictive risk factor for distant metastasis in CRC patients after radical resection.Adjuvant chemotherapy may be necessary in such patients,even if they have pT1 colorectal cancer.

Learning the signatures of the human grasp using a scalable tactile glove

Humans can sense, weigh and grasp different objects, deduce their physical properties at the same time, and exert appropriate forces – a challenging task for modern robots. Studying the mechanics of human grasping objects will play a supplementary role in visual-based robot object processing. These tools require large-scale tactile data sets with high spatial resolution. However, there is no large human-grasped tactile data set covering the whole hand, because dense coverage of the human hand with tactile sensors is challenging. Hence, the capability of observing and learning from successful daily humanobject interactions is the long-term goal of aiding the development of robots and prosthetics.

Growth of aligned SnS nanowire arrays for near infrared photodetectors

Aligned SnS nanowires arrays were grown via a simple chemical vapor deposition method.As-synthesized SnS nanowires are single crystals grown along the[111]direction.The single SnS nanowire based device showed excellent response to near infrared lights with good responsivity of 267.9 A/W,high external quantum efficiency of 3.12×10^4%and fast response time.Photodetectors were built on the aligned SnS nanowire arrays,exhibiting a light on/off ratio of 3.6,and the response and decay time of 4.5 and 0.7 s,respectively,to 1064 nm light illumination.

Conceptual design studies of the 5 m terahertz antenna for Dome A, Antarctica

As the highest, coldest and driest place in Antarctica, Dome A provides exceptionally good observing conditions for ground-based observations over terahertz wavebands. The 5 m Dome A Terahertz Explorer （DATES） has been proposed to explore new terahertz windows, primarily over wavelengths between 350 and 200 pm. DATE5 will be an open-air, fully-steerable telescope that can function by unmanned operation with remote control. The telescope will be able to endure the harsh polar environment, including high altitude, very low temperature and very low air pressure. The unique specifications, including high accuracies for surface shape and pointing and fully automatic year-around remote operation, along with a stringent limit on the periods of on-site assembly, testing and maintenance, bring a number of challenges to the design, construction, assembly and operation of this telescope. This paper intro- duces general concepts related to the design of the DATE5 antenna. Beginning from an overview of the environmental and operational limitations, the design specifications and requirements of the DATE5 antenna are listed. From these, major aspects on the conceptual design studies, including the antenna optics, the backup structure, the pan- els, the subreflector, the mounting and the antenna base structure, are explained. Some critical issues of performance are justified through analyses that use computational fluid dynamics, thermal analysis and de-icing studies, and the proposed approaches for test operation and on-site assembly. Based on these studies, we conclude that the specifications of the DATE5 antenna can generally be met by using enhanced technological approaches.

Current Development Situations of Ziziphus Jujuba Industry in South Xinjiang and Recommendations

Through surveying current development situations and existing problems of planting and processing of Ziziphus jujuba in south Xinjiang,this paper discussed planting,processing mode of Ziziphus Jujuba in south Xinjiang and development direction of enterprises in Ziziphus Jujuba production. It is expected to ensure and increase quality and sales volume of Ziziphus Jujuba and promote sound and sustainable development of Ziziphus Jujuba industrial chain in south Xinjiang.

Appropriate treatment of acute sigmoid volvulus in the emergency setting

AIM:To investigate an appropriate strategy for the treatment of patients with acute sigmoid volvulus in the emergency setting.METHODS:A retrospective review of 28 patients with acute sigmoid volvulus treated in the Department of Colorectal Surgery,Changhai Hospital,Shanghai from January 2001 to July 2012 was performed.Following the diagnosis of acute sigmoid volvulus,an initial colonoscopic approach was adopted if there was no evidence of diffuse peritonitis.RESULTS:Of the 28 patients with acute sigmoid volvulus,19(67.9%)were male and 9(32.1%)were female.Their mean age was 63.1 ± 22.9 years(range,21-93 years).Six(21.4%)patients had a history of abdominal surgery,and 17(60.7%)patients had a history of constipation.Abdominal radiography or computed tomography was performed in all patients.Colonoscopic detorsion was performed in all 28 patients with a success rate of 92.8%(26/28).Emergency surgery was required in the other two patients.Of the 26 successfully treated patients,seven(26.9%)had recurrent volvulus.CONCLUSION:Colonoscopy is the primary emergency treatment of choice in uncomplicated acute sigmoid volvulus.Emergency surgery is only for patients in whom nonoperative treatment is unsuccessful,or in those with peritonitis.

Study on the pointing model of a slant-axis terahertz antenna

This paper describes the establishment and verification of an accurate pointing model for a1.2 m aperture slant-axis terahertz antenna.A new analytical pointing model for the slant-axis antenna is presented based on an analogy to that of the alt-azimuth antennas.Furthermore,extra error terms are added to the pointing model based on the structure and mechanical analysis of the slant-axis antenna.To verify the pointing model experimentally,a pointing error measurement method based on photogrammetric techniques is proposed.Using this method,pointing behaviors of the antenna are accurately measured without the aid of astronomical observations,and major sources of the pointing errors are measured individually by photogrammetry and their respective coefficients are compared with those in the analytical pointing model.The results show that an extended pointing model consisting 21 error terms can significantly reduce the residual systematic errors compared with the traditional model,more details are given in the following sections.

Conceptual Design of the Aluminum Reflector Antenna for DATE5

DATE5, a 5 m telescope for terahertz exploration, was proposed for acquiring observations at Dome A, Antarctica. In order to observe the terahertz spectrum, it is necessary to maintain high surface accuracy in the the antenna when it is exposed to Antarctic weather conditions. Structural analysis shows that both machined aluminum and carbon fiber reinforced plastic （CFRP） panels can meet surface accuracy requirements. In this paper, one design concept based on aluminum panels is introduced. This includes panel layout, details on panel support, design of a CFRP backup structure, and detailed finite element analysis. Modal, gravity and thermal analysis are all performed and surface deformations of the main reflector are evaluated for all load cases. At the end of the paper, the manufacture of a prototype panel is also described. Based on these results, we found that using smaller aluminum reflector panels has the potential to meet the surface requirements in the harsh Dome A environment.

Science with the 2.5-meter Wide Field Survey Telescope(WFST)

The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.

基于银纳米线/PDMS微结构复合电介质的柔性透明电容式压力传感器及其在穿戴式触摸键盘的应用（英文）

对可穿戴电子设备来说,采用简易制备技术得到具有高灵敏度、快速响应的压力传感器至关重要.本文成功地研制了一种基于特殊微结构银纳米线/PDMS复合电介质层材料的柔性透明电容式压力传感器.与采用纯PDMS平面结构的电介质层器件相比,有微结构的传感器具有更高的灵敏度(0.831 kPa-1,<0.5 kPa),更低的检测范围,更好的稳定性和耐久性.本文对导电填料含量和微结构的增强传感机理也进行了讨论.此外,还研制了一个5×5的传感器阵列并用于柔性透明的可穿戴式触摸键盘系统.研究结果表明所研制的压力传感器在未来的电子皮肤领域将具有良好的应用前景.

Fabrication of flexible reduced graphene oxide/Fe2O3 hollow nanospheres based on-chip micro-supercapacitors for integrated photodetecting applications

Micro-supercapacitors （MSCs） as important on-chip micropower sources have attracted considerable attention because of their unique and advantageous design for optimized maximum functionality within a minimized sized chip and excellent mechanical flexibility/stability in miniaturized portable electronic device applications. In this work, we report a novel, high-performance flexible integrated on-chip MSC based on hybrid nanostructures of reduced graphene oxide/Fe2O3 hollow nanospheres using a microelectronic photo-lithography technology combined with plasma etching technique. The unique structural design for on-chip MSCs enables high-performance enhancements compared with graphene-only devices, exhibiting high specific capacitances of 11.57 F·cm^-3 at a scan rate of 200 mV·s^-1 and excellent rate capability and robust cycling stability with capacitance retention of 92.08% after 32,000 charge/discharge cycles. Moreover, the on-chip MSCs exhibit superior flexibility and outstanding stability even after repetition of charge/discharge cycles under different bending states. As-fabricated highly flexible on-chip MSCs can be easily integrated with CdS nanowire-based photodetectors to form a highly compacted photodetecting system, exhibiting comparable performance to devices driven by conventional external energy storage units.

Two-dimensional Ni（OH）2 nanoplates for flexible on-chip m icrosu pe rcapac itors

有集成电路的在薄片上几何学的在薄片上 microsupercapacitors (MSC ) 兼容机也能在 microelectronic 设备或作为精力存储或精力受体附件单位被用作分开的电源供应。在这个工作，我们报导灵活二维的 Ni 的制造(哦)基于 nanoplates 的 MSC，它在扫描完成了 8.80 F/cm 3 的一个特定的电容 100 mV/s 评估的 2 ，仅仅在 10,000 控告 / 解除以后失去 0.20% 它的原来的价值骑车。而且， MSC 到达了 0.59 mWh/cm 3 的精力密度和电源密度直到比得上传统的基于碳的设备的 1.80 W/cm 3, 。当使遭到了到以各种各样的条件弯曲时，灵活 MSC 展出了好电气化学的稳定性，说明象为便携精力存储的电极的有希望的申请。

High-performance rigid and flexible ultraviolet photo- detectors with single-crystalline ZnGa2O4 nanowires

ZnGa2O4 nanowires （NWs） as a ternary oxide semiconductor were successfully synthesized by a simple vapor transport method for application as high- performance ultraviolet （UV） photodetectors. A single-nanowire UV photodetector fabricated on a rigid silicon substrate exhibited excellent spectral responsivity （3,174 A/W） and high external quantum efficiency （1.1 - 106%） at 350 nm UV light illumination. A flexible single-nanowire photodetector on a polyethylene terephthalate （PET） substrate was also fabricated and showed similar properties. The as-fabricated flexible photodetector exhibited stable electrical properties and mechanical flexibility under different bending curvatures over many cycles, indicating its potential application in future flexible photoelectronic devices.

可拉伸SnO2-CdS交叠纳米线薄膜紫外光电探测器（英文）

快速响应、可拉伸紫外光电探测器在可穿戴电子和嵌入式生物医学器件中有广泛应用.然而,对于大多数基于传统二元氧化物纳米线的光电探测器来说,大量表面缺陷产生的俘获中心使得探测器表现出非常慢的响应速度.本工作利用SnO2-CdS交叠纳米线薄膜作为敏感材料,通过多重模板抽滤法制备出了响应速率显著提高的可拉伸紫外光电探测器.研究表明,与纯SnO2纳米线光电探测器相比,基于交叠纳米线的光电探测器具有更低的暗电流和更大的响应速率(>100倍).此外,本文还讨论了相关的载流子产生和传输的机制.另外,由于在预拉伸循环过程中纳米线/PDMS层的表面形成了波浪形的褶皱, SnO2-CdS交叠纳米线薄膜光电探测器在50%的拉伸应变下展现出了优异的电学稳定性和拉伸循环特性,在150次拉伸循环后仍未表现出明显的性能衰减.作为一种简单有效的制备快速响应可拉伸紫外光电探测器的策略,交叠纳米线结构也可以被应用到其他纳米线组合中,比如ZnO-CdS交叠纳米线.金属氧化物-CdS纳米线交叠结构制备能够快速响应的紫外光电探测器是一种普适的方法,其在未来的可拉伸和可穿戴光电器件中具有巨大的应用潜力.

基于碳布上直接生长的Nb2O5纳米管的高性能钠离子电容器

钠离子混合电容器是连接超级电容器与电池之间的桥梁,在大规模储能领域中具有广阔的应用前景.然而,设计出能够与正极材料相匹配,并且兼具快速动力学行为和长循环寿命的负极材料仍然是目前面临的重要挑战之一.本文通过简单的水热工艺,通过调节溶液的pH值,可以将Nb2O5纳米管以及纳米线/纳米管同质结直接生长在碳布(CC)上.所制备的Nb2O5@CC纳米管在1500次循环后,电流密度为1 A g-1时表现出175 mA h g-1的高可逆容量以及97%的库伦效率.以Nb2O5@CC为负极、活性炭为正极制备的钠离子混合电容器的能量密度和功率密度分别可达到195 W h kg-1和7328 W kg-1.即使在5000次循环后仍然具有80%的电容保持率.另外,该柔性钠离子混合电容器可以在各种可弯曲条件下正常工作.因此,Nb2O5@CC纳米管在未来有望成为一种柔性可穿戴能源存储器的理想电极材料.

Recent advances in low-dimensional semiconductor nanomaterials and their applications in high-performance photodetectors

Low-dimensional(including two-dimensional[2D],one-dimensional[1D],and zero-dimensional[0D])semiconductor materials have great potential in electronic/optoelectronic applications due to their unique structure and characteristics.Many 2D(such as transition metal dichalcogenides and black phosphorus)and 1D(such as NWs)materials have demonstrated superior performance in field effect transistors,photodetectors(PDs),and some flexible devices.And in some hybrid structures of 0D materials and 1D or 2D materials,the modification of 1D and 2D devices by 0D materials is embodied.This type of hybrid heterostructure has a larger performance optimization compared with the original.In the application of PDs,the variety of lowdimensional materials and properties enable wide-spectrum detection from ultraviolet UV to infrared,which provide a potential option for PDs under various conditions.For flexible electronic devices,high performance and mechanical stability are two important features.Low-dimensional materials offer unparalleled advantages in flexible devices.In this review,we will focus on the various low-dimensional materials that have been extensively studied and their applications in the electronics/optoelectronic and flexible electronics.From the composition and lattice structure of materials(including alloys)to the construction of various devices and heterostructures,we will introduce their application and recent development under various conditions.These works can provide valuable guidance for the construction and application of more highperformance and multifunctional devices.