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We prepared peapod-like titanium dioxide@graphene@carbon (TiO2@GO@C) nanofiber membranes through electrospinning. Due to the porous structure, large surface area, abundant surface functional groups and excellent thermal conductivity, GO can capsulize TiO2 nanoparticles to form a pea-like TiO2@GO structure. Subsequently, TiO2@GO can be wrapped by the carbon nanofiber during an electrospinning process, forming peapod-like TiO2@GO@C nanofiber membranes. The existence of a peapod-like structure is beneficial for enhancing the crystallinity of TiO2, and preventing the phase transformation of TiO2 from anatase to rutile phase at the same time. Furthermore, on the basis of the excellent carrier transport property of GO, the peapod-like TiO2@GO@C structure could also improve the light absorption, reduce recombination of hole–electron pairs, and improve the carrier transport and finally photocatalytic degradation property of methylene blue. Besides, the pea-like TiO2@GO structure shows a dispersion strengthening effect in the carbon nanofibers, preventing the carbon nanofibers from fracture. In particular, by optimizing the heat treatment temperature and additional amount of GO, the peapod-like TiO2@GO@C nanofiber membranes with 0.3 wt% GO show an excellent photocatalytic degradation efficiency of 98.5% in 3 h, and a high strength of 356.07 cN per dtex.

Zepeng Yu,1,* Xingwei Sun,1,* Xuming Bai,1 Wei Ding,2 WeiDong Wang,2 Liang Xu,3 Wenming Qin,4 Ling Wen,5 Yong Jin1 1Department of Intervention, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, Jiangsu, People’s Republic of China; 2Department of Intervention, Wuxi People’s Hospital Affiliated to Nanjing Medical University, Wuxi, 214023, Jiangsu Province, People’s Republic of China; 3Department of General Surgery, Changshu Hospital Affiliated to Nanjing University of Chinese Medicine, Changshu, 215500, Jiangsu, People’s Republic of China; 4Department of Anesthesiology, Bazhong Central Hospital, Bazhong, Sichuan, 636000, People’s Republic of China; 5Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou, 215004, Jiangsu, People’s Republic of China*These authors contributed equally to this workCorrespondence: Yong JinDepartment of Intervention, The Second Affiliated Hospital of Soochow University, Suzhou, 215004, Jiangsu, People’s Republic of ChinaTel +86 13776097707Email 578898234@qq.comLing WenDepartment of Radiology, The First Affiliated Hospital of Soochow University, Suzhou, 215004, Jiangsu, People’s Republic of ChinaEmail wenling@suda.edu.cnPurpose: The totally implantable venous access port (TIVAP) provides patients with safe, effective and long-term convenient venous access for the administration of medications such as chemotherapy drugs. The implantation and long-term use of TIVAP are related to thrombosis, infection and other complications. In this study, the medical records of multicentre patients were collected, and the perioperative and postoperative complications were retrospectively analysed to objectively evaluate the safety of the implantation of supraclavicular, ultrasound-guided TIVAP via the brachiocephalic vein (BCV).Patients and Methods: We retrospectively analysed the clinical data of 433 adult patients who had undergone ultrasound-guided TIVAP implantation via the BCV at four hospitals in China from March 2018 to May 2019. The success rates of the first puncture, operation time, and perioperative and postoperative complications were analysed.Results: All the TIVAPs were implanted successfully (100%). The average TIVAP carrying time was 318.15 ± 44.22 days (range: 38– 502 days) for a total of 197,694 catheter days. The success rate of the first puncture was 94.92% (411/433), and the average operation time was 29.66 ± 7.45 min (range: 18– 60 min). The perioperative complications included arterial puncture in 4 patients and pneumothorax in 1 patient. The incidence of postoperative complications was 5.08% (22/433), including poor incision healing (n = 2), catheter-related infection (n = 3), port infection (n = 6), thrombosis (n = 2) and fibrin sheath formation (n = 8). Another patient had infusion disturbance 2 days after the operation, and chest X-ray showed bending at the connection between the catheter and port. No other serious complications occurred, such as catheter rupture and drug leakage. The total incidence of complications was 6.24% (27/433).Conclusion: This study showed excellent tolerance of supraclavicular, ultrasound-guided BCV puncture to implant TIVAP and a low incidence of complications. As a safe and effective method of TIVAP implantation, it can provide a new choice for clinicians.Keywords: complications, totally implantable venous access ports, ultrasound-guided, brachiocephalic vein

Gamma-phase cesium lead tri-bromide perovskite nanocrystals (γ-CsPbBr3 NCs) possess potentially photo-catalytic degradation ability and long-term stability. However, their serious aggregation issue decreases their active surface area, and the recombination of photo-generated hole-electron pairs weakens their photo-catalytic property. Furthermore, these NCs can be easily absorbed on the surface of dyes [e.g., methylene blue (MB)] or dissolved in the dye solution during the photo-catalytic degradation process, thus reducing the amount of γ-CsPbBr3 NCs and their photo-catalytic degradation ability. Besides, the residual γ-CsPbBr3 NCs in the photo-catalytic degradation products also present the toxicity issue (containing Pb) and are hazardous to the ecological environment and human health. In the present study, we fabricated γ-CsPbBr3 NCs/polymethyl methacrylate electrospun nanofibrous membranes (γ-CsPbBr3 NCs/PMMA ENMs) by using electrospinning technology to solve the above problems. It is found that the synthesized γ-CsPbBr3 NCs/PMMA ENMs show a large surface area and the abundant functional groups on their surfaces, which are benefit for forming multiple kinds of chemical bonding effect between γ-CsPbBr3 NCs and PMMA ENMs. In addition, γ-CsPbBr3 NCs could disperse homogeneously in or on the surface of PMMA ENMs. These abundant chemical bonds and homogeneous distributions of γ-CsPbBr3 NCs on the surface of PMMA ENMs can significantly decrease the recombination of photo-generated hole-electron pairs and toxicity issue of γ-CsPbBr3 NCs during the photo-catalytic degradation process. Exhilaratingly, γ-CsPbBr3 NCs/PMMA ENMs could maintain a superior photo-catalytic degradation ability toward various dyes and reveal a high photo-catalytic degradation efficiency of 99.18% in 60 min for MB.

Geophones are key instruments used for seismic data acquisition, and the quality of seismic data acquired for prospecting depends directly on their performance. With the development of geophysical prospecting technologies and high-resolution exploration requirements, especially in tight marl oil exploration, an increased demand on the accuracy and quality of seismic data is presented, which includes broadening the frequency band and increasing the fidelity and signal to noise ratio in an attempt to better identify lithology, pore fluids, and fractured reservoirs. In the Jizhong Depression, the tight marl oil is mainly located in the Shulu Sag, where the background interference is strong and the marl strata are deeply buried with variable occurrence. These factors pose new challenges on the ability of digital geophones to detect oil. In this paper, the operation and performance characteristics of digital geophones are described, and then we focus on the first test conducted for tight marl oil exploration in the Shulu Sag. The test results show that compared with analog geophones, seismic data acquired using digital geophones are characterized by providing less waveform distortion, broader frequency bandwidth, and more abundant information. These improvements lay a foundation for high-resolution processing and identification of fractured reservoirs.

The oil fields in eastern China have already been explored several times with 3D seismic exploration in most areas. With the further exploration of deeper targets and new reservoirs, the existing 3D seismic data can hardly meet the demand for revealing these complex structures. In this paper, we will present some integrating techniques for multi 3D seismic survey. Multi 3D seismic survey means 3D seismic data acquired repeatedly in the same area by a uncertain time interval which is usually about ten years. Here we will integrat the 3D data acquired in the different times and new 3D data into the same data volume. The techniques include geometry design based on prestack image and inversion, spatial-time domain comprehensive static correction and integrated data processing techniques etc. .

Along with the deepening of exploration works, static problem are getting more and more serious so that it has become an important factor that influences the quality of near-surface anisotropy data. Inappropriate low-frequency statics affects the structural features of the section; and inappropriate high-frequency statics affects the imaging quality of the data. In this paper, a tailor-made static method, which can better solve the static problems caused by near-surface anomaly, is advanced.

Summary At present, we always use the rectangular orthogonal mode layout for control point in near-surface structure investigation. Only in areas where the lithology or the near-surface structure is vary significantly, do we increase the density of control points in order to control the variation of the long-wavelength static correction. Because the accuracy requirements for near-surface structure investigations are increasing, it is necessary to study and analyze the control point layout mode. In this paper we study the problem of uniformity of control point layout in near-surface structure investigation by theoretical analysis and demonstration using real seismic data in order to research the influence of control point layout mode on the near-surface structure model and static corrections in nearsurface structure investigations.

Summary The ongoing exploration in the Saihantala Depression has been focused on lithologic reservoirs. It is difficult to reduce ambiguity and to assess uncertainty in seismic lithology discrimination and fluid type identification using conventional compressional wave (P-wave) exploration. A three dimensional, three component (3D-3C) seismic survey with P-wave source and 3C geophones has been performed in the study region, taking advantage of combining P-wave and converted wave (C-wave or PS-wave) exploration. Instead of using vibroseis, a dynamite source is used to improve the signal-to-noise (S/N) ratio and bandwidth of the C-wave data. High quality C-wave imaging has been achieved using four-parameter velocity analysis and anisotropic pre-stack time migration (PSTM). Sedimentary facies have been well discriminated using the obtained Vp/Vs ratios in the target layer. Our study shows that the combined exploration method effectively characterizes the lithologic reservoir.