Lead sulfide (PbS) is an important IV-VI semiconductor material with narrow bandwidth and wide wave width, which attracts people's attention. Nano-level PbS has many novel optoelectronic properties and has a wide range of applications in the field of optoelectronics, such as infrared optoelectronic devices, photovoltaic devices, light-emitting devices and display devices. In this paper, Pbs is produced by solvent thermal method by using lead acetate as lead source, sulfur power as sulfur source, ethylene glycol as solvent, and acetic acid to provide acidic environment. The reaction acidity, type of lead source, amount of sulfur source and other aspects will be explored. The products obtained under different conditions were characterized by X-ray diffraction (XRD), optical microscopy and scanning electron microscopy (SEM). The results showed that PbS produced at 140°C for 24 hours, using 14mL ethylene glycol and 1.2mL acetic acid has the best morphology. It has a non-planar six-arm symmetrical structure. Finally, we prepare the lead sulfide composite Ni/PbS, and characterized it.

Introduction: Chest trauma has a high incidence and pneumothorax is the most frequent finding. The literature is scarce on what to do with asymptomatic patients with pneumothorax due to penetrating chest trauma. The aim of this study was to evaluate what are the findings of the control radiography of patients with penetrating chest trauma who are not initially taken to surgery, and their usefulness in determining the need for further treatment. Methods: A retrospective cohort study was performed, including patients older than 15 years who were admitted for penetrating chest trauma between January 2015 and December 2017 and who did not require initial surgical management. We analyzed the results of chest radiography, the time of its acquisition, and the behavior decided according to the findings in patients initially left under observation. Results: A total of 1,554 patients were included, whose average age was 30 years, 92.5% were male and 97% had a sharp weapon wound. Of these, 186 (51.5%) had no alterations in their initial X-ray, 142 had pneumothorax less than 30% and 33 had pneumothorax greater than 30 %, hemopneumothorax or hemothorax. Closed thoracostomy was required as the final procedure in 78 cases, sternotomy or thoracotomy in 2 cases and discharged in 281. Conclusion: In asymptomatic patients with small or moderate pneumothorax and no other significant lesions, longer observation times, radiographs and closed thoracostomy may be unnecessary.

A three-factor experiment was set at the Horticulture Laboratory, Hajee Mohammad Danesh Science and Technology University, Dinajpur, to study the effects of the controlled deterioration (CD) on the pea seeds at the constant temperature of 35 ℃. The 3 factors considered were: 3 pea seed sources (Rangpur Local/RL, Dinajpur Local/DL and Thakurgaon Local/TL); 3 ageing periods (0, 8 and 16 days); and 3 seed moisture contents (12, 16 and 20% MC). The 27 treatment combinations compared in the CRD with the 3 repetitions for the 8 arenas were: % germination, % abnormal seedlings, % dead seeds, % soil emergence and seedling evaluation test for the root and shoot lengths as well as their dry matter contents. Identical prototypes of notable (5–1% level) degradations were recorded everywhere. But the disparities were lucid under the extreme stresses. Moreover, highly noteworthy (1% level) relations were traced amid all the traits ranging from -0.9847 (soil emergence × abnormal seedling) to 0.9623 (soil emergence × normal seedling). So, the CD technique was very effectual in judging the physiological statuses of the seed sources studied. Thus, the germination test might be add-on by a vigor test, the latter of which could be assessed by quantifying the seedlings’ root and shoot lengths and/or their dry matter accumulations. Moreover, in the seed quality certification, the suitable limits of vigor for the chosen traits could also be got by this technique. But the seeds of several pea varieties should be exploited to fix-up the agreeable limits of the traits. Furthermore, to save time, the ageing period could be squeezed by raising the seed MC.

Dredging and reclamation operations are pivotal aspects of coastal engineering and land development. Within these tasks lie potential hazards for personnel operating dredging machinery and working within reclamation zones. Due to the specialized nature of the work environment, which deviates from conventional workplace settings, the risk of workplace accidents is significantly heightened. The aim of this study is to conduct a comprehensive risk analysis of the safety aspects related to dredging and reclamation activities, with the goal of enhancing safety and minimizing the frequency and severity of potential dangers. This research comprises a thorough risk analysis, integrating meticulous hazard identification from sample projects and literature reviews. It involves risk assessment by gathering insights from experts with direct working experience and aims to assess potential risks. The study focuses on defining effective risk management strategies, exemplified through a case study of a nearshore construction project in Thailand. The study identified numerous high and very high-risk factors in the assessment and analysis of occupational safety in dredging and reclamation work. Consequently, a targeted response was implemented to control and mitigate these risks to an acceptable level. The outcome of this study will provide a significant contribution to the advancement of guidelines and best practices for improving the safety of dredging and reclamation operations.

In the context of Vietnam’s extensive international integration, economic concentration emerges as a pivotal strategy employed by businesses across various sectors, notably the retail industry, to foster expansion and bolster competitiveness within the market. As this trend evolves, it necessitates the formulation by the Vietnamese Government of a comprehensive and stringent legal framework tailored to regulate economic concentration among enterprises. Such measures are imperative to preclude the curtailment of market competition, which could potentially undermine the equity and vitality of the business environment in Vietnam. This paper meticulously examines and elucidates theoretical nuances surrounding economic concentration in the retail sector. Additionally, it scrutinizes the current landscape, assessing the impact of extant legislation governing economic concentration and the efficacy of enforcement activities in this realm within the Vietnamese retail sector. Consequently, the paper proffers judicious recommendations to enhance the efficacy of legal mechanisms governing economic concentration to foster competition and fortify Vietnam’s overall economic prowess, particularly within the retail sector.