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This paper focuses on the main problems of unstable neutron yield and continuous decrease in neutron yield when using static water-cooled target in the D-D neutron generator. A multifunctional compact rotating target device was developed, which adopted an integrated design and was compact in structure and small in size, equipped with functions such as high-speed rotation and water-cooled of target body, visual monitoring of target point, real-time measurement of target surface temperature, and real-time monitoring of neutron yield. This paper introduced the performance parameters of several major high current neutron generators rotating targets in the world, and elaborated on the advantages of rotating targets compared to traditional static targets. The main structure and functional design of the device were introduced. The main structure of the target was composed of a vacuum target chamber, target plates, beam pipes, circulating cooling water pipes, accompanying particle pipes, target monitoring pipes, stepper motors, and corresponding seals. The functions and structural components of each device were elaborated in detail. In order to study the influence of the structure of the rotating target device on neutron scattering, the energy spectrum distribution of source neutron at various angles in space was simulated by using TARGET software. The energy spectrum data was input into the MCNP data card, and 40 point detectors were set up, with 0°-360° distributed at a distance of 1 m from the target surface. The influence of target structure on neutron scattering was calculated using MCNP simulation. The result of simulation data shows that the target structure broadens the neutron spectrum peak by 0-0.057 7 MeV, and the relative angular yield of scattered neutrons at various angles accounts for 10.53%-26.75%. The influencing factors of neutron scattering effects at several key angles based on energy spectrum curves were analyzed. The vacuum degree, target surface temperature load, and neutron yield stability of the rotating target device were tested. First of all, the average energy of a 300 keV deuterium particle beam in a target thickness of 1 mg/cm2 deuterium titanium target was theoretically calculated. The source neutron flux was calculated using the average energy, and then the device was installed on a neutron generator at Chinese Institute of Atomic Energy to conduct preliminary tests on various performance. The test results show that the vacuum degree of the rotating target remains stable at around 3×10−5 Pa for a long time. Compared with static targets, rotating target improves neutron yield stability by one order of magnitude, and the maximum temperature of the target decreases by 13 ℃. And the cooling effect of the rotating target device was analyzed under different rotational speeds. The results show that as the rotational speed increases, the cooling effect gradually improves. Therefore, the rotating target device designed in this paper basically achieves the expected function, effectively solving the problem of continuous decrease in neutron yield, and the functional test results are normal with low neutron scattering effect. Finally, this paper also analyzes the problems in the simulation calculation results and measurement results, and proposes improvement and optimization plans.

The effective performance of target materials within neutron generators is pivotal in determining neutron yield and ensuring system stability. This research investigates the adverse effects that arise from the formation of intermetallic alloys between titanium films and bases in deuterium titanium targets, a prevalent issue that causes substantial degradation in target performance. Aiming to address and counter this challenge, the study introduced an innovative gold-plated technique. The gold-plated was meticulously applied to serve as a barrier between the hydrogen storage layer and the base material of the target. This method was executed to intercept the diffusive processes that could lead to deleterious alloying between the titanium film and the base. The successful application of this technique is paramount in maintaining the integrity and concentration of titanium elements within the coating and, crucially, in protecting the active deuterium nuclei that are essential for effective neutron generation. The investigation proceeded with rigorous comparative analyses conducted under specific beam conditions to evaluate the efficacy of the molybdenum base gold-plated deuterium titanium targets against other materials. The findings are clear and significant and the molybdenum base gold-plated deuterium titanium target demonstrates a superior neutron output with a yield of 1.61×109 s−1, outstandingly surpassing that of both the copper base gold-plated and pure molybdenum base deuterium titanium targets. The integrity of these results was further consolidated through meticulous electron microscope spectral analysis. This analysis confirms the enriched presence of titanium in the molybdenum base gold-plated deuterium titanium target, which helps explain the observed increase in neutron yield. Moreover, detailed computational simulations were employed to discern any possible influence of temperature on deuterium retention within the target. The simulation leads to the exclusion of temperature rise as a contributory factor for deuterium loss, affirming the resilience of the target design against heat-related performance issues. In summary, this seminal piece of research provides vital insights into the intricacies of neutron generation, particularly highlighting the impact of target material selection and surface integrity. Through careful experimentation and analysis, the study advocates the use of a molybdenum base gold-plated for deuterium titanium targets as an effective strategy for ensuring high neutron yields and stable generator operation. The conclusions drawn from this work lay a robust groundwork for the optimization of neutron generator targets, potentially revolutionizing practices within the field. Future applications of this research are expected to extend not only to the improvement of current neutron generator designs but also to the innovation of new systems where maximum neutron yield and stability are crucial. This comprehensive inquiry, therefore, transcends conventional understanding and presents a transformational approach to material engineering in neutron generation, setting a precedent for excellence and efficiency that will undoubtedly guide future advancements in the domain.

With the upgrading of environmental protection requirements and the development of automobile industry technology,more and more high demanding work focus on the improvement of automobile energy use.The fuel consumption especially for NEDC cycle is affected greatly by the transmission efficiency. An experimental study on the transmission efficiency improvement base on using of different type of lubricant is presented. The effect of the variables of input speed,input torque,and gear position on the efficiency is compared throughout the transmission performance testing and analyzing. The experiment study shows that the selecting optimized lubricant numbered with 2 has a noticeable improving on the transmission efficiency with an insignificant difference in the viscosity compared to the based type of lubricant. There is some difference between different gear positions in transmission efficiency,although in the improvement of efficiency the results are almost unchanged when it is replaced with different type of lubricant. It is showed that the input torque has a negative effect on the improvement for different type of lubricant because of the transmission efficiency increasing with the torque increasing. It is also showed that an average improvement of 2 percent point on the transmission efficiency as well as 3% improvement on the fuel consumption of NEDC cycle when selecting optimized lubricant numbered with 2 used in the vehicle test.

The fluxes of dissolved nutrients at sediment-water interface were investigated at 4 stations in the HAB area of East China Sea in May 2001 and May 2002. The benthic fluxes of nutrients were determined by incubating the sediment core samples with bottom seawater bubbled with air or nitrogen. The transfer of nutrients was more active under anoxic condition. The fluxes of dissolved nutrients were generally high at the stations close to the coast. The sediment was the source of SiO3(2-), which accounted for 6% of primary production. For DIN and PO4(3-), the sediment was the sink. DIN and PO4(3-) adsorbed by sediment accounted for 5.9% and 67% of the riverine DIN and PO4(3-) inputs, respectively, and the inputs of SiO3(2-) accounted for 7.8%.

In order to study the effects of atmospheric wet deposition on red tide, five kinds of nutrient elements were measured with 64 rainwater samples collected at Shengsi Archipelago from May 2000 to April 2001. The results showed that there were obvious differences between monthly average concentrations, due to the different resource and precipitation. The variation of seasonal fluxes suggested that the wet deposition might cause red tide except in winter. The annual concentrations of NO3-N, NH4(+)-N, NO2(-)-N, PO4(3-)-P and SiO3(2-)-Si were 20.23, 30.14, 0.11, 0.045 and 3.43 mumol.L-1, respectively, and their annual fluxes were 2.67 x 10(8), 3.98 x 10(8), 0.014 x 10(8), 0.0059 x 10(8) and 0.45 x 10(8) mol, respectively. Compared with river input, they were much more smaller.