This paper presents a control strategy of obstacle avoidance for nonfully constrainedmobilerobots in unknown environment.The avoidance of unexpected obstacles is consideredin a reactive way by following the contour of the obstacles.The robot backwardsmotions are avoided and the robot heading is always in the direction of thegoal point facilitating the obstacle handling. The stability of obstacle avoidance is analyzed under the reasonable conditions. Finally, the goodperformance and the feasibility of this approach are shown through several experimental results.

Continuing from the preceding article, this article was based on an example of some shale oil finery plant. After the analysis and solving schemes on low oil yield rate with Fushun retort on shale oil production, the Fushun retort unit, heat supply system and oil-gas recovery system were analyzed and researched. The traditional shale oil production technology with Fushun retort was reformed collectively, and a new process technology was performed. The result proves that 80% to 85% of oil yield can be obtained with this new technology. If it is under regular operation and management, the production effect is expected to be better. Besides, the new process can increase productivity and autoimmunization degree. The better environmental protection goal, saving water source and reducing pollutants discharge can be realized. It overcomes the drawback of traditional process by technical innovation and upgrading. The superiority of handling low grade oil shale, rich operation and managerial experience can avoid a series of problems from old industrial enterprises, such as high investment, difficult operation and management through replacing retort unit and technology.

In new period of energy shortage, as an abnormal oil and gas resource, oil shale has great potential and advantages in supplying normal energy. To face industrialization production demand, technology reform on traditional oil shale production with Fushun retort is already turning into an important task to old enterprises because oil yield rate, work capacity, automatic degree and environment management of the old technology is lower. A shale oil refinery plant as an example, Fushun retort, a crucial unit in the traditional technology was analyzed from several points which are feeding materials, materials dropping and burning process in retort, and the retail solving schemes were offered. All these provide the theory for whole technology reform and have a significance, which can create notable economic and environmental benefit.

The pour point depressant for diesel was prepared by firstly making modifacation of C5 petroleum resin with maleic anhydride, and then modified with octadecanol. Four factors were studied on the influence of freezing point and cold filter plugging point, which are, respectively, the amount of maleic anhydride and initiator, the time of reaction, the temperature of reaction. The result shows that, the best depression capacity of pour point depressant for diesel is acquired with the amount of maleic anhydride is 15%，and the amount of the initiator is 1.0%, and the temperature is 180 ℃ and the time is 3.0 h.

The catalytic oxidation experiments were carried out to prepare the horniness oxidized wax from paraffin wax and polyethylene. The results show that good products can be obtained under the following conditions: reaction temperature 170 ℃, reaction time 7 h, mass ratio of paraffin wax and polyethylene 7∶3, the amount of catalyst 0.01%, the amount of additive 1.0%, the air flow 0.20 m3/h. acid number of the product was 9.82 mg(KOH)/g, saponification number is 79.19 mg(KOH)/g, penetration is 9.2 (0.1 mm), melting point was 87.4 ℃, index of refraction(75 ℃ ) was 1.453 6. As compared with natural hard wax(carnauba wax)，their properties were quite similar each other.