My Best Holiday

<正>Last month,I went to Yantai,Shangdong for my holiday.I went there by train with my parents.It took us about 4 hours to get there.On the first day,we walked around the city.It was quite a beautiful place.The sky was blue and the the air was nice and clean.We all enjoyed the beautiful views.People there were friendly,too.On the second day,we visited one of the most famous beaches and some museums.Then we had a great time in a famous theme park.     

We Had a Happy Weekend

<正>Last weekend I went to the river for fishing with my cousin.It was a small river.We sat on the river beach and waited for the fish.Hu Dong is two years older than I and he is my cousin.He had two fish but I had none."Why doesn’t fish come to my hook?"I asked Hu Dong."You’re too anxious to get     

Analysis of photosynthetic activity in the most polluted stretch of river Ganga

As a result of the increasing anthropogenic activities in the gangetic plain, Ganga water quantity as well as quality has declined over the years. A major effort to clean Ganga, named Ganga Action Plan (GAP) was instituted by the Government of India in 1984. The emphasis in GAP was on the reduction of organic load on the river through interception, diversion and treatment of wastewater reaching the river, thus maintaining the biochemical oxygen demand (BOD) and dissolved oxygen (DO) levels of river within the acceptable limits. A major criticism of GAP is that the significance of river ecology has not been addressed adequately during its conception and implementation. One of the important aspects from this perspective is the photosynthetic activity in the river Ganga. It has been postulated that photosynthetic activity plays an important role in maintaining high levels of DO in Ganga, and as a result the river can assimilate high organic loads without appreciable depletion in dissolved oxygen levels. Objective of the present study was to assess the photosynthetic activity and oxygen production rates in the river and correlate these values with various water quality parameters. Most polluted stretch of Ganga, which is known as the Kannauj-Kanpur stretch was chosen for this study. Based on the results of the study, it was concluded that despite implementation of phase I of GAP, and consequent diversion and reduction of organic loading to the river, both BOD and DO levels in the river has increased in the entire Kannauj-Kanpur stretch, except at Jajmau, where anaerobically treated effluent is discharged to the river. The nitrogen levels have also increased in the entire Kannauj-Kanpur stretch. Dissolved oxygen (DO) and alkalinity in the river water vary diurnally at all sites. Chlorophyll-a levels and oxygen production rates due to photosynthesis appear to be positively influenced by phosphate levels in the river water. Chlorophyll-a levels appear to be negatively correlated to the Ammonical and total Total Kjeldahl Nitrogen (TKN) content in the river water, suggesting the possibility of release of nutrients due to algal death and decomposition under certain circumstances.     

A Wonderful Summer Vacation

<正>How was your summer vacation?I had a great time in my summer vacation.I’m a member in a volunteer club.There are 8 people in the club.This summer vacation,we took part in lots of activities.We helped some homeless people and we also volunteered in the Plant Park.We helped the workers clean the ground and watered the plants there.We also volunteered in a poor village.We taught the children English and maths in the school.I like the     

Today I'm in Charge

<正>Today, my parents were not at home. They had something to deal with, so they left me alone. I was so happy because I could be in charge in my own house. It made me feel like I was a grown-up. I wanted to give my parents a surprise, so I planned to clean the house. It was     

The Person Who Has Influenced Me Most

<正>In my life,I should say my father has influenced me most.When I was a child,my father told me I should learn to take care of myself.So I had to go to school by myself,clean the bedroom for myself and even make study plans for myself.In fact I didn’t understand why my father did that to me.I thought he should take     

A Method for Managing River Abstractions and Protecting the Environment

A n I mproved method has been developed to assess and control the quantity of water available to river abstractors. The methodology quantifies the sensitivity of the river environment to abstraction by a weighting system, and uses this to establish, on a subcatchment basis, maximum permissible volumes of abstraction and minimum permissible river flows. Guidelines developed from the methodology have been used as the basis for determining applications for abstraction licences in North Yorkshire, before being extended to cover the rest of the Yorkshire Water area.     

Assessing the Impact of Fire Extinguisher Agents on Cultural Resource Materials

Portable fire extinguishers and their associated fire extinguishing agents play an important role in reducing the impact of fire on cultural resource collections. These may be valuable collections or the structure housing the resources which itself may be of cultural significance. A fire which can be suppressed with an extinguisher in its incipient stage will not grow to threaten adjacent materials. A range of extinguishing agents are commonly used in museums and libraries, including water, clean gaseous agents, dry chemicals, and foam. Their effectiveness in combating fires has been studied and is well-understood, but their effects on collection materials have not been adequately studied. What is less well understood is what effect these agents might have on the cultural heritage materials that are exposed to them. The primary goals of this project were to study the effects of portable fire extinguisher agents on cultural heritage materials, establish a repeatable test protocol, and assess potential cleaning methods. Eleven tests were conducted, which evaluated the following variables: exposure with and without fire, extinguisher type, material type, and sample exposure (direct vs. indirect). Thirteen materials were evaluated, which represented a wide range of the materials that can be found in cultural heritage buildings. The established test method was found to be adequate for exposing a large number of materials to the effects of extinguisher agents. These affects have been assessed on a wide range of cultural resource materials. The results indicated that, there was no single extinguisher which had no effect on all of the materials tested, even the clean agents. In fact, the corrosive effects of the thermal decomposition products from the clean agents were more pronounced in the fire tests. Several cleaning methods were also evaluated. None of the cleaning methods worked for all materials, but some worked better for certain materials. It was found that damage to samples was immediate and did not appear to progress incrementally with time. This suggests that in some cases (i.e., exposure to water mist, Halotron I and FE-36) immediate remediation may not be necessary. It is the intent that the data in this paper could be used as the foundation of an extinguisher selection matrix to be included in NFPA standards.     

An English Corner

<正>On Friday afternoon,Mr.Zhang told us that there would be an English corner in front of our teaching building.I went there soon after class in the afternoon.To my joy,the English corner had just been on for a few minutes.I joined them in their talk.At first,I was afraid that my English was so poor that I couldn’t follow them     

Evaluation of correlations between absorbance at 254 nm and COD of river waters

Correlations between the absorbance module at 254 nm (A_{254 nm}^{1 cm}) and COD by the permanganate and dichromate methods in rivers in the lower part of the Odra river basin are given. For the purpose of the conducted study a clean reach of the river, two short reaches with medium and high pollution, especially with lignin and humic substances and phenolic wastes below industrial waste outfalls have been selected. Investigation results from 1973 to 1978 have been evaluated mathematico-statistically: regression equations and empirical relations with average conversion factors and variation coefficient are presented. Relationships between absorbance and COD are also given graphically. Close relations have been found and the absorbance module at 254 nm has been recommended to be used as indicator of organic pollution in selected reaches of the river. The method is suitable for laboratory work as well as automatic monitoring of concentration changes in dissolved organic matter. This work is in relation with the results of many authors who carried out investigations in various localities.